Severe storms 2015 general chatter

[yoda]

I'll buy "I doubt these soundings come true" for 5,000 please Alex

 

 

 

 

[yoda]

00z NAM soundings even sillier for Monday evening... I know its the NAM being the NAM most likely, but its our next chance at severe weather... so yeah

[Kmlwx]

Not buying until Monday morning. And even then we'll find a way to screw this up. 

[yoda]

Not buying until Monday morning. And even then we'll find a way to screw this up. 

 

True... I am gathering remnant EML or MCS/complex is what NAM is advertising on its 18z and now 00z soundings... prob will change by 06z... but kinda ominous soundings for this area anyway.  We don't see that type of sounding here often... but as Ellinwood/Ian/you would say... NAM being the NAM

 

ETA:  3km EHI at 21z MON at KMRB is 8 and EHI is 6.6 with 45 kts bulk shear and 4000 SBCAPE... that's just silly

[yoda]

06z NAM soundings still very nice... even though it cut back a lil bit on the EHI numbers a little but... the hodograph curves starting at 21z as the 0-3km and 1km SRH increase rapidly all the way out to 06z

[Kmlwx]

06z NAM soundings still very nice... even though it cut back a lil bit on the EHI numbers a little but... the hodograph curves starting at 21z as the 0-3km and 1km SRH increase rapidly all the way out to 06z

by 06z it probably won't matter much with less instability. We're going to need stuff to comingle in the afternoon and early evening. Let's try not to let this become a 10pm peak event because we'll pretty much lose our potential if that's the case. 

[yoda]

by 06z it probably won't matter much with less instability. We're going to need stuff to comingle in the afternoon and early evening. Let's try not to let this become a 10pm peak event because we'll pretty much lose our potential if that's the case. 

 

Oh I know... i was just mentioning how the SRH increases from 21z on... 21z 1km SRH is just below 100 m2/s2 at DCA -- at 03z, its just over 155 m2/s2 -- with over 1300 SBCAPE

[WxUSAF]

Better get something this afternoon.  Cancelled our camping trip.  

[AvantHiatus]

Solid cluster rolled thru here. Wasn't expecting a backdoor front today, and winds have not veered strongly out of the NE.

[yoda]

decent curved hodo for Monday night:

 

 

 

[yoda]

18z NAM radar reflectivity for 00z TUES (8pm Monday) has what looks to be two supercells... one in N VA and one in C VA

[Kmlwx]

#wedgefail 2015

[Disc]

18z NAM radar reflectivity for 00z TUES (8pm Monday) has what looks to be two supercells... one in N VA and one in C VA

 

I'm not really seeing anything?

 

Timing is really off for us to see anything, except for any pre-frontal stuff that may blossom.

 

[yoda]

^ that above is the 4km NAM... i am talking about the regular NAM itself on its radar reflectivity

[Disc]

^ that above is the 4km NAM... i am talking about the regular NAM itself on its radar reflectivity

 

Gotcha. I was assuming you were talking about the 4km.

[yoda]

Hopefully its okay to post this -- from the 18z NAM at 54 hrs:

 

[WinterWxLuvr]

Hopefully its okay to post this -- from the 18z NAM at 54 hrs:

get_orig_img.png

Hard for me to believe a model can predict distinct storms at 54 hours.

[Ian]

Mon has potential but it's somewhat fragile to reach it as usual. Def looks like mainly a wind threat but there are some interesting soundings paritcularly n md into central PA at 21z and nearer the bay at 0z. DC also in heart of theta e pool suggests a good chance for good storms locally if the NAM is right.

[yoda]

Mon has potential but it's somewhat fragile to reach it as usual. Def looks like mainly a wind threat but there are some interesting soundings paritcularly n md into central PA at 21z and nearer the bay at 0z. DC also in heart of theta e pool suggests a good chance for good storms locally if the NAM is right.

