FXUS04 KWBC 281004
QPFPFD
 
QUANTITATIVE PRECIPITATION FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
604 AM EDT FRI JUL 28 2006
FINAL DAY 1...DAY 2 AND DAY 3 QPF DISCUSSION
VALID JUL 28/1200 UTC THRU JUL 31/1200 UTC
REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR
 
 
...DAY 1...

...UPDATE...
NAM/GFS SHOWED ONLY SLGT CHNGS ACRS THE CONUS. BIGGEST CHNG WAS
BETTER AGREEMENT WITH AN E-W ORIENTED BAND OF MOD/HVY RNFL FM UPST
NY THRU NRN NEW ENG INTO DOWNEAST ME. MDLS GNRLY SHIFTD NWD WITH
THIS PCPN. THIS HAPPENED LAST NGT OVR THE OH VLY AND MDLS WERE
CORRECT. COULD BE LINKED TO THE POS TILT OF THE SYS AND THE BROAD
RDG ACRS THE SRN CONUS. MDLS STILL SEEM TO BE UNDERPLAYG THE LOLVL
INSTBLTY THIS AFTN OUT AHD/SE OF THE SYS...SO ALTHOU PULLED PCPN
NWD...ALSO INCRSD AMTS INTO THE WRMR/MORE UNSTBL AIR ACRS THE NRN
MID ATLC STS INTO SRN NEW ENG.

OTHER CHNGS ACRS THE CONUS WERE MOSTLY DUE TO ONGOING RDR/SATL
TRENDS...WHICH SEEM TO FAVOR INCRSG PCPN OVR THE INITIAL DAY 1
FCST.

ECKERT


...SYNOPSIS...
VRY TYPICAL SUMMER PTRN ACRS THE CONUS WITH MAIN BAND OF WRLYS
ALNG THE U.S./CAN BORDER AND VRY WEAK FLOW OVR MUCH OF THE CONUS.
LATEST WV IMAGERY SHOWS MANY VORTS CAUGHT IN THE WEAK FLOW THAT WL
AID WITH MOSTLY DIURNAL CNVCTV DVLPMENT. MDLS ARE GNRLY ON THE
SAME PAGE WITH THE LRG SCALE FEATRS...BUT ARE HAVG TRBL WITH THE
SMALLER VORTS...SOME OF WHICH ARE NOT REAL. LOOKG BACK AT YSTRDAS
QPF FCSTS SHOWS THE NAM GNRLY DID BETTER THAN THE GFS.


...NERN U.S...
POS TILTED MIDLVL VORT MOVG THRU THE GRT LKS REGION THIS MRNG SHLD
MOV STEADILY EWD TDA THRU THE NERN U.S. AND SUPPORT A SWATH OF
MOD/HVY RNFL. ALTHOU THE MIDLVL SUPPORT IS DECENT...THE LOLVL
FOCUS IS WEAK. MDLS SEEM TO BE KEYG ON THE 8H BNDRY THAT IS
PROGGED TO PUSH THRU THE REGION. MDLS CONT TO SHOW SOME 8H CVRG
AND A WEAK THETA-E RDG AHD OF THE BNDRY. THIS MRNGS CNVCTN SHLD
ALSO SUPPORT A DECENT OUTFLOW BNDRY THAT WL AID WITH INCRSG LOLVL
CVRG. DEEP MSTR IS ALRDY IN PLC WITH PWS ARND TWO INCHES. CNVCTN
MOVG THRU THE GRT LKS THIS MRNG WL LKLY HOLD TOGETHER AND INCRS IN
STRNGTH THIS AFTN AS IT MOVS INTO A MORE UNSTBL AIRMASS ACRS
PORTIONS OF NEW ENG. XPCT SOME 1-2 INCH PER HR RNFL RATES.

