SOUTHWEST ARIZONA/SOUTHEAST CALIFORNIA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
945 AM MST TUE JUL 20 1999
.SYNOPSIS...
A WEAK SOUTHERLY FLOW WILL KEEP THE AIR MOIST AND UNSTABLE OVER THE
AREA...ESPECIALLY OVER SOUTH-CENTRAL ARIZONA. GENERALLY...THIS WILL
RESULT IN ISOLATED TO SCATTERED AFTERNOON AND EVENING THUNDERSTORMS
OVER SOUTHWEST AND SOUTH-CENTRAL ARIZONA. HOWEVER...A WEAK LOW
PRESSURE SYSTEM IS EXPECTED TO ROTATE NORTH ENHANCING THUNDERSTORM
DEVELOPMENT OVER SOUTH-CENTRAL ARIZONA TONIGHT.
.DISCUSSION...
NOT MUCH TO LOOK AT THIS MORNING WITH RESPECT TO NEW MODEL DATA...AND
MAY BE BETTER OFF BECAUSE OF IT. MODELS HAVE BEEN SHAKEY AT BEST WITH
RH TRENDS THE PAST FEW DAYS. LOOKING AT LATEST SATELLITE LOOPS
INDICATES MID/HI LEVEL MONSOON BOUNDARY HAS MOVED TO FAR SE AZ...
WHILE 12Z AZ SOUNDINGS INDICATE THAT LOW LEVEL BOUNDARY NOW FROM NEAR
4 CORNERS SW THRU PHX THEN TO E OF YUMA. ALSO...A WEAK UPPER LEVEL
VORT MAX LOCATED TO OUR S WHICH MAY HELP TO SERVE AS TRIGGER RIGHT
ALONG MOISTURE BOUNDARY. 15Z RUC SEEMS TO BE TOO FAR W WITH THIS
FEATURE. ANYWAY...PAST COUPLE OF SHIFTS HAVE NOTED THIS SHORT-WAVE
TROF AND HAVE UPPED THUNDERSTORM COVERAGE SCNTRL PORTIONS BECAUSE OF
IT. FOR NOW WILL LET THIS IDEA RIDE. NO UPDATES. ESTLE
FXUS65 KTWC 201636 az
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
240 PM EDT TUE JUL 20 1999
IN THE SHORT TERM...SEA BREEZES HAVE STARTED OFF BIG BEND AREA &
WILL SLOWLY PUSH N...THEN CONVECTION TO DRIFT NE WITH 7H STEERING
FLOW. MOST ACTIVE CONVECTION AREA SHOULD BE SE AL...WESTERN FL
PANHANDLE...& MAINLY WEST OF TLH. CAPES START AT 2000 (LI -6) FROM
AQQ TO 3200 (LI -7) IN SE AL TO FAR SW GA. IR SATELLITE HAS INDICATED
DRYING OF UPPER LEVELS...& TLH MODIFIED SOUNDING OF PRECIP WATER AT
1.65. RUC ALSO PICKING UP UPPER FEATURE WELL & DECREASE IN OVERALL
MEAN RH FROM TLH TO JAX & SRN GA.
OVERALL MODELS ARE PICKING UP FEATURES CONSISTENTLY. RIDGING PATTERN
HOLDS WITH CONTINUED DRIER ATMOSPHERE ON WED. ALSO MINIMAL SHORT
WAVE ENERGY INDICATED. BUT SURFACE WIND FLOW DOES GO MOVE W-NW. THIS
WOULD SET-UP MINIMAL SEA BREEZY CONVECTION WITH FLOW (20-30%
MAX)...AS WELL AS TAKE TEMPS A BIT HIGHER. THIS IS TYPE 8
SYNOPTIC REGIME...WHICH IS NOT FAVORABLE FOR RAIN IN TLH...BEST
ALONG COASTS.
MARINE...WIND SW 5 TO 10 KT AFTN BECMG VRBL 5 KT TNGT. WDLY SCT AFTN
EVE SHWRS/TSTMS. SEAS 2 FT OR LESS. LIGHT CHOP BECMG SMOOTH TNGT.
WINDS WILL SHIFT TO W-NW ON WED.
PRELIM...
TLH 072/094 073/096 074 3333
PFN 074/089 075/090 077 3333
DHN 072/094 074/096 074 3333
ABY 072/094 074/096 074 2213
VLD 072/094 073/096 073 2213
MCT
FXUS62 KJAX 201810 fl
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSONVILLE FL
230 PM EDT TUE JUL 20 1999
CURRENTLY...CONVECTION BEING LIMITED BY MAJOR SUBSIDENCE OVER AREA.
HARDLY A CU IN SIGHT OVER SE GEORGIA WITH A FEW THUNDERSTORMS OVER
THE EXTREME S CWA...NOTHING TOO IMPRESSIVE. DUE TO THE DRY AIR
ALOFT...ANY STORM COULD HAVE GUSTY WINDS. UPDATED ZONES REFLECT THIS
AND SHOULD WORK OUT FINE. SEA BREEZE STARTING ON BOTH COASTS AND
WILL EXPECT A FEW MORE STORMS OVER EXTREME S CWA LATER THIS PM.
FORECAST...STILL ANXIOUSLY AWAITING NEW MODEL DATA /ALTHO SEVERAL
MISSING SOUNDINGS IN THE SE/. ONLY THE 12Z NGM AND 15Z RUC HAVE BEEN
RECEIVED. ALL THE MODELS /OLD AND NEW/ FAIRLY SIMILAR WITH SFC AND
UPPER LEVEL FEATURES THRU 00Z THU. SLIGHT INCONSISTANCIES NOTED IN
SFC DEVELOPMENT OF WEAK LOW ALONG EXISTING TROF OVER MID-ATLANTIC
STATES...BUT NGM SHOWS 1014 LOW NEAR CAE BY 12Z THU. ETA IS THE
WEAKEST WITH THE 500 MB RIDGE OVER THE SE STATES IN THE SHORT TERM
WHILE THE NEW NGM...RUC AND OLD AVN MATCH UP FAIRLY WELL. THUS...
WILL USE NEW NGM DATA FOR THIS FCST. WILL GO ALONG WITH NGM DATA AND
TWEAK NUMBERS IF ANY DIFFERING DATA COMES IN FROM OTHER MODELS.
ALL THIS SAID...NGM RETROGRADES 500 MB HIGH BACK TO THE WEST OVER
THE MS VALLEY BY 48 HRS. THIS WILL ALLOW BROAD TROF OVER THE MID
ATLANTIC TO DIG SLIGHTLY AND SUPPORT WEAK AFFOREMENTIONED SFC LOW IN
THAT AREA. THIS PATTERN SHOULD ALLOW POPS TO APPROACH CLIMATOLOGY ON
WED AND THU AFTER TODAYS LESS-THAN-CLIMO POPS. WITH SLOWLY
STRENGTHENING LOW NORTH OF THE CWA...SFC RIDGE SHOULD REMAIN TO OUR
S CONTINUING SW TO W LOW-LEVEL FLOW. HOWEVER...WITH RIDGE ALOFT
SHIFTING BACK NW...WINDS ALOFT SHOULD COME AROUND TO MORE NE AT
MID-LEVELS. THIS WILL KEEP STORM MOTION SLOW AND POSSIBLY MORE NE TO
SW BY THE END OF THE PERIOD. IF LOW DOES DEVELOP AS INDICATED...
STRENGTHENING WESTERLY SFC WINDS MAY PRECLUDE E COAST SEABREEZE ON
THU. WILL GENERALLY ACCEPT NGM POPS ALTHO MAY LOWER A NOTCH. TEMPS
LOOK GOOD AS WELL...ALTHO WILL ADJUST DOWN 2ND PERIOD FOR SEABREEZE
ALONG E COAST.
MARINE...CURRENT PACKAGE LOOKS FINE. WILL TWEAK A BIT AND INCREASE
SPEED A BIT IN 3RD PERIOD.
AMG 72/94/72/95 1213
SSI 75/92/74/92 1213
JAX 73/93/73/94 1213
GNV 71/93/72/94 1324 31
CARROLL
FXUS62 KTBW 201756 fl
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
230 PM CDT TUE JUL 20 1999
18Z SFC ANALYSIS SHOWING SYNOPTIC FRNTL BOUNDARY EXTENDING FROM N CENT
IA SEWRD TO AROUND PIA AND BACK INTO CENT INDIANA. DECENT TEMP GRADIENT
ACROSS BOUNDARY WITH LWR 90S W CENT IL TO UPPER 70S NE IL. PLENTY OF
MOISTURE/HIGH INSTABILITY FEEDING NEWRD INTO FRNT WITH MIDDLE TO UPPER
70S TDS.
MAIN CONCERN THIS FCST PERIOD WILL BE TSRA CHANCE TONIGHT AND POSSIBLE
HIGHLIGHTS FOR HEAT INTO THU. MODELS DIFFER IN SOLUTION OF CONVECTION
DEVELOPMENT TONIGHT. ETA FARTHER S WITH NGM/RUC KEEP BEST SUPPORT TO
THE N. NGM SEEMS TO BE VERIFYING BEST WITH FEATURES AT 18Z AND SO WILL
BE MODEL OF CHOICE. SFC FRNT SHOULD BEGIN TO SHIFT N INTO NERN IL TNGT
AS SFC WAVE MOVES NE ALONG BOUNDARY INTO WI OVERNIGHT. IN RESPONSE...LOW
LEVEL TEMP/MOISTURE ADV MAXING OUT INTO N CENT IA/SRN MN THIS AFT AND
SHIFTING ACROSS SRN WI/EXTREME NE IL BY 12Z WED. BESIDES CURRENT
COMPLEX MAKING TURN TOWARD SE ACROSS SRN WI ATTM...WOULD EXPECT MORE
DEVELOPMNT INTO N CENT IA/SRN MN LATER THIS AFTERNOON AND TRACK ALONG
BOUNDARY. THIS SHOULD RESULT IN HEAVIEST PCPN REMAINING N OF AREA. THIS
THINKING MATCHES WELL WITH 94E. WILL CONT WITH POPS FOR THE AREA(HIGHEST
IN NRN GROUPS) AS OUTFLOW BOUNDARIES DRIFT S INTO CENT IL AND BOUNDARY
LINGERING IN N THIS EVENING.
HEAT ANOTHER AREA OF CONCERN. MORE SUN AND LESS TSRA THE NEXT 2 DAYS
SHOULD PLACE TEMPS A NOTCH OR SO HIGHER. A FEW PLACES HAVE ALREADY
TOUCHED ON HEAT ADVISORY CRITERIA TDY AND YEST AND BELIEVE IT WILL BE
MORE WIDESPREAD WED/THU WITH TEMPS IN MID 90S AND TDS POOLING IN
MID/UPPER 70S. THEREFORE WILL LIKELY ISSUE HEAT ADVISORY FOR THE ENTIRE
AREA THROUGH THU.
COORD THANKS...DVN/LSX/CHI/PAH
PRELIMINARY CCF...
SPI GG 074/095/074/095 075 36322
PIA GG 073/094/074/095 075 36432
DEC GG 074/095/074/095 075 36322
CMI GG 073/094/074/094 074 36432
MTO GG 075/096/076/096 076 36322
LWV GG 076/096/076/097 076 36322
.ILX...
IL...HEAT ADVISORY CENT/SE IL THROUGH THURSDAY
$$
FRIEDERS
FXUS63 KLOT 201906 il
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
927 PM CDT TUE JUL 20 1999
CONCERN FOR TNGT RMNS TSTM/HVY RAIN TRENDS. 01Z SFC ANLYS PLACES
FNT ALG KOLU-KFOD-KMSN LN WITH WEAK WV INVOF KFOD. MSAS PRES FALL
CNTR NOW OVR SRN WI SO TSTMS SHOULD BE RELEGATED TO AREAS E OF WV.
TSTMS NOW TRAINING ACRS BUTLER AND BREMER COUNTIES INVOF LAPS
THETA-E ADVCTN MAX. THUS WL DROP SRN AND WRN EDGES OF SVR TSTM
WATCH PER SPC UPDATE. HWVR SCNDRY PRES FALL CNTR ALSO NOTED ACRS
CNTRL NE WITH RECENT LOOP OF LOW LVL PROFILER WNDS INDCG BACKING
ACRS KS. 00Z RUC POINTS IN THIS DIRECTION AS WELL WITH REFOCUSING
OF LOW LVL CNVGNC TWRD KSUX BY 06Z OR 09Z...THEN WEAKENING TWRD
12Z. THUS EVEN THOUGH WRN PTNS OF FLASH FLOOD WATCH SHOULD SEE AT
LEAST A BREAK IN PCPN...DO NOT FEEL CONFIDENT ENOUGH TO DROP WATCH
THERE CONSIDERING GROUND MSTR CONDITIONS AND RAIN POSSIBILITIES. WL
LEAVE WATCH GOING WITH POP WORDING.
OTRW NO CHGS BESIDES COSMETICS TO FIT CURRENT WX. HEAT ADVY RMNS IN
EFFECT FOR TMRW.
.DSM...FLASH FLOOD WATCH OVNGT IAZ004>007-015>017-024>028-037>039-050
HEAT ADVY WED IAZ044>046-057>060-070>074-081>086-092>097
SMALL
FXUS63 KDMX 202029 ia
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1040 PM EDT TUE JUL 20 1999
SFC FRONTAL BOUNDARY HAS MOVED LITTLE THIS EVENING AND STILL
EXTENDED FROM NERN IA ACROSS NRN IL INTO CNTRL IN AT 02Z. MSAS DATA
SHOWED 70 DEG SFC DEWPOINTS AS FAR NORTH AS SWRN WI TO CHICAGO AREA
TO BEH AND SBN. UPPER LEVEL DISTURBANCE RIDING OVER TOP OF THE
SLOWLY NWD BUILDING RIDGE OVR THE CENTRAL PLAINS NOW FIRING MESOSCALE
CONVECTIVE COMPLEX OVER NRN IA AND EXTRM SWRN WI. THIS COMPLEX WILL
PROPAGATE SEWD ACROSS NRN IL OVERNIGHT.