 

00z NAM sounding at KDCA for 00z TUES (8pm Monday) had a somewhat curved hodo with around 130 m2/s2 at the 1km level and 234.7 m2/s2 at the 0-3km SRH level... leads me to believe that there might be a few tornado warnings Monday evening... but tor threat should be isolated

[Disc]

00z NAM sounding at KDCA for 00z TUES (8pm Monday) had a somewhat curved hodo with around 130 m2/s2 at the 1km level and 234.7 m2/s2 at the 0-3km SRH level... leads me to believe that there might be a few tornado warnings Monday evening... but tor threat should be isolated

 

[yoda]

From the new Day 2

 

 

..OH/TN VALLEYS TO THE NORTHEAST STATES/DELMARVA  

 
AN UPPER TROUGH IS EXPECTED TO AMPLIFY OVER THE UPPER OH RIVER  
VALLEY/NORTHEAST STATES ON MONDAY...WITH A COLD FRONT SPREADING  
EAST-SOUTHEASTWARD ACROSS THE OH/TN VALLEYS AND  
NORTHEAST/MID-ATLANTIC STATES. SCATTERED EARLY-DAY  
SHOWERS/THUNDERSTORMS AND RELATED CLOUD COVER ARE LIKELY TO  
ACCOMPANY THE ADVANCING FRONT...WHICH LEADS TO UNCERTAINTY REGARDING  
PRE-FRONTAL DESTABILIZATION PARTICULARLY WITH EAST-NORTHEASTWARD  
EXTENT INTO THE NORTHEAST STATES/DELMARVA WHERE VERTICAL SHEAR WILL  
BE STRONGER. SOUTH OF THE EARLY DAY CLOUD COVER/PRECIPITATION AND  
POSSIBLE OUTFLOW...CURRENT THINKING IS THAT STRONG/SEVERE  
THUNDERSTORMS ARE MOSTLY LIKELY TO INTENSIFY MONDAY AFTERNOON WITHIN  
A WEAKLY CAPPED/MODERATELY UNSTABLE ENVIRONMENT AHEAD OF THE FRONT  
ACROSS PORTIONS OF THE LOWER/MIDDLE OH VALLEY AND TN VALLEY TO THE  
CENTRAL APPALACHIANS VICINITY...BUT POTENTIALLY ALSO ACROSS PARTS OF  
PA/DELMARVA VICINITY WITH THE POSSIBLE AID OF WEAK PRE-FRONTAL  
TROUGHING/TERRAIN. THE WEST-SOUTHWESTERLY FEED OF MOIST/UNSTABLE AIR  
AND STRENGTHENING BELT OF WEST-SOUTHWESTERLY MID-LEVEL WINDS /30-60  
KT BETWEEN 700-500 MB/ WILL CONTRIBUTE TO ORGANIZED MULTICELLS/LINE  
SEGMENTS AND POTENTIALLY A FEW SUPERCELLS WITH DAMAGING WINDS/SEVERE  

HAIL AS THE PRIMARY HAZARDS.  

[yoda]

[yoda]

06z NAM soundings still good for Monday

[Kmlwx]

Ian and Yoda can talk me down from the severe ledge - but I'm just not super enthralled with Monday. I think we will definitely see storms but I'm not sure it'll be as exciting as some are hinting at. At least we got our slight

[yoda]

12z NAM continues the gung ho train for severe tomorrow afternoon/evening...def risk of an isolated tornado IMO if any sup can develop and stay discrete... DCA at 00z TUES has ~260 m2/s2 at the 0-3km level and around 140 m2/s2 on the 1km SRH level

[Kmlwx]

At the same time the parameters look good - sim reflectivity (fwiw) is pretty insistent that most of the good activity will be to our north and west. That's also where the best mixing of shear and CAPE is it seems. 

[yoda]

Day 2 1730 SPC OTLK snippet:

 

A TORNADO OR TWO WILL ALSO BE POSSIBLE...ESPECIALLY WITH ANY  

ESTABLISHED LEWP PATTERNS. THIS IS ESPECIALLY THE CASE FROM PARTS OF  
ERN PA AND ADJACENT SERN NY INTO CNTRL MD...WHERE RELATIVELY BACKED  
SFC WINDS WILL BOLSTER LOW-LEVEL SHEAR AND A FEW TRANSIENT SUPERCELL  

TSTMS MAY EVOLVE.