...OH VLY TO LWR MS VLY...
MIDLVL VORT OVR ERN ARK THIS MRNG IS FCST TO BCM ELONGATED TWD THE
NE TDA AS THE SYS TRYS TO PHASE WITH THE SHRTWV MOVG THRU THE NERN
U.S.. MDLS SHOW THE MIDLVL SYS CONTG TO WEAKEN...BUT LEAVG A SWATH
OF VRY HI PWS...NR 2.25 INCHES...ACRS THE REGION. XPCT PERIODIC
CVNCTN TO CONT TO FIRE UNDER THE VORT AND ASSOCD DEEP MSTR PLUME.
THE ACTVTY WL MOV VRY SLOLY...THEREFORE...SUPPORTG ISOLD TWO INCH
PER HR RNFL RATES IN SOME AREAS.

...FL/SERN U.S. CST...
SEA BREEZE CVRG AND DEEP MSTR WL SUPPORT CNVCTN FIRG LATER THIS
MRNG ALNG THE CSTS THAT SHLD PROGRESS WWD/INLAND THIS AFTN AND DIE
OUT THIS EVE. THE HVIEST/MORE ORGANIZED CNVCTN SHLD BE OVR SRN FL
WHERE LCLZD HVY RNFL IS PSBL.

...SRN PLNS TO OZARKS...
RIBBON OF DEEP MSTR LYG ACRS THE REGION AND A MIDLVL VORT STUCK IN
THE WEAK FLOW WL AID WITH ADDTNL CNVCTN INTO THIS AFTN ACRS THE
REGION. MDLS...ESPCLY THE GFS HAS BEEN PRDCG RNFL AMTS WELL ABV
OBSVD VALUES AND IT SEEMS LIKE THERE IS MORE FEEDBACK THIS MRNG.
NAM SHOWS THE MIDLVL SYS WEAKENG...WHILE THE GFS KEEPS IT STG.
ENSMEAN QPF/ENSQPF SCHEMES SUPPORTS GNRLY LGT/MOD AMTS ACRS THE
REGION. ISOLD HVY RNFL WL BE PSBL.

...AZ/NM...
NO MAJOR CHNGS TO PAST SVRL DAYS AS STG MIDLVL VORTS ARE CAUGHT IN
THE WEAK FLOW REGIME OVR THE REGION. MDLS CONT TO HAVE PRBLMS WITH
DEPICTG CNVCTN.YSTRDA WAS A RELATIVELY DOWN DAY FOR CNVCTN ACRS
AZ...WHILE NM HAD WDSPRD CVNCTN. THINK TDA SHLD BE MORE ACTV ACRS
AZ AND ALSO NM. XPCT CVNCTN TO FORM LATER THIS MRNG OVR THE HIER
TERRAIN AND GNRLY PROGRESS SWD THRU THIS EVE/TNGT WITH CELL
MERGERS SUPPORTG POCKETS OF VRY HVY RNFL. ISOLD 1-2 INCH PER HR
RATES WL BE PSBL.

...NRN PLNS INTO UPR GRT LKS...
MDLS ARE HINTG AT TWO AREAS OF CNVCTN DVLPG LATER TDA AND PSBLY
INTO TNGT ACRS THE REGION. MDLS SHOW MIDLVL DYNAMICS/LOLVL THERMAL
FORCG INCRSG THIS PD. SFC BNDRY SHLD HELP FOCUS LIFT ACRS THE UPR
GRT LKS WITH CNVCTN PSBLY DVLPG INTO AN MCS LATER TDA/TNGT ACRS WI
INTO THE U.P./NRN L.P. OF MI. HAVE BOOSTED QPF AMTS AS THE LLJ WL
LIE NRLY PARALLEL TO THE MID/UPR LVL FLOW AND SUPPORT SOME TRAING
AND MSTR POOLG WITH PWS INCRSG TO ARND 1.50 INCHES. LATER TNGT
MDLS SHOW INRSG LOLVL THERMAL FORCG ACRS ND THAT SHLD RESULT IN
INCRSG ELEVATED CNVCTN IN THIS AREA. MSTR REMAINS SOMEWHAT LIMITED
SO AMTS ARE LGT FOR NOW.
 