00Z RUC II AND 18Z MESOETA BOTH SUGGEST MOST OF THE CONVECTION WILL
STAY TO THE SOUTH AND WEST OF OUR CWA UNTIL 12Z. THIS SEEMS
REASONABLE GIVEN THE LACK OF ANY NWD MOVEMENT OF THE SFC BOUNDARY
THIS EVENING AND THE CONTINUED BACK-BUILDING CONVECTION OVER THE
CENTRAL PLAINS. MODEL THICKNESS PATTERNS SUGGEST CONTINUED SEWD
PROPAGATION OF CONVECTIVE CLUSTERS OVERNIGHT. BELIEVE SHOWER
ACTIVITY OVER CENTRAL AND EASTERN WI WILL MOVE ESEWD ACROSS CWA
OVERNIGHT...AFFECTING MAINLY THE WRN 1/2 OF THE CWA GIVEN THE DRY
LOW LEVELS TO OUR EAST (PER 00Z DTX SOUNDING). SHOWERS SHOULD
DISSIPATE AS THEY REACH MID MICHIGAN THRU DAYBREAK. WILL KEEP
MENTION OF POSSIBLE THUNDER WRN ZONES...BUT FEEL BEST CHANCE FOR ANY
ORGANIZED THUNDERSTORM ACTIVITY WILL BE AFTER 10Z FOR EXTRM SWRN
COUNTIES.
POPS LOWERED ERN CWA AND CONDITIONAL WORDING GIVEN FOR WRN CWA IN
THE ZONE FORECAST UPDATE ISSUED AT 1015 PM EDT.
.GRR...NONE
GREENE
FXUS63 KMQT 210230 mi
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
1030 PM EDT TUE JUL 20 1999
FORECAST ISSUE TONIGHT IS POSSIBLE SHOWERS ALONG THE WISCONSIN
BORDER.
500MB FLOW INTO THE U.P. IS MAINLY ZONAL WITH 500MB HIGH CENTERED
NEAR ST LOUIS AND FAST WESTERLIES ACROSS SOUTHERN CANADA AND
NORTHERN CONUS. EMBEDDED TROF ALOFT SHOWED BY 00Z RUC TO BE OVER
WISCONSIN IS HEADING EAST. THE U.P. WILL BE UNDER 700-300MB QVECTOR
CONVERGENCE TONIGHT DUE TO THIS TROF ALOFT...BUT 1000-500MB MOISTURE
IS LACKING OVER MUCH OF THE U.P. MOISTURE IS MORE ABUNDANT IN
WISCONSIN...WHERE SHOWERS (SOME VERY HEAVY) ARE CONTINUING. 88D
RETURNS HAVE SHOWN SHOWERS IN NORTHERN WISCONSIN WEAKENING AS THEY
MOVE EAST INTO DRIER AIR. NO RAIN IN THE U.P. SO FAR YET TONIGHT.
NGM...ETA...MESOETA...AND LATEST RUC QPF FORECASTS ARE IN ROUGH
AGREEMENT BY JUST GRAZING THE WISCONSIN BORDER WITH SOME SHOWERS
FROM 06-12Z AS 500MB TROF AND MOIST 1000-500MB LAYER ADVECT ACROSS
WISCONSIN. THESE MODELS APPEAR TO HAVE A REASONABLY GOOD HANDLE ON
CURRENT DISTRIBUTION OF SHOWERS IN WISCONSIN. AVN POORLY FORECAST
THE RAIN AT 00Z AND SHOWS PRECIPITATION MUCH FURTHER NORTH THAN THE
OTHER MODELS BY 12Z...AND IS NOT FAVORED.
SATELLITE IMAGERY SHOWS MAINLY CLEAR SKIES OVER NORTHERN
MINNESOTA... LAKE SUPERIOR... AND WESTERN U.P. WILL DROP
TEMPERATURES A COUPLE DEGREES IN NORTHERN U.P. COUNTIES WHERE CLOUDS
WILL BE LATE IN ARRIVING FROM WISCONSIN. HOWEVER...PERSISTENT LIGHT
SOUTHERLY WIND AND DEWPOINTS AROUND 60F SHOULD PREVENT A WHOLESALE
PLUNGE IN TEMPERATURES DUE TO RADIATIONAL COOLING.
.MQT...NONE.
ES
FXUS63 KAPX 210201 mi
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
1130 AM EDT TUE JUL 20 1999
SFC RIDGE REMAINS OVER MI THIS MORNING...WITH THE UPPER LEVEL RIDGE
AXIS W OF THE AREA OVER THE UPPER MISSISSIPPI. NOCTURNAL MCS
CONTINUES TO DIMINISH WITH TIME AS IT RUNS INTO DRIER...MORE STABLE
AIR UNDER THE SFC RIDGE ACROSS MI. MAIN FORECAST CONCERN FOR THE
AFTERNOON IS CLOUD COVER...SPECIFICALLY CU DEVELOPMENT FOR SRN
SECTIONS OF THE CWA WHERE HIGHER DWPTS RESIDE AND THICKENING DEBRIS
CI FOR THE ENTIRE CWA BLOWING OFF FROM THE CONVECTION TO THE W.
MODIFIED 12Z APX SOUNDING YIELDS A WEAK CAP WITH 300 CAPE AND LI'S
OF -1. DO NOT EXPECT ANY SIGNIFICANT VERTICAL CU DEVELOP AS RATHER
STRONG SUBSIDENCE AND WEAK CAPPING WILL INHIBIT VERTICAL GROWTH. BUT
DO EXPECT SCT-BKN CU...ESPECIALLY IN SRN SECTIONS OF THE CWA WHERE
HIGHER DWPTS RESIDE. LATEST RUC ALSO SUGGESTS ENHANCED AREA OF
300-500 MB RH MIGRATES E INTO LOWER MI THROUGHOUT THE AFTERNOON...
TAKING THE FORM OF DEBRIS CI FROM OVERNIGHT MCS TO THE W.
WILL KEEP CLOUD COVER FORECAST AS IS...WITH MOSTLY SUNNY A GOOD BET
FOR ERN UPR AND FAR NRN LOWER AND PARTLY SUNNY FOR THE REST OF THE
CWA. WILL TWEAK AFTERNOON HIGHS A BIT TO MATCH GOING TRENDS AND WILL
FRESHEN WORDING A BIT FOR THE WIND FORECAST.
.APX...NONE.
EME
FXUS63 KGRR 201532 mi
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
1100 AM EDT TUE JUL 20 1999
GOING FCST HAS A GOOD HANDLE ON SITUATION TODAY. OTHER THAN TO
FRESHEN WORDING BY REMOVING EARLY/MORNING REFERENCES...FEW IF ANY
CHANGES TO BE MADE.
LATEST SFC ANALYSIS SHOWS HIGH PRESSURE RIDGE EXTENDING FROM UPPER
MI EASTWARD. STATIONARY FRONT REMAINS WELL TO THE SOUTH ACROSS
NE/IA/IL/IN...AND CONVECTION CONTINUES N OF THAT BOUNDARY ACROSS SE
MN/NE IA. WV IMAGES SHOW SEVERAL SHORTWAVES TRACKING ACROSS S
CANADA ALONG MAIN BAND OF WESTERLIES TO THE N OF UPPER HIGH ACROSS
CNTRL U.S. THESE SHORTWAVES WILL STAY WELL TO N OF FA. SHORTWAVE
AIDING CONVECTION IN SE MN APPEARS TO BE NEAR KFSD. THIS SUPPORTED
BY PROFILER NETWORK.
12Z RUC SHOWS SFC HIGH PRESSURE RIDGE REMAINING ACROSS FA THRU AFTN.
ASSOCIATED LIGHT WIND REGIME...BOUNDARY LAYER WINDS LESS THAN 10
KNOTS...WILL ALLOW LAKE BREEZES TO DEVELOP ACROSS THE BOARD. CURRENT
ZONES REFLECT THIS.
OTHER THAN A PATCH OF LOW ST/STRATOCU IN BARAGA/IRON/MARQUETTE
COUNTY AREA...NOTHING BUT HIGH CLOUDS STREAMING INTO FA ACCORDING TO
VIS SATELLITE IMAGES. TEMPS THIS MORNING HAVE BEEN TRACKING WELL
WITH 11Z LAMP GUIDANCE WHICH INDICATES HIGHS IN CURRENT ZONES ARE IN
GOOD SHAPE. HOWEVER...FAIRLY THICK CI SHIELD SPREADING INTO FA MAY
HOLD TEMPS BACK A FEW DEGREES...ESPECIALLY SW COUNTIES.
GRB/MPX SOUNDINGS THIS MORNING SHOW FAIRLY LARGE DWPT DEPRESSIONS AT
LOW/MID LEVELS. THIS COMBINED WITH LACK OF UPPER LEVEL FORCING AND
CONTINUED ANTICYCLONIC LOW-LEVEL FLOW ASSOCIATED WITH SFC RIDGE
ACROSS FA INDICATES SHRA NOT A CONCERN THIS AFTN.
.MQT...NONE.
ROLFSON
FXUS63 KDTX 201430 mi
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
845 PM CDT TUE JUL 20 1999
THUNDERSTORMS HAVE SHIFTED EAST AND SOUTH OF FORECAST AREA WITH
FRONTAL BOUNDARY. LATEST RUC MODEL INDICATES SOME WAVING OF
BAROCLINIC BAND OVER SOUTHWEST MN TONIGHT WITH WEAK DIVERGENCE
ASSOCIATED WITH RIGHT ENTRANCE OF UPPER JET. WILL LEAVE A CHANCE
OF SHOWERS S CENTRAL ZONES. WITH HIGH BOUNDARY LAYER
MOISTURE...CONSIDERABLE CLOUDINESS REMAINS...ESPECIALLY SRN
ZONES.
.MSP...NONE.
SCOTT
FXUS63 KDLH 202035 mn
SOUTH CENTRAL NEBRASKA/NORTH CENTRAL KANSAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
135 PM CDT TUE JUL 20 1999
...TSRA CHCS 1ST PERIOD MAIN CONCERN W/ TEMPS THE PRBLM REST OF FCST...
WV IMAGERY SHOWED DISTINCT WV IN MONSOONAL FLOW TRACKING NE THRU ERN
CO. PROFILERS SHOW THIS WV NICELY AS WELL...ESP AT H7. ANOTHER WV IS
ALSO EVIDENT PER WV LIFTING NORTH THRU WRN KS UP BACKSIDE OF UPPER
RIDGE. ONCE AGAIN...WE ARE ON THE EDGE OF WARM MID LVL TEMPS. MEANWHL
DECENT LLVL MOISTURE REMAINS IN PLACE W/ H85 DWPTS AROUND 15C AND SFC
DWPTS FROM MID 60S SW TO LOWER 70S NE CWA.
SFC BOUNDARY HAS PUSHED INTO NW PARTS OF CWA LATE THIS AM WITH LARGE
ST DECK ON THE COOL SIDE VERY GRADUALLY ERODING. CONVECTIVELY INDUCED
VORT IN NEB PNHDL MAY HAVE HELPED PUSH THIS BOUNDARY TO THE SE. TRAJ
OF UPPER WVS MAKE TSRA CHCS IN NW AREAS PRETTY GOOD BY THIS EVENING.
SEEMS TO ME TO BE ENOUGH DRYING ON WV ALONG OUR WRN CWA TO HELP MAKE A
FEW STORMS SVR. IN ADDITION...MID LVL WIND FLOW ON MCK PROFILER SEEMS
AT LEAST MARGINAL FOR SVR STORMS...ESP IF H85 WINDS BACK JUST A LITTLE
PER RUC. WILL BASICALLY TRACK MOVEMENT OF SFC BOUNDARY THIS AFTN TO
FINE-TUNE LOCATION OF STORMS TONIGHT. AS OF 1PM...SW EDGE OF BOUNDARY
SEEMS TO BE WASHING OUT SOME. FROM LXN NE...HWVR...A DISTINCT SE PUSH
OF THE ST DECK SUGGESTS CONVERGENCE ON THIS PART OF FRONT WILL REMAIN
RELATIVELY STRONG AS WE HEAD THRU THE AFTN.
NGM IS BEST AT DEPICTING THIS SOUTHWARD PUSH WITH BOTH ETA/NGM KICKING
OUT SOME QPF THIS EVENING/TONIGHT IN AREAS OF CONCERN...PARTICULARLY
GRI NORTH. FCST...AGAIN...IS IN GOOD SHAPE WILL RESPECT TO TSRA CHCS.
WL PROBLY ONLY HAVE TO DO SOME MINOR TWEEKING.
AFTER THAT...RIDGE FCST TO BUILD WESTWARD...EFFECTIVELY SHUTTING DOWN
WIDESPREAD TSRA CHCS FOR REST OF FCST. THIS WILL ALSO KEEP RATHER WARM
AND HUMID CONDITIONS IN FCST AS RIDGE POSITION FROM LATE WEEK THRU THE
WEEKEND SUPPORTS S TO SE WINDS...KEEPING TEMPS...ON AVG...AROUND 95 W/
OVERNIGHT LOWS BASICALLY NEAR 70.
.GID...NONE.
