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Next Monday-Tues frontal passage


free_man

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Was going to make a thread on this but with working full time this summer not much time

:thumbsup: WEDNESDAY INTO THE END OF THE WEEK...

MDL SOLNS CONTINUE TO HIGHLIGHT A STRONG SFC HIGH PRES RIDGE IN

CONTROL OF THE RGNS WX BRINGING COOLER AND MUCH DRIER CONDITIONS TO

THE RGN. INITIALLY MODEST N/NW FLOW...WITH GUSTS 20-25 KTS...BEHIND

THE EXITING SYS WILL USHER SOME VERY COOL MID-LVL AIR SEWD WITH H925

TEMPS AS +10C. WILL SEE MIN TEMPS FALL INTO THE LOW TO MID 50S...

WARMER ALONG THE SHORE. SOME AREAS REPORTING UPR 40S FOR MINS

WED/THURS MORN IS NOT OUT OF THE QUESTION.

Just generally speaking, that type of airmass punching in is a good sign.

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SUNDAY NIGHT INTO MONDAY...

A COOL EVNG FOR SUNDAY NIGHT WITH LGT/VRB SLY FLOW. MAY SEE THE

INCREASE OF MID-LVL CLOUDS OVERSPREAD THE RGN AHEAD OF THE ONCOMING

SYNOPTIC SYS FOR TUESDAY. AS FOR MONDAY...ANTICIPATE PARTLY CLOUDY

CONDITIONS WITH CONVECTION PSBL TOWARDS AFTN. UNCERTAIN WHETHER THIS

CONVECTION IS A RESULT OF A LEE TROF AHEAD OF TUESDAYS COLD FRONT...

OR RATHER ISENTROPICALLY FORCED ALONG AND AHEAD OF A MID-LVL THERMAL

RIDGE ADVECTING OUT OF THE SW. ASIDE...MARGINAL SHEAR EVIDENT WITH

0-6KM VALUES OF 30 TO 40 KTS WITH VECTORS ORTHOGONAL TO A PSBL LEE

TROF...AN INDICATION OF POTENTIALLY SEEING DISCREET MULTI-CELLULAR

CONVECTION. INSTABILITY WILL BUILD ALONG WITH THE INFLUX OF WARM/

MOIST AIR VIA MODEST SW FLOW...GUSTING AT TIMES AT THE SFC...ALONG

AND AHEAD OF THE AFOREMENTIONED SYNOPTIC SYS. YET WARM AIR AT H85

MAY ACT TO CAP SFC DESTABILIZATION AND RESULT IN ELEVATED

CONVECTION...DEPENDENCE ON MOISTENING AT THE SFC WHICH FEEL PERHAPS

THE FAVORABLE GFS IS TOO ROBUST. HAVE CHC POPS FOR NOW WITH A BLEND

OF A FEW DEGREES ABOVE MAV/MOS GUIDANCE FOR TEMP AND DEW POINTS.

MONDAY NIGHT INTO TUESDAY...

EXPECT CONVECTION TO LIFT ENEWD AND GRADUALLY DISSIPATE INTO A LESS

FAVORABLE AIRMASS...WILL LIKELY SEE A LULL INTO MONDAY NIGHT WITH

CLOUDS KEEPING OVRNGT MINS MILD. INTO TUESDAY SFC COLD FRONT DRAGS

THRU THE RGN WITH A GOOD CHC FOR SHOWERS AND TSTORMS. STILL SOME

QUESTION CONCERNING WHETHER CONVECTION WILL BECOME SFC-BASED...