 
DAY 2...

SOUTHWEST/SRN ROCKIES...
THE UPPER RIDGE BUILDS EAST ACROSS THE CNTRL U.S...ALLOWING A SLY
FLOW TO INCREASE THE INFLUX OF ENERGY AND MONSOONAL MOISTURE INTO
THE INTERIOR SOUTHWEST.  PW VALUES ARE FCST TO REACH ABOVE 1.5
INCHES ACROSS PARTS OF AZ WHERE NAM/GFS SUPPORT THREAT FOR
LOCALIZED CONVECTIVE RAIN.  INDICATED .50 INCH PLUS AMTS THRU THE
FAVORED CLIMATOLOGICAL AREAS OF AZ...BUT ISOLD HEAVIER AMTS ARE
LIKELY.

UPR MS VLY AND GREAT LAKES...
NEARLY STNRY BNDRY IS FCST TO ALIGN FROM MN TO LOWER MI...AND
SERVE AS A FOCUS FOR CONVECTION.  FAVORABLE UPPER DIFFLUENT FLOW
OVER WI AND MI SHOULD HELP DEVELOPMENT AS WEAK VORTS RIPPLE ESE
ALONG THE SRN PART OF THE UPPER JET.  HIGH AVBL MOISTURE WITH PW
VALUES UP TO 1.75 INCHES ALSO COINCIDES ACROSS THE REGION.  EXPECT
A FEW CONVECTIVE COMPLEXES TO SLIDE THROUGH THE AREA CENTERED ON
WI...WITH SOME LOCALIZED 1 INCH PLUS QPF TOTALS.

SOUTHEAST...
DEEP MOISTURE WILL PERSIST THROUGHOUT THE SOUTHEAST AND SRN MID
ATLC TO ALLOW FOR MORE MOSTLY DIURNAL CONVECTIVE DEVELOPMENT. 
EXPECT ADDITIONAL ENHANCEMENT TO BE ALIGNED WITH A SHRTWV AND VORT
CENTER TRACKING ACROSS NC/VA DURING SAT....WHICH NAM/GFS BOTH
TRACK.  ADDITIONAL WEAK ENERGY OVER THE INTERIOR SOUTHEAST MAY
HELP TO IGNITE MORE CONVECTION AS PW VALUES HOVER AROUND 2 INCHES.
 


DAY 3...

UPPER MIDWEST...
NAM/GFS SUPPORT SOME 2 INCH PW VALUES AS THERMAL BNDRY LIFTS
SLOWLY NWD INTO UPPER MI.  WEAK VORT ENERGY SHOULD ROUND THE UPPER
RIDGE AND SLIDE SEWD IN THE UPPER DIVERGENT FROM OVER THE UPPER
MIDWEST.  EXPECT THIS TO ALLOW MORE AREAS OF CONVECTION FOCUSING
ON THE FRONTAL BNDRY WITH POTENTIAL FOR LOCALLY HVY RAIN FROM NRN
MN TO UPPER MI AND NRN WI.  

SOUTHEAST...
LINGERING SHRTWV ENERGY SHOULD BRING MORE CONVECTION FROM THE
CAROLINAS TO AL/GA AND NRN FL AS THE SOUTHEAST REMAINS ENTRENCHED
IN A TROPICAL AIRMASS WITH WIDESPREAD PW VALUES OF AROUND 2
INCHES.  ACTIVITY SHOULD BE CONCENTRATED DURING THE AFTN/EVNG
HOURS WITH ISOLD 1 INCH PLUS AMTS POSSIBLE.

SOUTHWEST...
PERSISTENT VORT ENERGY ON THE WRN SIDE OF THE UPPER RIDGE
CONTINUES OVER THE INTERIOR SOUTHWEST.  EXPECT MORE MAINLY DIURNAL
OROGRAPHIC CONVECTION OVER PORTIONS OF AZ AND SURROUNDING AREAS AS
MOISTURE IS PULLED NWD FROM MEXICO.


ECKERT/HEDGE