AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSONVILLE FL
128 PM EDT THU JUL 22 1999
SHORT TERM...UPPER RIDGE RETROGRADE WITH SOME LIFT AND TROUGHING
ALONG THE EAST COAST...SURFACE TROUGHING COUPLES WITH DIURNAL THERMAL
TROUGHING TO SHARPEN TROUGH AXIS FROM SE GA TO NEAR TLH. 15Z RUC
AND 12Z AVN MODELS DEVELOP LOW IN SOUTH CENTRAL GA OVERNIGHT...ETA
BUILDS IT FURTHER SOUTH AND WEAKER. LOOKS LIKE GOOD CHANCE OR BETTER
OF RAIN FOR BOTH FL AND GA CWA THIS EVENING AND OVERNIGHT. AMOUNTS
FROM QUARTER TO HALF INCH WIDESPREAD...WITH HEAVY RAIN UNDER A FEW
SLOW MOVING THUNDERSTORMS MOSTLY IN SOUTHERN END OF FL CWA...FOCUS
NEAR A LINE FROM ST AUGUSTINE TO PALATKA TO OCALA.
ETA AND NGM ARE NOW INDICATING LOW WIND SPEEDS FOR TOMORROW...AND
IT MATCHES WELL WITH SUBSIDENCE ROTATING SOUTH FROM MID ATLANTIC.
IF THIS ALL MATCHES UP MID DAY TOMORROW WE WILL BAKE...UPPER 90S.
GIVEN CURRENT LOW LEVEL MOISTURE AND TODAYS AM TEMPS OF 80 ALONG THE
COAST...A HEAT ADVISORY MAY BE IN ORDER FOR TOMORROW.
FRIDAY...ANOTHER HOT AFTERNOON. TEMPS IN MID 90S IN COASTAL SECTIONS
BUT VERY HOT INTERIOR...UPPER 90S. POPS ON FRIDAY BELOW
CLIMATOLOGICAL NORMALS.
MARINE...WINDS AND SEAS LIGHTER THAN PROGGED ACROSS THE AREA TODAY...
AND MODELS CONVERGING TO THAT SOLUTION FOR TOMORROW AS WELL.
WIND BECOMING 5 TO POSSIBLY 10 SOUTHWEST TONIGHT AND FRIDAY AFTER
TROUGH SHIFTS WESTWARD. OTHERWISE NO SIGNIFICANT CHANGES TO PACKAGE.
SORRY ABOUT THE NUMBERS...
AMG 75/97/73/95 3432
SSI 75/95/74/93 5333
JAX 75/98/75/95 6433
GNV 74/95/73/94 4533 13
WELSH
FXUS62 KJAX 221720 fl
AREA FORECAST DISCUSSION...CORRECTION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
1035 AM EDT THU JUL 22 1999
LATEST RUC ANALYSIS/H20 VAPOR LOOPS SHOWED LARGE UPPER HIGH CENTERED
OVER WRN TN VALLEY W/ REMNANTS OF CAROLINAS MVC DROPPING SWD OFF SC
COAST. 14Z LAPS/LAMP SURFACE ANALYSIS SHOWED NE-SW ORIENTED TROUGH
AXIS FROM E CAROLINA COAST INTO EXT SE GA. HIEST DEWPOINTS (75-80
DEG)/MOST UNSTABLE AIR (LI/S -5 TO -7) POOLED ALONG/E OF THIS
FEATURE...AS WELL AS OVER OFFSHORE WTRS BTWN CDR KEY AND TPA. AREA
VAD WIND PROFILES AND STREAMLINE ANALYSIS INDICATED 10-15 KT N-NWLY
OFFSHORE BOUNDARY LAYER FLOW...TYPICAL OF A TYPE 9 REGIME WHERE THE
PANHANDLE/BIG BEND SEA BREEZES REMAIN CLOSER TO THE COAST. 12Z TLH
RAOB PWAT A HALF-INCH WETTER THAN 24 HRS AGO (1.81 INCHES). MODIFIED
SOUNDING FOR MAX T/TD OF 96/72 YIELDED 5000+ J/KG CAPE...-9 LI...K
30 AND TOTALS 44.
MODEL RUNS STILL ADVERTISING SLOW WWD RETROGRESSION OF UPPER HIGH
INTO SCNTRL PLAINS NEXT 24 TO 36 HRS...WHICH WOULD IMPROVE CHANCES
OF WEAK IMPULSES ROTATING SWD INTO OUR CWA FROM N/NE. AVN STILL
BULLISH ON POPS FOR OUR CWA TODAY AS IT DEVELOPS A SURFACE LOW OVER
S GA AND HIGH MODEL PRECIPITATION AMOUNTS. ETA PROGGED SIMILAR...LESS
AGGRESSIVE SCENARIO. MODEL FCST SOUNDINGS CONTINUE RAISE PWAT VALUES
TO JUST ABOVE TWO INCHES...WITH LIMITED SEVERE POTENTIAL DUE TO A
TROPICALLY MOIST ADIABATIC PROFILE. 00Z MM5-DOF RUN SHOWED MAIN
CONVERGENCE/PCPN ALONG E-W AXIS FROM SE AL TO SE GA W/ 0.5-1.0 INCH
AMTS OVER SE GA AND GENERAL 0.25-0.50 INCH AMTS ELSEWHERE. BASED ON
THE AVAILABLE MODEL DATA...WILL RAISE POPS FOR ERN FL PH TO 40
PCT...CONSISTENT W/ SE AL ZONES...AND LEAVE SW GA/FL BIG BEND AT 50
PCT FOR THIS AFTN.
W/ CONTINUED OFFSHORE FLOW...COASTAL LOCALES WILL SEE AFTN READINGS
SIMILAR TO YESTERDAY W/ LOWER 90S. INLAND AREAS CAN EXPECT MOSTLY
MIDDLE 90S. RELATIVE HUMIDITIES AROUND 50 PERCENT WILL PRODUCE
HEAT INDICIES FROM 100 TO 105 DEG...ESPECIALLY FOR S GA/FL BIG BEND
ZONE GROUPINGS AND WILL HIGHLIGHT THESE.
MARINE: NO CHANGES/HIGHLIGHTS ON 1030 AM ISSUANCE.
MAJ
FXUS62 KTAE 221439 COR fl
EAST CENTRAL FLORIDA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MELBOURNE FL
1020 AM EDT THU JUL 22 1999
UPPER HIGH IS RETROGRADING WEST ACROSS MISSISSIPPI VALLEY AS SURFACE
TROUGH BUILDS SOUTH OVER THE PENINSULA. THIS IS ERODING THE
SUBSIDENCE WHICH HELPED SUPPRESS CONVECTION YESTERDAY. IN
ADDITION...STRONG DAYTIME HEATING...SUFFICIENT MOISTURE AND NUMEROUS
MESOSCALE BOUNDARIES WARRANT GOOD CHANCE POPS ACROSS THE AREA THIS
AFTERNOON. BIG QUESTION THIS MORNING IS WHETHER EAST COAST BREEZE
WILL FORM TODAY...AND IF SO WHERE. MODELS AGREE IN BACKING THE
SURFACE TROUGH WEST INTO THE PANHANDLE AND EASTERN GULF TODAY...
PRODUCING MORE OF A SOUTHWEST FLOW ACROSS THE FA. THIS REGIME IS NOT
CONDUCIVE FOR SEA BREEZE DEVELOPMENT NORTH OF CAPE CANAVERAL AND
EXPECT LATE DEVELOPMENT SOUTH OF THE CAPE. WITH AN ACTIVE AND
PROGRESSIVE WEST COAST BREEZE...A COLLISION MAY OCCUR LATE THIS
AFTERNOON/THIS EVENING OVER CENTRAL AND SOUTHERN COASTAL
SECTIONS...ENHANCING THE COVERAGE AND INTENSITY OF STORMS.
FORECAST LOOKS GOOD...NO UPDATES PLANNED.
MARINE...CURRENT FCST OF NIL SEA BREEZE DEVELOPMENT N OF COCOA LOOKS
REASONABLE CONSIDERING TIGHTENED PRES GRAD DEPICTED IN RUC/MESO-ETA.
MINIMAL CHGS TO FCST.
.MLB...NONE.
KELLY/BLOTTMAN
FXUS62 KEYW 221354 fl
STATE FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
1200 PM EDT THU JUL 22 1999
12Z SURFACE ANALYSIS SHOWED SURFACE HIGH PRESSURE OVER LOUISIANA
WITH THE 500 MB HIGH OVER THE TENNESSEE VALLEY. A WEAK SURFACE
TROUGH WAS LOCATED FROM THE CAROLINAS TO CENTRAL GEORGIA. WITH
PLENTY OF LOW LEVEL MOISTURE CONTINUING IN PLACE ALONG WITH
BOUNDARIES LEFT OVER FROM YESTERDAY'S CONVECTION...WILL KEEP CHANCE
POPS ACROSS THE STATE THIS AFTERNOON. DID NOT CHANGE POPS FROM
MORNING FORECAST. 03Z MESO ETA AND 12Z RUC DID SHOW A VORT MAX
DRIFTING SOUTH THROUGH EXTREME WESTERN GA INTO EASTERN ALABAMA
THROUGH THE AFTERNOON. WOULD EXPECT STORMS TO FORM EARLY THIS
AFTERNOON ACROSS N GA AND S TN AND DRIFT TO THE SOUTH AND SOUTHWEST
THROUGH THE STATE. WITH A MIN IN PLACE ACROSS E. GA...WOULD EXPECT
LESS ACTIVITY THERE...BUT NOT CONFIDENT ENOUGH TO LOWER POPS ACROSS
AHN AREA. AREA SOUNDINGS FROM 12Z DO SHOW PLENTY OF CAPE WITH 2245
J/KG ON THE FFC SOUNDING MODIFIED TO 91F. WOULD ONCE AGAIN EXPECT
HEAVY DOWNPOURS THIS AFTERNOON WITH PRECIP WATER AT 1.85. ALSO WIND
DAMAGE POSSIBLE LIKE YESTERDAY. TEMPS RUNNING ON TRACK TODAY AND DID
NOT CHANGE...BUT DID ADD "HEAT INDICES AROUND 105" IN MCN ZONE THIS
AFTERNOON.
