Jump to content
  • Member Statistics

    17,606
    Total Members
    7,904
    Most Online
    ArlyDude
    Newest Member
    ArlyDude
    Joined

Good Chance for Svr Tstms on Sunday 8/21/11


Dark Energy

Recommended Posts

FWIW, WFO PHI (our very own MGorse :)) had this to say in their 4PM AFD.

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...AN 18Z SURFACE ANALYSIS PLACED A COLD FRONT FROM SOUTHEASTERN CANADADOWN THROUGH THE OHIO VALLEY. A TROUGH WAS ACROSS EASTERNPENNSYLVANIA DOWN INTO VIRGINIA. AN UPPER AIR ANALYSIS PLACED ALARGE TROUGH ACROSS EASTERN CANADA AND GREAT LAKES INTO THE OHIOVALLEY. A STRONG 300 MB JET WAS FROM THE MIDWEST TO THE EASTERNGREAT LAKES REGION.SEVERE THUNDERSTORM WATCH 794 REMAINS IN EFFECT FOR OUR ENTIRE CWAUNTIL 01Z.A STRONG UPPER-LEVEL TROUGH WILL SETTLE ACROSS THE NORTHEAST AND MIDATLANTIC REGIONS TONIGHT WITH FALLING HEIGHTS. THE COMBINATION OFINCREASED SHEAR WITH AT LEAST MODEST INSTABILITY /MLCAPE 1500-2000J/KG/ AND INCREASING LARGE SCALE ASCENT IS ALLOWING FOR CONVECTIVEDEVELOPMENT. GIVEN THE FLOW NEARLY UNIDIRECTIONAL ABOVE THE SURFACE,STORM MODE HAS BEEN TENDING TO BE IN LINE SEGMENTS WITH A LOCALLYINCREASING DAMAGING STRAIGHT LINE WIND THREAT. HOWEVER SPECIAL16-18Z SOUNDINGS INDICATE THE FLOW BACKING A BIT IN THE LOWESTLEVELS WHICH WILL ENHANCE THE LOW-LEVEL SHEAR. THE PRESENCE OF ALOW-LEVEL JET THROUGH THIS EVENING MAY ALSO ENHANCE THE DAMAGINGWIND THREAT ACROSS PARTS OF THE AREA. THE INITIAL CONVECTION LOOKSTO SHIFT EASTWARD, HOWEVER A SECOND ROUND LOOKS TO ACCOMPANYSTRONGER HEIGHT FALLS AND THE ACTUAL COLD FRONT THIS EVENING. THEMID LEVEL TEMPERATURES AROUND -10C WILL ALLOW FOR SOME HAIL WITHSOME POSSIBLY SEVERE IN ASSOCIATION WITH MORE ROBUST UPDRAFTSESPECIALLY ANY WITH ROTATION ALOFT. THE MOIST LOW LEVELS WITH SOMEVEERING WITH HEIGHT IN THE LOWEST LEVELS ESPECIALLY IN THE PRESENCEOF A LEE SIDE TROUGH AND OUTFLOW BOUNDARIES COULD ALLOW FOR LOCALLYENHANCED LOW-LEVEL STORM ROTATION AND DISCRETE STORMS. THE MAINTHREAT IS DAMAGING STRAIGHT LINE SURFACE WINDS WITH ANY LINESEGMENTS, ALTHOUGH CANNOT RULE SOME LOCAL LOWER LEVEL ROTATIONGIVEN THE SHEAR IN PLACE. WE WILL CONTINUE THE ENHANCED WORDING OFSTRONG/DAMAGING WINDS IN THE FORECAST THROUGH ABOUT 01Z.THE COLD FRONT CROSSES THE AREA OVERNIGHT, HOWEVER DESPITE THEAIRMASS BECOMING MORE STABLE WITH THE LOSS OF HEATING AND ONGOINGCONVECTION, THE WIND FIELD IS FORECAST TO STRENGTH ALOFT WHICH MAYBE ABLE TO SUSTAIN CONVECTION INTO THE OVERNIGHT HOURS. WE WILLSTEP THE POPS DOWN FROM WEST TO EAST THROUGH THE NIGHT AS THECOVERAGE AND SEVERITY IS ANTICIPATED TO LESS DEEPER INTO THE NIGHT.OTHERWISE, THE CLOUDS WILL THIN AND WITH THE LOWER LEVELS OF THEATMOSPHERE REMAINING MOIST, THERE COULD BE PATCHY FOG. GIVEN LOWERCONFIDENCE WITH THIS WE OPTED TO LEAVE IT OUT ATTM. AS FORTEMPERATURES WE GENERALLY USED A BLEND OF THE NAM/MOS GUIDANCE.

Link to comment
Share on other sites

  • Replies 302
  • Created
  • Last Reply

Just issued:

mcd2036.gif

MESOSCALE DISCUSSION 2036

NWS STORM PREDICTION CENTER

NORMAN OK

0612 PM CDT SUN AUG 21 2011

AREAS AFFECTED...NY/VT/NH...SWD TO DELMARVA

CONCERNING...SEVERE THUNDERSTORM WATCH 794...795...

VALID 212312Z - 220015Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 794...795...CONTINUES.

NUMEROUS DISCRETE TSTMS HAVE DEVELOPED AND MERGED INTO A LARGER COMPLEX OF STORMS OVER SRN NY. THIS ALONG WITH MORE EXPANSIVE PRECIP OVER NRN NJ IS QUICKLY OVERTURNING AN AXIS OF INSTABILITY THAT EXTENDS ACROSS THE HUDSON VALLEY. GIVEN THE CURRENT TRENDS AND RADAR CHARACTERISTICS IT APPEARS DAMAGING WINDS ARE THE PRIMARY SEVERE THREAT...ALTHOUGH MARGINALLY SEVERE HAIL COULD ACCOMPANY THE STRONGER UPDRAFTS. CONVECTION SHOULD GRADUALLY SPREAD ACROSS SRN NEW ENGLAND OVER THE NEXT FEW HOURS AND A RISK OF SEVERE WILL CONTINUE UNTIL AIRMASS IS STABILIZED.

Link to comment
Share on other sites

over 12 inches of rain for the month now and we still have a good week and a half left

Yeah and if that tropical system gets here, we should easily break 20" But that severe thunderstorm warning today was one of the "weakest" warned storms I've ever seen-- and much weaker than many storms that have gotten no warnings here lol.

Link to comment
Share on other sites

It's not a bust. This is not a snowstorm that didn't materialize. They said the potential exists for strong to severe thunderstorms. Not everyone in the CWA is supposed to experience these conditions. So far the forecast is verifying just fine.

Link to comment
Share on other sites

It's not a bust. This is not a snowstorm that didn't materialize. They said the potential exists for strong to severe thunderstorms. Not everyone in the CWA is supposed to experience these conditions. So far the forecast is verifying just fine.

Exactly.

Severe watch doesn't mean that your block will be affected.

Event has produced severe weather already and continues to for some.

Far from a bust.

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

  • Recently Browsing   0 members

    • No registered users viewing this page.

×
×
  • Create New...