[Ian]

Shear has definitely backed off as we close. The trough sharpens a bit and allows it to hang back. Runs of the Euro from range and even the start of the short-range cycle still had it overspreading the warm sector pretty well. Now it's certainly most focused N/W basically along the SPC slight boundaries.  If NAM CAPE is right they are probably underestimating the risk in this area.. at least to within a county or so east of 95.. perhaps all the way east but not quite as unstable there. If storms drop into that area we'll get a pretty good run if not crazy widespread severe. 

 

edit: I'd probably lean toward it being a decent event but you know how this area goes.

[yoda]

Afternoon LWX AFD

 

AREA FORECAST DISCUSSION

NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
346 PM EDT SUN JUN 7 2015

.SYNOPSIS...
A WARM FRONT WILL CROSS THE REGION LATE TONIGHT AND MONDAY
MORNING...FOLLOWED BY A COLD FRONT WHICH WILL APPROACH THE AREA
LATE MONDAY AFTERNOON AND EVENING. THE COLD FRONT WILL STALL
ACROSS THE LOWER CHESAPEAKE BAY MONDAY NIGHT AND TUESDAY BEFORE
MOVING EAST OF DELMARVA TUESDAY NIGHT. WEAK HIGH PRESSURE BUILDS
INTO THE REGION WEDNESDAY AND THURSDAY.

&&

.NEAR TERM /THROUGH MONDAY/...
19Z VISIBLE SATL STARTING TO SHOW THE LOWER AND MID CLOUDS
FINALLY SCOURING OUT. THE LOW/MID DECK THAT PERSISTED MUCH OF
TODAY WAS CAUSED BY ATLANTIC MOISTURE ADVECTION AND COLD AIR
ADVECTION AT THE TOP OF THE BOUNDARY LAYER WITH THE ANTICYCLONIC
LLVL FLOW AROUND THE HIGH PRESSURE EAST OF SOUTHERN NEW ENGLAND.
AS THIS HIGH CONTINUES TO TREK TOWARDS THE NORTH ATLANTIC
TONIGHT...ANTICIPATING THE SKY COVER TO CONTINUE TO ERODE.
HOWEVER...THIS WILL BE MITIGATED TO SOME EXTENT BY THE HIGH DEBRIS
CLOUDS FROM THE MCS THAT WENT THROUGH THE GREAT LAKES REGION
EARLIER TODAY.

MONDAY WILL BE CHALLENGING FROM A CONVECTIVE FORECASTING STANDPOINT.
AS IS FAIRLY TYPICAL FOR THIS AREA...THE AREAL EXTENT AND
MAGNITUDE OF THE CONVECTION WILL BE TIED CLOSELY TO SKY COVER.
THERE SHOULD BE LEFT OVER HIGH CLOUDS FROM THE MIDWEST/GREAT LAKES
CONVECTION AND ANY POTENTIAL MCS THAT DEVELOPS TONIGHT.
HOWEVER...THE 09Z SREF BRINGS IN EFFECTIVE SHEAR AOA 30 KTS TO
CENTRAL AND WESTERN MD DURING MONDAY AFTERNOON. THIS COUPLED WITH
PROGGED MIXED LAYER CAPE VALUES RANGING FROM 1000-2000 J/KG AND
DECENT AREA UNDER THE HODOGRAPH WILL PRODUCE AN ENVIRONMENT
CONDUCIVE FOR BOWING LINE SEGMENTS AND ISOLATED MINI-SUPERCELLS.
THUS HAVE CONTINUED ENHANCED WORDING IN HWO FOR SEVERE ON MONDAY

AFTERNOON AND EVENING.

[yoda]

18z NAM still calling for 3000-4000 SBCAPE tomorrow afternoon/evening on the soundings