Flood Threat High Across Central Vermont

FLOOD WARNING UNTIL 2:30PM THIS AFTERNOON
(Click HERE For Details)

FLASH FLOOD WATCH IN EFFECT UNTIL 11PM TONIGHT
(Click HERE For Details)

Champlain Valley Weather Discussion:
     The National Weather Service in Burlington, Vermont has issued a Flash Flood Watch for portions of the area, as well as a Flood Warning for portions of the area. In all today 1-3 inches of rain is possible, across the watch area. Across the warning area, spotter reports and radar indicates that 1 to 1.5 inches of rain has already fallen as of 10:35AM. Additional rain of 1 to 2 inches is possible across the warning area.

     Current radar trends indicate that rain will continue for another 3-6 hours. Rain will be heavy at times, especially across Central, and Southern Vermont. Radar shows that precipitation has become more scattered since earlier this morning, across Central, and Southern Vermont. Right now the heaviest rain is falling in a band that stretches from Essex County New York, North and east into Orleans County Vermont. Doppler radar is estimating that rainfall rates are around a quarter inch per hour, with isolated higher rates. The heavier rain is expected to shift into Central, and Southern Vermont as time progresses. Stay tuned for further updates.

UPDATE: Severe Weather/ Flash Flood Potential

Champlain Valley Weather Discussion:
     Just a quick update to the current conditions, severe thunderstorm potential, and Flash Flooding potential.

     Currently temps have risen into the low to mid 80's with some upper 80's being reported such as Morrisville at 87F, Swanton Village at 87F, and Highgate at 86F. Dewpoints are in the upper 60's with isolated 70+ degree reading pushing up from the south, such as Glens Falls with a dewpoint of 71F, and 72F at Saratoga Springs, and Albany, New York. These higher dewpoints will continue to push north into our region. So my previous forecast of dewpoints around 70 still looks good. My temperature forecast of 82-87F will be increased to 84-89F and isolated areas good hit 90F, especially in the Champlain Valley.

     With the above mentioned, the severe weather aspect also needs to be tweaked. The atmosphere has destabilized significantly more then I had expected. CAPE values are now in the 1500-2000 j/kg range with isolated areas in the 2100-2300 j/kg range. Lifted Index's are in the -4 to -6 range with isolated areas in the -7 range. With mainly sunny skies expected for at least a couple more hours, it appears that CAPE values will max out in the 2000-2500 j/kg range, with isolated areas seeing 3000 j/kg possible. Lifted index's should range from -5 to -7 with isolated areas getting to -8 or -9. These parameters show the atmosphere is volatile right now, and once convection starts to form, it will become widespread. Any storms that become severe will have the potential to produce damaging winds, and large hail. An isolated tornado is possible, especially across Southern areas. My severe thunderstorm watch remains in effect.

     The Flash flood threat continues to be the greatest concern at this point. PWAT values are currently in the 1.4 to 1.6 range and will increase into the 1.7 to 2.0 range. These values are very high, meaning the potential for excessive rainfall is high. The upper level winds are also favorable for training/ back building of storms, which means a couple of inches of rain could fall in isolated areas, within just an hours time. Widespread rainfall totals should range from .75" to 1.5" inches, with very isolated areas seeing as much as 4 - 6 inches of rain. The isolated heaviest amounts are more likely across Southern Vermont where PWAT values may be locally greater then 2.0. My flash flood watch will remain in effect.

     Once again the National Weather Service has not issued any official alerts across our area. There is a Severe Thunderstorm Watch, and Flash Flood Watch across Extreme Southern Vermont. However there is no official National Weather Service alerts in effect for our area. Stay tuned for further updates!

Severe Storms/ Flash Flooding Possible Today

Champlain Valley Weather Discussion:
     Today is looking like an active day for portions of New England, and New York. An approaching front from the west, and a very moist atmosphere, along with a low pressure system riding up along the front, may prove to be a problem across the region today and tonight.

     Currently across our region temperatures are in the mid to upper 70's already. Infact overnight lows, especially across the Champlain Valley, were very warm. Overnight lows generally ranged from 65-70F. With a few warmer spots out there such as Burlington, Highgate, and Swanton Village where the overnight low was 72F degrees. Current dewpoints are in the mid to upper 60's. This is resulting in already humid conditions across the area this morning. Things will only get worse as high temps will range from 82-87F, and dewpoints will climb to near 70F. Today will be a warm, and humid day.

