Jump to content
  • Member Statistics

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

March 20-23 Severe Threat


Jim Martin

Recommended Posts

Well, almost everything is starting to scream "move along!" with this system, but the 00z ECMWF last night looked oddly encouraging given other trends. It had a very well-timed shortwave for Sunday, and then ejected the main energy fairly far south on Monday. The GFS, OTOH, is absolutely abysmal. The two have almost swapped places from a few days ago, with the GFS now stalling the trough on the W Coast for several days before shearing it out. The GGEM has been in the stall/shear out camp all along, and continues to show that this morning.

Link to comment
Share on other sites

  • Replies 420
  • Created
  • Last Reply

CENTRAL_GFS_ATMOS_CAPE_108HR.gif

Notice the cape nosing in there nicely across N Central OK and S Central KS at 7 pm cdt Sunday evening.

110316212144.gif

Not much of a cap either for Sunday evening.

110316210454.gif

Notice the winds here at 500 mb. Over 90 knots in the Texas Panhandle with 70-80 knot winds nosing into N Central OK an S Central KS.

Link to comment
Share on other sites

0z GFS trended better with regards to moisture both days, bringing 55 dews up to just east of AMA saturday with low 60's over central OK and a CAPE max of just short of 1500 j/kg in the eastern TX PH and breaks the cap near AMA saturday evening.

sunday its showing southern KS/northern OK the place to be with low 60 dew points and >1500 j/kg with backed sfc and sufficient shear for supercells but a stronger cap this day.

and the NAM isn't showing this...lol

Link to comment
Share on other sites

My interest in tomorrow has increased after seeing the activity this afternoon and what impacts it might have on tomorrow. The elevated, outflowy crap today laid down a network of outflow boundries that should come into play tomorrow, helping convection initiate and helping it after that. The 4 KM WRF looks mighty interesting by tomorrow evening as well...

refd_1000m_f24.gif

mxuphl_f24.gif

Link to comment
Share on other sites

From the DVN AFD earlier today...

MID

LEVEL LAPSE RATES IN THIS IMPLY THAT WE WILL HAVE AT LEAST SOME

EMBEDDED THUNDER...BUT WOULD NOT BE TOO SURPRISED TO SEE A FEW

SURFACE BASED DISCRETE CELLS SUNDAY AFTERNOON AND EVENING IN THE

WARM SECTOR SOUTH OF THE FRONT AS IT MOVES ACROSS THE AREA.

Hmm I didn't see that.

I'm not sold on this yet, there is quite the inversion looking at fcst soundings and the best juice in further south and west where the sfc winds become veered. It would be ice to see some better instability further east along the warm front where the wind profiles are very favorable for supercells and tornadoes but the cap is saying no go right now so we'll see what happens as we get closer.

showers/storms look to move through southern IA during the morning and early aftenoon hours so hopefully that will clear earlier and help sfc heating.

Link to comment
Share on other sites

SPC still going with a see text due to capping issues..

the key is going to be if we can get more sfc heating than forecasted.

DAY 2 CONVECTIVE OUTLOOK

NWS STORM PREDICTION CENTER NORMAN OK

1231 AM CDT SAT MAR 19 2011

VALID 201200Z - 211200Z

..NO SVR TSTM AREAS FORECAST

..SYNOPSIS

THE REMNANTS OF A SIGNIFICANT SHORT WAVE TROUGH...LIKELY REACHING

THE NORTHERN ROCKIES BY 12Z SUNDAY...ARE PROGGED TO ACCELERATE

EASTWARD WITHIN CONFLUENT FLOW ACROSS THE NORTHERN PLAINS INTO THE

UPPER GREAT LAKES REGION BY 12Z MONDAY. WEAK HEIGHT FALLS MAY

SUPPRESS MID-LEVEL RIDGING AS FAR SOUTH AS THE NORTH CENTRAL PLAINS

AND MID MISSOURI VALLEY DURING THE DAY SUNDAY...AND THE OHIO VALLEY

SUNDAY NIGHT...BUT RIDGING IS EXPECTED TO REMAIN GENERALLY STRONG

FROM THE SOUTHERN PLAINS INTO THE SOUTHEAST. MID-LEVEL HEIGHTS

APPEAR LIKELY TO BUILD QUICKLY IN THE WAKE OF THE UPPER

IMPULSE...ACROSS THE CENTRAL AND NORTHERN ROCKIES INTO THE ADJACENT

PLAINS...AS A MUCH MORE SIGNIFICANT SHORT WAVE TROUGH GRADUALLY

TURNS INLAND ACROSS THE CALIFORNIA COAST SUNDAY NIGHT.

