weatherwiz Posted July 16, 2012 Share Posted July 16, 2012 The last thread is over 1000 replies and with potential for severe weather across northern New England tomorrow and rest of southern New England on Wednesday it's probably a good time to make a new thread. As some were saying in the last thread Wednesday certainly offers some very good potential right now as the combination of high heat/humidity along with good shear and lapse rates with an approaching cold front will make the atmosphere quite prime for the potential for severe weather. As always though we could have some issues to deal with... 1) Timing of the front. While it's becoming more likely the timing of the front shouldn't be an issue this should still be watched. Some recent model runs actually slow the front too much which would give northern/central areas a better chance on Wednesday...again. 2) low-level winds. Certainly have to watch for a wind shift too early with sfc winds becoming more westerly. If this occurs this could actually allow for some drier air aloft to work down and mix the dewpoints out some which would reduce instability. The good news is the low-levels are fairly moist so if dewpoints were to mix out they should not lower too much, however, even a 2-3F drop in dewpoints can greatly reduce your cape values. 3) Any cloud debris? You always have to watch out for some leftover convective junk which can wreck havoc on forecasts Anyways there is a pretty good amount of speed shear aloft and with pure unidirectional wind fields along with the potential for moderate to extreme instability and steep lapse rates we could be looking at the potential for a very nasty bowing squall line! Link to comment Share on other sites More sharing options...
andyhb Posted July 16, 2012 Share Posted July 16, 2012 SPC mentioning isolated tornadoes in their latest D2... It's thread VI, btw Link to comment Share on other sites More sharing options...
CoastalWx Posted July 16, 2012 Share Posted July 16, 2012 I'm still on the fence about BOS. I think it may be more CT/RI and se MA. Link to comment Share on other sites More sharing options...
weatherwiz Posted July 16, 2012 Author Share Posted July 16, 2012 Looks like some decent confluence across central/southern New England too on Wednesday. Link to comment Share on other sites More sharing options...
powderfreak Posted July 16, 2012 Share Posted July 16, 2012 I'm liking tomorrow for us up this way... ...LAKE ONTARIO EWD ACROSS NRN NEW ENGLAND... TSTMS MAY BE ON-GOING ACROSS NRN NEW ENGLAND TUE MORNING AIDED BY STG LOW-LEVEL ISENTROPIC LIFT. ENOUGH HEATING IS LIKELY AHEAD OF THE EWD-MOVING COLD FRONT TO RESULT IN MLCAPE OF 1000-1500 J/KG BY MID-AFTN. LOW-MID LEVEL FLOW WILL STRENGTHEN DURING THE DAY RESULTING IN 0-6 KM SHEAR SUFFICIENT TO SUPPORT SUPERCELLS WITH LARGE HAIL...AND POSSIBLY BOWING SEGMENTS PRODUCING DAMAGING WINDS. ACROSS NRN PORTIONS OF THE SLIGHT RISK...AN ISOLD TORNADO MAY BE POSSIBLE WHERE BACKED LOW-LEVEL FLOW EXISTS IN ASSOCIATION WITH SFC LOW AND WHERE FCST SOUNDINGS DEPICT LOWER LCLS. Link to comment Share on other sites More sharing options...