     Since we have been talking about temperatures lets talk quickly about the potential for severe weather today. As stated temps are already in the mid to upper 70's with nearly full sunshine across the area. This with high dewpoints have resulted in Convective Available Potential Energy (CAPE) values already in the 400-800 j/kg across the region, with the highest values across the Champlain Valley, and St. Lawrence Valley, and Lifted index's are already in the 0 to -2 range. Skies are expected to remain sunny for at least a couple more hours across much of the region, before high clouds build in, and thicken. CAPE values should max out in the 1200 to 1600 j/kg range, and lifted index's should range from -3 to -6. With such good destabilization it wont take much for any storms that develop to become strong to occasionally severe. With this all in mind I have issued a Severe Thunderstorm Watch already this morning. I am confident that at least a few severe thunderstorms will form this afternoon. The primary severe threat will be strong to damaging winds, and isolated large hail. Across extreme southern Vermont, an isolated tornado or two is possible. With all storms this afternoon, and evening very heavy rainfall is possible. Discussion on heavy rainfall potential is next.

     With warm temperatures, and significant destabilization for the potential of severe storms, the most significant threat today and tonight will be the potential for heavy rain, with training/ back building thunderstorms. An approaching front, from the west is allowing a strong southerly flow to develop across the Eastern United States. This is helping transport warm sub-tropical moisture into our region. As stated above dewpoints are in the mid-upper 60's and will likely peak out to around 70 this afternoon. Precipitable Water (PWAT) Values are currently about 1.4 inches across the entire area. PWAT values are expected to rise into the 1.6 - 2.0 range later this afternoon. This is very moist, and any storms that develop in this atmosphere will have torrential downpours, and with the slow moving front and weak storm speeds, training/ back building of storms wont take much to occur, and with slow moving/ training/ back building storms, it wont take much to drop a couple inches within one hour. With that in mind, I have also issued a Flash Flood Watch for portions of the area. At this point it appears the heaviest rain will fall across Central, Eastern, and especially Southern Vermont. The GFS and ECMWF models are in nearly perfect agreement on this situation. One model is throwing a fly in the ointment, and that's the NAM model, although currently an outlier, it has proven before in these heavy rain situations that it can be right, even when its being an "outlier". The NAM is indicating the heavy rain axis will be across Eastern New York, and Western Vermont, while all other models are indicating the heaviest rain across Eastern, Central, and Southern Vermont. Only time will tell, either way stay tuned for further updates on this developing situation.

     There are no official alerts from the National Weather Service for our area at this time, but there has been some talk of possibly issuing a Flash Flood Watch later this morning or early this afternoon. Stay tuned!

Severe Weather Possible Again Today/ Review Of Yesterdays Storms

Review Of Severe Weather On 7/16/09:
     Yesterday was a significant day for severe weather across our region. It was extremely busy, over a dozen severe thunderstorm warnings were issued, including two tornado warnings. Numerous reports of wind damage and large hail were received by the National Weather Service, including hail stones that tied the largest hail ever recorded in Vermont history (3 Inch Diameter). Also the National Weather Service will be conducting a survey of a Severe Thunderstorm in Orange County Vermont, that may have produced a Tornado. Official results of that survey will be available around 5PM this evening.

Wind Damage:
     Yesterday 7 reports of wind damage were received. Ranging from numerous limbs down to large trees down, to even a barn roof being blow off, in Williamstown, Vermont, Located in Orange County, where the storm survey is being conducted today.