GURNEY
FXUS63 KOAX 201724 ne
WESTERN NEVADA AND EASTERN CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
900 AM PDT TUE JUL 20 1999
EARLY MORNING CONVECTION OVER NORTHERN WASHOE COUNTY DECREASING AT
THIS TIME. WILL LIKELY SEE REDEVELOPMENT AGAIN THIS AFTERNOON AS UPPER
LOW OFF NORTHERN CALIFORNIA COAST CONTINUES TO DRIFT NORTHEASTWARD.
NEW RUC CONTINUES TREND OF 00Z MODELS WITH KEEPING THE BEST MOISTURE
AND INSTABILITY NORTH OF RENO. 12Z KREV RAOB FAIRLY UNSTABLE WITH
INVERTED-V BUT WATER VAPOR SHOWING MID LEVEL DRYING AND THIS PICKED UP
IN RUC SO SHOULD SEE MOSTLY JUST SHALLOW CONVECTION. BEST DEVELOPMENT
WILL REMAIN OVER NORTHERN PORTION OF CWA WITH UPPER DIFFLUENCE..WEAK
COUPLETING AND A LITTLE MORE MOISTURE AND INSTABILITY. THIS CURRENTLY
IN FORECAST THOUGH COVERAGE MIGHT BE A LITTLE HIGHER THAN SLIGHT
CHANCE. SURFACE TEMPS DOWN 2-5 DEGREES FROM YESTERDAY WHICH IS ALSO IN
LINE WITH CURRENT FORECASTS. NO UPDATES THIS MORNING. PIKE
.REV...EASTERN CALIFORNIA...NONE.
WESTERN NEVADA...NONE.
FXUS65 KLKN 201554 nv
NORTHERN GREAT BASIN FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ELKO NV
850 AM PDT TUE JUL 20 1999
WIND PICKING UP ALREADY IN ELKO WITH SIG WINDS ALOFT ON MRNG
SOUNDING. WILL UPDATE A FEW ZONES TO RAISE WINDS TO BREEZY
CATEGORY. SOUNDING VERY DRY OVER ELKO SO SHOULD SEE ONLY A FEW CU
THIS AFTN. MAIN THREAT FOR ISOLD CONVECTION IN DIFLUENT AREA OVER
NW NV AND ALONG NRN NV BORDER. COULD SEE SOME BUILDUPS ALONG THE
EASTERN BORDER OF NV...BUT DEEPER MOISTURE SHOULD STAY IN UT. RUC
DOES NOT HAVE A HANDLE ON LOWER LEVEL WINDS...AND WILL GO WITH
STRONGER WINDS ON ELKO 12Z SOUNDING TO BE MIXING DOWN TODAY. NO
OTHER UPDATES PLANNED TO ZONES OTHER THAN WIND ADJUSTMENTS.
DRY SW FLOW TO CONTINUE WITH TROF REMAINING ALONG THE COAST. WILL
HAVE TO WATCH FOR SIG S/WVS EXITING TROF AS THESE COULD TRIGGER
DRY THUNDERSTORMS AT TIMES IN THE N PART OF CWFA.
KBB
.EKO...NONE.
FXUS65 KVEF 201526 nv
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
940 PM TUE JUL 20 1999
.DISC...SHANK...
LTST SATL LPS SHWS CI DEBRIS SPILLING ACRS ONT/QUE INTO XTRM WRN
NY...LTST MESO ETA AND RUC INDICATE SM UPR LVL MOIST ACRS THE CWA
OVERNIGHT BUT BELIEVE MOST OF IT TO BE SCTD AND THIN SO WL WRD
OVERNIGHT PTN OF FCST AS MNLY CLR...NO OTHR CHNGS PLANNED ATTM.
.ALY...NONE.
MAC
FXUS61 KBUF 210127 ny
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BINGHAMTON NY
908 PM TUE JUL 20 1999
SATELLITE SHOWS LARGE AREA OF CI ACROSS UPPER GREAT LAKES NOW MOVING
INTO THE NORTH SHORE OF LK ONTARIO. BUF RADAR EVEN SHOWS SOME AC
AROUND THE GEORGIAN BAY. MESO ETA AND RUC DEPICT THIS HIGH LVL
MOISTURE WELL AND HAVE IT MOVING ACROSS FA OVERNIGHT. WILL CHANGE
MAINLY CLEAR FORECAST TO PARTLY CLOUDY IN ALL ZONES. WITH CURRENT
DEWPOINTS IN THE MID 40S TO LOWER 50S...LOW TEMPS SHOULD STILL BE
REACHED EVEN WITH HIGH CLOUDS. NO OTHER CHANGES.
.BGM...NONE.
RRM
FXUS61 KOKX 210100 ny
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
940 PM EDT TUE JUL 20 1999
SHOWERS SEEN ON KGSP RADAR ARE SHOWING THE USUAL DIURNAL TENDENCY TO
WEAKEN AND SHOULD BE COMPLETELY GONE BY 03Z. SHOULD BE ABLE TO UPDATE
MOST OF THE ZONES TO REMOVE PRECIP CHANCES. THE MOUNTAINS MAY BE A
DIFFERENT STORY THOUGH. IR SATELLITE IMAGERY SHOWS PLENTY OF DEEP
CONVECTION ONGOING ACROSS KY. THE BULK OF THE MCS PRECIP SHOULD REMAIN
TO THE WEST OF THE FORECAST AREA OVERNITE. HOWEVER...THE 21Z RUC AND 18Z
ETA BRING SOME OF THIS PRECIP UP TO THE WESTERN EDGE OF THE MOUNTAINS
LATE TONITE...WHICH SEEMS POSSIBLE GIVEN THE TRAJECTORY OF THE 850-500MB
THERMAL WIND. FOR THAT REASON...WILL PLAN ON LEAVING A SMALL PRECIP
CHANCE IN THE MOUNTAINS OVERNITE. TEMPS LOOK OK.
.GSP...NONE.
MOORE
FXUS62 KCAE 210100 sc
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
944 AM EDT TUE JUL 20 1999
DISC: 13Z SFC ANALYSIS SHOWS HI PRES ALNG THE SE AND GULF CST. A WK
TROF LINGERS THE UPSTATE.
SATELLITE PICTURE THIS MORNING SHOWS SKIES TO BE SUNNY ACRS THE AREA
WITH HAZY CONDITIONS (TYPICAL SUMMER). MORNING RUC SHOWING NOT MUCH
CHANGE IN HEIGHTS OVR THE AREA TDA AS UPR RIDGE RMNS TO THE W OF THE
AREA. RUC SHOWING BEST MOISTURE CONVERGENCE THIS AFT OVR THE UPSTATE AND
NERN PTNS OF THE STATE. WITH TDS THIS MORNING IN THE LOWER 70S FOR MOST
LOCATIONS. THIS COUPLED ALNG WITH DAYTIME HEATING...THINK THE CURRENT
POPS WL DO FINE FOR THE AFT WITH WIDELY SCT CONVECTION POSSIBLE. DO NOT
THINK A HEAT ADVISORY FOR AREA WL BE NEEDED...ALTHOUGH IT COULD BE CLOSE
IN SOME AREAS BY AFT AS HEAT INDEX VALUES WL BE ARND 100 DEGREES.
.CAE...NONE.
LCV
FXUS62 KGSP 201110 sc
AREA FORECAST DISCUSSION FOR CENTRAL/NORTHCENTRAL AND NORTHEAST
SOUTH DAKOTA AND WEST CENTRAL MINNESOTA
NATIONAL WEATHER SERVICE ABERDEEN SD
915 PM CDT TUE JULY 20 1999
CLOUDS HAVE DISSIPATED AS FCST...SO NOW CONCERNS TURN TO FOG CHANCES
OVERNIGHT...FCSTD LOWS AND THE IMPACT OF ERN WY CONVECTION. AS FOR
FOG...ETA SHOWED THAT 925MB LAYER SLIGHTLY DRIED OVERNIGHT...WITH
HUMIDITIES NO LARGER THAN 70-80 PERCENT. 00Z RUC CROSS SECTION
HOWEVER SHOWED THAT 80+ RH GETS STUCK IN THE VALLEY BETWEEN THE MO
RIVER AND THE SISSETON HILLS. WINDS STILL FORECASTED TO BECOME LIGHT
FROM THE SE. FOG PRODUCT ON AWIPS SHOWS AREA OF LOW CLDS FORMING IN
RAIN COOLED AIR IN SOUTHERN AND CENTRAL MN...WITH MOTION TO THE NW.
WILL LEAVE FOG IN AND REMOVE TIMING. AS FOR LOWS...CURRENT FORECAST
HAS LOWS FALLING INTO THE LOW 60S...OR AROUND 60. BASED ON CURRENT
DWPTS AND RUC FORECASTED SOUNDINGS...THESE ARE TOO LOW. WILL UP THEM
ON ORDER OF 5 TO 7 DEGREES. LASTLY...THE S/W ASSOCIATED WITH THE
CONVECTION IN ERN WY IS FORECASTED TO WEAKEN CONSIDERABLY AS IT
MOVES OVER THE MEAN RIDGE...SO CONVECTION SHOULD NOT SURVIVE
OVERNIGHT. WE MAY HAVE SOME LEFTOVER MID CLOUDS OVER OUR CWA BY
MORNING...BUT PROBABLY WON'T SEE THEM DUE TO THE FOG.
WILL NEATEN UP ZONES...MAKE AFORMENTIONED CHANGES...AND GET ZONES
OUT SOON.
.ABR...NONE
HINTZ
FXUS63 KFSD 210211 sd
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1035 AM CDT TUE JUL 20 1999
SCTD SHWRS LINGERING OVR EAST PORTION OF CWA BUT HEAVY RAIN HAS
ENDED...AT LEAST FOR THE TIME BEING. KEPT FFA GOING PER CURRENT
FORECAST FOR NORTHWEST IA AND PORTIONS OF SW MN. WMFNT MEANDERING
ACRS NW IA AT 15Z...WITH SOME NORTHWARD MOVEMENT EXPECTED THIS
AFTN. FNT SHOULD ACT AS FOCUS FOR TS DEVELOPMENT...ESPECIALLY WHERE
LO CLDS BREAK OUT. MRNG SOUNDINGS SHOW LITTLE/NO CAP SO RAPID
DEVELOPMENT POSSIBLE. LATEST RUC IMPLIES BEST CHC FOR HEAVY RAIN
NORTH OF AREA HIT HARDEST LAST NIGHT...BUT AIRMASS OVR ENTIRE CWA
VERY MOIST AND UNSTABLE. GOING FORECAST OK...BUT AFTN TEMPS WILL
DEPEND A GREAT DEAL ON LOW CLD BREAKOUT. WILL MONITOR FOR NOW...BUT
UPDATE MAY BE NEEDED LATER TODAY.
.FSD...FFA CONT NWRN IA AND PARTS OF SWRN MN
HARMON
@@ W
FXUS63 KUNR 201513 sd
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
935 AM MDT TUE JUL 20 1999
CURRENT ZONES IN GOOD SHAPE. 15Z SURFACE MAP SHOWED WEAK HIGH
PRESSURE OVER SOUTHWEST SOUTH DAKOTA INTO SOUTHEAST WYOMING. SOME
PATCHY FOG/LOW CLOUDS EAST OF THE BLACK HILLS...BUT WILL BE BURNING
OFF SOON. WATER VAPOR IMAGERY SHOWING SHORTWAVE MOVING THROUGH
SOUTHWEST WYOMING. 12Z RUC MOVES SHORTWAVE INTO SOUTHEAST MONTANA BY
EVENING. FOCUS FOR CONVECTION WILL BE AHEAD OF SHORTWAVE AND ALONG
WEAK SURFACE BOUNDARY OVER EASTERN MONTANA. BEST CHANCE IN CWA WILL
BE OVER NORTHEAST WYOMING/NORTHWEST SOUTH DAKOTA. WITH WEAK
CAP...SOME THUNDERSTORMS SHOULD ALSO DEVELOP OVER BLACK HILLS. WITH
WEAK FLOW...LOCALLY HEAVY RAINFALL WILL BE THE MAIN THREAT FROM THE
THUNDERSTORMS.
.UNR...NONE.
KRC
FXUS63 KABR 201512 sd
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MIDLAND TX
238 PM CDT TUE JUL 20 1999
WIDESPREAD CU FIELD HAS DEVELOPED ACROSS AREA WITH DEWPOINTS 60-65
COMMON. 15Z RUC SOUNDINGS MODIFIED FOR CURRENT CONDITIONS INDICATE
LFC'S ATTAINABLE AND WITH VISIBLE IMAGERY INDICATING ENHANCED CU
FIELD ERN FORECAST AREA WILL OPT TO INCLUDE MENTION OF WDLY SCT POPS.
NE FORECAST AREA IS FAVORED (OUTSIDE OF MTNS) AS WATER VAPOR IMAGERY
INDICATES TROPICAL UPPER LOW FEEDING SLIGHTLY HIGHER THETA-E AIR NW
INTO LOW ROLLING PLAINS. TROPICAL UPPER LOW/ASSOCD SHEAR AXIS
EXPECTED TO REMAIN ACROSS W TX/SE NM WITHIN LIGHT STEERING FLOW THRU
FORECAST PERIOD AND WILL STICK WITH TOKEN MENTION OF POPS AS A
RESULT. MORE SIGNIFICANT THETA-E RIDGE AXIS WILL REMAIN W AND EXPECT
ACTIVE DIURNAL PATTERN TO CONTINUE MTNS AS A RESULT. MRF SUGGESTS MID
LEVEL MSTR SOURCE TO THE W WILL MOVE E IN THE EXTENDED PERIOD WITH
BROAD HIGH PRESSURE ALOFT STILL APPARENT...SO SLIGHT CHANCE POPS TO
CONTINUE.