LINGERING CLOUDS FROM PREV DAY CONVECTION...AS WELL AS WEAK

ISENTROPIC LIFT OF RICH THETAE AIR COULD LEND TO MID-LVL CLOUDS

OVERSPREADING THE RGN. ASIDE...MID-LVL MOISTENING AND SUBSEQUENT

COOLING WILL LEND TO SUBSTANTIAL ELEVATED INSTABILITY. CONTINUED

MODEST SHEAR ORTHOGONAL TO THE FRONTOGENETICALLY FORCING SFC COLD

FRONT...PARENT WITH ENHANCED ASCENT AS THE MAIN SHRTWV ENERGY DIGS

THRU N NEW ENGLAND...SHOULD PROVIDE THE POSSIBILITY FOR DISCREET

CONVECTION ACROSS THE FCST RGN. UNCERTAIN AS TO THE SEVERITY OF

WHICH...BUT CONFIDENT ENOUGH TO USHER SOME CONCERN OF POTENTIAL

THREATS. ANTICIPATE AS WE GET CLOSER TO TUESDAY THERE SHOULD BE A

BETTER HANDLE. CONTINUED WITH MAV/MOS GUIDANCE GOING A FEW DEGREES

HIGHER FOR TEMPS.

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We'll see what happens with the mid level lapse rates and all but as of right now Tuesday looks like it could be a decent damaging wind threat with large hail possible. Pretty steep low level lapse rates if we see good heating and fairly dry in the mid levels...which is good.

The setup looks good at first glance... Good w to wnw flow. S/W timing and lapse rates questionable, but the overall setup seems ok.

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The setup looks good at first glance... Good w to wnw flow. S/W timing and lapse rates questionable, but the overall setup seems ok.

I think what's important at this juncture is the setup looks good. I'm not really too worried about timing right now though, especially in a season like this. With such a strong ridge across the east the models have been fairly horrible and inconsistent with regards to timing. With this I would definitely expect a much slower timing, even probably slower then what the slowest model is showing...with this I'd think we see something with the front passing Tuesday night...perhaps even Wednesday AM.

The lapse rates are concerning but I think would just limit a much more widespread event or more in the way of significant severe weather reports (like lots of 65+ mph wind reports and 2"+ hail reports.

Something to watch for as well, which we really won't know until Tuesday AM is how are the sfc winds and winds in the lowest 900mb of the atmosphere. If these winds can stay more SW to the S this will make way for a few things; 1) It would prevent that dry air from mixing down into the lower levels and to the sfc which will keep the dewpoints from lowering and prevent instability from lowering. 2) It could enhance helicity given the flow in the mid levels is W/WNW, especially if the lower level winds are a bit stronger.

Still lots of questions but at least the setup shows potential so we can only go from there.

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I think what's important at this juncture is the setup looks good. I'm not really too worried about timing right now though, especially in a season like this. With such a strong ridge across the east the models have been fairly horrible and inconsistent with regards to timing. With this I would definitely expect a much slower timing, even probably slower then what the slowest model is showing...with this I'd think we see something with the front passing Tuesday night...perhaps even Wednesday AM.

The lapse rates are concerning but I think would just limit a much more widespread event or more in the way of significant severe weather reports (like lots of 65+ mph wind reports and 2"+ hail reports.

Something to watch for as well, which we really won't know until Tuesday AM is how are the sfc winds and winds in the lowest 900mb of the atmosphere. If these winds can stay more SW to the S this will make way for a few things; 1) It would prevent that dry air from mixing down into the lower levels and to the sfc which will keep the dewpoints from lowering and prevent instability from lowering. 2) It could enhance helicity given the flow in the mid levels is W/WNW, especially if the lower level winds are a bit stronger.

Still lots of questions but at least the setup shows potential so we can only go from there.

From what I can tell..boundary layer winds are sw, so that's good for now.

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From what I can tell..boundary layer winds are sw, so that's good for now.

Yeah that's what the 12z NAM showed which is definitely good...keeps pumping in the moisture and also allows for any clouds we may have to break up and mix out.

One of the most impressive things right now I think is the 34-45 knots of vertical shear modeled...combine that with 1500-2500 J/KG of SBcape and some great forcing and you could have some major fun.

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SUNDAY NIGHT INTO MONDAY...