Hail:
     The primary severe weather maker yesterday was hail, and some very large. 10 Reports of severe sized hail (three quarters of an inch or larger in diameter) were reported. 4 of those 10 hail reports were greater then one inch in diameter. Of most significance was the size of hail reported out of Northwestern Westford, in Chittenden County Vermont. Hail 3 inches in diameter, this ties the largest hail ever recorded in Vermont history, dating back to severe weather records from 1955. The last time a 3 inch hail stone was reported in Vermont, it was August 8th 1968, in Burlington, Vermont. Overall hail 2 inches in diameter or larger is rare for Vermont. The most recent large hail reported of 2 inches or greater across the region was in Swanton Village, Vermont on July 22nd, 2005, when hail 2 inches in diameter pounded the village, causing significant damage to cars. Other then that the most recent large hail was in 1988 when hail 2.5 inches in diameter fell in Rutland County Vermont. Hopefully pictures were taken of this most recent 3 inch hail stone. If I can get a picture of it, I will put it up for you all to see.

Tornadoes:
     Tornadoes are the most rare form of Severe weather in Vermont, although they are oddly becoming more frequent. What was an average of one tornado per year, seems to be increasing to 2 or 3 a year now. Although statistics still state an average of 1 per year for Vermont. It will be interesting to see what the National Weather Service finds in Orange County today. If infact a Tornado did touch down this will be the second Tornado this year in Vermont, and it will have occurred in the same county as the last Tornado occurred in.

Champlain Valley Weather Discussion:
     Once again it looks like today may be another busy day, although no massive hail, or tornadoes are expected to occur. Overall the Severe weather threat is smaller then yesterday, but the threat still does exists. Already temperatures have jumped into the lower to mid 70's across the region, and should continue to rise until they reach there highs of the upper 70's to lower 80's. Already the atmosphere is destabilizing with pockets of moderate instability across the region. A surface trough that will be approaching later this evening, should help trigger some thunderstorms, some of which could be strong to occasionally severe. Overnight these storms will transition into a heavy rain event, dropping a widespread rainfall of a half to one inch. Isolated higher amounts to near an inch and a half to two inches are possible where heavier thunderstorms persist. The possibility of localized flooding will need to be watched. Also if enough instability can form, then we may have to be under another Severe Thunderstorm Watch today. We will have to watch closely how thing evolve over the next several hours. Stay tuned for further updates!

Severe Thunderstorms End For Tonight

National Weather Service, Burlington, VT.

     The National Weather Service in Burlington, Vermont continues the Flash Flood Watch Until 5AM, for Western Vermont, and much of Northern New York. A Flood Advisory continues for Essex County in New York until 12:30AM, and a Flood Advisory continues for Clinton County in New York until 2:30AM. For more information on these alerts, please go to the above National Weather Service link, and click on the map in the vicinity of where you live.

Champlain Valley Weather Discussion:
     Thunderstorms are beginning to diminish, and the threat for them to be Severe has diminished. With the sun setting, daytime heating has ended too, and with the showers, and thunderstorms that have moved over the region, the atmosphere is stabilizing rapidly.

     Rain and non-severe thunderstorms will continue until midnight, and then rain showers will continue for a few more hours before all but ending. The most additional rain should fall in the Champlain Valley of Vermont, and New York, and the nearby Eastern Slopes of the Adirondack mountains, and the Western Slopes of the Green Mountains. Additional rainfall totals should range from a half to one and a half inches. The flash flood threat will persist for several more hours, but it should not be as high a threat as earlier. We may be doing this all over again tomorrow, so stay tuned for further updates!

Severe Thunderstorm Watch #533 In Effect For Parts Of Our Region

Overview: The National Weather Service, Storm Prediction Center out of Norman, Oklahoma, has issued Severe Thunderstorm watch #533 for parts of our region. Hail to 2 inches in diameter, and thunderstorm wind gust to 70MPH are possible in the strongest of storms. (Click on either map above for alert details)

Champlain Valley Weather Discussion:
     Today looks to be rather interesting. Significant sunshine was able to break through the clouds this morning, and destabilize the atmosphere significantly from the Champlain Valley, and points west. Currently the most unstable atmosphere is over the Champlain Valley itself, where sun has been prevalent much of the day. Across the Champlain and St. Lawrence Valleys, MUCAPE values range from 900 j/kg to 1500 j/kg, with SBCAPE values ranging from 800 j/kg to 1000 j/kg, and LI's in the -1 to -4 range. All together what this is indicating is that the atmosphere is unstable, and the likelihood for thunderstorms is fairly high, with severe thunderstorms possible.

