SWODY2
SPC AC 300546
DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1246 AM CDT SUN AUG 30 2009
VALID 311200Z - 011200Z
...NO SVR TSTM AREAS FORECAST...
...SYNOPSIS...
MODELS INDICATE THAT THE STRONGER WESTERLIES WILL BECOME CONFINED TO
THE HIGHER LATITUDES DURING THIS FORECAST PERIOD...GENERALLY WELL
NORTH OF THE CANADIAN/U.S. BORDER AREA. THIS IS EXPECTED TO OCCUR
AS THE REMNANTS OF THE CLOSED LOW/SIGNIFICANT POLAR TROUGH...NOW
OVER THE GREAT LAKES REGION...CONTINUE TO LIFT NORTHEAST OF THE
EASTERN CANADIAN PROVINCES...AS A VIGOROUS UPSTREAM IMPULSE DIGS
TOWARD HUDSON BAY. WEAK/WEAKENING CYCLONIC FLOW IS EXPECTED TO
LINGER EAST OF THE MISSISSIPPI VALLEY INTO THE ATLANTIC
SEABOARD...HOWEVER...WITH A BROADLY ANTICYCLONIC REGIME ACROSS MUCH
OF THE INTERMOUNTAIN WEST INTO THE PLAINS...DOWNSTREAM OF A LARGE
INCREASINGLY CUT-OFF LOW WEST OF THE BRITISH COLUMBIA/ NORTHERN
PACIFIC COAST. WITHIN THE WESTERN RIDGING...A MUCH SMALLER AND
WEAKER CLOSED LOW APPEARS LIKELY TO WEAKEN FURTHER...WHILE SLOWLY
DRIFTING ACROSS THE NORTHERN ROCKIES INTO THE NORTHERN HIGH PLAINS
BY LATE MONDAY NIGHT.
...INTERMOUNTAIN WEST/ROCKIES...
LIFT ASSOCIATED WITH THE CLOSED LOW...COUPLED WITH OROGRAPHIC
FORCING...PROBABLY WILL CONTRIBUTE TO NUMEROUS THUNDERSTORMS ACROSS
PARTS OF THE NORTHERN ROCKIES MONDAY. AT THE SAME TIME...MORE
SCATTERED AFTERNOON AND EVENING STORMS APPEAR POSSIBLE IN RESPONSE
TO STRONG HEATING ACROSS THE HIGHER TERRAIN OF THE SOUTHERN PLATEAU
AND SOUTHERN ROCKIES...BENEATH THE SUBTROPICAL HIGH CENTER.
SHEAR BENEATH WEAK TO MODEST WESTERLY/NORTHWESTERLY MID-LEVEL FLOW
TO THE LEE OF THE NORTHERN/CENTRAL ROCKIES MAY BE SUFFICIENT TO
ENHANCE WIDELY SCATTERED STORMS...BUT SUBSTANTIVE INSTABILITY
SUPPORTIVE OF HAIL/GUSTY WINDS MAY REMAIN CONFINED TO A NARROW ZONE
NEAR THE FRONT RANGE. OTHERWISE...COOL THERMODYNAMIC PROFILES IN
CLOSE PROXIMITY TO THE CLOSED LOW ACROSS PARTS OF SOUTHERN
MONTANA/NORTHERN WYOMING COULD SUPPORT ISOLATED STRONG OR SEVERE
STORMS CAPABLE OF PRODUCING SMALL TO MARGINALLY SEVERE HAIL.
...SOUTHEASTERN STATES...
LINGERING MOISTURE IS EXPECTED TO CONTRIBUTE TO SUFFICIENT
INSTABILITY SUPPORTIVE OF AT LEAST LOW PROBABILITIES FOR
THUNDERSTORMS ACROSS GULF COASTAL AREAS THROUGH THE CAROLINA COASTAL
PLAINS DURING THIS PERIOD. MUCH OF THE FLORIDA PENINSULA WILL
PROBABLY HAVE YET TO BE IMPACTED SUBSTANTIALLY BY COOLING/ DRYING
ASSOCIATED WITH THE EASTERN UPPER TROUGH...AND IT APPEARS POSSIBLE
THAT FORCING AHEAD OF THE UPPER TROUGH AXIS COULD CONTRIBUTE TO
CONSIDERABLE THUNDERSTORM ACTIVITY MONDAY. WITH PRECIPITABLE WATER
PROGGED UP TO AROUND 2 INCHES AND CAPE ON THE ORDER OF 2000
J/KG...HEAVY RAINFALL IS POSSIBLE IN STRONGER STORMS. HOWEVER... IN
THE PRESENCE OF WEAK DEEP LAYER FLOW/SHEAR...WARM SOUNDINGS WITH A
HIGH DEGREE OF SATURATION MAY MINIMIZE THE POTENTIAL FOR DAMAGING
WIND PRODUCING DOWNBURSTS.
..KERR.. 08/30/2009
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
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