.ATL...NONE
AP
ga
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
1035 PM EST THU JUL 22 1999
CONVECTION THIS EVE WILL NOT QUIT. STATIONARY FRONTAL BNDRY SE WI TO
SW OH STILL APPARENT PER 02Z LAPS. 21Z/00Z RUC MODEL RUNS BOTH
ADVERTISING INCREASING MOISTURE CONV ALNG THIS FTR ACRS NW IN LTR
TONIGHT. WITH SUCH LG THETA E RIDGE JUST W AND S OF FA AND BACKING
LOW LVL FLOW AHD OF PLAINS SW OVERNIGHT AND AFOREMENTIONED CONV INTO
DIFFUSE BNDRY FEEL SMALL CHANCE POP IN ORDER. KIWX RADAR LOOP DOES
SHOW RENEWED ACTIVITY DVLPG ALNG A GYY TO MZZ LINE AND LIKELY AN
INDICATION OF THIS OCCURRING ALREADY. OTHERWISE WITH DEBRIS CLOUDS
XPC TEMPS TO REMAIN SOMEWHAT HIGHER THEN LAST NIGHT AND HAVE
ADJUSTED LOWS SOMEWHAT HIGHER.
.IWX...HEAT ADVISORY CONTS FOR NRN IN THROUGH FRI
TEH
FXUS63 KIWX 222250 in
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
305 AM CDT THU JUL 22 1999
06Z SFC AND MSAS/LAPS ANALYSIS INDICATE PESKY FRONTAL BOUNDARY BECOMING
MORE DIFFUSE BUT CONTINUING TO HOLD ACRS CENTRAL IA TO WI/IL BORDER.
THIS FEATURE BEING SOMEWHAT HELD AT BAY BY WEAK SFC RIDGE TO THE NORTH
ACRS WI AND PARALLEL TO UPPER FLOW. LOW LEVEL MOISTURE CONVERGENCE
CONTINUES AROUND THE FRONT AS 75+ DPTS POOL ALONG AND SOUTH OF FEATURE
ACRS CENTRAL IA. DPTS DO DROP OFF SOMEWHAT FURTHER SOUTH/SOUTHWEST
OF REGION ACRS MO...KS AND SOUTHERN NE.
THE QUESTION OF CONTINUING HEAT NOT AN ISSUE...BUT THE QUESTION OF
PRECIP CHANCES NEAR BOUNDARY THIS AFTERNOON AND TONIGHT...AND AGAIN ON
FRIDAY IS.
THROUGH FCST PERIOD...SHORT RANGE MODELS SIMILAR IN EVENTUALLY RETRO-
GRADING UPPER RIDGE CENTER TO GRT BASIN BY 00Z SAT AS WESTERLIES REMAIN
ACRS NORTHERN TIER OF CONUS AND SOUTHERN CANADA. THIS PROCESS DOES
INDUCE A WEST-NORTHWEST FLOW ACRS OVER EAST IA AND WESTERN GRT LKS BY
END OF PERIOD AS WELL. W/V LOOP INDICATES WEAK VORT RIPPLING AROUND
WEST SIDE OF UPPER RIDGE OVER OK AND KS. NGM/ETA HAVE SO SO HANDLE ON
THIS FEATURE WITH RUC A BIT BETTER. MODELS HAVE THEIR DIFFERENCES...
BUT BRING WEAK VORT ACRS IA THIS AFTERNOON. AS WEST END OF BOUNDARY
LIFTS INTO SOUTHERN MN BY 00Z FRI...EAST END SHOULD MOVE LITTLE AS
WEAK SFC RIDGE SHIFTS SOUTHEAST ACRS SOUTHERN GRT LKS. AS INSTABILITY
BUILDS ONCE AGAIN ADJACENT TO BOUNDARY WITH 3K-4K+ J/KG CAPES ALONG
AND SOUTH OF IT...WEAK DISTURBANCE MAY BE ALL THAT IS NEEDED. H7 CAP
WILL BE MARGINAL...AND CONTINUING WEST-SOUTHWEST H85 FLOW WILL INDUCE
LOW TO MID LEVEL MOISTURE CONVERGENCE AND THTA-E ADVECTION ACRS
NORTHEAST IA...SOUTHERN WI AND INTO FAR NORTHERN IL BY THIS EVENING.
NICE H85 THTA-E GRADIENT SETS UP ACRS SE MN...SW WI AND NORTH CENTRAL
AND NORTHEAST IL AS WELL...WITH WEST-SOUTHWEST 15-20 KT H85 FLOW
AND MOISTURE FLUX SLICING ACRS IT. ALL THIS POINTS TO ANOTHER CHANCE OF
LATE AFTERNOON AND EVENING THUNDERSTORMS ACRS FAR NORTHERN TIER OF DVN
CWA AND WILL UP ONGOING LOW POPS TO 30 PERCENT. WILL KEEP ONGOING SLIGHT
CHANCE ACRS CENTRAL CWA...BUT WILL DROP POPS ACRS THE SOUTH AS FEEL ANY
ACTION THAT DOES DEVELOP WILL BE WELL TO THE NORTH OF SOUTHEAST IA AND
WEST CENTRAL IL.
MAY INTRODUCE SOME POPS ON FRI TO ACCOUNT FOR VORT DROPPING SOUTHEAST
IN DEVELOPING NORTHWEST UPPER FLOW ACRS MN AND WI...ALTHOUGH NGM MAY BE
TOO FAR SOUTH AND PRECIP PESSIMISTIC AS TRAILING VORT LOBE CLIPS EAST
IA AND NORTHERN IL. IF POPS ARE INTRODUCED...IT WILL BE ONLY FOR
NORTHERN TWO THIRDS OF DVN CWA.
AS FOR TEMPS...WILL GO TO SIMILAR TO WHAT HAPPENED YESTERDAY AND A
LITTLE WARMER IN THE NORTH. THIS IN LINE WITH THE WARMER AND MORE
ACCURATE FWC GUIDANCE WHICH DID WELL ON WEDNESDAY. DPTS ACRS SOUTHERN
CWA MAY NOT BE QUITE AS HIGH THOUGH AS SFC BOUNDARY AND ITS POOLING
EFFECT LIFT NORTH SOMEWHAT. TRAJECTORIES ALSO ADVECT IN LOWER DPTS FROM
SOUTHEAST KS AND NORTHEAST OK SOURCE REGION. WILL LEAVE HEAT ADVISORY
ONGOING THROUGH FRIDAY FOR ENTIRE CWA...ALTHOUGH FAR NORTHERN TIER/DBQ/
MAY NOT QUITE REACH ADVISORY CRITERIA.
COORDINATED WITH ARX...LSX...THANX.
.DVN...
IA...HEAT ADVISORY THROUGH FRIDAY FOR ZONES 040-042>051-054>
063-068>076-078>087-089>098-099.
IL...HEAT ADVISORY THROUGH FRIDAY FOR ZONES 001-002>007>009>
015-018-024>026>034>035.
HLADIK
ia
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
1030 PM EDT THU JUL 22 1999
MAIN FORECAST CONCERN TONIGHT IS POSSIBILITY OF THUNDERSTORMS.
SYNOPTIC PATTERN REMAINS LARGELY UNCHANGED FROM YESTERDAY...WITH
HIGH PRESSURE DOMINATING WEATHER OVER THE CONUS. LATEST SFC ANALYSIS
SHOWS PERSISTANT STATIONARY FRONT FROM SOUTHERN MN ACROSS SOUTHERN WI.
DEWPOINTS SOUTH OF FRONT IN LOW 80S AT SOME LOCATIONS. WEAK SFC TROF
ALSO LOCATED IN CENTRAL PLAINS. CONVECTION HAS RECENTLY FIRED UP IN
THIS REGION...WITH A WATCH BOX OVER EASTERN DAKOTAS.
CURRENTLY A QUIET NIGHT OVER THE U.P. SOME ISOLATED THUNDERSTORMS
MOVED ACROSS NORTHERN LAKE SUPERIOR AROUND 23Z...OTHERWISE NO PRECIP
TO SPEAK OF. INSTABILITY REMAINS IN PLACE ACROSS THE CWA.
HOWEVER...DIURNAL TREND...AND LACK OF ANY FORCING SHOULD PREVENT ANY
THUNDERSTORMS FROM DEVELOPING UNTIL VERY LATE TONIGHT/EARLY MORNING
IN WESTERN ZONES. AT 00Z CONVECTION WAS FIRING UP IN EASTERN DAKOTAS
ALONG THETA E RIDGE AXIS. NO REASON THIS AREA OF CONVECTION SHOULD
NOT PERSIST AS IT MOVES INTO MN...WHERE CAPES SURPASS 4000
J/KG...AND ETA INDICATES 250MB DIVERGENCE TO AID LIFT. IR IMAGERY
ALSO SHOWS SOME CONVECTION TRYING TO DEVELOP...BUT NOT AS
SUCCESSFULLY...IN SOUTHERN WI ALONG ANOTHER THETA E RIDGE. MESOETA
AND RUC PUSH THETA E RIDGE EASTWARD...TO WESTERN CWA BY 12Z. MESOETA
HINTS AT MCS DEVELOPMENT BETWEEN 9Z AND 12Z IN NW WI...JUST WEST OF
CWA. RUC AND MESOETA ALSO SHOW POSITIVE SI'S OVER CWA...WITH
NEGATIVE VALUES GETTING INTO WESTERN CWA NEAR 12Z. THE POSITIVE SI
VALUES MATCH UP PRETTY WELL WITH AREAS THAT ARE CONVECTION-FREE FROM
THE U.P. TO WESTERN MN AND TO SOUTHERN WI. BY 12Z...-2 SI LINE IS
JUST WEST OF MQT. CAPES APPROACH 3000 J/KG IN WESTERN COUNTIES
BETWEEN 9 AND 12Z. I THINK WE WILL SEE THE CONVECTION CURRENTLY IN
EASTERN DAKOTAS ADVANCE GENERALLY EASTWARD OVERNIGHT...WITH SOME
THUNDERSTORMS POSSIBLE IN WESTERNMOST...AND POSSIBLY CENTRAL
COUNTIES...TOWARD MORNING. TEMPS LOOK OK. WILL FRESHEN WORDING...AND
ADJUST WINDS.