powderfreak Posted July 16, 2012 Share Posted July 16, 2012 BTV's afternoon AFD take on the situation tomorrow... .SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/... AS OF 327 PM EDT MONDAY...AN ACTIVE WEATHER DAY IS ON TAP FOR THE NORTH COUNTRY TUESDAY WITH STRONG TO SEVERE STORMS POSSIBLE. TIMING WILL BE A LITTLE TRICKY AS A SURFACE WARM FRONT WILL PUSH A FEW SHOWERS/STORMS ACROSS THE REGION DURING THE MORNING HOURS...BEFORE A STRONG COLD FRONT SAGS SOUTHWARD ACROSS THE AREA DURING THE AFTERNOON/EVENING HOURS. WARM FRONT WILL BE ASSOCIATED WITH A LOW LEVEL JET FROM 925-850MB OF 40-50KTS SO FEEL THE ASSOCIATED MOISTURE/CLOUDS WILL BE QUICK TO CLEAR THE AREA MID- MORNING...ALLOWING FOR AMPLE SURFACE HEATING TO REACH CONVECTIVE POTENTIAL FOR THE AFTERNOON. MODELS CONTINUE TO SHOW A FAVORABLY ENVIRONMENT FOR WIDESPREAD CONVECTION WITH CAPE VALUES BETWEEN 1500-2000 J/KG AND 0-6KM SHEAR OF 35-45 KTS. SOUNDINGS CONTINUE TO SHOW UNIDIRECTIONAL FLOW THROUGH THE MID-TROPOSPHERE WITH 40-60KTS OF WIND FROM 850-500MB. WITH SUCH A WARM HUMID AIRMASS IN PLACE...FREEZING LEVELS WILL BE ABOUT 13-14KFT AND WBZ 11-12KFT WHICH SHOULD LIMIT THE OCCURRENCE OF LARGE HAIL...SO THINKING THE PRIMARY SEVERE MODE WILL BE DAMAGING WINDS WITH A SECONDARY THREAT OF LOCALIZED FLASH FLOODING AS PWATS RUN 1.5-2". FRONT IS SLOW TO SAG SOUTHWARD SO FEEL THE CONVECTIVE THREAT MAY LAST A LITTLE LONGER INTO THE EVENING PAST SUNSET FOR SOUTHERN VERMONT SO HAVE KEPT IN SOME LIKELY POPS THROUGH AT LEAST MIDNIGHT. THEREAFTER...SHOWERS/STORMS SHOULD BE CALMING DOWN GOING INTO THE OVERNIGHT HOURS. I'll be stationed up at 3,700ft all day tomorrow, so should be interesting to see how it all shakes out. I like the 40-50kt low level jet at 925-850mb that BTV mentions, and the mountain forecast has sustained winds of 30-40mph with higher gusts tomorrow, so should at least be semi-interesting up there. Link to comment Share on other sites More sharing options...
weatherwiz Posted July 17, 2012 Author Share Posted July 17, 2012 I could see some supercells up near the US/Canadien border tomorrow where being closer to the sfc low will result in backed sfc winds and increased helicity. Link to comment Share on other sites More sharing options...
ChrisM Posted July 17, 2012 Share Posted July 17, 2012 I'm liking tomorrow for us up this way... ...LAKE ONTARIO EWD ACROSS NRN NEW ENGLAND... TSTMS MAY BE ON-GOING ACROSS NRN NEW ENGLAND TUE MORNING AIDED BY STG LOW-LEVEL ISENTROPIC LIFT. ENOUGH HEATING IS LIKELY AHEAD OF THE EWD-MOVING COLD FRONT TO RESULT IN MLCAPE OF 1000-1500 J/KG BY MID-AFTN. LOW-MID LEVEL FLOW WILL STRENGTHEN DURING THE DAY RESULTING IN 0-6 KM SHEAR SUFFICIENT TO SUPPORT SUPERCELLS WITH LARGE HAIL...AND POSSIBLY BOWING SEGMENTS PRODUCING DAMAGING WINDS. ACROSS NRN PORTIONS OF THE SLIGHT RISK...AN ISOLD TORNADO MAY BE POSSIBLE WHERE BACKED LOW-LEVEL FLOW EXISTS IN ASSOCIATION WITH SFC LOW AND WHERE FCST SOUNDINGS DEPICT LOWER LCLS. Ouch Link to comment Share on other sites More sharing options...
HoarfrostHubb Posted July 17, 2012 Share Posted July 17, 2012 Wiz, you going chasing with your NH bud? Link to comment Share on other sites More sharing options...
weatherwiz Posted July 17, 2012 Author Share Posted July 17, 2012 Wiz, you going chasing with your NH bud? He has work as do I. I do get out at 3:30 on Wednesday though so if it's looking real good perhaps Chris would want to go if we have anything good going on around here. Link to comment Share on other sites More sharing options...
CoastalWx Posted July 17, 2012 Share Posted July 17, 2012 SREFs slowed which isn't a surprise considering they were the fastest. Link to comment Share on other sites More sharing options...
