000
FXUS61 KCTP 082033
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
333 PM EST SUN FEB 8 2009

.SYNOPSIS...
A WEAK FRONT WILL SWEEP THROUGH THE AREA TODAY BRINGING GUSTY
WINDS AND SLIGHTLY COOLER TEMPERATURES FOR THE START OF THE NEW
WEEK. HIGH PRESSURE WILL MOVE EAST OF THE REGION BY LATER
MONDAY...PAVING THE WAY FOR A SERIES OF FRONTAL SYSTEMS THAT WILL
KEEP US UNSETTLED FOR MUCH OF THE REMAINDER OF THE WEEK.

&&

.NEAR TERM /UNTIL 11 PM THIS EVENING/...
THE WINDS ARE SLOWLY DIMINISHING OVER WESTERN AREAS AND WILL BEGIN
TO DO SO OVER EASTERN AREAS OVER THE NEXT SEVERAL HOURS. BY ABOUT
6 PM THE GUSTY WINDS SHOULD SETTLE DOWN AS HIGH PRESSURE BUILDS IN
OVER THE REGION AND THE STRONG GRADIENT SHIFTS TO OUR EAST.

TEMPERATURES SHOULD SLIDE INTO THE 20S AND 30S LATER THIS
EVENINGS. MOSTLY CLEAR SKIES SHOULD DOMINATE IN THE SOUTH AND
EAST. THE CLOUDS IN THE NORTHERN MOUNTAINS WILL SLOWLY ERODE EARLY
TONIGHT.

&&

.SHORT TERM /11 PM THIS EVENING THROUGH MONDAY NIGHT/...
STRONG HIGH PRESSURE MOVES OVER THE REGION TONIGHT AND EARLY
MONDAY. THIS SHOULD PROVIDE FOR A MOSTLY CLEAR NIGHT AND MOSTLY
SUNNY DAY ON MONDAY. THIS SHOULD ALSO PROVIDE FOR LIGHT WINDS.
OVERNIGHT LOWS SHOULD RANGE FROM THE TEENS IN THE COLDER AREAS OF
THE NORTH THROUGH THE TWENTIES IN MOST OTHER LOCATIONS. SOME URBAN
AREAS IN THE SOUTHEAST MIGHT REMAIN NEAR 30F.

THE HIGH PRESSURE RETREATS TO OUR EAST MONDAY AFTERNOON AND THE
UPPER-LEVEL RIDGE LINE SLIDES TO OUR EAST TOO. SOME HIGH CLOUDS
COULD MOVE OVER THE REGION FROM WEST TO EAST AS THE RIDGE LINE
ALOFT SHIFT EASTWARD. THE SURFACE WINDS WILL COME AROUND TO THE
SOUTHWEST LATE IN THE DAY AND EVENING HOURS.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
MODELS AND ENSEMBLES OFFER A SIMILAR LARGE SCALE PATTERN
EVOLUTION FOR THE UPCOMING WEEK...RESULTING IN AVERAGE TO BETTER
THAN AVERAGE CONFIDENCE IN THE MEDIUM TO LONG RANGE PERIOD.
HOWEVER...IT IS QUITE AN ENERGETIC WINTER FLOW REGIME FOR MUCH OF
NOAM WITH INHERENT EMBEDDED SHORTWAVE TIMING DIFFERENCES THAT WILL
LIKELY BECOME RESOLVED AT SHORTER TIME SCALES. IN SHORT...THIS
PERIOD WILL INITIALLY BE DOMINATED BY ABOVE NORMAL WARMTH FOLLOWED
BY A SHARP COLD FRONTAL PASSAGE AROUND MID WEEK. COLDER...NEAR
NORMAL TEMPERATURES ARE FORECAST BY THE END OF THE PERIOD WITH A
POTENTIAL WINTER WEATHER EVENT FOR THE WEEKEND.

GUIDANCE REMAINS IN-SYNC WITH PREVIOUS RUNS SUSTAINING A MEAN
TROUGH OVER THE WRN CONUS. STRONG...FAST-MOVG SHORT WAVES WILL
ROTATE AROUND THE BASE OF THE TROUGH OVER SOCAL AND EJECT EWD
INTO THE PLAINS/OH VLY/SERN U.S...WHERE THEY WILL INTERCEPT GOMEX
MOISTURE. THIS PATTERN SUGGESTS A SEVERE WEATHER THREAT FROM THE
PLAINS SWD INTO THE LWR MS VLY MON-TUE...EVENTUALLY SPREADING E OF
THE MS INTO THE MID SOUTH/OH VLY WED. ENSEMBLE DATA CONTINUES TO
SHOW A MORE SUPPRESSED H5 FLOW BY THE WEEKEND.

AS FOR SOME DETAILS...
WARM FRONT WILL LIFT N OF PA BY WEDNESDAY AFTN...PLACING THE
REGION FIRMLY IN A WARM SECTOR COMPLETE WITH DEEP LYR SRLY FLOW ON
THE WRN PERIPHERY OF A DEPARTING ATLC SFC HIGH. H5 HEIGHTS ARE
FCST TO BE ABOVE NORMAL DOWNSTREAM OF A STG MID LVL TROUGH HEADING
NEWD FROM THE SRN PLAINS. SOME LEAD SHORT WAVE ENERGY COMBINED
WITH INC WARM ADV/LYR PWS INVOF OF A LINGERING LO LVL BNDRY SHOULD
LEAD TO SOME SCTD RAIN/SHOWER ACTIVITY TUE/WED. IF PCPN WHERE TO
ARRIVE EARLY TUE MORNING...FCST SFC TEMPS APPEAR TO BE COLD ENUF
TO SUPPORT A VERY BRIEF PERIOD OF LIGHT FZRA ACROSS THE NCENT
MOUNTAINS AND UPPER SUSQ VLY. DEWPOINTS WILL STILL BE RATHER
LOW...AND INITIAL PCPN MAY HAVE DIFFICULTY REACHING THE SFC. AS
PREVIOUSLY THOUGHT YESTERDAY...THE MAIN STORY WILL BE MILD/MUCH
ABOVE NORMAL TEMPS /10-20F ABOVE CLIMO/ BASED ON MANUAL GUID
BLEND.