MQT...NONE.
JS
FXUS63 KAPX 230126 mi
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
1135 AM EDT THU JUL 22 1999
FCST CONCERNS FOR THE AFTN ARE TEMPS AND POSSIBLE CONVECTION ARRIVING
FROM WEST AND DEVELOPING ON LK BREEZE BOUNDARIES.
WV IMAGERY SHOWS WELL DEFINED SHORTWAVE MOVING INTO S SASKATCHEWAN.
ANOTHER SHORTWAVE IN ND AIDING TSRA IN E ND/N MN. AT THE SFC...
REMNANTS OF STATIONARY FRONT LINGERS ACROSS N IA AND S WI. DWPTS
ACROSS FA HAVE RISEN TO 65 TO 72F WITH HIGHEST READINGS NEAR LK
MICHIGAN.
RADAR TRENDS AND LIGHTNING DATA INDICATE TSRA MOVING E ACROSS NCNTRL
MN IS WEAKENING SIGNIFICANTLY AS IT MOVES AWAY FROM LOW-LEVEL CONV
REGION AND BEST INSTABILITY. NEW CONVECTIVE DEVELOPMENT OCCURRING
FARTHER WEST IN E ND/FAR NW MN WHERE BEST PARAMETERS PERSIST. 12Z
RUC SHOWS SLOW PROGRESS EAST OF LOW-LEVEL JET AND SHORTWAVE THIS
AFTN. THETA-E RIDGE WHERE TSRA OCCURRING ALSO REMAINS W OF FA. SO
EXPECTATION IS THAT TSRA IN NCNTRL MN WILL DISSIPATE BEFORE REACHING
UPPER MI. ONLY AFFECT WILL BE CI BLOWOFF OVERSPREADING FA.
NEXT CONCERN IS POSSIBLE TSRA DEVELOPMENT E FA FROM INTERACTION OF
LK BREEZES OFF LAKE SUPERIOR AND LAKE MICHIGAN THIS AFTN. 03Z ETA HAS
BACKED OFF FROM PREVIOUS RUN ON HIGH CAPES PROGGED OVER E FA. EVEN
SO...CAPES OF 1000-2000J/KG ARE INDICATED BY LATE AFTN ALONG LK
MICHIGAN COUNTIES. 12Z GRB SOUNDING SHOWS FORMIDABLE CAP WHILE APX
SOUNDING SHOWS CAP WILL BE BROKEN WHEN TEMPS REACH UPPER 80S WITH
DWPTS LOW 70S. MODIFIED SOUNDING YIELDS CAPE OF 3600J/KG. HOWEVER...
AIRMASS ALOFT IS VERY DRY WITH DWPT DEPRESSIONS GENERALLY 15-20C
ABOVE 850MB...K INDEX BELOW 10. DESPITE LOW-LEVEL CONV THAT WILL
DEVELOP AS LAKE BREEZES MOVE INLAND...WILL MAINTAIN CURRENT DRY FCST
GIVEN DRY AIR ALOFT. WILL NEED TO KEEP AN EYE ON CU DEVELOPMENT THAT
OCCURS ALONG LK BREEZES THOUGH.
GOING FCST HAS HIGHS GENERALLY AROUND 90. TEMP TRENDS THIS MORNING
AND LATEST LAMP GUIDANCE SUGGEST FCST ON TRACK. HOWEVER...INCREASING
CI WILL LIMIT SUNSHINE A BIT...ESPECIALLY W. WILL MAKE A FEW MINOR
DOWNWARD ADJUSTMENTS ON UPDATE.
MQT...NONE.
ROLFSON
FXUS63 KDTX 221530 mi
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
1102 AM EDT TUE JUL 20 1999
LATEST SURFACE OBSERVATIONS SHOWING MORNING FOG LIFTING AND
DISSIPATING ACROSS NORTHERN LOWER MICHIGAN... DUE TO LATE MORNING
MIXING OF DRIER AIR FROM ALOFT. APX MORNING SOUNDING SHOWED 850 DEWPTS
AROUND 4C. LATEST RUC SHOWING SURFACE AND UPPER LEVEL RIDGING BUILDING
OVER THE GREAT LAKES REGION AND STRENGTHENING DURING THE DAY. THE MAIN
AREA OF CONCERN THIS AFTERNOON... WILL BE THE CHANCE OF LAKE BREEZE
DEVELOPMENT AND THE CHANCE OF THUNDERSTORMS OVER EAST UPPER AND
THE STRAITS AREA.
WITH TEMPERATURES RISING INTO THE UPPER 80S MOST LOCATIONS TODAY
AND NORTHERN GREAT LAKES WATER TEMPERATURES IN THE MIDDLE AND UPPER
60S... DELTA T'S WILL BE GREAT ENOUGH FOR LAKE BREEZE DEVELOPMENT. 12Z
RUC SHOWING 925 MB WINDS OVER EAST UPPER TO BE WEST AROUND 15 KNOTS
WHICH IS A WEAK ENOUGH FLOW FOR A LAKE BREEZE TO FORM. HOWEVER IT WILL
ALSO ADD TO WIND CONVERGENCE OVER EAST UPPER THIS AFTERNOON. 850 DEW
PTS ARE EXPECTED TO INCREASE TO AROUND 10C THIS AFTERNOON OVER EAST
UPPER WITH SOME WEAK 850-700 QVECTOR CONVERGENCE NOTED BY 18Z.
THEREFORE WILL LEAVE MENTION OF THUNDER IN THE FORECAST FOR EAST UPPER
AND STRAITS AREA.
THE REST OF THE FORECAST LOOKS IN LINE...HOWEVER WILL DROP MENTION
OF THUNDER FROM THE SOUTHEAST ZONES AS DRIEST 850 DEW PTS AND
STRENGTHENING UPPER LEVEL AND SURFACE RIDGING SHOULD LIMIT ANY
CONVECTION.
.APX...NONE.
SWR
FXUS63 KGRR 221417 mi
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
945 AM CDT THU JUL 22 1999
FORECAST SCENARIO FROM THIS MORNING SEEMS TO BE GENERALLY ON TRACK
WITH A FEW MINOR DIFFERENCES. MCS WEAKENING AS IT MOVES FARTHER INTO
MN BUT LEAVING A BOUNDARY SOUTH OF DTL INTO NE SD. THINK THIS AREA
WILL BE THE FOCUS FOR OUR NW CWA LATE AFTERNOON AND EVENING. 12Z RUC
CONTINUES WITH A TREND OF SOME UPPER DIV ACROSS ACROSS N PART OF CWA
AND INSTABILITY GRADIENT DEVELOPING ACROSS CENTRAL MN. LIMITING
FACTOR WILL BE WEAKER LOW LEVEL FLOW. SOEM AREAS MAY BE
CAPPED..INITIALLY.. AS WELL. OTHER CONCERN..IS POSSIBILITY OF ISOLATED
CONVECTION SOUTH CENTRAL IN AREA OF WEAKER CAP NEAR OLD BOUNDARY TO
OUR SOUTH. WILL ADD A SMALL POP HERE.
.MSP...NONE.
JPR
FXUS63 KMPX 220849 mn
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
230 PM CDT THU JUL 22 1999
...THUNDERSTORM PROBABILITIES CONTINUE TO BE FORECAST CHALLENGE...
UPPER PATTERN REMAINS UNCHANGED WITH RIDGING OVER MUCH OF THE U.S. AND
TROFING OVER THE NORTHWEST AND NORTHEAST. WV PICS SHOW MONSOON
CONTINUES TO SPREAD FROM THE SOUTHWEST ACROSS WESTERN NEBRASKA AND INTO
THE NORTHERN PLAINS. AT THE SURFACE...A TROF EXTENDS THROUGH CENTRAL
SOUTH DAKOTA ACROSS WESTERN NEBRASKA. CONVECTION IS FIRING ALONG ZONE
OF ENHANCED LOW LEVEL CONVERGENCE FROM NEAR VTN TO SNY.
MOST RECENT TWO RUNS OF RUC DEVELOPED CONVECTION IN GENERAL AREA OF
CURRENT ACTIVITY...ETA ALSO DEVELOPED CONVECTION BUT NOT UNTIL 00Z
ALTHOUGH BOTH MODELS DO APPEAR TO BE TOO FAR WEST. NGM WAS FAR TOO
PROGRESSIVE AND DEVELOPED CONVECTION EAST OF CWFA AND WILL BE
DISREGARDED. OVERALL...ETA AND AVN HAVE BEST HANDLE AND WILL BE USED.
CONVECTION ALREADY FIRING ALONG ZONE OF ENHANCED LOW LEVEL
MOISTURE/THETA E CONVERGENCE IN VICINITY OF TROF OVER WESTERN PART OF
CWFA. CAPES AHEAD OF TROF RANGE FROM 3K TO 5K J/KG WITH CAP COMPLETELY
ERODED. SHEAR REMAINS NONEXISTANT SO PULSE TYPE STORMS WITH PRIMARY
THREAT FOR GUSTY WINDS AND HEAVY RAINS EXPECTED. WEAKNESS IN FLOW SHOWS
AT H5 ON BOTH ETA/AVN BUT WILL NOT LIKELY PROVIDE ENOUGH VERTICAL
MOTION TO SUSTAIN STORMS ENTIRELY THROUGH THE NIGHT. SINCE SHEAR IS WEAK
...STORMS SHOULD DISSIPATE BY MIDNIGHT WITH LOSS OF HEATING THIS
EVENING.