yoda Posted July 17, 2012 Share Posted July 17, 2012 New Day 2... hope Wiz isn't working late ..SRN NY AND NEW ENGLAND...PA...FAR NERN OHSTORMS SHOULD FORM RELATIVELY EARLY ACROSS THE ENTIRE REGION AFTER A FEW HOURS OF HEATING AS CIN WILL BE NEGLIGIBLE AND MOISTURE AND INSTABILITY WILL BE IN PLACE. STRONG INSTABILITY WILL RESULT IN ROBUST UPDRAFTS WITH LARGE PRECIPITATION LOADING...AND MEAN DEEP LAYER FLOW AROUND 30 KT WILL BE SUFFICIENT TO CREATE CLUSTERS OF STRONG TO SEVERE STORMS WITH DAMAGING WINDS AND HAIL. THE BEST AREA FOR SUPERCELLS WILL BE OVER SRN NEW ENGLAND...WHERE SOME HAIL STONES COULD APPROACH 2.00 INCHES DIAMETER. LOW LEVEL SHEAR WILL BE WEAK FOR ANY TORNADO THREAT...BUT A BRIEF TORNADO CANNOT BE RULED OUT THERE. Link to comment Share on other sites More sharing options...
yoda Posted July 17, 2012 Share Posted July 17, 2012 Link to comment Share on other sites More sharing options...
weatherwiz Posted July 17, 2012 Author Share Posted July 17, 2012 I lol'd at this Today's Day 1: ALTHOUGH MIDLEVEL LAPSE RATES WILL BE MODEST /6.5-7 C PER KM/ For New England with a setup like this that's pretty decent. Link to comment Share on other sites More sharing options...
weatherwiz Posted July 17, 2012 Author Share Posted July 17, 2012 I haven't looked at overnight data yet...just woke up but I was surprised to see the mention of such large here for this area tomorrow. Given freezing levels which were a tad on the high side along with a dominant unidirectional flow with little helicity I thought it would be difficult to perhaps get some good hailers tomorrow. Link to comment Share on other sites More sharing options...
ice1972 Posted July 17, 2012 Share Posted July 17, 2012 I haven't looked at overnight data yet...just woke up but I was surprised to see the mention of such large here for this area tomorrow. Given freezing levels which were a tad on the high side along with a dominant unidirectional flow with little helicity I thought it would be difficult to perhaps get some good hailers tomorrow. Sorry but when you say tomorrow do you mean Tuesday or Wednesday? Sorry, I'm delerious at 38,000 feet on the red eye from SFO to ATL...then gotta take the 2.5 hour flight to BDL...can't sleep Link to comment Share on other sites More sharing options...
weatherwiz Posted July 17, 2012 Author Share Posted July 17, 2012 Just looked at some of the overnight data and I'm pretty impressed with both today and tomorrow! For today, I think we could see probs come fairly close to moderate risk up north, especially if they can really destabilize. Across central VT/NH into ME and points north conditions certainly look ripe for some monster supercells probably capable of 2'' hail and damaging winds probably in excess of 65-70 mph. An isolated tornado certainly can't be ruled out. If the SPC SREF is correct and the strong low-level helicity holds in place longer there certainly could be potential for a few tornadoes and you really couldn't rule out the potential for a strong tornado as long as they achieve maximum instability and hold onto those >250 m2s2 of 0-1km helicity and 0-3km helicity. THese trends have to be watched...perhaps an upgrade to 10% TOR probs? As for tomorrow 0-3km helicity does look a tad more impressive than past runs which would explain the introduction to the potential for some extremely large hail. Computer models showing moderate to extreme instability across southern New England and I really like central MA into northern CT/RI for some big action tomorrow...here will be the greatest combination of extreme instability along with the strongest shear. If sfc winds can become backed (which is actually quite possible in the CT Valley) than I could see an isolated supercell tomorrow. Link to comment Share on other sites More sharing options...
weatherwiz Posted July 17, 2012 Author Share Posted July 17, 2012 Sorry but when you say tomorrow do you mean Tuesday or Wednesday? Sorry, I'm delerious at 38,000 feet on the red eye from SFO to ATL...then gotta take the 2.5 hour flight to BDL...can't sleep It's alright I meant for Wednesday. Link to comment Share on other sites More sharing options...
weatherwiz Posted July 17, 2012 Author Share Posted July 17, 2012 The WRF drives a cluster of storms south through MA and CT during the early evening hours tonight. Link to comment Share on other sites More sharing options...