A COOL EVNG FOR SUNDAY NIGHT WITH LGT/VRB SLY FLOW. MAY SEE THE

INCREASE OF MID-LVL CLOUDS OVERSPREAD THE RGN AHEAD OF THE ONCOMING

SYNOPTIC SYS FOR TUESDAY. AS FOR MONDAY...ANTICIPATE PARTLY CLOUDY

CONDITIONS WITH CONVECTION PSBL TOWARDS AFTN. UNCERTAIN WHETHER THIS

CONVECTION IS A RESULT OF A LEE TROF AHEAD OF TUESDAYS COLD FRONT...

OR RATHER ISENTROPICALLY FORCED ALONG AND AHEAD OF A MID-LVL THERMAL

RIDGE ADVECTING OUT OF THE SW. ASIDE...MARGINAL SHEAR EVIDENT WITH

0-6KM VALUES OF 30 TO 40 KTS WITH VECTORS ORTHOGONAL TO A PSBL LEE

TROF...AN INDICATION OF POTENTIALLY SEEING DISCREET MULTI-CELLULAR

CONVECTION. INSTABILITY WILL BUILD ALONG WITH THE INFLUX OF WARM/

MOIST AIR VIA MODEST SW FLOW...GUSTING AT TIMES AT THE SFC...ALONG

AND AHEAD OF THE AFOREMENTIONED SYNOPTIC SYS. YET WARM AIR AT H85

MAY ACT TO CAP SFC DESTABILIZATION AND RESULT IN ELEVATED

CONVECTION...DEPENDENCE ON MOISTENING AT THE SFC WHICH FEEL PERHAPS

THE FAVORABLE GFS IS TOO ROBUST. HAVE CHC POPS FOR NOW WITH A BLEND

OF A FEW DEGREES ABOVE MAV/MOS GUIDANCE FOR TEMP AND DEW POINTS.

MONDAY NIGHT INTO TUESDAY...

EXPECT CONVECTION TO LIFT ENEWD AND GRADUALLY DISSIPATE INTO A LESS

FAVORABLE AIRMASS...WILL LIKELY SEE A LULL INTO MONDAY NIGHT WITH

CLOUDS KEEPING OVRNGT MINS MILD. INTO TUESDAY SFC COLD FRONT DRAGS

THRU THE RGN WITH A GOOD CHC FOR SHOWERS AND TSTORMS. STILL SOME

QUESTION CONCERNING WHETHER CONVECTION WILL BECOME SFC-BASED...

LINGERING CLOUDS FROM PREV DAY CONVECTION...AS WELL AS WEAK

ISENTROPIC LIFT OF RICH THETAE AIR COULD LEND TO MID-LVL CLOUDS

OVERSPREADING THE RGN. ASIDE...MID-LVL MOISTENING AND SUBSEQUENT

COOLING WILL LEND TO SUBSTANTIAL ELEVATED INSTABILITY. CONTINUED

MODEST SHEAR ORTHOGONAL TO THE FRONTOGENETICALLY FORCING SFC COLD

FRONT...PARENT WITH ENHANCED ASCENT AS THE MAIN SHRTWV ENERGY DIGS

THRU N NEW ENGLAND...SHOULD PROVIDE THE POSSIBILITY FOR DISCREET

CONVECTION ACROSS THE FCST RGN. UNCERTAIN AS TO THE SEVERITY OF

WHICH...BUT CONFIDENT ENOUGH TO USHER SOME CONCERN OF POTENTIAL

THREATS. ANTICIPATE AS WE GET CLOSER TO TUESDAY THERE SHOULD BE A

BETTER HANDLE. CONTINUED WITH MAV/MOS GUIDANCE GOING A FEW DEGREES

HIGHER FOR TEMPS.

I'm thinking less success with any big high "punching" south during the time frame in question. I believe everything about that meridional flow and attending confluence is borderline wrong, and is also a bias perpetrated by the ECM in particular for much of the season.

That said, it doesn't take much of a frontal passage with evacuation kinematics aloft to produce interesting severe weather.

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Wait - i'm an idiot i think. were you talking about July 11-13?

no you aren't an idiot, the thread title may have been misleading or the timestamp on the image shown (time sensitive) and I thought that when creating the thread. Thoughts for early next week? Intuitively there should be some isolated but nasty storms as long as the dews get up there.

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