THE PRELIMINARY GUIDANCE BELOW IS FOR COORDINATION PURPOSES ONLY.
OFFICIAL FORECASTS ARE CONTAINED WITHIN THE WEST TEXAS/SOUTHEASTERN
NEW MEXICO ZONE FORECAST.
MAF 069/091/069/092 020/010/010
LSA 068/090/068/092 020/010/010
E41 069/091/069/092 020/010/010
6R6 072/091/073/091 020/010/020
MRF 059/084/060/085 030/020/030
CNM 070/091/070/092 020/020/020
.MAF...
TX...NONE.
NM...NONE.
GPM
FXUS64 KCRP 201939 tx
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
310 PM EDT TUE JUL 20 1999
AWIPS SATELLITE LOOP INDICATED PLENTY OF CLOUDS ACROSS WESTERN
PORTIONS OF RNK CWA. AT 18Z TEMPERATURES STILL MANAGED TO REACH
AROUND 90 DEGREES IN SOUTHSIDE VA. KFCX 88D THIS AFTERNOON SHOWED
SCT SHOWERS AND THUNDERSTORMS MAINLY IN THE SOUTHWEST. MOSTLY
LEFTOVERS FROM OLD MESOSCALE COMPLEX DROPING SE. REVIEW OF THE 15Z
RUC INDICATED BEST MOISTURE AND LIFT IN THE WEST DURING THE NEXT 12
HOURS. UNABLE TO RETRIEVE THE MM5 SE FROM INTERNET THIS AFTERNOON.
PROBLEMS AT NCEP HAS DELAYED MODELS. GENERAL REVIEW OF WHAT MODEL
DATA THAT IS AVAILABLE INDICATED THAT 5H HIGH CENTER REMAINS
ANCHORED TO OUR SW DURING THE PERIOD. SEVERAL VORT MAXS PIVOT
SOUTHEASTWARD DURING THE PERIOD...WITH A HEALTHY VORT MAX PLACED
AROUND STATE COLLEGE...PA AT 48 HOURS. TIMING OF SFC FRONT WHICH
DROPS SOUTH AND HOW FAR SOUTH IS SLIGHTLY DIFFERNT DEPENDING ON
MODEL OF CHOICE. IN GENERAL SIMILIAR WITH...WEAK WAVE/LOW IN NRN NC THIS
RETROGRADES S INTO SC ON WED. WRN EDGE OF FRNT REMAINS ACR FAR WRN
VA THRU WED. TREND OF SOLUTIONS ALL POINT TO PERIODS OF CLOUDS AND A
CHC OF SHOWERS AND THUNDERSTORMS. BEST CHANCES APPEAR TO BE IN THE
WEST. ETA/NGM LIS OF MINUS 2 TO MINUS 4 NOTED ACROSS KY-TN. WITH
TODAYS PCP WATER AROUND ONE AND A QUARTER INCH...MAY HAVE TO WATCH FOR
TRAINING OF ECHOES...DROPPING MCS S FOR POSSIBLE LOCAL FLASH
FLOODING. IN THE LONGER RANGE...THE BASIC TREND OF THE MRF/ECMWF
MEANS IS PERSISTENCE. ZONE PACK ARRIVAL AROUND 345 PM. HAVE A GUD
EVENING.
.RNK...
VA...NONE.
NC...NONE.
WV...NONE.
KK
FXUS61 KAKQ 201848 va
WAKEFIELD FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
857 PM EDT MON JUL 19 1999
LSTS SFC OBS AND MSAS PLACE THE FRNT JST S OF MFV XTENDG NW TO NR DCA
AND MRB. THIS LINES UP FAIRLY WELL WITH THE RUC. SO FOLLOWING ITS
PROG THRU 00Z...THE FRNT SULD PUSH INTO THE NC CNTYS THIS AFT BUT
LINGER ACRS WRN CNTYS AS A WAVE DEV ACRS NCNTRL NC. MOST OF THE UPR
LVL DYNAMICS WL STAY TO THE S...HOWEVER A DECENT VORT AT H850 MOVES
INTO WRN AREAS THIS AFT WHICH SHULD HELP TSTM DEV.
VIS SHOWS A FAIRLY SHARP CUT-OFF BTWN THE MS AND MCLO AREA. THE
CLDS ARE INTO MOST OF THE NWRN CNTYS. XPCT THIS AREA TO CONT
TO SPREAD SE THRU THE AFT. SO WL GO MCLO OR BECMG MCLO IN ALL
ZNS. REGIONAL RADAR LOOP SHOW SOME SCT LT SH JST BEHIND THE LEADING
EDGE OF THE CLD BAND FROM NR ILG SW TO NR HSP. MORE WIDESPREAD
ACTIVITY IS SPREADNG OUT OF OH AND WV. SOME OF THE ACT IN WV MAY MAKE
IT INTO A FEW OF THE SWRN CNTYS BUT FOR NOW WL LEAVE 30 POP. WILL
INCLUDE A 30 POP IN MD ZNS FOR THE SCT ACT IN THE N.
CWF...MADE SLIGHT ADJUSTMENTS TO THE WNDS AFTER LOOKING AT LTST OBS.
OTHERWISE NO CHANGES.
.AKQ...NONE.
SHADE
va
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
945 PM CDT TUE JUL 20 1999
IMPRESSIVE LINE OF TSTMS WITH HVY RAINS STRETCHED OUT ALONG FRONT ACRS
NRN IA. MORE SCT TSTMS WITH HVY RAINS JUST S OF MY FCST AREA...WITH MORE
STRATIFORM PCPN ACRS THE SRN PART OF MY FCST AREA.
00Z RUC CONT TO TRY TO SHIFT HVY PCPN ENE WITH TIME. HOWEVER...THIS JUST
DOESN/T SEEM TO BE HAPPENING YET. ONE FEATURE THAT COULD STILL MAKE THIS
HAPPEN IS SHRTWV SEEN ON WV IMAGERY LIFTING NE THROUGH WRN IA. ONLY
REPORTS OF ANY FLOODING THUS FAR ARE FROM WOOD COUNTY...AND THAT WAS
MINOR. HAVE COVERED THAT WITH URBAN AND SMALL STREAM FLOOD ADVISORY.
WITH THE GROUND AS WET AS IT IS IN CENTRAL WI...WILL HOLD ONTO WATCH
UNTIL I/M CERTAIN THAT RAINS WITH IA VORT ARE GOING TO REMAIN S OF THE
AREA.
PCPN HAS MOVED OUT OF N-C WI. ALTHOUGH RUC CONT TO TRY TO PUSH PCPN THIS
FAR N LATER TNGT...THERE IS LITTLE SUPPORT FOR THIS ON LATEST STLT AND
RADAR. WILL PULL PCPN FROM FAR N-C WI...AND BACK OFF TO CHC POPS ACRS
THE REST OF N-C WI.
UPDATED ZONES AND STATEMENT UPDATING THE WATCH WILL BE ISSUED SHORTLY.
.GRB...FLASH FLOOD WATCH TONIGHT
WIZ035>037-045-048-
SKOWRONSKI
WWW.CRH.NOAA.GOV/GRB
FXUS63 KMKX 210201 AMD wi
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
900 PM CDT TUE JUL 20 1999
FFW TO CONTINUE FOR MKX CWA.
12Z NGM LOOKS BETTER WITH QPF THAN ETA OR 18Z RUC. AVN NOT DOING
TOO BAD EITHER BUT AMOUNTS MAY BE ON THE LOW SIDE.
00Z ANAL SHOWS COPIOUS MOIST AT SFC THRU H8 LEVEL BEING
ADVECTED INTO SRN WI. SFC BOUNDARY ACROSS NRN IA THEN RUNNING SE
INTO NRN IL. IR IMAGERY SHOWS CONTINUED COOLING AND EXPANSION OF
COLDER TOPS INTO SW WI WITH STG MOISTURE CONVERGENCE/THETAE ADVECTION
NOTED TOO. KMKX 88-D IMAGERY PAINTING GOOD COVERAGE OF 40 TO 50 DBZ
RETURNS SAGGING INTO SRN WI.
MOST INTENSE CELL WEST OF DBQ LOOKS TO BE THE HOT AREA FOR SVR WX
THUS REMOVED THAT WORDING FOR MOST OF CWA. SPC DISCUSSION WILL DROP
WATCH AT 3Z SO CAN LET GO OF THAT WORDING IN OUR FAR SW CNTYS AT THAT
TIME.
LOWERED TEMPS A TOUCH TO ACCOUNT FOR PRESENT TRENDS.
.MKX...FLASH FLD WATCH TNGT ZONES 46..47..51..52..56>60..62>72.
COLLAR
FXUS63 KGRB 210056 wi
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
800 PM CDT TUE JUL 20 1999
FLASH FLOOD SITN CONT TO UNFOLD ACROSS THE RGN...BUT HEAVIEST RAINS THUS
FAR HAVE REMAINED S OF MY FCST AREA. AIR ACRS IA IS VERY MOIST AND
UNSTABLE AIR...WITH DWTS AOA 80F AND SFC-BASED LI/S BLO -10. 21Z RUC
PROGS THIS TO MV TOWARD THE AREA LATER TNGT. RUC PROGS MAX 850 MB MOIST
FLUX CONV TO MV THROUGH C/EC WI BTWN 06Z AND 09Z...ACCOMPANIED BY HVY
RAIN.
HOWEVER...I AM SOMEWHAT SKEPTICAL OF THIS BECAUSE LATEST SFC CHART
INDICATES THAT CONVECTION IN NRN IA HAS FORCED THE FRONT TO START MOVG
BACK TO THE SOUTH. THIS CONVECTION SHOULD CONTINUE TO INTERCEPT MUCH OF
THE INCOMING MOISTURE. WHILE HEAVIEST RAINS WILL BE SOUTH OF MY FCST
AREA...THERE IS CERTAINLY ENOUGH RISK OF FLOODING TO KEEP THE WATCH
GOING. ESPECIALLY SINCE THE SW CORNER OF MY FCST AREA IS VERY WET AFTER
SOME AREAS RECEIVED 3 INCHES OF RAIN 2 DAYS AGO.
.GRB...FLASH FLOOD WATCH TONIGHT
WIZ035>037-045-048-
SKOWRONSKI
WWW.CRH.NOAA.GOV/GRB
FXUS63 KARX 202033 wi
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO IL
241 AM CDT WED JUL 21 1999
CANCELLED FLASH FLOOD WATCH N IL AT 230 AM.
AT 07Z PRFILER SHOW 35-40 KT LOW LVL JET AT 925 MB FRM N KS TO
CNTRL IA FEEDING INTO TS OVER NE IA. AT 850 FLO DOWN TO 25 KT.
AT 06Z ALL MDLS SIMILIAR SHOWING WX VORT MAX IN MN WITH TAIL BACK
TO NE. THIS ALSO AIDING IA TS. 06Z RUC SHOWS STG VORTICITY PACKING
XTRM N IA INTO XTRM S WI THRU 15Z SO EXPECTE THE IA TS TO CONT MOV
MAINLY DUE E. BY 18Z RUC HAS VORTICTY CHANNEL OVER N IL AND FLO
LITTLE MORE NW SO SOME TS TO MOV ESE LTR . HOWEVER FLO AT 925 UP
BCMS MORE W DIMINISHING THE CONVERGENCE.
AT 06Z WK FRONT NR A LINE DAY-PIA-SUX TO SLOWLY DRIFT N TDY TO WI
BRDR THIS AFTN.
WITH FRONT IN AREA AND SOME S DRIFT TO VORTICITY CHANNEL WITH
CARRY SCT TS THRU DAY. EXPECT THE IA TS TO EVENTUALLY MOVE ESE AND
WEAKEN BUT EXPCT SCT TS TO DVLP VCNTY FRONT IN S PORTION CWA WHERE
WILL SEE MORE SUN TO HEAT THINGS UP. COULD NOT RULE OUT ERLY EVE
TS BUT WILL LV TNGT DRY AND MUGGY. HOTTER THU AND DRY.
.CHI...NONE
AF
FXUS63 KILX 210734 il
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
425 AM EDT WED JUL 21 1999
KAPX 88D SHOWING MCS REMNANTS REMAINING SOUTH OF US-10 EARLY THIS MORNING
WITH RAIN SOUTH OF AN LDM-MT PLEASANT LINE AND GENERALLY PROPAGATING OFF
TO THE EAST-SOUTHEAST. UPSTREAM...SCATTERED LIGHT SHOWERS HAVE BEEN
DEVELOPING OVER NORTHEAST WI IN AREA OF INCREASING ISENTROPIC LIFT OVER
PAST 3 HOURS. SOME RADAR ECHOES OVER NORTHERN LAKE MICHIGAN AND SOUTH
CENTRAL UPPER...BUT GIVEN DRY AIR IN PLACE OVER THE FORECAST AREA PER
00Z APX SOUNDING...UNLIKELY ANY OF THIS REACHING THE GROUND ATTM. RAIN
CHANCES TODAY AND THURSDAY IN INCREASINGLY WARM AND HUMID AIR MASS THE
FOCUS OF TODAY'S FORECAST.
