Flash Flood Warning 83, NWS State College, PA

CENTRAL PENNSYLVANIA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
220 PM EDT TUE JUN 23 1998

...DISCUSSION...
S/WV...MOVING THRU OHIO EARLY THIS AFTN...IS PROGGED TO PASS EAST OF
PA LATE THIS EVENING WITH A NORTHERLY LL FLOW OF DRIER AIR TO
FOLLOW.  WILL KEEP CHC POPS IN FCST THIS EVENING WITH HIGHEST POPS
IN THE E.  ALSO WILL MENTION FOG IN MOST ZONES AS CLRING SKIES
DEVELOP LATE.  RISING HEIGHTS COMBINED W/LL DRYING WILL RESULT IN A
LULL IN THE SHWERS/TSRA OVERNIGHT AND WED.

WEDNESDAY...RISING HEIGHTS COMBINED W/LL DRYING WILL RESULT IN A
LULL IN THE SHWERS/TSRA OVER MOST OF CWA. SFC CDFRT AND ASSOCIATED
DRYING PROGGED TO MAKE IT TO LOWER SUSQ VALL...THEN STALL.  WILL
THEREFORE MENTION POPS FOR AFTN TSRA ONLY ACROSS THE S TIER.  OVER N
PA...SFC DWPTS PROGGED TO FALL INTO THE LOW 60S.  FEEL MOSTLY SUNNY
SHOULD DO IT IN THIS REGION...SIMILAR TO THE WX OVER MICHIGAN
TODAY.  HIGHS WILL BE RATHER UNIFORM ACROSS C PA DUE TO AN EAST-WEST
8H TEMP GRADIENT MITIGATING THE NORMAL RANGE BETWEEN MOUNTAINS AND
SUSQ VALL.

WEDNESDAY NIGHT...WARM FRT LIFTING TO OUR N AND W WILL LIKELY
PRODUCE CONVECTION AT NOSE OF LL JET OVER E GRT LKS.  HAVE ADDED AN
INCREASE IN CLDS WED NITE AS BLOW OFF FM THIS ACTIVITY WUD TRACK SE
INTO PA.

THURSDAY...WARM FRT FINALLY MOVES BACK THRU PA...RESULTING IN PARTLY
SUNNY...WARM AND INCREASINGLY HUMID WX WITH CHC OF A TSRA.

FITZGERALD

PAZ004>006-010>012-017>019-024>028-033>037-041-042-045-046-049>053-
056>059-063>066-232015-

SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1120 AM EDT TUE JUN 23 1998

...THUNDERSTORMS WITH LOCALLY HEAVY RAINFALL POSSIBLE TODAY AND
TONIGHT...

...FORECAST DETAILS...

SHOWERS AND THUNDERSTORMS SCATTERED ACROSS THE REGION DURING THE
MIDDAY HOURS WILL BECOME MORE WIDESPREAD DURING THE MID AND LATE
AFTERNOON...AS A COLD FRONT SLIDES SOUTHEAST TOWARD THE REGION.

WEAK STEERING WINDS IN THE ATMOSPHERES MID LEVELS WILL CAUSE THE
SHOWERS AND THUNDERSTORMS TO MOVE SLOWLY...RESULTING IN LOCALLY
HEAVY RAINFALL AMOUNTS.

THE GREATEST THREAT FOR HEAVY RAINFALL OF OVER AN INCH...APPEARS TO
BE ACROSS THE CENTRAL AND SOUTH-CENTRAL MOUNTAINS ALONG WITH THE
LAUREL HIGHLANDS THIS AFTERNOON AND EARLY EVENING. THE THREAT OF
LOCALLY HEAVY RAINFALL THIS EVENING WILL LIKELY SHIFT INTO THE
SUSQUEHANNA VALLEY REGION...AND OVER THE EXTREME SOUTH CENTRAL
COUNTIES OF PENNSYLVANIA...NEAR THE MARYLAND BORDER.

RAINFALL AMOUNTS OF ONE AND ONE-HALF/1.5/ TO TWO/2.0/ INCHES IN ONE
HOUR OR ROUGHLY THREE/3.0/ TO FOUR/4.0/ INCHES IN THREE HOURS IS THE
THRESHOLD FOR FLASH FLOODING OF SMALLER STREAMS AND CREEKS. RAINFALL
OF THIS MAGNITUDE IS NOT EXPECTED OVER A WIDE AREA...BUT COULD OCCUR
LOCALLY WHERE THE THUNDERSTORMS PERSIST THE LONGEST.

IF THE THREAT OF HEAVY RAINFALL BECOMES MORE CERTAIN IN A PARTICULAR
AREA THIS AFTERNOON...FLASH FLOOD WATCHES WILL BE ISSUED.

...WEATHER SYNOPSIS...

A SLOW-MOVING COLD FRONT WILL MOVE INTO WESTERN AND CENTRAL
PENNSYLVANIA BY TONIGHT AND STALL OVER THE SOUTHERN PART OF THE
STATE EARLY WEDNESDAY MORNING. ABUNDANT MOISTURE AHEAD OF THIS FRONT
WILL TRIGGER SHOWERS AND THUNDERSTORMS THIS AFTERNOON AND TONIGHT IN
PENNSYLVANIA.

...OTHER INFORMATION...

STAY TUNED TO NOAA WEATHER RADIO...RADIO OR TELEVISION FOR THE
LATEST UPDATES CONCERNING THIS DEVELOPING WEATHER SITUATION.
LISTEN FOR POSSIBLE FLASH FLOOD WATCHES.

OFFICIAL NATIONAL WEATHER SERVICE FORECASTS...STATEMENTS...
WATCHES...WARNINGS AND ADVISORIES FOR PENNSYLVANIA CAN BE FOUND
ON THE WORLD WIDE WEB AT THE FOLLOWING ADDRESS:

HTTP://IWIN.NWS.NOAA.GOV/IWIN/PA/PA.HTML

OR  140.90.6.254/IWIN/PA/PA.HTML

LAMBERT