AT LOWER LEVELS...MODELS INDICATE THAT A MODEST SURFACE WAVE MAY

DEVELOP ALONG A RETREATING FRONTAL ZONE FROM THE NORTH CENTRAL

PLAINS INTO THE GREAT LAKES DURING THE PERIOD. HOWEVER...INFLOW OF

MOISTURE OFF THE WESTERN GULF OF MEXICO WILL REMAIN INHIBITED BY

RIDGING EXTENDING FROM A HIGH CENTER SHIFTING OFF THE NORTH ATLANTIC

COAST...WEST SOUTHWESTWARD THROUGH THE WESTERN GULF COAST. HIGHER

BOUNDARY LAYER MOISTURE CHARACTERIZED BY SURFACE DEW POINTS NEAR 60F

APPEARS LIKELY TO BE CONFINED TO NARROW CORRIDORS ALONG REMNANTS OF

A FRONTAL ZONE ACROSS PARTS OF THE LOWER OHIO/TENNESSEE VALLEYS AND

THE FLORIDA PENINSULA...AS WELL AS ALONG A DRY LINE INTO THE

VICINITY OF THE FRONTAL WAVE...FROM WESTERN OKLAHOMA INTO IOWA LATE

IN THE AFTERNOON. WHILE MODEST DESTABILIZATION MAY OCCUR ACROSS

THESE AREAS WITH DAYTIME HEATING ...CONVECTIVE POTENTIAL IS EXPECTED

TO BE SUPPRESSED BY CONSIDERABLE MID-LEVEL INHIBITION AND GENERALLY

SUBSIDENT FLOW ALOFT.

HIGHEST THUNDERSTORM PROBABILITIES THROUGH THE PERIOD ARE STILL

EXPECTED TO BE IN ASSOCIATION WITH WEAK DESTABILIZATION WITHIN

LOW-LEVEL WARM ADVECTION TO THE NORTH AND EAST OF THE RETREATING

FRONT. ACTIVITY MAY BE ONGOING AT 12Z SUNDAY ACROSS UPPER PORTIONS

OF THE MIDDLE MISSISSIPPI VALLEY...BEFORE DEVELOPING NORTHWARD INTO

PARTS OF THE UPPER GREAT LAKES DURING THE DAY... THEN EASTWARD

ACROSS THE GREAT LAKES AND OHIO VALLEY DURING THE LATTER HALF OF THE

PERIOD.

..SOUTH CENTRAL PLAINS INTO MID MISSOURI VALLEY

MIXED LAYER CAPE PROBABLY WILL EXCEED 1000 J/KG BY PEAK HEATING NEAR

THE DRY LINE...LIKELY TO EXTEND ACROSS WESTERN OKLAHOMA INTO THE

VICINITY OF A COLD FRONT ACROSS NORTHEAST KANSAS LATE SUNDAY

AFTERNOON...PERHAPS NORTHEASTWARD WITHIN A PRE-FRONTAL CORRIDOR TO

THE DEVELOPING LOW OVER IOWA AS WELL. BEFORE MID-LEVEL HEIGHTS

BEGINS TO RISE...LOW-LEVEL FORCING NEAR THE LOW MAY BE SUFFICIENT TO

SUPPORT ISOLATED STORMS IN THE PRESENCE OF STRONG SHEAR FAVORABLE

FOR SUPERCELLS. LOW-LEVEL HODOGRAPHS SHOULD BE LARGE AND CLOCKWISE

CURVED ALONG A 40+ KT SOUTHERLY LOW-LEVEL JET...BENEATH 50-70 KT

WESTERLY 500 MB FLOW. HOWEVER...IT IS STILL NOT CLEAR WHETHER THIS

ACTIVITY WILL FORM WITHIN THE UNSTABLE WARM SECTOR BOUNDARY

LAYER...OR IN THE VICINITY OF A WARM FRONT EXTENDING TO THE EAST OF

THE LOW. REGARDLESS...THE TENDENCY MAY BE FOR ACTIVITY TO QUICKLY

SPREAD EASTWARD ABOVE A RAIN-COOLED AND STABLE BOUNDARY LAYER ACROSS

EASTERN IOWA AND NORTHERN ILLINOIS...BEFORE DIMINISHING SUNDAY

EVENING.