GEFS DATA CONTINUES TO SHOW AN ANOMALOUS /-2 TO -3SD/ SFC LOW
PRES OCCLUDING OVER THE GRT LKS BY WED NGT...IN ASSOC WITH A
DYNAMIC AND VIGOROUS SHORTWAVE TROUGH POISED TO TAKE ON A NEG
TILT BEFORE SHEARING OUT BY EARLY THURSDAY. ANOMALIES IN THE KEY
FCST FIELDS ALONG WITH MINIMAL SPREAD IN THE 2M TEMP PLUMES
SUGGEST A RATHER HIGH CONFIDENCE IN A SIGNIFICANT/SHARP FRONTAL
PASSAGE WED NGT. STG SLY LO LVL WINDS/HIGH PWS WILL SUPPORT A
BRIEF PD OF MOD TO HVY RNFL AHEAD OF THE CLD FNT. SOUTH/SOUTH EAST
PRE-FRONTAL LO LVL WINDS WILL BE GUSTY. HOWEVER...A HIGH WIND
THREAT EXISTS IN THE WAKE OF THE COLD FROPA GIVEN STG ISALLOBARIC
PRESSURE RISES AND CAA. BIG BUST POTENTIAL FOR THURSDAYS HIGH AS A
STEADY TO NON-DIURNAL TREND IS IN ORDER WITH MUCH COLDER AIR
SWEEPING INTO THE REGION FROM THE NORTH/WEST.

MORE TYPICAL POST-FRONTAL REGIME SHOULD SUPPORT UPSLOPE SNOW/RAIN
SHOWERS ACROSS THE ALLEGHENIES ON THUR...THEN TAPERING OFF FRI.

BY THE END OF THE WEEK...THE FINAL...FLATTER SHORTWAVE WILL LOOK
TO SPAWN A RELATIVELY WEAKER SFC LOW /COMPARED TO THE MID WEEK
STORM SYS/ SOMEWHERE ACROSS THE SERN THIRD OF THE CONUS. LATEST
SUITE OF 08/12Z MODEL AND ENSEMBLE GUID HAS CONSIDERABLY MORE
SPREAD THAN YESTERDAYS RUNS...WITH THE OP GFS MORE PROGRESSIVE AND
FURTHER SOUTH COMPARED THE ECMWF. THE GEFS LOOKS LIKE A BROAD
COMPROMISE OF THE GFS/ECMWF WITH A LOW OFF OFF CAPE HATTERAS NC AT
15/00Z. HPC PROGS FAVOR THE ECMWF SOLN...WHICH IS MUCH MORE
FAVORABLE FOR SNFL OVER PA GIVEN A LOW TRACK ACROSS CENTRAL VA.

&&

.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
THE STRONG AND GUSTY NORTHWEST WINDS BEHIND THE SURFACE COLD FRONT
HAVE ALREADY BEGUN TO DECREASE IN INTENSITY OVER WESTERN AREAS AND
SHOULD DO THE SAME IN EASTER AREAS LATER THIS AFTERNOON OR EVENING.
FLYING BEFORE 20Z TODAY BEWARE OF STRONG GUSTY WINDS ESPECIALLY
EAST OF IPT-SEG-THV. WIND GUSTS 25-35KTS ARE LIKELY. IN THE WEST GUSTS
ARE DROPPING OFF FAST...BUT STILL SOME AREAS OF 15-25KTS.

MOSTLY VFR CONDITIONS THIS AFTERNOON SOME MVFR IN THE CLOUDS OVER
THE WESTERN MOUNTAINS AND ALONG THE NY BORDER.

HIGH PRESSURE SHOULD CLEAR THINGS OUT AND QUICKLY ALLOW THE WINDS
TO SUBSIDE. THUS...VFR CONDITIONS AND LIGHT WINDS SHOULD DOMINATE THE
FLYING REGION BY 0000Z.

MONDAY LOOKS VFR AND LIGHT WINDS ALL DAY.

THE COMING WEEK SHOWS POTENTIAL FOR A PERIOD OF LOW CIGS/VIS WITH
STORM SYSTEM PASSING TO OUR WEST THEN A COLD FRONT. THUS A PERIOD
OF IFR/MVFR WED-THU IS POSSIBLE. GUSTY WINDS BEHIND THE COLD
FRONT AND EVEN SNOW SHOWERS COULD BE A PROBLEM THURSDAY.

YET ANOTHER STORM SYSTEM COULD BE AT THE...HEART...OF THE MATTER
ON 14 FEBRUARY (VALENTINES DAY). IF THIS SYSTEM VERIFIES WE COULD SEE
LOW CIGS/VISBY SOMETIME FRIDAY INTO PERHAPS EARLY SUNDAY.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...LACORTE
NEAR TERM...GRUMM
SHORT TERM...GRUMM
LONG TERM...STEINBUGL
AVIATION...GRUMM