WEAKNESS IS EXPECTED TO BE EAST OF THE STATE FRIDAY MORNING WITH THE
RIDGE REBOUNDING. LARGE SCALE SUBSIDENCE...CAP...WEAK SHEAR...AND LACK
OF LOW LEVEL CONVERGENCE OR UPPER LEVEL KICKER SHOULD INHIBIT
THUNDERSTORM DEVELOPMENT. YET ANOTHER HOT ONE WITH H85 TEMPS VERY
SIMILAR TO TODAY.
FRIDAY NIGHT AND SATURDAY PROMISE MORE OF THE SAME AS THE RIDGE IS
EXPECTED TO AMPLIFY FURTHER IN RESPONSE TO UPSTREAM SHARPENING OF TROF.
LEE SURFACE TROF FORECAST TO STRENGTHEN WITH INCRESING WINDS OVER THE
CWFA. DEEPER MIXING SHOULD LOWER DEWPOINTS AND ALLOW TEMPS TO REACH 100
OR BETTER IN MANY PARTS OF THE CWFA.
IN THE EXTENDED...ALL MEDIUM RANGE MODELS EJECT CURRENT EASTERN PACIFIC
TROF OVER THE RIDGE SUNDAY/MONDAY AND PUSH A FRONT THROUGH THE PLAINS.
AS OF NOW...LOOKS LIKE FRONT WILL PASS SUNDAY NIGHT...STALL AND UNDERGO
FRONTOLYSIS JUST SOUTH AND EAST OF CWFA. WILL PUSH MENTION OF THUNDER
BACK TO SUNDAY NIGHT AND MONDAY WITH HOT AND DRY CONDITIONS BOTH
SATURDAY AND TUESDAY.
.LBF...NONE
DJB
FXUS63 KOAX 221925 ne
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
915 PM EDT THU JUL 22 1999
SHRA/TSRA ACTIVITY STILL STRETCHING ACROSS ERN LI SOUND AND JUST OFF
ERN LI ATTM. WL KEEP AN EYE ON THIS TO DETERMINE IF ERN ZONES NEED
MENTION.
LOOKING UPSTREAM...VERY ISOLATED TSRA SEEN. LATEST RUC SHOWS YET
ANOTHER JET STREAK SET TO MOVE SE FROM CANADA LATER TONIGHT. THIS
IS SEEN ON WATER VAPOR IMAGERY. MAY NEED TO KEEP A 30 POP DUE TO JET
AND INSTABILITY. ENHANCED CLOUDS ASSOC WITH THE JET WILL MOVE ACROSS
THE REGION AFTER MIDNIGHT. OTHERWISE...CURRENTLY SOME LOW CLOUDS
HERE AND THERE. WL MENTION VARIABLY CLOUDY FOR THE OVERNIGHT SINCE
WE COULD SEE SOME CLR SKIES EARLY. WL ALSO MENTION PATCHY FOG.
TEMP/DEW PT SPREADS MINIMAL AND LEFTOVER MOISTURE FROM
EARLIER RAINS COULD RESULT IN SOME FOG.
NO OTHER CHANGES TO THE FCST.
.NYC/OKX...NONE.
WICHROWSKI
FXUS61 KALY 221922 ny
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
1000 AM EDT THU JUL 22 1999
H5 SHRT WV MOVG S OF THE FCST AREA THIS MRNG...WITH NRN EDGE OF
ASSOCD PCPN SCRAPING THE RGN.
SFC WRMFNT WL STAY WELL TO OUR S THIS AFTN AND TNGT. RUC INDICATES
ANOTHER SHRT WV MOVG BY THE RGN LTR THIS AFTN INTO THIS EVE. THIS WL
BE ENUF TO TOUCH OFF SCT CNVCTN. TIL THEN HWVR DO NOT SEE MUCH IN
THE WAY OF PCPN FOR THE NXT FEW HOURS.
SO IN THE UPDTD FCSTS WL KNOCK DOWN THE POPS FM "LKLY' TO "CHC". WL
ALSO BE A BIT MORE OPTIMISTIC WITH THE CLD CVR AND GO WITH VRBL
CLDNS. THIS ALSO MEANS BUMPING UP THE HI TMPS IN MANY OF THE ZNS.
.NYC/OKX...NONE.
EY
FXUS61 KBGM 221355 ny
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC
945 AM EDT THU JUL 22 1999
AREAS OF FOG TRYING TO LIFT OUT THIS AM. HWVR CONTD VSBYS TO 1 MI OR
LESS CONT. SHUD BE GONE SHORTLY. WNDS OVR THE WTRS THIS AM LGT AND
FRM THE S OR SW. TEMPS ALRDY RCHG INTO THE LWR TO MID 80S THIS AM
AND AS F CLRS TEMPS WL JUMP QUICKLY.
SWV IN WV THIS AM DROPG TWRD FA. MOD SNDG NOT AS UNSTBL AS YSTRDY.
HWVR MOD CAPES ARE ARND 4000 AND ACTVTY SHUD BE ENHNCD AS SWV OVR WV
THIS AM MVS THRU. THAT IS XPCTD ARND MAX HTG TM. WK WND SHIFT EVIDNT
ON SFC ANAL PROGGD BY BOTH RUC AND MASS TO CONT OVR CNTRL NC AND
PSBLY DRIFT SLOWLY E THRU THE AFTN HRS. CUD GET INTERESTING THIS
AFTN. MA NEED TO UP POPS. DCNT AMT OF CLDS TDY SHUD KP TEMPS DWN
INTO THE MID 90S THIS AFTN. HV CNSDRD HT ADV AND XPCT WE WL GET NR
CRITERIA. HWVR WL NOT ISSUE AN ADV THIS AFTN BUT WL HILITE IN ZONES.
CRRNT RUC SHWG LOBE OF STG INCRSG THETA E MVG THRU AT MAX HTG AND
VORT LOBE MVG OUT OF AREA AFT 21Z. XPCT ACTVTY TO DIE DWN THIS EVE
AS SWV MVS OUT OF AREA AND HTG DSSPRS.
.MHX...NONE
FXUS62 KILM 221340 nc
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
940 AM EDT THU JUL 22 1999
DISC: NOT MUCH CHANGE FROM YESTERDAY EVENING OVER THE CWA WITH PW
WATERS AT A JUST ABOVE 2.0 INCHES. PLAN VIEW OF WSR-88D VAD WIND PROFILE
DOES SHOW AN INVERTED TROF AT 3 K FT ALONG THE COASTAL AREA OF OUR
CWA. ANOTHER TROUGH ALBEIT WEAK IS SEEN RUNNING MORE EAST-WEST TO
NORTH OF THE FORECAST. THE 09Z RUC SHOWS A WEAK SHOULD MOVING ACROSS
THE AREA AROUND NOON TODAY AND THIS SHOULD OFFER SOME WEAK LIFT. SO
WITH LIGHT WINDS...EXPECT SEA BREEZE AND ANY REMAINING OUTFLOW
BOUNDARIES TO BE THE FOCUS FOR TODAYS CONVECTION.
CWF...WITH LIGHT WINDS AND MINIMAL SEAS EXPECT NO MAJOR CHANGES TO
THE MORNING FORECAST.
.ILM...NONE.
HAWKINS
nc
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON OH
941 PM EDT THU JUL 22 1999
00Z SFC ANALYSIS INDICATED A CONVERGENCE BOUNDARY EXTENDING FROM
SERN WI TO THE MID-ATLANTIC STATES. A SHORTWAVE SHOWN ON THE 00Z
RUC WAS OVR IN. THIS HAS RESULTED IN SEVERAL CONVECTIVE COMPLEXES
FOCUSING ALONG THE BOUNDARY.
THE 00Z RUC INDICATES THAT THE SHORTWAVE WILL REMAIN W OF THE FA
OVERNIGHT WHICH SHOULD KEEP THE TSRA GOING MUCH OF THE NIGHT. WL
KEEP POPS IN FOR MUCH OF AREA OVERNIGHT BUT WL BREAK OUT GROUPS TO
ELIMINATE PRECIP FROM AREAS NOT GETTING RAIN.
ONLY OTHER CHANGE WL BE TO THE WINDS.
FORECAST WILL LIKELY BE ISSUED LATER THAN NORMAL DUE TO UPDATES
ALREADY ISSUED.
.ILN...NONE.
WILKINSON
FXUS61 KCLE 230041 oh
EASTERN OKLAHOMA/NORTHWEST ARKANSAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TULSA OK
1000 AM CDT THU JUL 22 1999
SURFACE ANALYSIS SHOWS THAT THE WESTERN EXTENT OF THE BERMUDA HIGH
HAS PINCHED OFF INTO A CLOSED HIGH OVER LA/ERN TX THIS MORNING WITH
WEAK RIDGING POKING NORTH INTO ERN OK/WRN AR. DUE TO THIS...WILL
UPDATE FCST ONLY TO TWEAK WINDS FROM SOUTH TO SOUTHWEST IN SOME OF
THE MORE ERN ZNS.
OTHERWISE...12Z RUC SHOWS THE UPPER RIDGE DOMINATING OUR WEATHER
TODAY WITH 500 MB TEMPS WARMING FROM AROUND -6/-7C THIS MORNING TO
-4/-5C THIS AFTERNOON. SURROUNDING 12Z SOUNDINGS SHOW K-INDICES NEAR
30...WHICH IS WHERE THEY HAVE BEEN ALL WEEK. THEREFORE...CONVECTIVE
OUTLOOK SHOWS LITTLE CHANGE WITH JUST A SHOWER OR TWO POSSIBLE OVER
HIGHEST TERRAIN DURING PEAK HEATING THIS AFTERNOON.
22
.TUL...
AR...NONE.
OK...NONE.
FXUS64 KTSA 220828 ok
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
850 PM EDT THU JUL 22 1999
EVENING RAOBS FROM AROUND THE AREA SHOW CAPES OF 3000 TO 3500.
