Quantitative Precipitation Forecast
Issued by NWS

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FOUS30 KWBC 050126
QPFERD

EXCESSIVE RAINFALL DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
925 PM EDT MON MAY 04 2015

...VALID 03Z TUE MAY 05 2015 - 00Z WED MAY 06 2015...
...REFERENCE AWIPS GRAPHIC UNDER...DAY 1 EXCESSIVE RAINFALL...


SLIGHT RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
60 SW F05 30 E BPG 40 SSE MAF 15 NNE FST 15 SW PEQ 25 E GDP
25 SSW ATS 30 WNW ROW 30 NNE 4CR 25 NNW CQC 20 NNE SKX
30 NNW VTP 35 ESE MYP 35 SE CCU 20 WSW BJC 15 WSW FNL 10 NNW DEN
BKF 15 NE MNH 15 SE MNH 20 NNE PUB 15 ESE PUB 35 S LHX
15 ENE SPD 20 N PYX 30 ESE HHF 60 SW F05.

MODERATE RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
25 NE PVW 40 WSW CDS 55 E LBB 25 NW SNK 35 NW BPG 35 NNW ODO
10 ESE HOB 30 WNW HOB 40 ENE ATS 60 NNW HOB 35 ESE CVN 25 NE PVW.


...FRONT RANGE OF THE ROCKIES SOUTHEASTWARD INTO THE SOUTHERN HIGH
PLAINS OF TX/OK/NM...

AGAIN..NO CHANGES TO THE PREVIOUS FCST AND REASONING ACRS THIS
REGION.  AS A SOUTHERN STREAM SHORTWAVE STRENGTHENS AND APPROACHES
FROM THE WEST...FLOW FIELDS AND MOISTURE TRANSPORT WILL
INCREASE...LEADING TO WIDESPREAD RAINFALL.  THE MODELS HAVE
CONSISTENTLY ADVERTISED AN ORGANIZED HEAVY RAIN EVENT IN THIS AREA
AND SEE NO REASON TO DISAGREE.  THE LOW LEVEL JET IS FORECAST TO
INCREASE ABOVE 50 KNOTS FROM THE SSE UNDER INCREASINGLY FAVORABLE
UPPER DIFFLUENT PATRN BETWEEN SLIGHTLY NEG TILT UPR TROF AND STGR
SUBTROPICAL JET WINDS TO THE SOUTH.  THE MODELS HAVE CONSISTENTLY
PLACED THE MAXIMUM CAPE AXIS AND 850 MB MOISTURE TRANSPORT OVER
FAR SE NM AND SW TX...BETWEEN LUBBOCK AND MIDLAND IN THE 00-09Z
TIME FRAME.  SMALL LATITUDE DIFFERENCES REMAIN WITH PLACEMENT OF
HEAVIER QPF MAX WITH MOST GLOBAL MODELS A BIT NORTH OF THE 12Z HI
RES GUIDANCE WITH THE EXCEPTION OF THE GFS WHICH IS CLOSER TO HI
RES GUIDANCE AXIS BUT ALSO APPEARS TO BE SUFFERING FROM GRID SCALE
FEEDBACK.   HAVE STAYED CLOSER TO SRN END OF GUIDANCE ALONG WITH
CONTINUITY...TOWARD OPTIMUM UPR DIFFLUENCE AND INFLOW WITH MODELS
SUGGESTING AREAL AVG AMOUNTS IN EXCESS OF 3 INCHES WITH LOCALIZED
AMOUNTS IN EXCESS OF 5 INCHES WHERE CONVECTION BECOMES ANCHORED OR
SLOWER MOVING..SUPPORTING A MODERATE RISK OF RAINFALL EXCEEDING
FLASH FLOOD GUIDANCE.

A BROAD SLIGHT RISK AREA SURROUNDS THE MODERATE...AND INCLUDES
MUCH OF EASTERN NM AND THE OK/TX PANHANDLES. SLOW MOVING
SUPERCELLS WILL POSE SOME RISK OF HEAVY RAIN..AND MOISTURE AND
FORCING MECHANISMS INCREASE UP THROUGH THE PANHANDLES OVERNIGHT.

A SECONDARY HEAVIER QPF MAX IS PSBL ALONG THE FRONT RANGE OF CO
WITH PERSISTENT ELY UPSLOPE CONDS THAT ARE EXPECTED TO LINGER INTO
LATER TONIGHT AS THE AXIS OF THE H5 TROF EVENTUALLY LIFTS NEWD
INTO THE SRN ROCKIES BY LATE TUE.  SOME EMBDD CONVECTIVE ELEMENTS
ARE LIKELY GIVEN INCREASING COLD POOL ALOFT WHICH COULD RESULT IN
LOCALIZED HEAVIER RAINFALL AMOUNTS AND A RISK OF RUNOFF ISSUES AS
A RESULT OF LOWER FFG VALUES ACRS THE AREA.



...PARTS OF THE CENTRAL PLAINS INTO THE MO VALLEY/MIDWEST...

WELL DEFINED VORT OVER SCNTRL NE AT THIS TIME IS FORECAST TO MOVE
SLOWLY ENEWD OVER THE CREST OF UPR RIDGE INTO THE MO
VALLEY/MIDWEST OVERNIGHT.  THE VORT IS EXPECTED TO TRACK MORE OR
LESS PARALLEL OR NEARLY PARALLEL TO WEAK FRONTAL BNDRY THAT IS
EXPECTED TO BECOME QSTNRY AND A BIT MORE E/W ORIENTED THRU MON
NIGHT/TUE MRNG.  THIS WILL LIKELY ENHANCE LIFT INTO THE BNDRY
WHERE POOLING OF 1.25 TO 1.5 INCH PWS IS EXPECTED ALONG WITH BROAD
20 TO 30 KT S TO SWLY 85H INFLOW.  ALL THIS WILL LEAD TO
INCREASING CONVECTION WITH POTNL FOR REPEAT ACTIVITY/BACKBUILDING
WITH BEST LOW LEVEL JET/INSTABILITY CONTINUING TO FEED INTO THE
BNDRY EVEN BEHIND PASSAGE OF MID LEVEL VORT THROUGH THE MON
OVERNIGHT PD.   FEEL GREATEST POTNL FOR HEAVIER RAINS WILL BE FROM
CNTRL KS INTO SRN IA/NRN MO..PSBLY EXTENDING INTO PORTIONS OF NRN
IL..WITH THE POTNL FOR 1 TO 2+ INCH RAINFALL AMOUNTS.  FELT BLEND
OF WRF ARW..NMM..AND NSSL WRF WERE REASONABLE ACRS THIS AREA WHILE
MOST OF THE GLOBAL MODELS WERE A TAD FAR NORTH WITH THEIR AXES.

TERRY
$$




USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.