MODELS ALL SHOWING SMALL DIFFERENCES REGARDING MOISTURE COVERAGE AND
DYNAMICS THIS FORECAST PERIOD...AND EACH PROG APPEARS TO HAVE ITS GOOD
AND BAD POINTS. BIGGEST DIFFERENCE FROM LAST NIGHT'S RUNS IS LACK OF
STRONG SHORT WAVE ENERGY CROSSING NORTHERN LOWER THIS AFTERNOON...THOUGH
SMALL VORTICITY MAX EVIDENT IN WV IMAGERY OVER SOUTHWEST WI WILL CROSS
SOUTHERN LOWER DURING THE AFTERNOON. ISENTROPIC LIFT OVER NORTHERN
WISCONSIN OCCURRING ALONG LEADING EDGE OF MOISTURE AXIS...AND THIS
PROGGED TO SLIDE INTO NORTHERN LOWER THIS MORNING. NGM/RUC BRING
MOISTURE FARTHER NORTH THAN THE ETA THIS MORNING...AT LEAST TO THE
STRAITS. CURRENT SATELLITE TRENDS SUPPORT THIS IDEA. MODEL 305/310K
ISENTROPIC PROGS INDICATE VEERING LOW AND MID LEVEL FLOW PUSHING BETTER
MOISTURE TO THE SOUTH DURING THE AFTERNOON IN CONJUNCTION WITH DECENT
LOW/MID LEVEL Q-VECTOR DIVERGENCE...A SITUATION SIMILAR TO THE ONE THAT
OCCURRED MONDAY. BIGGEST HURDLE TO RAIN TODAY WILL BE INITIAL DRYNESS
TO BE OVERCOME...NONE OF THE MODELS ARE KEEN ON INCREASING RH VALUES
AOB 850MB NORTH OF M-32. SO...CURRENT PLAN IS TO CONTINUE THE DRY
FORECAST FOR EASTERN UPPER AND CHARLEVOIX-EMMET-CHEBOYGAN-P.I.-ALPENA
COUNTIES IN FAR NORTHERN LOWER. WILL JUST MENTION SCATTERED SHOWERS
OVER THE REMAINDER OF NORTHERN LOWER...LACKING ELEVATED INSTABILITY TO
MENTION THUNDER. AS BEST LIFT AND MOISTURE INFLOW BECOMED FOCUSED ON
SOUTHERN LOWER THIS AFTERNOON...WILL END THE CHANCES FOR RAIN WITH SOME
CLEARING EXPECTED FROM NORTHWEST TO SOUTHEAST.
HAVE CONTINUED THE DRY FORECAST FOR TONIGHT ACROSS THE AREA...WITH LOW
TEMPERATURES REMAINING WELL INTO THE 60S. LIGHT WINDS AND HIGH DEW POINTS
MAY LEAD TO A LITTLE FOG DEVELOPMENT AS WELL. THURSDAY LOOKS TO BE WARM
AND HUMID...LOW LEVEL WINDS PROGGED TO BE A BIT STRONG FOR LAKE BREEZE
DEVELOPMENT OVER EASTERN UPPER AND THE HURON SIDE OF NORTHERN LOWER NORTH
OF APN. WEAKER 925MB WINDS SOUTH OF APN MAY ALLOW A LAKE BREEZE TO
DEVELOP...AND WITH MODIFIED MODEL SOUNDINGS FOR 88/68 YIELDING CAPES
NEAR 2500 J/KG WITH LITTLE CAP...HAVE ADDED A SMALL CHANCE POP FOR THE
AFTERNOON SOUTH OF APN. REST OF NORTHERN LOWER WILL KEEP DRY...KEPT IN
THE CHANCE FOR AFTERNOON THUNDERSTORMS OVER EASTERN UPPER IN CONCERT
WITH MQT FORECAST. STRONGER 850MB THETA-E ADVECTION PUNCHING ACROSS
UPPER MICHIGAN DURING THE AFTERNOON COULD KICK OFF SOME ACTIVITY LATE
IN THE DAY AND CONTINUING INTO THE EVENING. ETA PROGGING A RATHER
STRONG VORTICITY MAX AND ASSOCIATED QG FORCING INTO WESTERN UPPER BY
THURSDAY AFTERNOON...MAY BE A BIT OVERDONE. ALSO MADE SOME UPWARD
ADJUSTMENTS TO TEMPERATURES IN THE EXTENDED FORECAST FOR BOTH EASTERN
UPPER AND NORTHERN LOWER...WITH HUMID AIR MASS IN PLACE OVERNIGHT
LOWS LIKELY TO BE WELL INTO THE 60S TO NEAR 70 DEGREES. LATEST AVN
FORECASTING 850MB TEMPERATURES AROUND 20C ACROSS EASTERN UPPER ON
FRIDAY...WHICH WOULD PUSH HIGHS TO AROUND 90. FOR NOW HAVE NUDGED
FRIDAY'S HIGHS INTO THE MID TO UPPER 80S FOR EASTERN UPPER.
COORDINATED WITH MQT. ARBZFPAPX TO FLY BY 0830Z.
.APX...NONE.
JPB
FXUS63 KGRR 210817 mi
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
341 AM CDT WED JUL 21 1999
QUITE A FEW CONCERNS THIS FORECAST CYCLE RANGING FROM LOW CLOUDS/FOG
THIS MORNING TO SEVERE WX THURSDAY.
FRONTAL BOUNDARY REMAINS STATIONARY JUST SOUTH OF MN EARLY THIS
MORNING. THUNDERSTORM ACTIVITY CONTINUES TO DEVELOP ALONG THE FRONT
AND MOVE EAST JUST MISSING FAR SOUTHERN MN SO FAR. NEW THUNDERSTORM
COMPLEX HAS BEEN DEVELOPING OVER NW IOWA BETWEEN 07Z-08Z AND THIS MAY
BRUSH OUR FAR SOUTHERN TIER. 06Z RUC INDICATES THAT THE MID/UPPER
LEVEL FLOW WILL BE VEERING AND THIS IS ONE PLUS ON KEEPING THIS
ACTIVITY JUST SOUTH OF THE STATE THIS MORNING. SHORT WAVE CURRENTLY
OVER THE SOUTHERN MN WL ALSO BE SHIFTING EAST DURING THE MORNING.
FOG/STRATUS COVERING JUST ABOUT ALL OF THE CWA WITH THE MAIN LOW
CLOUD DECK ALONG AND SOUTH OF A RICE LAKE TO WILLMAR LINE. MODELS
PRETTY SIMILAR IN SHOWING A SMALL AREA OF HIGH PRESSURE MOVING OVER
CENTRAL MN THIS MORNING WITH GOOD DRYING AT H8 SPREADING SOUTH
ACROSS MUCH OF THE SOUTHERN CWA BY AFTERNOON. WILL HAVE SKIES
BECOMING PARTLY CLOUDY. HIGHS TODAY STILL LOOK ON TRACK FOR MID 80S
OVER THE NORTHERN WI CWA TO NEAR 90 SW CWA.
THE FORECAST CHALLENGE BEGINS TONIGHT. AS USUAL...THE ETA DEPARTS
FROM THE NGM AFTER 24 HOURS. THE ETA INTENSIFIES A VORT MAX OVER ND
BY 22/06Z WHERE AS THE NGM/AVN REMAIN FLAT. DPROG/DT ON THE ETA SHOWS
EXCELLENT CONSISTENCY WITH THE 20/12Z RUN SO THIS DEVELOPMENT TAKEN
SERIOUSLY. THUNDERSTORM COMPLEX SHOULD GET UNDER WAY OVER THE
NORTHERN HIGH PLAINS WEDNESDAY EVENING AND PUSH INTO NW MN BY
DAYBREAK THURSDAY. IT APPEAR A BOW ECHO WILL MOVE ACROSS NORTHERN MN
THURSDAY MORNING AND THIS SHOULD BRUSH THE NORTHERN CWA WITH
DAMAGING WINDS POSSIBLE.
QUITE IMPRESSIVE H8-H7 THETA-E ADVECTION AND H7 OMEGA FIELD DEVELOP
OVER CENTRAL AND EASTERN MN AND WESTERN WI DURING THURSDAY. SFC BASED
CAPE EXCEEDS 4000 J/KG WHILE 700-500 MB LAPSE RATES ARE STEEP AT 7.5
DEGREES C/KM. SOUNDING DATA SHOWS NICE VEERING PROFILE WHILE 700 MB
TEMPERATURES REMAIN NEAR 10 DEG C OVER EASTERN MN AND WESTERN WI
THRU THE DAY. WILL INCLUDE A CHANCE OF THUNDERSTORMS FOR THURSDAY
AFTERNOON FROM WESTERN WI THROUGH THE TWIN CITIES TO WILLMAR. SOME
OF THESE STORMS COULD BE SEVERE WITH DAMAGING WINDS AS WELL.
WILL MAKE A SMALL CHANGE TO THE EXTENDED AND ADD THUNDERSTORMS FOR
THURSDAY NIGHT OVER ALL BUT THE FAR SOUTHERN CWA AS ALL MODELS SHOW
A WEAK VORT LOBE MOVING IN FROM THE DAKOTAS. H8 THETA-E VALUES
APPROACHING 350 DEG K THURSDAY EVENING OVER THE WESTERN AND NORTHERN
CWA WITH K INDEX VALUES 35 TO 40!!
.MSP...NONE.
HILTBRAND
FXUS63 KDLH 210745 mn
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
231 AM EDT WED JUL 21 1999
ONE OR TWO THUNDERSTORMS OVER FORECAST AREA EARLIER TONIGHT
DISSIPATED SHORTLY AFTER MIDNIGHT ACROSS HORRY COUNTY. STILL SOME
LIGHT HAZE/FOG AROUND WITH TEMPERATURES NOT TOO FAR FROM 80 THIS LATE
INTO THE NIGHT IN MANY PLACES. SOLID VEIL OF CIRRUS WITH SCT MID
CLOUDS OVERHEAD AND JUST UPSTREAM.
LOOKS AS THOUGH H5 HIGH CENTERED ACROSS FAR WEST KENTUCKY EARLY THIS
MORNING. CONVECTION ROTATING AROUND THIS FEATURE IN RING OF FIRE
CONFIGURATION. UPSTREAM SHORT WAVE IN LINE TO AFFECT FORECAST AREA
THIS MORNING.
FRONTAL BOUNDARY HAS MOVED VERY LITTLE IN PAST 18 HRS. AIR MASS
CHANGE STILL WELL UP THE COAST (NORTH REACHES OF DELMARVA AREA).
SATELLITE COMBINED WITH STREAMLINE ANALYSIS INDICATING STRONG LOW
LEVEL CONVERGENCE AND UPPER DIFFLUENCE ALONG A BOUNDARY (PRE-FRONTAL
TROUGH) STRETCHING FROM ATLANTIC TO NORTH CAROLINA/SOUTH CAROLINA
LINE. CONVECTION BUILDING BACK IN FROM THE OCEAN TOWARD THE FORECAST
AREA. TOPS WARMING SLOWLY WITH THIS BUT STILL SOME LIGHTNING
ASSOCIATED WITH THIS. RUC INDICATES THIS FEATURE WILL PASS JUST SOUTH
OF AREA BUT INITIALIZED IT TOO FAR NORTH.
BELIEVE COLD FRONT WELL TO NORTH WILL BECOME INDISTINGUISHABLE
TODAY AND WILL HAVE LITTLE TO DO WITH ANY CONVECTION THIS FAR SOUTH.
MORE IMPORTANTLY HOWEVER WILL BE SHORT WAVES TOPPING WESTWARD
DRIFTING RIDGE AND DIVING SOUTHEAST IN NORTHWEST FLOW ALOFT WHICH
OVER NEXT SEVERAL DAYS WILL HELP TO CARVE OUT A PRETTY GOOD
TROUGH RIGHT ALONG EAST COAST. UPSTREAM SOUNDINGS SHOW A
SLIGHT COOLING IN MID LEVELS WHICH SHOULD DIMINISH CAP FOR TODAY.
MORE CLOUDS AND SCATTERED CONVECTION SHOULD HOLD DOWN TEMPERATURES A
FEW DEGREES FROM YESTERDAY AND WILL THUS NOT ISSUE ANY HEAT
ADVISORIES AT THIS TIME. NO CHANGE IN DEWPOINTS. WILL KEEP SCATTERED
COVERAGE OF CONVECTION TODAY THROUGH THURSDAY.
PRECIPITABLE WATERS ON THE ORDER OF 2 INCHES AND FLOW IS LIGHT AND
SO EXPECT ANY CONVECTION TO BE HEAVY RAIN MAKERS. WET BULB ZEROS
WELL OVER 13 KFT AND SO WOULD NOT EXPECT HAIL TO BE A CONCERN.
WIDESPREAD CONVECTION NOT ANTICIPATED AND SO WILL NOT ISSUE A
FLOOD WATCH WITH THIS PACKAGE.
CWF: SOUTHWEST WINDS OF AROUND 15 KTS AT TIME WITH 3 FOOT SEAS.
WEAK LOW LEVEL CIRCULATION ROTATES FROM W TO E AND INTO COASTAL
WATERS THROUGH THURSDAY. WIND SPEEDS SHOULD BECOME LIGHT AND
PRIMARILY FROM THE SOUTHWEST OR WEST WITH SEAS OF 2 TO 3 FT.
SMALL CRAFT ADVISORY CONDITIONS NOT EXPECTED.
PRELIMINARY CCF:
ILM BB 092/075 092/075 092 27333
FLO BB 092/073 092/073 092 27333
MYR BB 088/073 088/073 088 27333
.ILM...NONE.
DIGIORGI
FXUS62 KRAH 210210 nc
FORECAST DISCUSSION FOR EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
330 AM CDT WED JUL 21 1999
FCST CHALLENGE: PCPN EXTENT 2ND AND 3RD PERIOD.