DESPITE SUCH HIGH CAPES HOWEVER...WIDELY SCATTERED CONVECTION DIED
RAPIDLY WITH SUNSET. APPARENTLY THE WEAK SHORTWAVE THAT THE 21Z RUC
SHOWS MOVING SOUTH OVER WRN CAROLINAS ATTM IS NOT PROVIDING
SUFFICIENT LIFT TO RAISE MOIST BOUNDARY LAYER AIR TO THE LFC. VERY
DRY MID/UPR LEVELS CAN BE SEEN ON THE WV IMAGERY MOVING SOUTH AND
WILL EVENTUALLY ROTATE AROUND ANTICYCLONIC CIRCULATION ACROSS THE
AREA OVERNIGHT...CONSISTENT WITH LATEST MODEL GUIDANCE. THIS
COMBINED WITH FAIRLY STRONG NVA IN THE WAKE OF SHORTWAVE SHOULD KEEP
WEATHER QUIET OVERNIGHT. WILL DROP POPS...BUT LEAVE TEMPS AS
FORECAST.
.GSP...NONE.
MOYER
FXUS62 KCHS 221939 sc
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
145 PM EDT THU JUL 22 1999
E AND S PORTIONS OF AREA APPROACHING HEAT ADVSIORY CRITERIA...
BUT DEW POINTS MAY MIX OUT A BIT LATER THIS AFTERNOON. WILL
HANDLE WITH HEAT INDEX NOWCAST. WEAK IMPULSE TO MOVE CROSS NC
LATE THIS AFTERNOON AND SC THIS EVENING. RUC SHOWS BEST DYNAMICS
BETWEEN I-77 AND I-95. BEST LOW LEVEL MOISTURE E OF CWA. RADAR
SHOWS CONVECTION IN VA MOVING TOWARD CENTRAL NC...WITH MORE
DEVELOPING IN NC MOUNTAINS/FOOTHILLS. CONVECTION TO TAPER OFF
LATE TONIGHT AS IMPULSE MOVES S. AREA BETWEEN IMPULSES FRI AND
FRI NIGHT...BUT STILL MOIST AND UNSTABLE. PAIR OF SHORTWAVES TO
APPROACH SAT...ALTHOUGH NGM WEAKENS FIRST SYSTEM AS IT REACHES
APPALACHIANS. TEMPERATURES TO REMAIN WARM FRI WITH HEAT ADVISORY
CRITERIA AGAIN APPROACHED S AND E. TEMPERATURES COOL A BIT SAT
WITH SLIGHT LOWERING OF HEIGHTS AS RIDGE RETROGRADES...AND
POSSIBLY CI FROM CONVECTION IN OH VALLEY.
AVL 68/90/68/89 2113
CLT 74/96/74/93 3112
GSP 72/95/73/93 2112
.GSP...NONE.
JAT
FXUS62 KCAE 221410 sc
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
959 AM EDT THU JUL 22 1999
DISC: 13Z ANALYSIS SHOWS HI PRES OVR THE CTNRL GULF CST AREA AND A WK
TROF ALNG THE ERN PTN OF THE STATE.
SATELLITE SHOWS SOME CLDS MAINLY ACRS THE SWRN PTN OF THE STATE WITH A
NICE AREA OF MS/SU CONDITIONS OVR NC AND N/NE SC. OBS CONT TO SHOW HZ
FOR MOST AREAS. 00Z ETA AND MORNING RUC...ALTHOUGH TIMING A BIT
DIFFERENT SHOW A WK S/W TO MOVE ARND UPR HI AND INTO THE STATE THIS AFT.
THIS COMBINED WITH SOME WK DIFFLUENCE ALOFT SHOULD HELP TOUCH OFF A FEW
SHRA/TSRA LATER THIS AFT. TEMPS GETTING OFF TO A GOOD START THIS MORNING
WITH MINS HIGHER THAN WED. TDS RUNNING A BIT HIGHER THAN YESTERDAY...SO
WL CONT WITH HEAT ADVISORY FOR AFT. LOOKING FOR HEAT INDEX VALUES
BETWEEN 105 AND 110 DEGREES.
.CAE...HEAT ADVISORY TODAY SCZ015-016-018-020>022-025>031-035>038-041.
HEAT ADVISORY TODAY GAZ040-063>065-077.
LCV
FXUS62 KCHS 221359 sc
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
850 AM EDT THU JUL 22 1999
RUC SHOWS WEAK IMPULSE DROPPING S THROUGH CWA BETWEEN 18 AND 21Z.
BEST DYNAMICS I-77 CORRIDOR. MID AND UPPER LEVEL DRYING TO TAKE
PLACE TODYA...BUT LEVELS BELOW 700 MB TO REMAIN MOIST. MID LEVEL
TEMPERATURES RATHER WARM...GREATER THAN 10 C AT 700 MB...YET NO
CAP APPARENT IN AREA SOUNDINGS AND UPSTREAM TEMPERATURES NOT
MUCH WARMER. CAPES AROUND 3700 EXPECTED THIS AFTERNOON IF MID 90S
REACHED AT SURFACE. WILL CONSIDER RAISING POPS TO 40 OR EVEN 50
PERCENT. AREA OFF TO A WARM START WITH GSP/CLT 1 DEGREE ABOVE
WARM FWC GUIDANCE AT 12Z AND AVL AT GUIDANCE. CURRENT ZONES
ALLOW FOR UP TO 5 DEGREES WARMING AT GSP/CLT TODAY AND WILL LEAVE
AS IS. WILL RAISE TEMPERATURES NC FOOTHILLS ONE CATEGORY TO
ACCOUNT FOR WARMING ABOVE YESTERDAY'S LOW 90S READINGS. WILL PUT
GREATER RANGE NC MOUNTAINS TO ALLOW FOR A STRAY 90 OR TWO.
.GSP...NONE.
JAT
sc
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
815 PM MDT THU JUL 22 1999
SURFACE TROF HAS PUSHED THROUGH ALL BUT FAR SOUTH CENTRAL
COUNTIES....WITH THUNDERSTORMS MOVING EAST OF CWA. 00Z KUNR SOUNDING
SHOWS THAT MOISTURE IS VERY SHALLOW...WITH DRY AIR FROM 850MB TO
500MB. WATER VAPOR IMAGERY IS SHOWING A WEAK SHORTWAVE MOVING
THROUGH WESTERN WYOMING...AND IS DEPICTED WELL BY 21Z RUC. ISOLATED
THUNDERSTORMS HAVE DEVELOPED OVER SOUTHEAST MONTANA LAST FEW HOURS.
HOWEVER WITH THE DRY AIR...THREAT OF THUNDERSTORMS IS LOW. WILL
UPDATE ZONES TO REMOVE MENTION OF EVENING THUNDERSTORMS. REST OF THE
FORECAST IN GOOD SHAPE.
.UNR...NONE
KRC
FXUS63 KFSD 230143 sd
AREA FORECAST DISCUSSION FOR CENTRAL/NORTHCENTRAL AND NORTHEAST
SOUTH DAKOTA AND WEST CENTRAL MINNESOTA
NATIONAL WEATHER SERVICE ABERDEEN SD
1010 AM CDT THU JULY 22 1999
OUTFLOW BOUNDARY FROM THE ND CONVECTION MOVING SE ACROSS THE ABR CWA
THIS MORNING. THIS OUTFLOW BOUNDARY ALONG WITH SFC HEATING WILL BREAK
UP THE LOW CLOUDS AND FOG ACROSS NE SD AND WC MN BY NOON. THIS OUTFLOW
BOUNDARY ALONG WITH A LOW PRESSURE TROUGH EXTENDING N TO S ACROSS THE
ABR CWA COULD PROVIDE THE NECESSARY LIFT TO GENERATE TSRAS THIS
AFTERNOON. THE LATEST FORECAST FROM THE RUC KEEPS TEMPS AT 70H +12 OR
HIGHER TODAY WHICH MAY BE TOUGH TO BREAK. ALSO...IT WILL BE VERY
UNSTABLE ACROSS NE SD AND WC MN THIS AFTERNOON. SO...WILL LEAVE POPS IN
FORECAST. WITH THE DWPTS IN THE LOWER TO MID 70S ACROSS THE AREA AND
TEMPS RISING INTO THE 90S TO AROUND 100...HEAT INDICES COULD RISE TO 100
TO 110 ACROSS THE AREA. MAY HAVE TO GO WITH A HEAT ADVISORY FOR C SD FOR
THIS AFTERNOON. HAVE ALREADY UPDATED NE SD AND WC MN TO TAKE OUT FOG.
OTHERWISE...THE REST OF THE FORECAST LOOKED OK.
.ABR...NONE.
MOHR
FXUS63 KFSD 221459 sd
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NASHVILLE TN
124 PM CDT THU JUL 22 1999
WELL...LATEST SURFACE ANALYSIS HAS SURFACE HIGH OVER MSY WITH
ISOLATED AFTERNOON CONVECTION CONTINUING IN EARNEST. THE TWO MOST
IDENTIFIABLE FOCUSING MECHANISMS ARE A SURFACE TROUGH FROM LEX-BNA
AND ANOTHER FROM CMI-PAH-MEM-GWO. LATEST MSAS DATA HAS LIS IN THE
-6 TO -8 RANGE AND DEW POINTS IN THE MID 70S. BASICALLY THE ENTIRE
FORECAST CAN BE SUMMED UP WITH TYPICAL SUMMER TIME TEMPERATURES AND
HUMIDITY ALONG WITH ISOLATED TO WIDELY SCATTERED AFTERNOON AND
EARLY EVENING TSRA.
MAIN CONCERN WITH PRECIPITABLE WATER VALUES OF 2.1 INCHES AND
MEAN STORM MOTION OF 310 DEGREES AT 3 KNOTS. YESTERDAY A COUPLE OF
STORM SPOTTERS REPORTED OVER 1 INCH OF RAIN IN 15-20 MINUTES FROM
LARGE DROP SIZE AND HIGH MOISTURE CONTENT.