     The primary severe threat will be large hail, due to freezing heights being slightly lower then normal due to the upper level low pressure system over the Great Lakes region. Secondary threat will be damaging winds, and the final threat being the possibility of a very brief tornado, due to some rotation.

     Aside from the severe thunderstorm aspect, overall the main threat today, will be for isolated Flash Flooding. With Precipitable water values in the 1.0 - 1.5 range today, and the possibility of training/ backing thunderstorms, it wont take much to get storms to drop 1-2 inches in a short period of time. Some isolated storms could even produce up to 3 inches! The greatest threat for any Flash Flooding would be across the higher terrain of Clinton, and Essex Counties in New York, and the Western slopes of the Green Mountains in Vermont, especially where areas in Vermont received 1-2 inches of rain yesterday, leading to lowering Flash Flood Values. With this in mind, I have extended the Flash Flood Watch on my "Suggested Alerts" map, and it now covers the entire Champlain Valley coverage area. The reason I expanded it west, is because that's where storms should be most numerous, however any slow moving storms that can push into the Western Slopes, and Eastern Vermont will have the potential to produce isolated Flash Flooding.

     Aside from the Severe weather details, recently Champlain Valley Weather has had a team put together to do some Storm Chasing. Currently we do not have computer access in the Chase Vehicles so we have our own Storm Tracker in which we stay in frequent contact with, so we are sent to the hot spots. With all this in mind we urge you to view the site frequently, as days when we are out chasing we will send texts direct to the Champlain Valley Weather site so you know exactly whats going on out on the roads. Today we plan on Chasing from 3-8PM if storms being to develop, so stay tuned to the site for Chase posts, with live from the scene damage or flooding photos!

Isolated Severe Thunderstorms Possible For Tuesday

Champlain Valley Weather Discussion:
     As of 11:55PM Doppler Radar has calmed down quite a bit from earlier, when we had all that rain. All that's left on radar right now are some very widely scattered showers. Not only did small streams, brooks, and small rivers rise to near or above bankfull, but a few of the large stem rivers (Missisquoi, Lamoille, and Passumpsic) had some significant within bank rises of 3-5 feet. Below is a list of rainfall totals for the rain we received today.

(Note: Some of these readings are from personal automated rain gauges, so some of the data may be slightly inaccurate. I will have a more detailed list once the CoCoRaHS reports come in tomorrow morning.)

Rainfall Totals:
North Troy-(Missisquoi River Rain Gauge): 2.55"
West Glover: 2.12"
East Berkshire: (Missisquoi River Rain Gauge): 1.66"
Elmore: 1.59"
Hyde Park: 1.44"
Worcester: 1.28"
Island Pond: 1.21"
St. Albans: 0.99"
Marshfield: 0.89"
Swanton Village: 0.85"
South Burlington: 0.69"
Plattsburgh: 0.45"
Beekmantown: 0.41"

     Now we will move on to tomorrow. An upper level low near the Great Lakes region will bring a round of showers and thunderstorms as the cold air aloft, will fight with the warmer surface air, and cause some instability. At this point it is still not certain how unstable the atmosphere will become. If we can get some breaks of sun tomorrow, for any extended period of time, then the atmosphere would be able to become more unstable then currently anticipated. Never-the-less breaks or no breaks of sun, showers, and thunderstorms are expected to develop in the afternoon, with some isolated severe storms possible in the mid afternoon to early evening time frame.

     Of most concern will be the potential for some localized flash flooding, especially across Central and Northern Vermont where widespread .75 to 1.5 inch, and isolated 2.0 - 2.5 inch rainfall totals occurred today. Flash Flood Guidance indicates that 1hr/3hr/6hr Flash flood values range from 1-3 inches across Northern and Central Vermont. With precipitable water values (PWATS) expected to be in the 1.2 - 1.6 inch range tomorrow, it wont take much to get a strong thunderstorm to drop that much rain within the 1hr/3hr/6hr time frame. With this in mind, on my suggested alerts map, I have issued a Flash Flood Watch for Chittenden, Franklin, Lamoille, and Washington Counties in Vermont. As of right now, there are no official alerts in effect from the National Weather Service in Burlington, Vermont. Please stay tuned for any further updates!!

