SWODY1
SPC AC 082000
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0300 PM CDT TUE JUN 08 2010
VALID 082000Z - 091200Z
...THERE IS A SLGT RISK OF SVR TSTMS OVER A PORTION OF CNTRL AND SRN
PLAINS THROUGH THE MID MS AND OH VALLEY...
...CNTRL PLAINS AREA THROUGH MID MS AND OH VALLEYS...
OUTFLOW BOUNDARY EXTENDS FROM SRN IL WWD THROUGH WRN MO AND THEN
NWWD INTO NERN KS WHERE IT INTERSECTS A COLD FRONT. THE FRONT THEN
EXTENDS SWWD INTO SWRN KS...THE TX PANHANDLE THEN NWWD THROUGH CNTRL
CO. OBJECTIVE ANALYSIS SHOWS THE ATMOSPHERE TO BE VERY UNSTABLE IN
WARM SECTOR ACROSS CNTRL THROUGH ERN KS INTO WRN MO WITH MLCAPE FROM
3500 TO 4000 J/KG. VISIBLE IMAGERY SHOWS CUMULUS INCREASING ALONG
THE FRONT FROM THE TX PANHANDLE THROUGH E-CNTRL KS...AND STORMS WILL
LIKELY DEVELOP BY 20-21Z. STRONGEST VERTICAL SHEAR IS LOCATED ACROSS
ERN KS/WRN MO PORTION OF WARM SECTOR. HODOGRAPHS ARE ALSO LARGEST
OVER ERN KS INTO WRN MO WHERE A 40 KT SWLY LOW LEVEL IS IMPINGING
UPON THE OUTFLOW BOUNDARY. THIS ENVIRONMENT IS SUPPORTIVE OF
SUPERCELLS WITH VERY LARGE HAIL AND ISOLATED TORNADOES...ESPECIALLY
AS STORMS DEVELOP EWD AND INTERACT WITH THE OUTFLOW BOUNDARY. STORMS
ARE EXPECTED TO EVENTUALLY GROW UPSCALE INTO AN MCS THIS EVENING AND
SPREAD EWD THROUGH THE OH VALLEY WITH PRIMARY THREAT TRANSITIONING
TO DAMAGING WIND.
STORMS DEVELOPING FARTHER SWWD ALONG THE BOUNDARY INTO THE TX
PANHANDLE ARE MOST LIKELY TO BE MULTICELL IN CHARACTER WITH ISOLATED
DAMAGING WIND AND LARGE HAIL THE MAIN THREATS.
OTHER STORMS SHOULD DEVELOP ALONG NERN EXTENSION OF BOUNDARY INTO IA
WHERE VERTICAL SHEAR IS SUFFICIENT FOR UPDRAFT ROTATION BUT
INSTABILITY IS MORE MARGINAL. ISOLATED DAMAGING WIND AND HAIL WILL
BE POSSIBLE.
...SERN CO...
PREVIOUS DISCUSSION/FORECAST APPEARS ON TRACK.
...ERN ND/WRN MN...
PREVIOUS DISCUSSION/FORECAST APPEARS ON TRACK.
..DIAL.. 06/08/2010
.PREV DISCUSSION... /ISSUED 1130 AM CDT TUE JUN 08 2010/
...CENTRAL PLAINS EWD INTO THE MID MS/WRN OH VALLEYS...
MORNING MCS OVER MO HAS TURNED ESEWD ALONG ELEVATED INSTABILITY
AXIS. STORMS HAVE BEEN MAINTAINED BY UNSTABLE AIR MASS BEING FED BY
30-40 KT SWLY WINDS BETWEEN 900-700 MB. STORMS ARE MOSTLY EXPECTED
TO REMAIN EAST OF STRONGER INSTABILITY AND ALSO SHIFT SLOWLY SWD
INTO WEAKER MID LEVEL WINDS. WHILE AN ISOLATED SEVERE STORM OR TWO
IS POSSIBLE WITH THIS ACTIVITY...THE LACK OF STRONGER FORCING ALOFT
AND WEAKER WINDS ALOFT SUGGEST THESE STORMS SHOULD REMAIN MOSTLY
NON-SEVERE IN THE SHORT TERM. HOWEVER ...AS UPPER TROUGH NEARS MORE
INTENSE STORMS ARE LIKELY TO DEVELOP ALONG BOUNDARY LATER TODAY.