MODEL SELECTION: ETA IS HANDLING SFC PRESSURE FIELDS BETTER THIS
MORNING THAN EITHER NGM OR AVN...WITH HIGHER PRESSURES OVER NRN MN
AFTER 06Z LEADING TO A CLOSED HIGH BUBLE OVER THE FGF CWFA. IN THE
UPPER LEVELS...ETA HOLDS A WEAK WAVE OVR WRN ND AT 12Z AND SLIGHT
RIDGING OVR NRN MN. THE 06Z RUC SEEMS TO FAVOR THIS IDEA AND HAS
DISSEMBLED THE WEAK VORT CENTERS BEST...IN THE DIFFLUENT FLOW OF ERN
MT/WY. SO WILL FAVOR THE ETA AND RUC SOLNS.
NEAR TERM: THOUGH SFC BASED INSTABILITIES REMAIN IN THE MODERATE
CATEGORY THIS MORNING ACROSS NERN ND AND THE NRN RRV...A STRONG CAP
HAS REDEVLOPED...WHICH MAY SHUNT ANY AM CONVECTION INTO SRN MAN.
HOWEVER...WILL CARRY ISOLD SHWRS ACROSS THESE ZONES. THE SFC HIGH
WEAKENS SLIGHTLY OVER NRN MN THIS AFTERNOON AND THE SOUTHERLY
MOISTURE FEEDS OPENS ALONG THE H8 THETAE RIDGE THROUGH CENTRAL ND.
MOST OF THE CWFA WILL SEE FAIR SKIES AND LIGHT SOUTH WINDS.
MID TERM: EXPECT DEEP CONVECTION FROM ERN MT INTO WRN ND THIS
EVENING...TO MOVE ACROSS NRN ZONES THROUGH THURSDAY...AS THETAE
RIDGE LEANS INTO THE RRV. WILL CARRY SCT POPS NRN ZONES 2ND AND 3RD
PERIODS...WIDELY SCT IN SRN ZONES. WILL CONTINUE WARMING TREND INTO
THUR WHILE STAYING FEW DEGREES BELOW MOS AS HAS BEEN CUSTOM.
EXTENDED: NO CHANGES HERE. NEW MRF KEEPS WITH TREND FOR STRONGER
WAVE IN NRLY FLOW BY SUNDAY. CURRENT PACKAGE SUGGESTS COOLING TEMPS
AND CHC PRECIP DAY5.
.FGF...NONE
GUST
FXUS63 KBIS 210824 nd
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
207 AM EDT WED JUL 21 1999
FOR THE SHORT TERM PERSISTENCE IS THE WAY TO GO WITH THE FORECAST.
DEEP ANTICYCLONE CENTERED OVER TN WL SLOWLY RETROGRESS THROUGH THE
PERIOD...WITH WEAK IMPULSES DROPPING DOWN THE E SIDE OF THE HIGH.
HOWEVER...NONE OF THE IMPULSES LOOK AS IF THEY WL AFFECT US. THE
FIRST SUCH S/W IS NOW CROSSING INTO SRN WI AND IS PROGGED BY THE
ETA/AVN TO CROSS THE NRN MID ATLANTIC THIS EVENING. WHILE A 30KT H5
JET IS CROSSING MD...WE CONTINUE W/WEAK NRLY FLOW. INFACT...THE S/W
MAY ACTUALLY STRENGTHEN THE RIDGE OVER US. LAPSE RATES ARE QUITE
SHALLOW OVER THE AREA AGAIN TDA...WITH NO OBVIOUS COLD TROUGHS.
HOWEVER...THERE WAS QUITE AN EXPLOSION OF CONVECTION OVER KY TUE...
VERY NEAR THE CENTER OF THE UPPER LEVEL RIDGE. I'M FAIRLY SURE THIS
WAS THE RESULT OF EXISTENT OUTFLOW BOUNDARIES AND A WEAK MCV FROM IA
CONVECTION THE DAY BEFORE. 03Z RUC SHOWS NO SIGNS OF SUCH A
CONVECTIVE VORT MAX W/THE KY CONVECTION...SO THAT IS OUT AS FAR AS
FORCING MECHANISMS GO.
THUS...WL GO W/THE EVER-PRESENT 30 POPS MTNS AND 20 POPS ELSEWHERE
AGAIN TDA. ONLY REAL CHANGE TO GOING FORECAST WL BE MORE OPTIMISTIC
CLOUD WORDING IN THE NRN MTNS.
LIFE GETS A LITTLE MORE INTERESTING ON THU AS HGHTS BEGIN TO FALL
OVER THE NE. AS A RESULT THE ETA SFC BNDRY FALLS INTO SRN VA
W/CONVERGENCE INCREASING SOME ALONG LEE TROUGH IN THE ERN CWA. OF
COURSE...CONSIDERING 03 SFC ANALYSIS SHOWS SFC LOW OVER ERN NC
(THERMAL LOW?) THIS ISN/T MUCH OF A CHANGE. AT ANY RATE...WL NOT
FOLLOW MODEL TREND OF LOWERING POPS...BUT KEEP THE THU POPS IN AS
THEY ARE IN THE PRESENT ZONES.
MRF SHOWS AIRMASS DRYING OUT QUITE A BIT SAT AND SUN. NOT SURE WHAT
TO DO ABOUT THIS AS RAH HAS NO POPS IN FOR THE WEEKEND WHILE WE AND
CAE DO. I THINK I/LL GO SOMETHING LIKE WIDELY SCATTERED AFTN AND
EVENING TSRA IN THE NC ZONES TO SPLIT THE DIFFERENCE.
CAEWRKGSP OUT AROUND 245 AM
PRELIMINARY NUMBERS:
AVL 86/66/87/66 323
CLT 92/71/93/72 213
GSP 94/70/94/71 213
.GSP...NONE.
MCAVOY
FXUS62 KGSP 210140 sc
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LUBBOCK TX
300 AM CDT WED JULY 21 1999
CYCLONIC CIRCULATION NEAR THE 300MB LEVEL HAS CAUSED SCATTERED
THUNDERSTORMS ACROSS THE FORECAST AREA THE PAST FEW DAYS. THIS
MORNING TWO AREAS OF CYCLONIC CIRCULATION CAN BE SEEN ON WATER VAPOR
IMAGERY. ONE AREA IS NEAR THE BIG BEND AND THE OTHER IS OVER
NORTHEAST TEXAS. MOST MODELS PICK UP ON THESE FEATURES IN THE
VORTICITY FIELD...THE TRACK OF THESE FEATURES IS STILL UNCERTAIN. IF
THE RUC CONTINUES ITS TRACK OF THE ONE OVER NORTHEAST TX...IT
APPEARS THAT CONVECTION COULD FIRE IN THE NORTHEAST COUNTIES THIS
AFTERNOON. THE ETA MOVES IT FARTHER NORTH INTO OKLAHOMA LATER
TODAY...IF THAT SCENARIO HAPPENS THEN RAIN CHANCES SHOULD DIMINISH
FOR THE NORTHEAST.
THE CIRCULATION OVER THE BIG BEND REMAINS SOMEWHAT STATIONARY. ON
THE NORTH AND EASTERN EDGE OF THIS CIRCULATION IS WHERE THE
CONVECTION THRIVED THE PAST COUPLE OF DAYS. WILL INCLUDE CHANCE OF
THUNDERSTORMS IN THE WEST AND NORTHEAST TODAY. TONIGHT...WILL KEEP
IN CHANCE FOR THE WEST AND SOUTHEAST.
WILL KEEP PERSISTENCE FORECAST WITH TEMPS AND A SLIGHT WARM UP
THROUGH THE EXTENDED.
PRELIMINARY NUMBERS
FRIONA 88/65/89/66 2211
TULIA 90/66/91/67 0101
CHILDRESS 95/71/96/72 21-1
BROWNFIELD 91/66/92/67 221-
LUBBOCK 90/68/92/69 1101
ASPERMONT 97/71/98/73 12-0
.LBB...NONE.
AC
FXUS64 KFWD 210757 tx
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
330 AM CDT WED JUL 21 1999
SFC FRONT THRU CENTRAL WISCONSIN AT 06Z WITH DEWPOINTS IN 50S AND 60S TO
THE NORTH AND 70S TO THE SOUTH. THIS BOUNDARY SEEMS TO HAVE MOVED SOUTH
THE LAST FEW HOURS AS SFC WAVE MOVES THRU AND CONVECTION NEAR BOUNDARY
GIVES IT A PUSH. LOTS OF MOISTURE IS BEING LIFTED OVER THE FRONT AND
PRODUCING LOW CLOUDS OVER MUCH OF OUR FCST AREA. 925MB AND 850MB
PROFILER WINDS AT 07Z SHOW SW FLOW BRINGING THE MOISTURE UP. 40KT 850MB
WINDS AT SLATER IOWA PROFILER HELPING TO KEEP TRW IN NORTHERN IOWA AND
SOUTHERN WI. MODELS BRING LOW LVL FLOW MORE WRLY ACROSS AREA THIS
AFTERNOON WHICH SHOULD PUSH MOST OF PCPN TO THE SOUTH TODAY. BUT IT MAY
KEEP GOING IN THE FAR SOUTH FOR GOOD PART OF THE DAY SOUTH OF MANITOWOC
AND OSHKOSH. TRICKY PART OF FCST IS CLOUD COVER AND IT/S EFFECT ON
TEMPS. CLOUDS KEPT MOST OF AREA IN THE 70S YESTERDAY DESPITE WARM 850MB
TEMPS. THIS MIGHT HAPPEN AGAIN TODAY. RUC AND 29KM ETA MODEL BOTH KEEP
LOW CLOUDS OVER ABT THE ERN 1/2 OR THIRD OF FCST AREA MOST OF THE DAY...
WHICH WOULD KEEP TEMPS 5 TO 10 DEGS COOLER THAN MOS GUIDANCE. SKIES IN
NRN ZONES SHOULD CLEAR TODAY...BUT SLIGHT CAA WILL KEEP THEM FROM
GETTING TO WHAT MODELS MIGHT FCST. SO WILL GO WITH RW ENDING TODAY FROM
THE NW WITH MOSTLY CLOUDY SKIES S OF A AUW TO MNM LINE. WILL GO SEVERAL
DEGREES COOLER THAN MOS GUIDANCE. SUBSIDENCE FCST TONIGHT BY MODELS...
EXCEPT FOR WEAK VORTICITY CENTER MOVING THRU THE NORTH. SEEING AS THERE
IS LOTS OF TRW ALONG SFC BOUNDARY THE PAST SEVERAL DAYS AND NIGHTS...
THINK THERE MIGHT BE SOME AGAIN TONIGHT WITH ANY KIND OF FORCING...SO
WILL PUT A CHANCE OF TRW IN SRN GROUP OF ZONES.
.GRB...NONE.
RDM
WWW.CRH.NOAA.GOV/GRB
FXUS63 KGRB 210431 wi
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
945 PM CDT TUE JUL 20 1999
IMPRESSIVE LINE OF TSTMS WITH HVY RAINS STRETCHED OUT ALONG FRONT ACRS
NRN IA. MORE SCT TSTMS WITH HVY RAINS JUST S OF MY FCST AREA...WITH MORE
STRATIFORM PCPN ACRS THE SRN PART OF MY FCST AREA.
00Z RUC CONT TO TRY TO SHIFT HVY PCPN ENE WITH TIME. HOWEVER...THIS JUST
DOESN/T SEEM TO BE HAPPENING YET. ONE FEATURE THAT COULD STILL MAKE THIS
HAPPEN IS SHRTWV SEEN ON WV IMAGERY LIFTING NE THROUGH WRN IA. ONLY
REPORTS OF ANY FLOODING THUS FAR ARE FROM WOOD COUNTY...AND THAT WAS
MINOR. HAVE COVERED THAT WITH URBAN AND SMALL STREAM FLOOD ADVISORY.
WITH THE GROUND AS WET AS IT IS IN CENTRAL WI...WILL HOLD ONTO WATCH
UNTIL I/M CERTAIN THAT RAINS WITH IA VORT ARE GOING TO REMAIN S OF THE
AREA.
PCPN HAS MOVED OUT OF N-C WI. ALTHOUGH RUC CONT TO TRY TO PUSH PCPN THIS
FAR N LATER TNGT...THERE IS LITTLE SUPPORT FOR THIS ON LATEST STLT AND
RADAR. WILL PULL PCPN FROM FAR N-C WI...AND BACK OFF TO CHC POPS ACRS
THE REST OF N-C WI.
UPDATED ZONES AND STATEMENT UPDATING THE WATCH WILL BE ISSUED SHORTLY.
.GRB...FLASH FLOOD WATCH TONIGHT
WIZ035>037-045-048-
SKOWRONSKI
WWW.CRH.NOAA.GOV/GRB
FXUS63 KMKX 210201 AMD wi
EXTREME SOUTHWESTERN CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
900 AM PDT WED JUL 21 1999
ONSHORE FLOW AND THE MARINE LAYER WILL CONTINUE AREAS OF NIGHT AND
MORNING COASTAL LOW CLOUDS AND FOG...EXTENDING LOCALLY INLAND.
OTHERWISE...DRY SOUTHWEST FLOW ALOFT WILL KEEP THE WEATHER FAIR.
GRADUAL WARMING TREND AS UPPER LEVEL HIGH PRESSURE BUILDS.
12Z NKX SOUNDING INDICATES THE MARINE LAYER DEPTH IS LITTLE CHANGED
FROM 12Z TUESDAY. RECENT PIREP OUT OF KSAN PUT THE TOPS OF THE
STRATUS AROUND 1800 FEET. STRATUS BURNED OFF MOST AREAS AFTER
SUNRISE BUT REMAINS NEAR THE COAST AND LOCALLY INLAND SOUTH SAN
DIEGO COUNTY AREA. NO EDDY IS APPARENT ON SATELLITE PHOTOS AND
NEITHER THE RUC OR THE MESO ETA MODEL SUPPORT AN EDDY TODAY.