Severe Weather Threat Has Diminished

CHAMPLAIN VALLEY WEATHER DISCUSSION (Update):
     The National Weather Service, Storm Prediction Center in Norman, OK. Has allowed the Severe Thunderstorm watch for 7PM to expire, and cancelled the 10PM watch around 8PM, for our area. Numerous severe thunderstorms occurred this afternoon, mainly south of the Champlain Valley, and Western slopes of the green mountains. The only county in the Champlain Valley that received reports of severe thunderstorm damage was Addison County, with Essex County, New York witnessing large hail, up to 1 inch in diameter, but no reported wind damage. The majority of the severe weather occurred from Southern Essex County, NY to Addison, Washington, and Orange Counties in Vermont, and points south. Some minor flooding was also reported across Chittenden county, with minor flooding likely elsewhere that was not reported. The most susceptible areas for flooding this afternoon were Chittenden, Addison, Franklin, Orleans, and Lamoille Counties in Vermont. Where rainfall rates reached 2 inches per hour, and Doppler radar estimated maximum rainfall totals reached 1.5 - 2.0 inches. A list of storm damage, hail, and flood reports can be found HERE

     For the remainder of the night, additional showers, and perhaps a rumble of thunder can be expected, especially across Northern areas. Additional rainfall totals will range from a tenth to a quarter of an inch. Localized additional amounts to near a half inch could occur with any of the heavier showers. No additional severe weather is expected overnight. Non-thunderstorm related winds should increase into the 10-20MPH range overnight, with gusts up to 35MPH. Some isolated gusts of 40-45MPH could occur, especially across the western slopes of the green mountains, and the higher elevations.

     An updated 7 day forecast should hopefully be up within the next couple of days. Stay tuned!

Severe Weather With Isolated Tornadoes Possible Today

SEVERE THUNDERSTORM WATCH IN EFFECT UNTIL 7PM (Click HERE For Details!)

     I apologize for no recent updates, I have been extremely busy, but with this said, although I am on call, I have made time to send out an update. Severe weather is possible today. Details below...


     The National Weather Service, Storm Prediction Center out of Norman, OK has issued a Severe Thunderstorm Watch for Western Vermont, and Much of New York, this includes much of the Champlain valley, and adjacent western slopes. For some reason Franklin County, VT is not included. However in my suggested alerts, I feel almost all of Vermont is needed in a watch as well. In a Mesoscale discussion they issued prior to the watch they stated that isolated tornadoes were also possible. This discussion can be found HERE



CHAMPLAIN VALLEY WEATHER DISCUSSION:
     Currently across the Champlain Valley and adjacent western slopes a Severe Thunderstorm Watch is in effect until 7PM. For some reason the Storm Prediction Center has excluded the extreme Northeastern Champlain Valley, and Adjacent western slopes. This being Franklin County in Vermont. I feel that Franklin county, as well as much of the state should be under a severe thunderstorm watch, as storms rapidly moving east, combined with a strong jet and moderate instability will result in severe storms. As you can see on my suggested alerts map, I have a Watch up for everyone.

     Looking at radar, some potent storms across Northern, and Western New York right now. An apparent long lived supercell or multicell is across St. Lawrence County New York right now, this area of storms has had a history of producing large hail, and damaging winds. There is actually some occasional rotation noted with it. I wouldn't be surprised to see a tornado warning or two issued today. With that said I don't feel there will be widespread tornadoes or strong tornadoes for that matter, but an isolated tornado or two could occur, especially across Central New York, and Southern Vermont. I will continue to keep a close eye out on the Severe Thunderstorm currently over Southwestern St. Lawrence County. Stay tuned for further updates.

Another Warm Day Today With A Chance Of Thunderstorms

CLICK ON IMAGES TO ENLARGE!

Champlain Valley Region
Counties/ Portions of Counties Include: Grand Isle, Western Franklin, Western Chittenden, Western Addison in Vermont, and Eastern Clinton, and Eastern Essex Counties in New York.

Today/Tonight: Mostly sunny with increasing clouds. A chance of showers and thunderstorms after 11AM. High around 76, and a low around 42. Winds will sustained at 5-15MPH with gusts up to 25MPH. Chance of rain 40%

Wednesday/Wednesday Night: Mostly sunny, and cooler with a High around 62, and a low around 34. Winds will be calm with gusts up to 10MPH.