MORNING ANALYSIS AND WV IMAGERY SHOW A PRONOUNCED UPPER TROUGH
MOVING EWD INTO THE DAKOTAS...WITH THE SRN PORTION OF THE TROUGH
EXTENDING SWD INTO WRN NEB/NERN CO. IN ASSOCIATION WITH THIS
TROUGH...A COLD FRONT STRETCHED FROM THE ND/MN BORDER SWWD INTO NWRN
KS/SERN CO. AS THE PRE-MENTIONED TROUGH/FRONT SHIFTS EWD...THERE IS
STRONG MODEL CONSENSUS OF THUNDERSTORMS REDEVELOPING IN ERN KS/WRN
MO AROUND 21Z...NEAR INTERSECTION OF FRONT AND OUTFLOW BOUNDARY
LEFTOVER FROM MORNING STORMS. SUBSEQUENT STORMS ARE LIKELY TO
DEVELOP SWWD ALONG THE FRONT INTO S CNTRL KS...WITH STORM COVERAGE
INCREASING EWD INTO MO ALONG REMNANT OUTFLOW BOUNDARY LATE THIS
AFTERNOON. DEEP LAYER SHEAR AND STRONG INSTABILITY WILL SUPPORT
SUSTAINED SUPERCELLS. THE RESIDUAL RAIN-COOLED BOUNDARY AND
ACCENTUATED LOW LEVEL SHEAR ALONG OUTFLOW BOUNDARY MAY SUPPORT A FEW
TORNADOES. IN TIME...AS OTHER STORMS DEVELOP ALONG FRONT...OUTFLOWS
ARE EXPECTED TO MERGE WITH THE POSSIBLE EVOLUTION TO A QLCS. THE
PRIMARY THREAT WOULD THEN BECOME WIND DAMAGE...WITH A TORNADO OR TWO
POSSIBLE IN BOW HEADS. OVERNIGHT...A FORWARD PROPAGATING MCS WITH
WIND DAMAGE IS EXPECTED TO BE THE MAIN THREAT ACROSS IL AND POSSIBLY
AS FAR EAST AS WRN OH.
...CENTRAL HIGH PLAINS INTO WRN/SRN KS...
UPSLOPE FLOW SHOULD AID STORMS FORMING LATE AFTERNOON OVER THE
HIGHER TERRAIN OF ERN CO/NERN NM. STEEP MID LEVEL LAPSE RATES SHOULD
SUPPORT SBCAPE UP TO 1000 J/KG...WITH 40-50 KT WLY 500 MB FLOW
FAVORING SUPERCELLS. DRIER AIR FILTERING IN FROM THE NORTH WILL
STABILIZE THE PLAINS IN NERN CO...SO STORMS MAY STRUGGLE TO MOVE OFF
THE HIGHER TERRAIN. FURTHER SOUTH...A MORE MOIST ENVIRONMENT MAY
ALLOW STORMS TO SHIFT SEWD INTO SERN CO AND EVEN SWRN KS. HAIL AND
WIND DAMAGE WOULD BE THE PRIMARY THREATS.
...SRN AND MIDDLE TX GULF COASTAL PLAINS...
A THUNDERSTORM BAND IS CURRENTLY MOVING NWD WEST OF HOU AND OTHERS
MAY EVOLVE DURING THE FORECAST PERIOD AS UPPER LOW REMAINS
QUASI-STATIONARY IN FAR SRN TX. COMBINATION OF PW VALUES AROUND 2
INCHES AND...AT TIMES...THE ORGANIZED OUTFLOW...MAY RESULT IN A FEW
STRONG WIND GUSTS. ALSO...ENHANCED/SLIGHTLY BACKED LOW LEVEL WINDS
COULD SUPPORT AN ISOLATED BRIEF TORNADO IN MORE DISCRETE STORMS.
...ERN ND/WRN MN...
COMBINATION OF PARTLY SUNNY SKIES/WARMING...COOLING TEMPERATURES
ALOFT FROM -16C TO -18C AND FORCING ASSOCIATED WITH UPPER TROUGH
SHOULD RESULT IN SCATTERED DIURNAL THUNDERSTORMS. STEEP MID/HIGH
LEVEL LAPSE RATES WILL MAY BE SUFFICIENT FOR A FEW STORMS TO YIELD
MARGINALLY SEVERE HAIL THIS AFTERNOON.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
To unsubscribe from WX-STORM send e-mail to LISTSERV@LISTSERV.ILLINOIS.EDU with
"unsub wx-storm" in the body of your message. For more information write cnovy@cox.net.
No comments:
Post a Comment