NEW 12Z ETA IS SIMILAR TO THE EARLIER RUNS OF THE AVN/MRF IN SLOWLY
RETROGRADING THE HIGH OVER THE SOUTHERN PLAINS WEST TO NEAR FOUR
CORNERS BY 36 HOURS AS THE S/WV TROUGH OVER THE PACIFIC NORTHWEST
LIFTS NORTHEAST IN RESPONSE TO ANOTHER S/WV DEVELOPING INTO A CUT
OFF LOW WEST OF THE CENTRAL CALIFORNIA COAST. PATTERN KEEPS SOUTHERN
CALIFORNIA UNDER A DRY SOUTHWEST FLOW ALOFT THROUGH THE PERIOD.
RISING HEIGHTS SHOULD LOWER THE MARINE LAYER SOMEWHAT WITH A LITTLE
EARLIER CLEARING ALONG THE COAST. RISING THICKNESS SHOULD BRING SOME
WARMING TO MOST AREAS INCLUDING THE COAST.
MRF KEEPS THE SOUTHWEST RIDGE IN PLACE THROUGH 240 HOURS. THE MRF
700 MB MOISTURE FIELD LOOP INDICATES THE MONSOONAL MOISTURE REMAINS
SOUTH AND EAST OF THE AREA THROUGH THE PERIOD. WILL HAVE TO WAIT AND
SEE. POSITION OF THE HIGH CENTER BASED ON THE MRF IS FAR ENOUGH
NORTH THAT SOME INCREASE IN MOISTURE CAN BE EXPECTED THROUGH THE
PERIOD.
EXPECT BETTER CLEARING NEAR THE COAST THAN THE CURRENT FORECAST
INDICATES SO WILL DO AN UPDATE.
SAN 000
.SAN...NONE.
HORTON
FXUS66 KEKA 211539 ca
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE/WASHINGTON
1015 AM EDT WED JUL 21 1999
KLWX 88D SHWS SHRA EXITING AREA TO THE SE. NXT AREA OF ALREADY
ESTABLISHED ACTVTY TO WATCH WUD BE MCS OVR NW OHIO/LERI...AND NEW
CELLS FIRING AHD OF COMPLEX. LWX/RNK SNDG DO NOT SHW GRT LAPSE
RATES...PBZ HAS A LTL POTL H10-8. FRTHR...EXISTING CIGS SHUD BE
REPLACED BY CI BLOWOFF FM NW...THUS PREVENTING HTG/ADDTL
DESTABILIZATION. RUC HAS VORT VA/WVA LN TRACKING TO THE SE...TO
VCNTY RDU BY 21Z...AND ACTUALLY A LTL NVA ACRS CWFA. 03Z ETA PAINTS
SIMLR SCENE...WITH THE VORT CLSR TO NC CST. EITHER WAY...DO NOT SEE
TRIGGER FOR AFTN STORMS...ASIDE FM ACTVTY ADVECTING IN FM GRTLKS.
MODIFIED SNDGS DO NOT SHW ALARMING CONVCTV POTL. GRANTED ANY
MIDDAY/AFTN SUNSHN BFR THICK CS CANOPY ARRIVES FM W CUD SPAWN A
STORM OR TWO...AND IT WUD BE A DECENT RAINER. WL INCR CLDS FOR SKED
UPDT AND AS A RSLT WIDEN TEMP RNG DWNWD. WL ALSO LWR PCPN CHC ONE
NOTCH...WHICH WL MEAN A SLGT CHC METRO DC/BALT AND ERN HLF OF FA.
PRODUCTS TO BE RLSD BTWN 1030-1045.
.LWX...NONE.
HTS
FXUS61 KLWX 210627 md
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
1110 AM EDT WED JUL 21 1999
KAPX 88D SHOWING AREA OF -RA OVER NORTHERN LAKE MICHIGAN MOVING EAST
INTO ANTRIM AND CHARLEVOIX COUNTIES. THIS IS IN RESPONSE TO A WEAK MAX
AND H8 DEWPOINT BOUNDARY MOVING THROUGH NORTHERN MICHIGAN. THIS WILL
CONTINUE TO SINK SOUTH DURING THE MORNING. LOOKS THIS WILL BE MAINLY A
FEW SPRINKLES JUST SOUTH OF THE STRAITS AS RUC SOUNDINGS SHOW DRY AIR
IN THE MID LEVELS. EXPECT CLOUDS TO MOVE OUT DURING THE AFTERNOON AS H5
RIDGE BEGINS TO BUILD IN. FARTHER SOUTH...REMANTS OF LAST NIGHT/S MCS
CONTINUING TO MOVE SSEWD ALONG BOUNDARY. WILL GO WITH SCATTERED SHOWERS
IN THE SOUTHEAST PART OF CWFA WITH PARTIAL CLEARING LATER.
ELSEWHERE...EXPECT SKY TO BECOME PARTLY SUNNY IN NORTHERN LOWER
MICHIGAN AS THE PRECIP AREAS CONTINUE EASTWARD TRACK AND SUBSIDENCE TO
BREAK UP THE CLOUDS SOME. CLOUDS FROM THESE SYSTEMS WILL STAY FOR THE
MOST PART SOUTH OF THE STRAITS SO WILL GO MOSTLY SUNNY IN THE UP.
.APX...NONE.
JSL/SWR
FXUS63 KMQT 211508 mi
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
1107 AM EDT WED JUL 21 1999
A FEW CHGS TO GOING FCSTS BASED ON CURRENT TRENDS AND 12Z RUC. STL
QUITE A BIT OF SUNSINE ROUGHLY N OF A LINE FM IWD TO ISQ. LYRD
CLDS S OF THIS LINE XTND BACK TO CVR MOST OF WI AND A PART OF
SRN MN. WAVY STNRY BNDRY IN THIS AREA PROVIDING THE LOW LVL
CNVRGC W/ A WEAK WAVE NOTED BY MSAS NR GRB HELPING TO HOLD CLDS
IN AS WELL.
A FEW BREAKS IN THE CLDS...HOWEVER SFC DWPTS ARE QUITE HIGH. SOME OF
THE BREAKS WILL REFILL. 12Z RUC DOES SHOW 1000-700 MB MSTR TO BE
DCRSG DURG THE AFTN...SUPPRESSED TOWARD THE S. WL KEEP LAKESHORE
AREAS OF SRN CNTYS CLOUDIEST...AND TRY TO ACCOMODATE SOME SML
INCREASE IN SUNSHINE ELSEWHERE.
FURTHER TO THE N...CU SHD BEGIN TO DVLP SHORTLY AND ONSHORE BREEZES
WL PROVIDE THE LOW LVL CNVRGNC NECESSARY FOR SCTD TSTMS. CHCS BEST
IN THE NW CNTYS WHERE DWPTS WL BE THE HIEST. FIGHTING AGNST THE
TSTMS IS A PROGGED INCRS IN TEMPS IN THE LOWEST PORTION OF THE ATM
...W/ NEG AREAS FAIRLY LRG ON BUFKIT SOUNDINGS. ALSO...Q/VEC
CNVRGC ASSOC W/ ND STORMS MAY PASS FARTHER TO THE N THAN PVSLY
THOT...REMOVING ONE DYNAMICAL FACTOR. STL...WL LEAVE SML CHC POPS AS
CAPE PROGGED TO BE AOA 1100 BY LATE AFTN.
WL NUDGE TEMPS ACCORDING TO CLD FCST.
.MQT...NONE.
DESROSIERS
FXUS63 KMQT 210815 mi
AREA FORECAST DISCUSSION...CORRECTED TEXT IN THE CWF SECTION
NATIONAL WEATHER SERVICE WILMINGTON NC
1010 AM EDT WED JUL 21 1999
HOT AND HUMID CONDITIONS ALONG W/ AREAS OF HAZE PERSIST ACROSS THE
REGION W/ DEWPOINTS IN THE 70S ACROSS THE CAROLINAS. UPPER HIGH
CONTINUES TO DOMINATE MUCH OF THE NATION W/ THE REGION POSITIONED
ON ITS ERN PERIPHERY. AT THE SURFACE...A PRESSURE TROF ORIENTED
NEARLY E-W ACROSS ERN NC IS WHAT IS LEFT OF VERY DIFFUSE FRONT.
SURFACE CONVERGENCE...PER MSAS...IS HIGHEST ACROSS THE OUTER
BANKS/SOUNDS THIS MORNING THOUGH A SHIFT TO THE S DURING THE
AFTERNOON IS PROBABLE. IN FACT...THE LATEST RUC PEGS LOW LEVEL
CONVERGENCE ACROSS THE ERN ILM CWFA THIS AFTERNOON/EVENING AND
GIVEN INCREASING INSTABILITY AND DECENT CAPES A CONTINUED CHANCE OF
SHRA/TSRA INTO THIS AFTERNOON LOOKS GOOD. PWS 2.36 AT CHS AND K
INDICES RANGE IN THE M-U 30S FROM MHX TO CHS SO EXPECT ANY TSRA
THAT GET GOING TO PRODUCE A GOOD SHOT OF HEAVY RAFL.
TEMPERATURES ARE STARTING TO TAKE-OFF AND SHOULD END UP IN THE BALL
PARK IF NOT EXCEED CURRENT FORECAST NUMBERS BY A CATEGORY. ALTHOUGH
SCT CLOUDS AND TSRA ARE ANTICIPATED TO COUNTER TEMPERATURES LATER
TODAY...DURING THE INTERIM SOME AREAS MAY APPROACH HEAT ADVISORY
LEVELS. WILL CONTINUE TO MONITOR AND MAY EVENTUALLY HAVE TO ISSUE A
HEAT ADVISORY...WILL SEE HOW THINGS TRANSPIRE OVER THE NEXT COUPLE
OF HOURS.
CWF: W TO SW FLOW CONTINUES ACROSS THE COASTAL WATERS. WILL
CONTINUE TO ADVERTISE WINDS BECOMING VRBL FOR THE NC WATERS WHILE
W FLOW SHOULD CONTINUE SRN WATERS.
.ILM...NONE.
PFAFF
FXUS62 KMHX 211357 nc
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
1027 AM EDT WED JUL 21 1999
DISC: 13Z SFC ANALYSIS SHOWS TO OUR N AND NE OVR NC WITH HI PRES ALNG
THE GULF CST.
SATELLITE SHOWS JUST A FEW CLDS OVR THE STATE...BUT MOST AREAS ARE SUNNY
WITH QUITE A BIT OF HAZE. NOT A REAL BIG CHANGE IN AIRMASS TO THE N OF
THE BNDRY OVR VA...AS TDS ARE STILL IN THE UPR 60S TO LWR 70S. UPR HI
CENTERED OVR WRN KY/SRN IL THIS MORNING WITH SYS MOVG ARND HI. MORNING
RUN OF THE RUC PRETTY CLOSE TO LAST NIGHTS ETA RUN. ONLY SLIGHT
DIFFERENCE IN POSITION OF UPR HI...RUC A BIT FARTHER TO THE N AND W THAN
00Z ETA RUN...BUT SFC FEATURES VERY SIMILIAR. WITH TEMPS ALREADY IN THE
LWR TO MID 80S THIS MORNING...CLOSE TO OUR JUST ABOVE TUE MORNING
TEMPS...COMBINED WITH TDS IN THE LWR TO MID 70S WL CONT WITH HEAT ADV
FOR THE AFT. AS FAR AS CHC FOR PCPN...RUC KEEPS THE BEST MOISTURE
CONVERGENCE OVR THE UPSTATE/MTS AND CLOSER TO THE BNDRY OVR THE PEE DEE
REGION. THINK AN ISOLATED AFT TSRA/SHRA IS POSSIBLE ANYWHERE WITH HOT
TEMPS AND SUFFICIENT LOW LVL MOISTURE...BUT BEST CHCS WL BE ACRS THE
UPSTATE AND PEE DEE AREAS. CHS RAOB SHOWING PRECIP WATER BETTER THAN 2
IN. WITH LIKELY SLOW STORM MOVEMENT...SO SOMEONE COULD GET A GOOD
SOAKING. WL ADD THE REMAINDER OF THE MIDLANDS TO THE HEAT ADVISORY FOR
THE AFT. LOOKING AT MAX TEMPS FROM TUE...MANY LOCATIONS WERE JUST AS HOT
ACRS THE NRN MIDLANDS AS THE CNTRL AND SRN MILDANDS AND CSRA.
.CAE...HEAT ADVISORY THIS AFTERNOON SCZ015-016-018-020>022-
025>031-035>038-041.
HEAT ADVISORY THIS AFTERNOON GAZ040-063>065-077.
LCV
FXUS62 KGSP 211421 sc
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1021 AM EDT WED JUL 21 1999
RUC SHOWING VORTICITY MAX OVER SOUTHERN PORTION OF THE AREA WITH
ANOTHER MOVING SOUTHEAST INTO THE EASTERN CAROLINA LATER TODAY AND
TONIGHT. LEE SIDE TROF THAT HAS BEEN ACROSS PIEDMONT THE PAST
SEVERAL DAYS HAS BECOME ORIENTED EAST-WEST ACROSS THE SOUTHERN PART
OF THIS CWFA.
WILL MAINTAIN SMALL CHANCE FOR AFTN TSTMS DUE TO GOOD INSTABILITY...