Thursday/Thursday Night: Sunny, with a high around 65, and a low around 36. Winds will be calm with gusts up to 10MPH.

Friday/Friday Night: Breezy. Chance of showers, and thunderstorms. High around 65, and a low around 42. Winds will be sustained 10-20MPH with gusts up to 35MPH. Chance of rain 30%.

Saturday/Saturday Night: Chance of showers in the morning, and early afternoon, then becoming partly sunny, with a high around 58, and a low around 37. Winds will be sustained in the 5-15MPH range with gusts up to 25MPH.

Sunday/Sunday Night: Mostly cloudy with a high around 62, and a low around 34. Winds will be calm with gusts up to 10MPH.

Monday/Monday Night: Partly cloudy with a high around 62, and a low around 34. Winds will be calm with gusts up to 10MPH.




Green Mountains Region
Counties/Portions of Counties Include: Orleans, Lamoille, Washington, Eastern Franklin, Eastern Chittenden, and Eastern Addison Counties in Vermont.

Today/Tonight: Mostly sunny with increasing clouds. A chance of showers and thunderstorms after 3PM. High around 74, and a low around 40. Winds will sustained at 10-15MPH with gusts up to 30MPH. Chance of rain 40%

Wednesday/Wednesday Night: Mostly sunny, and cooler with a High around 60, and a low around 30. Winds will be calm with gusts up to 10MPH.

Thursday/Thursday Night: Sunny, with a high around 64, and a low around 33. Winds will be calm with gusts up to 10MPH.

Friday/Friday Night: Breezy. Chance of showers, and thunderstorms. High around 64, and a low around 39. Winds will be sustained 15-20MPH with gusts up to 40MPH. Chance of rain 30%.

Saturday/Saturday Night: Chance of showers in the morning, and early afternoon, then becoming partly sunny, with a high around 56, and a low around 35. Winds will be sustained in the 5-15MPH range with gusts up to 30MPH.

Sunday/Sunday Night: Mostly cloudy with a high around 60, and a low around 31. Winds will be calm with gusts up to 10MPH.

Monday/Monday Night: Partly cloudy with a high around 60, and a low around 31. Winds will be calm with gusts up to 10MPH.



CHAMPLAIN VALLEY WEATHER DISCUSSION:
     Very interesting temperatures across the region this morning. They dont really show any pattern, or reason for being the way they are. Two things probably contributing to it is the possibility of some downsloping with some moderate wind gusts still around, and some clouds which are not allowing the heat to break free into the atmosphere, and away from the surface. Anyway, I will give you just a couple examples of the temperatures across the region right now. One may say "Now I know them mountains are definitely cooler right now." well generally that is the case, especially looking at the temperature at Morisville, VT a refreshing 58 degrees compared to the 80's yesterday afternoon. But then you have Derby, VT also in "the mountains", with a temperature of 71 degrees. Whats up with that!? Just wait, it gets better. Currently in Grand Isle the temperature is 62, so this must mean the Champlain Valley is in a cooler area right? Wrong. In Swanton Village the temperature has risen to 67 degrees. The temperature has risen 5 degrees in the past hour and a half or so. And its 3AM! Its gets even crazier then this. In Burlington right now the temperature is 65 degrees, and a couple counties south of that, the town of Rutland is 79 degrees!!!! Yes nearly 80 degrees at 3AM!!! The temperature in Rutland has risen 13 degrees since midnight!! If you think there could be a malfunction with the thermometer, guess what, another personal weather station near Rutland is reporting 78 degrees, along with Danby reporting 77 degrees, and East Wallingford reporting 76 degrees. This is absolutely insane for April, let alone it being like this in April at 3AM!!!!!
     Anyway, enough with the temperature craziness, lets say, I believe I busted the overnight lows, just a tad, for some places. For today though, temperatures should make it to near 80 before a cold front moves through. The front will likely trigger some scattered showers, and thunderstorms, but at this point none are looking to be severe. Temperatures will be substantially cooler come Wednesday. Stay tuned for any further updates!