OTHERWISE...AN ISOLATED STORM OR TWO STILL APPEARS POSSIBLE ALONG

THE DRY LINE ACROSS THE CENTRAL PLAINS...MAINLY WHERE SURFACE

HEATING MAXIMIZES AND LOCALLY WEAKENS INHIBITION. IF THIS

OCCURS...THE ENVIRONMENT WILL FAVOR SUPERCELLS...BUT IT IS NOT CLEAR

HOW LONG STORMS WILL SURVIVE AS THEY PROPAGATE EAST OF THE DRY

LINE...WHICH MAY BEGIN TO SLOWLY RETREATING NORTHWESTWARD DURING THE

EVENING HOURS.

..KERR.. 03/19/2011

Link to comment
Share on other sites

Where is Hoosier?

Okay, the main problem I'm seeing here is the lack of lift in that timeframe and that is reflected in model qpf showing pretty much all of the precip farther north. If we could actually get something to pop in that favorable environment, then it could be something to watch.

Link to comment
Share on other sites

Okay, the main problem I'm seeing here is the lack of lift in that timeframe and that is reflected in model qpf showing pretty much all of the precip farther north. If we could actually get something to pop in that favorable environment, then it could be something to watch.

Ya all the precip at 0z is north of the warm front and elevated.

waiting for the new day 2..

Link to comment
Share on other sites

DAY 2 CONVECTIVE OUTLOOK

NWS STORM PREDICTION CENTER NORMAN OK

1230 PM CDT SAT MAR 19 2011

VALID 201200Z - 211200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PART OF SRN IA/NRN

MO...FAR NERN KS AND FAR WEST CENTRAL IL...

..SYNOPSIS

CLOSED MID-UPPER LEVEL LOW...CURRENTLY LOCATED OFF THE PACIFIC NW

COAST...IS EXPECTED TO EVOLVE INTO A MORE AMPLIFIED TROUGH EXTENDING

FROM THE COASTS OF BC TO NRN BAJA BY 12Z MONDAY...WHILE THE CLOSED

LOW ITSELF BECOMES AN OPEN WAVE BY THE END OF THE FORECAST PERIOD.

THE NRN EXTENT OF AN UPPER RIDGE LOCATED OVER THE ERN HALF OF THE

CONUS WILL BE BROKEN DOWN DURING DAY 2 AS A MIDLEVEL SHORTWAVE

TROUGH TRACKS EWD FROM THE NRN ROCKIES THROUGH THE NRN PLAINS TO THE

GREAT LAKES. AN ATTENDANT SURFACE LOW TO THIS TROUGH SHOULD OCCLUDE

AS IT TRACKS FROM ND INTO NRN MN AND THE UPPER GREAT LAKES ON

SUNDAY...WHILE A SECONDARY LOW MOVES FROM THE CENTRAL PLAINS INTO IA

BY EARLY SUNDAY EVENING AND THEN ENEWD INTO LOWER MI DURING LATTER

HALF OF THE PERIOD. A WARM FRONT DEVELOPING NWD INTO THE LOWER MO

VALLEY SHOULD BECOME ESTABLISHED ALONG THE IA/MO BORDER EARLY DAY 2

SUPPORTED BY ONGOING ELEVATED CONVECTION LOCATED N OF THIS BOUNDARY

WITHIN WAA REGIME IN THE NOSE OF SWLY LLJ. THIS WARM FRONT WILL

ADVANCE ENEWD THROUGH THE OH VALLEY SUNDAY NIGHT.

..PARTS OF SRN IA/NRN MO/FAR NERN KS TO FAR WRN IL

MODELS DIFFER WITH THE DEGREE OF HEIGHT FALLS EXPECTED ACROSS IA AS

THE NRN ROCKIES SHORTWAVE TROUGH ADVANCES EWD. HOWEVER...EVEN WEAK

HEIGHT FALLS COMBINED WITH LOW LEVEL CONVERGENCE INVOF A SURFACE LOW

MOVING ENEWD INTO CENTRAL IA BY 21/00Z AND SWWD ALONG A TRAILING

COLD FRONT/DRY LINE INTO NERN KS SHOULD SUPPORT CONVECTIVE

DEVELOPMENT. MODELS SUGGEST MLCAPE TO AROUND 1000 J/KG AND

INCREASING EFFECTIVE BULK SHEAR /35-50 KT/ BY LATE AFTERNOON AND

EARLY EVENING WILL SUPPORT STRONG TO SEVERE STORMS INITIALLY OVER

SWRN IA/FAR NERN KS AND ADVANCING EWD. ADDITIONAL THREAT IS

POSSIBLE ALONG SWWD TRAILING DRY LINE...THOUGH WEAKER FORCING DOES

NOT WARRANT HIGHER PROBABILITIES.

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...