FXUS04 KWBC 060850
QPFPFD
 
QUANTITATIVE PRECIPITATION FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
403 AM EDT MON SEP 06 2010
PRELIM DAY 1...DAY 2 AND DAY 3 QPF DISCUSSION
VALID SEP 06/1200 UTC THRU SEP 09/1200 UTC
REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR
 
DAY 1...
...NRN PLAINS INTO THE UPR MS VALLEY/UPR LAKES...
MODELS ARE IN FAIRLY GOOD AGRMNT DAY 1 WITH STRONG AND
INCREASINGLY NEGATIVELY TILTED HT FALLS PUSHING EWD THRU THE
CNTRL/NRN HIGH PLAINS MON AND INTO THE UPR MS VALLEY MON
NIGHT/EARLY TUE.  STRONGLY DIFFLUENT UPR FLOW AHEAD OF THESE HT
FALLS WL INDUCE STRONG LARGE SCALE UVVS ALONG THE INVERTED TROF
EXTENDING NWWD FROM THE DEEPENING SFC LOW PUSHING NEWD OUT OF THE
ERN PORTIONS OF THE CNTRL/NRN PLAINS AND INTO THE UPR MS VALLEY. 
A WELL DEFINED COMMA HEAD/DEFORMATION PCPN BAND EXPECTED TO
DEVELOP ACRS A LARGE PORTION OF ND...CNTRL TO NRN SD AND INTO
LARGE PORTIONS OF MN.   THERE IS POTENTIAL FOR THIS COMMA HEAD TO
PIVOT INVOF ERN ND/NWRN MN LATE MON AFTERNOON INTO MON
NIGHT...WITH HVY TO ISOLATED EXCESSIVE RAINFALL AMTS ACRS THESE
AREAS.  TO THE EAST AND NORTHEAST OF THE DEVELOPING
LOW...STRENGTHENING SLY TO SWLY LOW LEVEL FLOW WL SUPPORT
OVERRUNNING PCPN STREAKING NEWD INTO THE UPR LAKES DAY 1.  PCPN
HERE WL BE FAIRLY PROGRESSIVE WHICH SHOULD KEEP PCPN AMTS LIGHTER
THAN THE AFOREMENTIONED AREAS UPSTREAM.  
...LOWER MO VALLEY INTO THE CNTRL PLAINS...
LATEST MODELS GUIDANCE DOES NOT DEPICT MUCH PCPN ALONG THE
TRAILING CDFNT FROM THE UPR MS VALLEY LOW EXTENDING SWWD INTO
PORTIONS OF THE LOWER MO VALLEY AND CNTRL PLAINS.  GIVEN THE
STRONG FRONTAL CONVERGENCE AND INCREASING PWS ALONG THIS FRONT
AFTER 0000 UTC TUE SEP 7 THERE MAY BE A QUICK MOVG LINE OF
CONVECTION ALONG THIS FRONT. DAY 1 QPF INCREASED PCPN ACRS
IA...NWRN MO AND INTO ERN KS...BUT WITH THE QUICK MOVEMENT OF THE
FRONT...KEPT AREAL AVG AMTS LIGHT.
...S TX..
NEWLY FORMED T.D. 10 OVER THE SWRN GULF IS EXPECTED TO PUSH NWWD
DAY 1 INTO NERN MEXICO.  THERE ARE UNCERTAINTIES WITH HOW QUICKLY
THIS SYSTEM WL PUSH NWWD..WITH MOST OF THE LATEST GUIDANCE FASTER
THAN THE OFFICIAL TRACK FORECAST.  FOR DAY 1...THE CORE OF THE
HEAVIEST RAINS ARE DRAWN FOR THE OFFICIAL TRACK...WITH A 5"+ MAX
OVER NERN MEXICO.  TO THE NORTH OF THIS...LOW LEVEL SELY FLOW OFF
THE WRN GULF WL SUPPORT INCREASING SHOWER ACTIVITY WELL TO THE
NORTH OF THE CNTR OF T.D. #10.  THIS WL SUPPORT HVY RAINFALL
POTENTIAL FOR FAR S TX AND NEWD ALONG THE SRN TO CNTRL TX COAST.  
...PAC NW...
WELL DEFINED MID TO UPR LEVEL HT FALLS EXPECTED TO DROP SEWD ALONG
THE B.C. COAST TO A PSN OFF THE PAC NW COAST DAY 1.  THESE HT
FALLS WL SUPPORT INCREASING ONSHORE WLY TO SWLY FLOW INTO THE PAC
NW EARLY TUE...WITH WEAKENING OF THIS ONSHORE FLOW WITH TIME LATER
DAY 1.  DAY 1 QPF LEANED TOWARD THE 12 KM NAM OUTPUT FOR DETAILS
ACRS THIS REGION...WITH MDT .25-.50 AREAL AVG AMTS DEPICTED IN THE
FAVORED TERRAIN AREA OF THE WA CASCADES AND WA COAST AND OLYMPIC
RANGES.
 
DAYS 2 AND 3...
...PAC NORTHWEST/NRN GRT BASIN/NRN ROCKIES...  
  