FORECAST CONUNDRUM OF THE DAY...POPS...ESPECIALLY FRI NIGHT/SAT
LAST CONCERN IS NGM AND AVN H5 SHORT WAVE FROM 36-42 HOURS THAT MOVES
FROM IL-MO SEWARD. THIS COULD INITIATE A SMALL MCS FRIDAY NIGHT
AND INCREASE OUR POPS. HAVE ALREADY COORDINATED WITH MEM/PAH AND
LOU AND HAVE DECIDED TO RECONFIGURE THE ZONES FROM THE NW TO THE SE
TO ACCOUNT FOR MOST DISCERNIBLE SHORT WAVE OVER THE LAST SEVERAL
DAYS. THIS COULD BE A CLASSIC NOTORIOUS NORTHWEST FLOW NIGHTTIME
CONVECTION SCENARIO.
H7 TEMPS ARE +10 BUT STILL NOT WARM ENOUGH TO INHIBIT CONVECTION. NEW
MOS GUIDANCE INCREASED TO A 20 POP FOR THE 2 DAY PERIODS AND
CURRENT FORECAST REFLECTS THIS. WITH H7 TEMPS PROGGED TO BE LESS
THAN 12 C FOR THE NEXT 24 HOURS WILL CONTINUE THE ISOLATED TO WIDELY
SCATTERED POPS IN ALL BUT THE WESTERN TIER OF CWA. NONE OF THE MAIN
MAIN MODELS OR THE RUC HAVE BEEN DOING A GOOD JOB ON QPF. HOWEVER
THE MM5 HAS BEEN TARGETING THE CORRECT AREA. WILL USE THIS FOR THE
FIRST 12 HOURS OF THE QPF FORECAST.
TORRID FWC HAS COOLED DOWN FROM ITS 100 FORECAST YESTERDAY...BUT
STILL SEEMS BE 2-4 DEGREES TO WARM.
AS FOR THE EXTENDED...SEE NO REASON TO CHANGE THE GIST OF THE
FORECAST...AS HERCULEAN UPPER HIGH DOMINATES THE WEATHER WITH MOIST
AND UNSTABLE AIRMASS UNDERNEATH IT.
PRELIMINARY NUMBERS FOR FORECAST COORDINATION PURPOSES ONLY...
BNA 075/095 075/096 10/20 30/20
CSV 069/088 070/089 20/20 20/20
JDG
FXUS64 KOHX 221430 tn
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NASHVILLE TN
927 AM CDT THU JUL 22 1999
WELL...LATEST SURFACE ANALYSIS HAS FAIRLY SIMILAR WEATHER
SCENARIO AS THE PAST FEW DAYS. DEW POINTS ARE IN THE LOW TO
MID 70S WITH MOST APPARENT TROUGH FROM CMI-MVN-JBR. SURFACE
THROUGH H7 HIGH ANCHORED FROM MST-MOB WITH H5 THRU H3 HIGH
OVER TN.
CAP IS FAIRLY TENUOUS...UNDERNEATH A CAPE OF 2400 J/KG...LI OF -5
AND K INDEX OF 33. MOST CONCERNED WITH PRECIPITABLE WATER VALUES OF
2.1 INCHES AND MEAN STORM MOTION OF 310 DEGREES AT 3 KNOTS. WITH
CONVECTIVE TEMPERATURE AROUND 90 DEGREES AND A VERY MOIST AND
UNSTABLE ENVIRONMENT THE WIDELY SCATTERED AFTERNOON AND EARLY
EVENING TSRA BRIGADE WILL CONTINUE.
LATEST RUC HAS VERY WEAK VORT MAX OVER THE PLATEAU BY 18Z WHICH MAY
FURTHER ENHANCE CONVECTION. H7 TEMPS STILL <12 DEGREE C SO NO MID
LEVEL CAP YET.
CURRENT FORECAST IN ON TARGET AND PLAN TO MAKE NO ADJUSTMENTS TO THE
GIST OF THE 4 AM PACKAGE.
JDG
FXUS64 KMRX 221338 tn
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE SAN ANGELO TX
919 PM CDT THU JUL 22 1999
CUMULUS FROM AFTERNOON AND EARLY EVENING HAVE DISSIPATED AND
SATELLITE LATE THIS EVENING INDICATES A CLEAR SKY ACROSS OUR CWFA.
TEMPERATURES AT 9 PM ARE RUNNING A FEW DEGREES HIGHER THAN 24 HOURS
AGO. THE ETA AND LATEST RUC MODEL 925 MILLIBAR WIND AND RELATIVE
HUMIDITY FIELDS INDICATE THAT PATCHY LOW CLOUDS SHOULD DEVELOP AND
MOVE NORTH INTO THE SOUTHERN HALF OF OUR CWFA TOWARD MORNING. WILL
SEND UPDATED ZONES TO ADJUST OVERNIGHT SKY COVER...AND WILL RAISE
OVERNIGHT LOWS INTO THE 70 TO 75 RANGE FOR ALL EXCEPT OUR SE
COUNTIES.
19
FXUS64 KLUB 230220 tx
SOUTHEAST TEXAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
845 PM CDT THU JUL 22 1999
CLEAR TO PARTLY CLOUDY ACROSS SERN TX THIS EVENING. THE MAIN UPDATE
ISSUE IS PATCHY FOG/LOW CLOUDS DEVELOPING TOWARD SUNRISE. COVERAGE
ON THU MORNING WAS LIMITED TO THE FOG-BELT FROM CLL-LFK-CXO-DWH-CLL.
00Z CRP/LCH AND FSL/RUC2 SOUNDINGS SHOW A MOIST NOTCH AROUND 900
MB...WHILE THE 21Z RUC AND 12Z ETA/NGM TIME-SECTIONS SHOW THE
TYPICAL HIGH-RH BULLSEYE AROUND 12Z FOR EARLY MORNING CLOUDS/FOG.
THEREFORE...THE ZONE UPDATE WILL INCLUDE PATCHY DENSE FOG AND LOW
CLOUDS ROUGHLY NORTH OF US-290 WEST OF METRO HOUSTON...THEN
NORTH OF I-10 IN AND EAST OF METRO HOUSTON.
.HGX...NONE.
31/40
PREVIOUS PRELIMS...
CLL UB 073/098 073/096 073 000-
IAH UB 072/097 073/097 073 000-
GLS UB 080/093 080/093 080 0001
FXUS64 KCRP 230147 tx
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE MIDLAND TX
1049 AM CDT THU JUL 22 1999
WATER VAPOR IMAGERY SHOWS TUTT LOW CENTERED OVER BIG BEND NATIONAL
PARK WITH SLIGHT NORTHWARD MOVEMENT NOTED. 12Z RUC SHOWS THIS
FEATURE BEST AT 300MB AND KEEPS IT IN SAME PLACE THROUGH DAY.
ALTHOUGH THERE MAY BE OLD OUTFLOW BOUNDARIES IN PORTIONS OF CWA FROM
YESTERDAY/S CONVECTION...THEY ARE VERY DIFFICULT TO FIND OR WASHED
OUT. THEREFORE...WILL LEAVE PRECIPITATION CHANCES AS THEY ARE.
DROPPED MORNING WORDING AND LOW CLOUDS IN ALL EXCEPT TERRELL COUNTY
FOR THIS AFTERNOON. TEMPERATURES ROSE TO UPPER 80S YESTERDAY IN
SAME AREA AND WITH MORE CLOUD COVER TODAY HAVE SPLIT PECOS/TERRELL
GROUP AND WENT WITH CATEGORY LOWER TEMPERATURES THAN CURRENT FORECAST
IN TERRELL.
VISIBLE SATELLITE SHOWS EXTENSIVE CLOUD COVER JUST SOUTH/SOUTHWEST
BIG BEND/PRESIDIO DEVELOPING/MOVING NORTHWARD INTO THESE AREAS. WILL
OPT FOR PARTLY SUNNY THERE...BUT THINK TEMPERATURES WILL BE O.K.
ALSO TWEAKED WIND DIRECTIONS OVER MUCH OF EASTERN COUNTY WARNING
AREA. REST OF FORECAST APPEARS ON TRACK. WILL SEND UPDATED ZONES
AND STATE SHORTLY.
AKL
FXUS64 KSJT 221546 AMD tx
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BURLINGTON VT
930 AM EDT THU JUL 22 1999
09 UTC RUC NICELY PICKING UP THE SHORTWAVE DROPPING SOUTHEASTWARD
OUT OF EASTERN ONTARIO. THE MODEL IS FOCUSING THE STRONGEST UPPER
DYNAMICS FROM THE ADIRONDACKS AND UPPER HUDSON VALLEY THROUGH
SOUTHERN VERMONT AND INTO SOUTHERN NEW ENGLAND LATE THIS AFTERNOON
AND EVENING. RUC BUFKIT SOUNDINGS SUPPORT 00/03 UTC ETA IDEA OF
WEAKENING CAP STRENGTH OVER SOUTHERN PORTIONS OF OUR FORECAST AREA
THIS AFTERNOON. HAVE THUS BUMPED THUNDERSTORM POPS TO 50 PERCENT
THESE AREAS TODAY. STRATUS DECK HANGING TOUGH IN ADIRONDACKS AND
SOUTHWESTERN VERMONT...SHOULD NOT AFFECT ZONE-WIDE TEMPERATURE RANGES
BUT WILL ADD MORE CLOUDS TO FORECAST NONETHELESS. A FEW OTHER MINOR
WORDING CHANGES BUT REST OF FORECAST IN GOOD SHAPE.