Damage In Tolland Posted July 17, 2012 Share Posted July 17, 2012 Tomorrow looks like a very damaging day around the area. Things look great ...SRN NY AND NEW ENGLAND...PA...FAR NERN OH... STORMS SHOULD FORM RELATIVELY EARLY ACROSS THE ENTIRE REGION AFTER A FEW HOURS OF HEATING AS CIN WILL BE NEGLIGIBLE AND MOISTURE AND INSTABILITY WILL BE IN PLACE. STRONG INSTABILITY WILL RESULT IN ROBUST UPDRAFTS WITH LARGE PRECIPITATION LOADING...AND MEAN DEEP LAYER FLOW AROUND 30 KT WILL BE SUFFICIENT TO CREATE CLUSTERS OF STRONG TO SEVERE STORMS WITH DAMAGING WINDS AND HAIL. THE BEST AREA FOR SUPERCELLS WILL BE OVER SRN NEW ENGLAND...WHERE SOME HAIL STONES COULD APPROACH 2.00 INCHES DIAMETER. LOW LEVEL SHEAR WILL BE WEAK FOR ANY TORNADO THREAT...BUT A BRIEF TORNADO CANNOT BE RULED OUT THERE. Link to comment Share on other sites More sharing options...
powderfreak Posted July 17, 2012 Share Posted July 17, 2012 65/63 and pouring outside. Thought I heard some low rumbles this morning. Hopefully we can clear out enough to go SVR this evening. After this moves through then we'll see what happens later today. INDICATIONS ARE THAT THERE WILL BE A GOOD DEAL OF CLOUD DEBRIS ALL DAY...BUT THERE SHOULD BE ENOUGH SUN TO ALLOW TEMPS TO CLIMB INTO THE 80S NORTH AND AROUND 90 SOUTH. THIS SHOULD BE MORE THAN SUFFICIENT TO GENERATE SB CAPE VALUES OF 1000-2000 J/KG THIS AFTERNOON. IN ADDITION...STRENGTHENING WIND FIELD WILL RESULT IN 0-6KM SHEAR OF 35-45 KTS. SOUNDINGS CONTINUE TO SHOW UNIDIRECTIONAL FLOW THROUGH THE MID-TROPOSPHERE WITH 40-60 KTS OF WIND FROM 850-500MB. THESE CONDITIONS COMBINED WITH APPROACHING COLD FRONT WILL BE ENOUGH TO SUPPORT WIDESPREAD AND POTENTIALLY SEVERE CONVECTION...WITH DAMAGING WINDS THE MAIN THREAT FROM SUPERCELLS OR BOWING SEGMENTS. Now time to go off to 3,700ft for the day... love watching storms from that vantage point at work. Link to comment Share on other sites More sharing options...
OSUmetstud Posted July 17, 2012 Share Posted July 17, 2012 The Dacks are the place to be today. Link to comment Share on other sites More sharing options...
HoarfrostHubb Posted July 17, 2012 Share Posted July 17, 2012 The Dacks are the place to be today. Maybe central Vt too Link to comment Share on other sites More sharing options...
CoastalWx Posted July 17, 2012 Share Posted July 17, 2012 Tomorrow looks pretty good imo. Link to comment Share on other sites More sharing options...
dryslot Posted July 17, 2012 Share Posted July 17, 2012 Could be an interesting day up here later on, Will see how it plays out Link to comment Share on other sites More sharing options...
CoastalWx Posted July 17, 2012 Share Posted July 17, 2012 The meso models have an interesting thing going on. It;s like the front washes out overhead and we have a bit of seabreeze convergence helping out tomorrow. Link to comment Share on other sites More sharing options...
Tropopause_Fold Posted July 17, 2012 Share Posted July 17, 2012 The meso models have an interesting thing going on. It;s like the front washes out overhead and we have a bit of seabreeze convergence helping out tomorrow. i noticed that as well. also have rather interesting storm motion on some. it's like the activity starts to lift NE. Link to comment Share on other sites More sharing options...
CoastalWx Posted July 17, 2012 Share Posted July 17, 2012 i noticed that as well. also have rather interesting storm motion on some. it's like the activity starts to lift NE. That's something I didn't want to see because I could envision storms away from this area. I need the rain. Luckily, the shear perhaps would blow it back east. Anyways, the euro really developed convection farther nw so I'm not sure how to believe the NAM. Still looks like a light wind/big CAPE day. Link to comment Share on other sites More sharing options...
OSUmetstud Posted July 17, 2012 Share Posted July 17, 2012 Degree of clearing and instability is definitely a concern for northern New England today give the strong shear. Could end up ripping the updrafts apart. Link to comment Share on other sites More sharing options...
Damage In Tolland Posted July 17, 2012 Share Posted July 17, 2012 Tomorrow looks pretty good imo. You believe the WRF for today with storms ripping down from Mass thru CT? Seems odd Link to comment Share on other sites More sharing options...
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