STG SHRTWV ENERGY DIGGING SEWD DOWN THE COAST OF BRITISH COLUMBIA
IS AGAIN EXPECTED TO LEAD TO THE FORMATION OF A DEEP LARGE SCALE
UPR TROF AND ASSOC CLSD LOW INVOF THE PAC NW BY EARLY  
TUE...WITH THE LOW WILL DEEPENING FURTHER TUE NIGHT/EARLY WED
WHILE DRIFTING TWD THE NRN GRT BASIN. PAC MSTR FLUX INTO THE
REGION SHOULD BE RATHER MODEST...BUT STEEPENING LAPSE RATES AND HT
FALLS COUPLED WITH OROGRAPHICS WILL GENERATE NUMEROUS
SHWRS...INITIALLY OVER THE CASCADES...BUT THEN DEVELOPING WELL
INLAND ACRS THE GRT BASIN AND INTO THE NRN ROCKIES BY WED.
GENERALLY FOLLOWED A BLEND OF THE HIGHER RES 12Z/00Z ECMWF SOLNS.
...FOUR CORNERS REGION...
THE DEVELOPING DEEP TROF OVER THE WRN CONUS WILL DRAW INCREASING
MONSOONAL MSTR INTO PORTIONS OF THE FOUR CORNERS REGION THROUGH
THE PD. PCPN AMTS SHOULD TEND TO BE LIMITED GIVEN THAT THE MSTR
FEED SHOULD BE RATHER NARROW...BUT THE CONVECTIVE COVERAGE SHOULD
INCREASE WITH AT LEAST SCT DIURNALLY DRIVEN AND OROGRAPHICALLY
ENHANCED SHWRS/TSTMS BY WED. THE MAIN FOCUS SHOULD BE OVER AZ AND
SPREADING INTO WRN NM/CO.
  
...UPR MS VLY/GRT LAKES/NRN NEW ENGLAND...  
  
A VIGOROUS UPR TROF EXITING THE UPR MS VLY/GRT LAKES REGION WILL
ADVANCE INTO THE ST LAWRENCE RIVER VLY AND NORTHEAST BY WED. SOME
ADDITIONAL SHWRS MAY BE POSSIBLE OVER THE UPR MS VLY AND GRT LAKES
REGION IN ASSOC WITH THE DEPARTING DEFORMATION ZONE ASSOC WITH
THIS SYS...BUT THERE WILL BE STRENGTHENING WARM ADVECTION
DOWNSTREAM INTO THE NORTHEAST. THIS COUPLED WITH A FRONT ALREADY
DRAPED ACRS NRN NEW ENGLAND AND INCREASINGLY DIV FLOW ALOFT ASSOC
WITH THE HEIGHT FALLS SHOULD PROMOTE A BAND OF SHWRS/TSTMS THROUGH
TUE NIGHT. A MUCH MORE DYNAMICAL PCPN EVENT THOUGH IS LIKELY BY
WED AS THE UPR TROF IS EXPECTED TO DEEPEN AND AMPLIFY SOMEWHAT AS
IT CROSSES NRN NEW ENGLAND. PORTIONS OF NRN NEW ENGLAND ARE
EXPECTED TO GET INTO A RATHER ROBUST MID LVL DEFORMATION ZONE
GIVEN THE LOW TRACK OF THIS SYS...AND A POTENTIAL FOR SFC LOW
DEVELOPMENT ALONG THE MAINE COAST. THIS WILL RESULT IN A SWATH OF
MDT TO POTENTIALLY HVY RAIN FOR NRN NEW ENGLAND WED AND WED NIGHT.
HPC QPF LEANED TWD THE 12Z/00Z ECMWF SOLNS. 
  
...WRN GULF COAST/SRN PLAINS/LWR MS VLY...  
THE LATEST NHC FCST TRACK FOR NEWLY FORMED T.S. HERMINE OVER THE
BAY OF CAMPECHE SUPPORTS A LANDFALL ACRS EXTREME NERN
MEXICO...WITH ITS POOL OF DEEP TROPICAL MSTR/ENERGY EXPECTED TO
THEN CROSS THE RIO GRANDE VLY EARLY THIS PD ON TUE AND ADVANCE
STEADILY NWD ON WED TWD THE S CNTRL PLAINS AS IT ROUNDS THE WRN
PERIPHERY OF THE SUBTROPICAL RIDGE OVER THE GULF COAST STATES. THE
SYS SHOULD WEAKEN STEADILY AS IT ADVANCES NWD...BUT THE MID LVL
VORTICITY/CIRC WITH THE SYS EMBEDDED WITHIN SUCH DEEP MSTR AND
INSTABILITY WILL SUGGEST A POTENTIAL FOR SOME NOCTURNAL
CONSOLIDATION OF THE CONVECTION...AND A POTENTIAL FOR A CORE OF
VERY HVY RAINFALL TOTALS NR THE CENTER THROUGH THE PD. PLS SEE THE
LATEST NHC FCST DISC/ADVISORY FOR MORE INFORMATION.
...FLORIDA...  
  
HIGH PWATS AOA 2 INCHES COUPLED WITH STG DIURNAL HEATING SHOULD
RESULT IN SOME ADDITIONAL SCT AREAS OF SHWRS/TSTMS THROUGH TUE.
DRIER AIR THOUGH IS PROGGED THEREAFTER TO BEGIN FILTERING OVER THE
PENINSULA AND SO BY WED...THE ACTIVITY SHOULD BE MORE ISOLATED.
GENERALLY FOLLOWED THE 12Z ECMWF WAS THIS SOLN.
ORAVEC/ORRISON