ST. JEAN
.BTV...NONE.
vt
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSONVILLE FL
128 PM EDT THU JUL 22 1999
SHORT TERM...UPPER RIDGE RETROGRADE WITH SOME LIFT AND TROUGHING
ALONG THE EAST COAST...SURFACE TROUGHING COUPLES WITH DIURNAL THERMAL
TROUGHING TO SHARPEN TROUGH AXIS FROM SE GA TO NEAR TLH. 15Z RUC
AND 12Z AVN MODELS DEVELOP LOW IN SOUTH CENTRAL GA OVERNIGHT...ETA
BUILDS IT FURTHER SOUTH AND WEAKER. LOOKS LIKE GOOD CHANCE OR BETTER
OF RAIN FOR BOTH FL AND GA CWA THIS EVENING AND OVERNIGHT. AMOUNTS
FROM QUARTER TO HALF INCH WIDESPREAD...WITH HEAVY RAIN UNDER A FEW
SLOW MOVING THUNDERSTORMS MOSTLY IN SOUTHERN END OF FL CWA...FOCUS
NEAR A LINE FROM ST AUGUSTINE TO PALATKA TO OCALA.
ETA AND NGM ARE NOW INDICATING LOW WIND SPEEDS FOR TOMORROW...AND
IT MATCHES WELL WITH SUBSIDENCE ROTATING SOUTH FROM MID ATLANTIC.
IF THIS ALL MATCHES UP MID DAY TOMORROW WE WILL BAKE...UPPER 90S.
GIVEN CURRENT LOW LEVEL MOISTURE AND TODAYS AM TEMPS OF 80 ALONG THE
COAST...A HEAT ADVISORY MAY BE IN ORDER FOR TOMORROW.
FRIDAY...ANOTHER HOT AFTERNOON. TEMPS IN MID 90S IN COASTAL SECTIONS
BUT VERY HOT INTERIOR...UPPER 90S. POPS ON FRIDAY BELOW
CLIMATOLOGICAL NORMALS.
MARINE...WINDS AND SEAS LIGHTER THAN PROGGED ACROSS THE AREA TODAY...
AND MODELS CONVERGING TO THAT SOLUTION FOR TOMORROW AS WELL.
WIND BECOMING 5 TO POSSIBLY 10 SOUTHWEST TONIGHT AND FRIDAY AFTER
TROUGH SHIFTS WESTWARD. OTHERWISE NO SIGNIFICANT CHANGES TO PACKAGE.
SORRY ABOUT THE NUMBERS...
AMG 75/97/73/95 3432
SSI 75/95/74/93 5333
JAX 75/98/75/95 6433
GNV 74/95/73/94 4533 13
WELSH
FXUS62 KJAX 221720 fl
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
1030 PM EDT THU JUL 22 1999
MAIN FORECAST CONCERN TONIGHT IS POSSIBILITY OF THUNDERSTORMS.
SYNOPTIC PATTERN REMAINS LARGELY UNCHANGED FROM YESTERDAY...WITH
HIGH PRESSURE DOMINATING WEATHER OVER THE CONUS. LATEST SFC ANALYSIS
SHOWS PERSISTANT STATIONARY FRONT FROM SOUTHERN MN ACROSS SOUTHERN WI.
DEWPOINTS SOUTH OF FRONT IN LOW 80S AT SOME LOCATIONS. WEAK SFC TROF
ALSO LOCATED IN CENTRAL PLAINS. CONVECTION HAS RECENTLY FIRED UP IN
THIS REGION...WITH A WATCH BOX OVER EASTERN DAKOTAS.
CURRENTLY A QUIET NIGHT OVER THE U.P. SOME ISOLATED THUNDERSTORMS
MOVED ACROSS NORTHERN LAKE SUPERIOR AROUND 23Z...OTHERWISE NO PRECIP
TO SPEAK OF. INSTABILITY REMAINS IN PLACE ACROSS THE CWA.
HOWEVER...DIURNAL TREND...AND LACK OF ANY FORCING SHOULD PREVENT ANY
THUNDERSTORMS FROM DEVELOPING UNTIL VERY LATE TONIGHT/EARLY MORNING
IN WESTERN ZONES. AT 00Z CONVECTION WAS FIRING UP IN EASTERN DAKOTAS
ALONG THETA E RIDGE AXIS. NO REASON THIS AREA OF CONVECTION SHOULD
NOT PERSIST AS IT MOVES INTO MN...WHERE CAPES SURPASS 4000
J/KG...AND ETA INDICATES 250MB DIVERGENCE TO AID LIFT. IR IMAGERY
ALSO SHOWS SOME CONVECTION TRYING TO DEVELOP...BUT NOT AS
SUCCESSFULLY...IN SOUTHERN WI ALONG ANOTHER THETA E RIDGE. MESOETA
AND RUC PUSH THETA E RIDGE EASTWARD...TO WESTERN CWA BY 12Z. MESOETA
HINTS AT MCS DEVELOPMENT BETWEEN 9Z AND 12Z IN NW WI...JUST WEST OF
CWA. RUC AND MESOETA ALSO SHOW POSITIVE SI'S OVER CWA...WITH
NEGATIVE VALUES GETTING INTO WESTERN CWA NEAR 12Z. THE POSITIVE SI
VALUES MATCH UP PRETTY WELL WITH AREAS THAT ARE CONVECTION-FREE FROM
THE U.P. TO WESTERN MN AND TO SOUTHERN WI. BY 12Z...-2 SI LINE IS
JUST WEST OF MQT. CAPES APPROACH 3000 J/KG IN WESTERN COUNTIES
BETWEEN 9 AND 12Z. I THINK WE WILL SEE THE CONVECTION CURRENTLY IN
EASTERN DAKOTAS ADVANCE GENERALLY EASTWARD OVERNIGHT...WITH SOME
THUNDERSTORMS POSSIBLE IN WESTERNMOST...AND POSSIBLY CENTRAL
COUNTIES...TOWARD MORNING. TEMPS LOOK OK. WILL FRESHEN WORDING...AND
ADJUST WINDS.
MQT...NONE.
JS
FXUS63 KAPX 230126 mi
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON OH
941 PM EDT THU JUL 22 1999
00Z SFC ANALYSIS INDICATED A CONVERGENCE BOUNDARY EXTENDING FROM
SERN WI TO THE MID-ATLANTIC STATES. A SHORTWAVE SHOWN ON THE 00Z
RUC WAS OVR IN. THIS HAS RESULTED IN SEVERAL CONVECTIVE COMPLEXES
FOCUSING ALONG THE BOUNDARY.
THE 00Z RUC INDICATES THAT THE SHORTWAVE WILL REMAIN W OF THE FA
OVERNIGHT WHICH SHOULD KEEP THE TSRA GOING MUCH OF THE NIGHT. WL
KEEP POPS IN FOR MUCH OF AREA OVERNIGHT BUT WL BREAK OUT GROUPS TO
ELIMINATE PRECIP FROM AREAS NOT GETTING RAIN.
ONLY OTHER CHANGE WL BE TO THE WINDS.
FORECAST WILL LIKELY BE ISSUED LATER THAN NORMAL DUE TO UPDATES
ALREADY ISSUED.
.ILN...NONE.
WILKINSON
FXUS61 KCLE 230041 oh
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
1110 AM EDT FRI JUL 23 1999
IN THE SHORT TERM...WILL UPDATE FORECAST MAINLY FOR WORDING. HEAT
ADV STILL LOOKS GOOD AS TEMPS WILL REACH MID/UPR 90S...& INDEXES TO
105-115. MAIN CONCERN IS CHANCE OF ANY STRONG TO PULSE SEVERE
STORMS. 12Z TLH SOUNDING HAS PRECIP WATER AT 2.06 INCHES...DRY AIR
ALOFT OF 5H...LI OF -9...CAPE 4800...& CONVECTIVE TEMP OF 92. WHEN
MODIFIED...ALL FACTORS BECOME MORE UNSTABLE. RUC IS INDICATING SOME
SURFACE & UPPER TROUGHING TO AFFECT CWA...LI TO MAX OUT AT -9 TO -7
FROM N FL TO SRN AL-GA. SEA BREEZY SHOULD PENETRATE A BIT FARTHER
NORTH AS SURFACE N FLOW HAS WEAKENED...& WOULD BRING CONVECTION MORE
OVER CWA. HAZARDOUS WEA OUTLOOK HAS BEEN UPDATED...WILL ALSO UPDATE
HEAT ADV FOR CONCISENESS & WORDING.
MARINE...IN RESPONSE TO TROUGHING...WINDS SHOULD GENERALLY SHIFT TO
MORE WEST THROUGH AFTERNOON. CURRENT FCST OK.
MCT
FXUS62 KMLB 231426 fl
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
1117 AM EST FRI JUL 23 1999
GOES CAPES AND SOUNDERS SHOWING 3 AXIS OF HIR CAPE AND ERODING CINH.
ONE FM SRN WI WSW TO CNTRL IA...SRN IL NOSING NNE AND ALONG AND S OF
WK BNDRY ACRS SWRN OH INTO EXTRM NERN IN. LTST RUC V17Z EVEN MORE
UNSTABLE WITH 4K + J/KG. WL UPDATE FOR MINOR CHNGS TO BUMP TEMPS
SLIGHTLY TO MID 90S IN AND LWR 90S MI AND 40 POP WITH SCT WORDING
LATE AFTN.
.IWX...NONE
MURPHY
FXUS73 KIND 230838 in
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
1035 PM EST THU JUL 22 1999
CONVECTION THIS EVE WILL NOT QUIT. STATIONARY FRONTAL BNDRY SE WI TO
SW OH STILL APPARENT PER 02Z LAPS. 21Z/00Z RUC MODEL RUNS BOTH
ADVERTISING INCREASING MOISTURE CONV ALNG THIS FTR ACRS NW IN LTR
TONIGHT. WITH SUCH LG THETA E RIDGE JUST W AND S OF FA AND BACKING
LOW LVL FLOW AHD OF PLAINS SW OVERNIGHT AND AFOREMENTIONED CONV INTO
DIFFUSE BNDRY FEEL SMALL CHANCE POP IN ORDER. KIWX RADAR LOOP DOES
SHOW RENEWED ACTIVITY DVLPG ALNG A GYY TO MZZ LINE AND LIKELY AN
INDICATION OF THIS OCCURRING ALREADY. OTHERWISE WITH DEBRIS CLOUDS
XPC TEMPS TO REMAIN SOMEWHAT HIGHER THEN LAST NIGHT AND HAVE
ADJUSTED LOWS SOMEWHAT HIGHER.