SOME DIVERGENCE ALOFT AND WEAK OMEGA UPLIFT VARYING AROUND THE AREA BUT
THINK COVERAGE PROBABLY A BIT LESS THAN YDA. ACTIVITY SHOULD BE OVER
LITTLE QUICKER ALSO AS HELP FROM DIVERGENCE ALOFT AND OMEGA UPLIFT
LESSEN BY LATE AFTERNOON.
TEMPS WILL REMAIN ON THE WARM SIDE.
.GSP...NONE.
RBN
FXUS62 KCAE 211420 sc
WESTERN COLORADO & EASTERN UTAH AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
224 PM MDT WED JUL 21 1999
TSTMS HELD OFF UNTIL 1 PM THIS AFTERNOON AND HAVE BEEN OROGRAPHIC
DRIVEN THUS FAR. WEAK SPEED MAX PROGGED BY NGM AND ETA TO MOVE THRU
CWA AROUND 00Z WILL PROVIDE A SMALL AMOUNT OF DYNAMIC LIFT WHICH
SHOULD HELP MOVE SOME OF THE STORMS OFF THE HILLS FROM AROUND SUNSET
AND FOR A FEW HOURS THEREAFTER. ONLY RUC RESOLVES A VERY MINOR VORT
MAX BENEATH THIS SPEED MAXIMA. PRECIPITABLE WATER ON GJT 12Z
SOUNDING WAS AS FORECAST BY YESTERDAY'S MODELS...LESS THAN .75 OF AN
INCH AND INCREASING TO ABOUT 1.0 INCH AROUND THE 4-CRNRS AND 1.25
INCH SOUTH TO SRN AZ/NM...THIS MATCHES GOES SOUNDINGS. WITH PWS AT
THIS LEVEL BRIEF HEAVY RAIN IS POSSIBLE. WV IMAGERY SHOWS MONSOON
MOISTURE PLUME BULGED WESTWARD OVERNIGHT INTO SRN UT AND NRN AZ.
COULD NOT LOCATE THE SOURCES OF THIS PUSH...BUT CAN'T IGNOR THE FACT
THAT IT IS THERE...EVEN IF THE MODELS HAVE. THUS WILL KEEP THE HIGHER
POPS FOR THIS EVENING...ACCOUNTING FOR THE DYNAMIC HELP PROVIDED BY
THE UPWARD FORCING FROM THE SPEED MAX.
THURSDAY LOOKS THE MONSOON PLUME WILL STAY IN PLACE WITH FORECAST
PW VALUES AT 0.80 INCHES OR HIGHER OVER MUCH OF CWA...BUT NOTHING
DYNAMIC TO ASSIST THE CONVECTION...AT LEAST NOTHING RESOLVED BY THE
MODELS NOR EVIDENT IN SATELLITE IMAGES. WILL KEEP THE CURRENT
CATEGORIES OF POPS.
MRF DOESN'T SHOW MUCH CHANGE FROM PREVIOUS RUNS...AS MIDWEST
RIDGES RETROS WEST ATTEMPTING TO CUT OFF MONSOON FLOW. STILL NOT
CONVINCED OF THIS DRYING TREND AND WILL STAY WITH CHC PCPN AS LOW
OF WEST COAST IN DOESN'T MOVE MUCH PROVIDING SWLY GRADIENT THAT
OUGHT TO CARRY MOISTURE BACK INTO THE AREA EVEN IF IT DOES SLIDE
WEST. CUOCO
.GJT...NONE.
FXUS65 KPUB 211936 co
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
400 PM EDT WED JUL 21 1999
RATHER CONVOLUTED PATTERN AFFECTING THE FORECAST AREA LATE THIS
AFTERNOON. WEAK SURFACE WAVE ALONG POORLY ORGANIZED WEST-EAST
STATIONARY FRONT WAS LOCATED OVER CENTRAL LAKE MICHIGAN AT 19Z. THE
ETA/RUC GRADUALLY WEAKEN THIS FEATURE WHILE MOVING IT OFF TO THE SE THIS
EVENING. REMAINING LIGHT SHOWERS WILL MOVE OFF SHORE INTO LAKE HURON BY
EARLY EVENING. SATELLITE SHOWS RATHER EXTENSIVE CLOUD COVER ACROSS
NORTHERN LOWER -- BACK ACROSS NORTHERN WI. RECENT TRENDS HAVE SHOWN SOME
THINNING OF THESE CLOUDS...WITH THE LOWER CLOUDS BECOMING PROGRESSIVELY
MORE CONVECTIVE LOOKING. SKIES WILL BECOME PARTLY CLOUDY FROM NW TO SE
THIS EVENING ACROSS NORTHERN LOWER WITH INCREASING LOW LEVEL
DIVERGENCE...WHILE EASTERN UPPER REMAINS MOSTLY CLEAR. WITH LIGHT
WINDS...ELEVATED DEW POINTS...RECENT RAINFALL...AND LIMITED DIURNAL
HEATING...EXPECT FOG TO FORM OVERNIGHT AS SKIES BECOME PARTLY CLOUDY.
DENSEST FOG IS EXPECTED SOUTH OF TVC-APN.
FORECAST CONCERNS BEYOND TONIGHT INCLUDE TEMPERATURES AND CHANCES FOR
CONVECTION. MODELS ALL SHARPEN 850/500 MB RIDGING ACROSS THE AREA ON
THURSDAY...AS 850 MB TEMPERATURES WARM TO AROUND 20C. THIS WILL RESULT
IN WARMER TEMPERATURES...ALONG WITH SOME DIURNAL CU. MIXING THROUGH
850 MB SHOULD YIELD MID/UPPER 80S FOR EASTERN UPPER...WITH 85-90 FOR
NORTHERN LOWER. THOUGH LARGE SCALE FORCING FOR CONVECTION WILL BE
NEGLIGIBLE...LIKE THE GOING FORECAST THINKING WHICH INCLUDES A RISK OF
LAKE-BREEZE INDUCED CONVECTION OVER EASTERN UPPER AND NEAR LAKE HURON S
OF APN AFTER 18Z ON THURSDAY. OTHERWISE...HEAT AND HUMIDITY WILL RULE.
WILL CONTINUE A CHANCE OF THUNDERSTORMS FOR EASTERN UPPER THURSDAY
NIGHT...CONSIDERING THE PROSPECTS FOR A SCATTERED DIURNAL STORM TO
LINGER INTO THE EVENING...ALONG WITH WHAT APPEARS TO BE SOME QG FORCING
MOVING ACROSS THE LAKE SUPERIOR REGION LATE IN THE NIGHT. THIS MAY
BRING AN MCS IN FROM THE WEST.
WITH THE HIGH SLIPPING OFF TO THE EAST ON FRIDAY AND AN INCREASING SW
FLOW DEVELOPING...HAVE ADDED A SMALL CHANCE FOR CONVECTION TO ALL AREAS
FRIDAY. LOW LEVEL SUPPORT MAY BE WEAK UNTIL THE FRONT DRAWS NEARER LATE
IN THE DAY ON FRIDAY.
EXTENDED DISCUSSION...SAME STORY -- DIFFERENT DAY. MEDIUM RANGE
MODELS CONTINUE TO ADVERTISE WARMTH AND HUMIDITY ACROSS THE FORECAST
AREA THROUGH THE UPCOMING WEEKEND IN ASSOCIATION WITH UPPER RIDGING
ACROSS THE CENTRAL U.S.. THE MRF/ECMWF ARE THE FASTEST MOVING THE
FIRST SURFACE BOUNDARY THROUGH THE AREA BY 12Z SATURDAY...WHILE THE
CANADIAN MODEL IS A BIT SLOWER. THE SLOWER SOLUTION APPEARS MORE
CONSISTENT WITH THIS MORNING/S 12Z MODEL RUNS. AS A RESULT...WILL
CARRY A RISK OF THUNDERSTORMS AREAWIDE FRIDAY NIGHT AND ONLY ACROSS
NORTHERN LOWER INTO EARLY SATURDAY. EXPECT RIDGING ACROSS THE LOWER
LAKES TO KEEP THE AREA DRY ON SUNDAY...THOUGH WE/LL HAVE TO WATCH FOR A
POSSIBLE MCS TO MOVE IN FROM THE WEST LATE -- ESPECIALLY OVER EASTERN
UPPER. FOR MONDAY...THE MODELS ARE GENERALLY SIMILAR IN INCREASING LOW
LEVEL INFLOW AS SURFACE BOUNDARY APPROACHES -- SO WILL HAVE ANOTHER
CHANCE FOR CONVECTION. TEMPERATURES WILL CONTINUE ABOVE NORMAL THROUGH THE
PERIOD -- WITH SUNDAY LIKELY THE WARMEST OF THE DAYS IN BETWEEN SYSTEMS.
.APX...NONE.
SMITH
FXUS63 KDTX 211951 mi
AREA FORECAST DISCUSSION...CORRECTION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
335 PM EDT WED JUL 21 1999
LITTLE CHANGE IN OVERALL PATTERN THIS FORECAST PERIOD...BUT MODELS
LEANING TO EVEN LESS AFTERNOON AND EARLY EVENING SHOWER AND THUNDERSTORM
ACTIVITY... AS A BIT WARMER AIR ALOFT WORKS IN BY FRIDAY AM AT 700
MB AND 500 MB. THE WARMER AIR ALOFT SHOULD LESSEN LAPSE RATES AND
INSTABILITY MAKING IT HARDER FOR THUNDERSTORMS TO DEVELOP. ALSO MODELS
ARE INDICATING WEAKER LOW LEVEL MOISTURE CONVERGENCE WITH LEE SIDE TROF
LESS EVIDENT THAN IT HAS BEEN THIS PAST WEEK.
WE SHOULD SEE LESS MID AND UPPER LEVEL MOISTURE THURSDAY AFTERNOON
THROUGH THE WEEKEND AS THE BLOW OFF FROM THUNDERSTORMS THAT FORM IN
THE MIDWEST...OHIO VALLEY AND MID ATLANTIC MOVE EAST OF THIS CWFA.
WITH FEWER SHOWERS AND CLOUDS...TEMPS SHOULD WARM A COUPLE DEGREES
HIGHER THROUGH THIS FORECAST PERIOD.
FOR SHORT TERM...ISOLATED TO WIDELY SCATTERED SHOWERS AND A FEW
THUNDERSTORMS HAVE FORMED...MOSTLY ALONG THE EASTERN ESCARPMENT OF
THE MOUNTAINS. LATEST RUC SHOWING GOOD MOISTURE CONVERGENCE INTO THE
EVENING TO HELP A FEW STORMS DEVELOP. SO FAR THE STORMS HAVE NOT
DEVELOPED TO BIG...BUT WITH PRECIPITABLE WATER VALUES QUITE
HIGH...THERE COULD BE SOME VERY LOCALIZED HEAVY RAIN FROM A FEW OF
THESE THIS AFTERNOON. ANY HAIL SHOULD HAVE A HARD TIME MAKING IT TO
THE GROUND WITH FREEZING LEVELS UP NEAR 15 THOUSAND FEET.
PRELIMINARY CCF...
AVL...67/88/67/88 2/2/1/1
CLT...73/93/74/94 2/2/1/1
GSP...73/94/73/94 2/2/1/1
.GSP...NONE.
RBN
FXUS62 KGSP 211934 sc
AREA FORECAST DISCUSSION
335 PM EDT WED JUL 21 1999
LITTLE CHANGE IN OVERALL PATTERN THIS FORECAST PERIOD...BUT MODELS
LEANING TO EVEN LESS AFTERNOON AND EARLY EVENING SHOWER AND THUNDERSTORM
ACTIVITY... AS A BIT WARMER AIR ALOFT WORKS IN BY FRIDAY AM AT 700
MB AND 500 MB. THE WARMER AIR ALOFT SHOULD LESSEN LAPSE RATES AND
INSTABILITY MAKING IT HARDER FOR THUNDERSTORMS TO DEVELOP. ALSO MODELS
ARE INDICATING WEAKER LOW LEVEL MOISTURE CONVERGENCE WITH LEE SIDE TROF
LESS EVIDENT THAN IT HAS BEEN THIS PAST WEEK.
WE SHOULD SEE LESS MID AND UPPER LEVEL MOISTURE THURSDAY AFTERNOON
THROUGH THE WEEKEND AS THE BLOW OFF FROM THUNDERSTORMS THAT FORM IN
THE MIDWEST...OHIO VALLEY AND MID ATLANTIC MOVE EAST OF THIS CWFA.
WITH FEWER SHOWERS AND CLOUDS...TEMPS SHOULD WARM A COUPLE DEGREES
HIGHER THROUGH THIS FORECAST PERIOD.
FOR SHORT TERM...ISOLATED TO WIDELY SCATTERED SHOWERS AND A FEW
THUNDERSTORMS HAVE FORMED...MOSTLY ALONG THE EASTERN ESCARPMENT OF
THE MOUNTAINS. LATEST RUC SHOWING GOOD MOISTURE CONVERGENCE INTO THE
EVENING TO HELP A FEW STORMS DEVELOP. SO FAR THE STORMS HAVE NOT
DEVELOPED TO BIG...BUT WITH PRECIPITABLE WATER VALUES QUITE
HIGH...THERE COULD BE SOME VERY LOCALIZED HEAVY RAIN FROM A FEW OF
THESE THIS AFTERNOON. ANY HAIL SHOULD HAVE A HARD TIME MAKING IT TO
THE GROUND WITH FREEZING LEVELS UP NEAR 15 THOUSAND FEET.
PRELIMINARY CCF...
AVL...67/88/67/88 2/2/1/1
CLT...73/93/74/94 2/2/1/1
GSP...73/94/73/94 2/2/1/1
.GSP...NONE.
RBN
FXUS62 KCHS 211931 sc