Heat in Pennsylvania, August 1 to 5, 2002

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
250 PM EDT WED JUL 31 2002

EARLY/MID AFTERNOON TEMPS RUNNING EVEN TO -3 DEGREES COMPARED TO 24
HOURS AGO. DEWPOINTS ARE DOWN 5 TO 10 DEGREES. HEAT INDICES SHOULD
TOP OUT IN THE LOWER TO MID 90S IN MOST AREAS.

NOT TOO MUCH CHANGE BETWEEN LAST NIGHT/S 06Z RUNS AND THIS MORNING/S
12Z RUNS WITH SURFACE HIGH PRESSURE SPRAWLED ACROSS THE EASTERN HALF
OF THE NATION. THE WESTERLY H5 FLOW WILL TURN MORE NW THIS EVENING
HELPING TO DISSIPATE THE SHOWERS NOW ACROSS WESTERN PA/NY. WE SHOULD
SEE A FEW CLOUDS THIS EVENING...BUT WILL STILL CALL SKIES MOSTLY
CLEAR. ANOTHER H5 S/W IS PROGGED TO MOVE OVER THE REGION TOMORROW
AFTERNOON/EVENING. THE AVN CONTINUES TO PRODUCE MEASURABLE
THROUGHOUT THE CWA. THIS HAS BEEN THE TREND OF LATE WITH THESE WEAK
SYSTEMS IN A W/NW FLOW. WILL CONTINUE TO DISCOUNT AND SIDE WITH THE
ETA SOLUTIONS. I GUESS WHAT THROWS THE THOUGHT OF POSSIBLE
SHOWERS/THUNDERSTORMS TOMORROW AFTERNOON IN MY MIND IS THAT WE/LL
HAVE MORE SURFACE CONVERGENCE WITH THE LEE SIDE TROF AND THE CAP WE
HAVE TODAY IS FORECAST TO DISSIPATE. AT THE MOMENT...WE/LL THROW
10/20 POPS IN...KEEPING THE EVENT UNDER THE CHANCE CATEGORY.

OVER THE NEXT 48 HOURS...MODELS FORECAST A MODEST 5 DEGREE RISE
IN DEW POINTS AND ABOUT A 2 DEGREE RISE IN H8 TEMPS. NOT THE WORST
CASE SCENARIO...BUT ENOUGH TO TRIGGER AN EXCESSIVE HEAT WARNING FOR
THURSDAY AND FRIDAY(URBAN AREAS ONLY). THE ROAD THE MODELS ARE
TRAVELING LOOK REASONABLE AS BL WINDS ARE QUITE VARIABLE AS WELL AS
LIGHT DURING THIS TIME UNTIL FRIDAY AFTERNOON WHERE THEY BECOME MORE
PERSISTENT FROM THE WEST. WITH PERSISTENCE NOT IN THE FORECAST...
THE MODEST RISES WE WILL EXPERIENCE WILL BE MORE FROM LOCAL EFFECTS
MODIFYING THE AIRMASS COMPARED TO ADVECTION. WITH THE L/V WINDS...
SEA BREEZES WILL BE TAMING TEMPS ACROSS THE SHORE.

FOR FRIDAY...BESIDES A BIT MORE HEAT AND HUMIDITY...WILL INTRODUCE A
CHANCE OF SHOWERS LATE IN THE DAY FOR THE NWRN ZONES AS A WEAK
SURFACE COLD FRONT APPROACHES THE REGION. H5 FLOW TRIES TO BECOME
MORE CYCLONIC WHILE SURFACE CONVECTIVE PARAMETERS INDICATE GREATER
INSTABILITY. DON/T THINK WE/LL BE CAPPED EITHER.

BEYOND THE 48 HOUR TIME FRAME...WE/LL KEEP THE CHANCE OF SHOWERS
GOING FOR FRIDAY NIGHT. AS WITH THE MOST RECENT COLD FROPA WHERE
TEMPS WERE NOT THAT DIFFERENT ON THE BACK SIDE...THIS NEXT COLD
FRONT IS STARTING TO LOOK SIMILAR. AFTERNOON HIGHS WILL BE
BUMPED UP A CATEGORY OVER THE WEEKEND. WILL KEEP EVERYTHING ELSE
PRETTY MUCH IN TACT WITH THE NEXT THREAT OF PRECIPITATION ON TUESDAY.

QUIET ON THE OCEAN AND BAY.

FCSTID = 29
MPO   67  89  69  90 /   0  20  10  30
ABE   70  93  71  94 /   0  20  10  30
RDG   71  94  72  95 /   0  20  10  30
PHL   75  95  75  96 /   0  10  10  20
12N   67  90  69  91 /   0  20  10  30
SMQ   70  94  70  95 /   0  10  10  20
TTN   71  95  72  96 /   0  10  10  20
MIV   71  94  72  95 /   0  20  10  20
ACY   75  89  75  89 /   0  10  10  20
ILG   71  95  72  96 /   0  10  10  20
DOV   72  94  74  95 /   0  20  10  20
GED   72  93  74  94 /   0  20  10  20
ESN   71  93  73  94 /   0  20  10  20

.PHI...
DE...EXCESSIVE HEAT WARNING THROUGH FRIDAY FOR ZONE DEZ001.
MD...NONE.
NJ...EXCESSIVE HEAT WARNING THROUGH FRIDAY FOR ZONES NJZ015-017>019.
PA...EXCESSIVE HEAT WARNING THROUGH FRIDAY FOR ZONES PAZ067>071.
MARINE...NONE.

KRUZDLO