.IWX...HEAT ADVISORY CONTS FOR NRN IN THROUGH FRI
TEH
FXUS63 KIWX 222250 in
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
325 AM CDT FRI JUL 23 1999
WEAK SURFACE TROF EXTENDED ACROSS CENTRAL PART OF THE STATE AT 06Z
WITH SEVERAL CLUSTERS OF THUNDERSTORMS EMBEDDED IN PLUME OF
MONSOONAL MOISTURE FROM NEBRASKA INTO MINNESOTA. SHORT TERM PROBLEM
WILL BE CHANCE OF THUNDERSTORMS THIS MORNING. SMALL BAND OF SHOWERS
AND A FEW THUNDERSTORMS MOVED INTO NWRN CWA AROUND MIDNIGHT BUT HAD
DISSIPATED BY 230 AM. STORMS OVER CENTRAL NEBRASKA HAVE GENERALLY
BEEN WEAKENING WITH TOPS WARMING ON SATL LOOP. WITH SFC TROF
PUSHING INTO AREA DURING THE MORNING AND RUC INDICATING CHC OF SOME
PRECIP IN AREA OF WEAK WARM ADVECTION OVER THE SOUTHEAST WILL PUT
SOME LOW POPS IN FOR THE MORNING THERE AND KEEP IN FOR NERN
AREAS.
SFC TROF WASHES OUT FOR MOST PART DURING THE AFTERNOON WITH LITTLE
IN THE WAY OF FORCING ALOFT OR AT THE SURFACE TONIGHT AS NEXT WAVE
MOVES INTO THE WESTERN U.S. WITH NEW SFC DEVELOPMENT OVER THE NRN
PCKYS. WILL KEEP THINGS DRY THEN FOR TNGT AND SAT.
HOT AND HUMID CONDITIONS TO CONTINUE THROUGH PERIOD WITH LIGHT WINDS
TODAY NOT HELPING THINGS. WILL CONTINUE CURRENT HEAT ADVISORY
THROUGH SATURDAY.
.OMA...HEAT ADVISORY TODAY THROUGH SATURDAY - ALL ZONES IN FCST AREA
OF ERN NE AND SWRN IA
DF
FXUS63 KGID 230706 ne
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
920 AM EDT FRI JUL 23 1999
DISC: 13Z ANALYSIS SHOWS HI PRES OVR THE TX/LA GULF CST AND A WK TROF
ALNG THE CSTL AREAS OF THE CAROLINAS.
SATELLITE SHOWS LOTS OF SUN ACRS THE STATE THIS MORNING WITH OBS SHOWING
PLENTY OF HZ. 09Z RUC A LITTLE DIFFERENT THAN 00Z ETA...BY SHOWING A WK
S/W TO MOVE SWD OUT OF SW VA THIS MORNING INTO THE NRN PTN OF SC BY AFT.
STILL HAVE QUITE OF BIT OF LOW LVL MOISTURE OVR THE AREA. WITH GOOD
HEATING THIS AFT...AIRMASS SHOULD BECOME MODERATELY UNSTABLE WITH CAPES
SIMILAR TO THU ARND 4000. EXPECT SOME ISO/WDLY SCT AFT/EARLY EVENING
SHRA/TSRA OVR THE AREA. LOOKING AT CHS RAOB PCPN WATER OVR 2.5 INCHES
AND SLOW STORM MOTION...LOCALLY HEAVY RAIN FOR SOME. TEMPS ALREADY OFF
TO A FAST START THIS MORNING...BETTER THAN THU...DUE TO PLENTY OF SUN.
SHOULD HAVE NO PROBLEM REACHING ADVISORY CRITERIA TDA. HI HERE ALREADY
APPROACHING 100 DEGREES.
.CAE...HEAT ADVISORY TODAY AND SATURDAY
SCZ015-016-018-020>022-025>031-035>038-041.
GAZ040-063>065-077.
LCV
FXUS62 KGSP 231323 sc
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
922 AM EDT FRI JUL 23 1999
RUC SHOWS WEAK VORT MAX MOVING FROM N NC MOUNTAINS TO METRO CLT
TODAY. MODIFIED AREA SOUNDINGS YIELD CAPE AROUND 4000 WITH MINIMAL
SHEAR. EXPECT ANOTHER DAY OF WIDELY SCATTERED CONVECTION IN THE
MOUNTAINS AS DIFFERENTIAL HEATING TAKES PLACE. EXPECT A FEW
STORMS TO APPROACH SEVERE LIMITS. WILL EXPAND SMALL POP TO ALL
MOUNTAIN ZONES AND MAYBE NC FOOTHILLS TO ENCOMPASS BLUE RIDGE.
HEAT ADVISORY CRITERIA REACHED FOR ONE HOUR AT CLT YESTERDAY AND
WILL BE APPROACHED AGAIN TODAY. WILL NOT ISSUE ADVISORY DUE TO
EXPECTED SHORT DURATION OF HEAT INDEX 105 OR GREATER. WILL HANDLE
WITH STRONGLY WORDED NOWCAST. TEMPERATURES RUNNING 2-4 DEGREES
ABOVE FWC GUIDANCE...BUT GUIDANCE HAS BEEN WAY TOO HIGH LATELY.
EXPECT TEMPERATURES TO BE A DEGREE OR TWO WARMER THAN YESTERDAY.
CURRENT TEMPERATURE FORECAST APPEARS ON TRACK.
.GSP...NONE.
JAT
FXUS62 KCHS 230708 sc
INTERIOR CENTRAL CALIFORNIA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
930 AM PDT FRI JUL 23 1999
CWFA REMAINS SANDWICHED BETWEEN EPAC TROUGH AND THE UPPER RIDGE
OVER THE SOUTHWEST STATES. WV IMAGERY IS SHOWING THE UPPER LOW
APPROACHING THE NORCAL COAST WITH A DRY MIDLEVEL FLOW ACROSS
CENTRAL CA. 12Z OAK RAOB IS REFLECTING THE INCREASED ONSHORE WITH
SUBSTANTIAL COOLING BETWEEN 900 AND 1000 MB PAST 24 HRS WHILE DRA
HAS SHOWN WARMING ALOFT UNDER GENERAL SUBSIDENCE ASSOCIATED
WITH THE UPPER HIGH.
FORECAST CONCERN THIS MORNING IS TEMPERATURES AND WINDS TODAY.
MODELS IN GOOD AGREEMENT WITH THE H5 PATTERN THROUGH SAT MORNING
WITH VERY MODEST 5OO MB HEIGHT FALLS ACROSS THE SOUTH PORTION
OF THE CWFA AND ABOUT A 60M DECREASE ACROSS THE FAR NORTH.
24HR CHANGE SHOWING SJV VALLEY TEMPS ON PAR WITH YESTERDAY ACROSS
THE NORTH AND SLIGHTLY AHEAD OF YESTERDAY ACROSS THE SOUTH.
12Z ETA/NGM DIFFER ON H8 TEMP OUTCOME TODAY WITH THE NGM SHOWING
MORE COOLING. WITH THE INCREASED ONSHORE FLOW EXPECTED TO BRING
SOME COOLER AIR INTO THE SJV THIS AFTERNOON AND HEIGHTS
TRENDING DOWN...FEEL THE SLIGHT DOWNWARD TREND IN TEMPS REFLECTED IN
ZONES LOOKS REASONABLE.
P-GRADIENTS ON THE INCREASE TODAY WITH THE ETA SHOWING A SFO-LAS
GRADIENT NEAR 12MB BY LATE AFTERNOON WHILE THE RUC IS A FEW MB
WEAKER. EXPECT LOCALLY BREEZY CONDITIONS TO DEVELOP THIS AFTERNOON
THROUGH THE DESERTS AND MOUNTAIN PASSES...AS WELL AS ALONG THE WEST
SIDE OF THE SJV VALLEY. WILL UPDATE ZONES FOR MINOR ADJUST TO
WINDS.
.HNX...NONE
LINDQUIST
FXUS66 KSTO 231624 ca
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
152 PM EDT FRI JUL 23 1999
WEAK VORT LOBE DEPICTED BY MORNING RUC SHOWN BY ETA/NGM TO STALL
OVER AREA TONIGHT. MORE VIGOROUS VORT LOBE APPROACHES AREA SAT
AS UPPER RIDGE RETROGRESSES AND TROUGH AMPLIFIES OVER E COAST
ALLOWING NW FLOW INTO MID ATLANTIC STATES. MID LEVEL COOLING
NOTED OVER AREA SAT/SUN...MOST PRONOUNCED IN ETA. LEE TROUGH TO
DEVELOP SAT...PROVIDING FOCUS FOR CONVECTION. MAX OMEGA OVER AREA
SAT AFTERNOON WITH DEEPEST MOISTURE. HIGH/MID LEVEL DRYING SAT
NIGHT. ANOTHER VORT LOBE APPROACHES AREA SUN IN NW FLOW...BRINGING
MORE SCATTERED CONVECTION.
WITH LOWER HEIGHTS AND MORE CLOUDS AROUND EXPECT SLIGHT COOLING
SAT. TEMPERATURES STILL ABOVE NORMAL. VEERING LOW LEVEL FLOW W
SIDE LEE TROUGH TO LOWER DEW POINTS A BIT SAT. CONTINUED VEERING
WILL LEAD TO IMPROVED DOWNSLOPE FLOW SUN RESULTING IN SLIGHT
WARMING LEE OF MOUNTAINS. FWC TEMPERATURES CONSISTENTLY TOO HIGH.
WILL LEAN TOWARD COOLER FAN.
AVL 68/89/66/89 2433
CLT 71/94/70/95 1433
GSP 72/95/71/96 1433
.GSP...NONE.
JAT
FXUS62 KCHS 231418 sc