INTERIOR CENTRAL CALIFORNIA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
845 PM PDT FRI AUG 13 1999
CLOSED UPPER LOW CENTERED JUST OFF THE WA COAST. HEIGHTS ACROSS
CENTRAL CA ARE SLOWLY LOWERING PER RUC ANALYSIS. WEAK SHORT WAVE ON
BACK SIDE OF LOW MOVING SOUTH AND APPROACHING 40N. NEW ETA APPEARS
FAIRLY WELL INITIALIZED AND SWINGS THIS WAVE INTO NRN CA EARLY SAT.
IN RESPONSE...HEIGHTS TO LOWER ACROSS CENTRAL CA ANOTHER 40 METERS
OR SO SAT...LOWERING TEMPS 3 OR 4 DEGREES FROM TODAY. MARINE LAYER
ALONG THE COAST IS FAIRLY MIXED...SO COOLING NEXT TWO DAYS WILL BE
TIED TO DYNAMIC PROCESSES...RATHER THAN ANY SIGNIFICAN INLAND PUSH.
CURRENT FCSTS HANDLE SITUATION VERY WELL...SO NO UPDATES.
IN THE EXTENDED...VARIATIONS IN MODELS NOT TOO SIGNIFICANT...WITH
NOGAPS/CANADIAN/MRF KEEPING GENERAL TROFINESS ALONG THE COAST THRU
MID WEEK. TOUGHEST FCST IN THE EXTENDED WILL BE DAY TO DAY
FLUCTUATIONS IN TEMPS...DEPENDENT ON LOCATIONS OF SHORT WAVES MOVING
THRU MEAN TROF. ALL POPS ZERO. BINGHAM
.HNX...NONE.
FXUS66 KMTR 140340 ca
INTERIOR CENTRAL CALIFORNIA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
235 PM PDT FRI AUG 13 1999
UPPER LOW SOUTH OF VANCOUVER ISLAND CONTS TO APPROACH THE NORTHERN
WA COASTLINE THIS AFTERNOON. ALTHOUGH 12Z MODELS AGREE ON LOW
SHIFTING INTO PAC NW LATE TONIGHT/EARLY SATURDAY WITH ASSOCIATED TROUGH
DEEPENING ALONG WEST COAST STATES...GUIDANCE DIVERGES AFTER 18Z SAT
WITH AVN/ETA MAINTAINING A STRONGER TROUGH OVER CA. DESPITE ABOVE
DIFFERENCES...PROGS AGREE ON H5 HEIGHTS DECREASING 50-60M BY 00Z SUN
AS LOW SHIFTS INLAND AND TROUGH STRENGTHENS OVER THE REGION.
DECREASING THICKNESSES AND H85 TEMPS SHOULD PRODUCE SOME SYNOPTIC
COOLING THROUGHOUT THE FORECAST AREA SAT. HOWEVER...ETA/S LOW LEVEL
THERMAL PROFILE APPEARS TOO WARM GIVEN IT/S FORECAST TROUGH STRENGTH
FOR SAT AND WILL THEREFORE FAVOR AVN/NGM SOLUTIONS. ALTHOUGH SURFACE
PRESSURE GRADS REMAIN RELATIVELY WEAK THUS FAR...GRADS HAVE BEEN
TIGHTENING DURG THE PAST FEW HOURS AND BOTH 12Z ETA AND 15Z RUC
INDICATE ONSHORE FLOW INCREASING THROUGH THE EVENING HOURS WITH
ADDITIONAL GRAD INCREASES ACROSS THE CENTRAL CA INTERIOR. PROGGED
8-10MB GRADS SHOULD RESULT IN LOCALLY BREEZY CONDITIONS ACROSS
FAVORED LOCATIONS IN KERN MOUNTAINS/DESERTS WHILE ALSO BRINGING SOME
REINFORCEMENT OF COOLER MARINE PRESENCE TO THE CENTRAL/SOUTHERN SJ
VALLEY.
ALTHOUGH AVN AND SUITE OF EXTENDED MODELS INDICATE SOME RECOVERY IN
HEIGHTS SUN THRU TUES AS RIDGE ATTEMPTS TO STRENGTHEN OVER
INTERMOUNTAIN STATES...MODELS AGAIN DIVERGE REGARDING STRENGTH OF
NEXT TROUGH TO AFFECT THE WEST COAST BY MIDWEEK. CONTD SW FLOW
ALOFT...HOWEVER...WILL KEEP CWA FREE OF ANY MONSOONAL MOISTURE
THROUGH AT LEAST THE MIDDLE OF NEXT WEEK. ALL POPS ZERO.
.HNX...NONE.
FAT UU 060/087 058/088 060 88000
BFL UU 059/086 058/086 059 88000
YNP UU 050/080 050/082 052 88000
NESMITH
FXUS66 KMTR 132129 ca
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
912 AM PDT FRI AUG 13 1999
MAIN WEATHER TODAY IS DEALING WITH WEAK SHORT WAVES ROTATING AROUND
MAIN UPPER CIRCULATION OVER THE VANCOUVER ISLAND. SHORT WAVE WHICH
SUPPORTED CONVECTION LAST NIGHT IN FAR NORCAL HAS LIFTED INTO ERN
OREGON. A WEAKER SECONDARY WAVE IS SEEN ON SATELLITE EXTENDING TO
THE SOUTHWEST. 12Z ETA AND RUC PICK UP ON THIS FEATURE AND DRAG IT
ACROSS NORCAL MIDDAY. SOME INSTABILITY AND THE TAIL OF H7 MOISTURE
IS ALSO NOTED ON THESE MODELS. IN ADDITION...H85 MSTR CONVERGENCE
AND UPPER DIVERGENCE FROM DEPARTING JET IS PROGGED IN THIS REGION.
TIMING WITH MAX HEATING IS NOT PERFECT BUT SLIGHT CHANCE FOR TSRA
OVER NRN MTNS STILL LOOKS GOOD.
MARINE LAYER THIS MORNING WAS OBSERVED NEAR 1300 FEET. MORNING
SOUNDINGS FROM KOAK AND AIR RESOURCES BOARD SHOW LITTLE CHANGE TO
ATMOSPHERE TEMP PROFILE. VISIBLE PICTURES SHOW ONLY STRATUS ALONG THE
CARQUINEZ STRAIT THIS MORNING AND SOME CLOUDS OVER COASTAL RANGE.
STRATUS OVER OCEAN IS BROKEN UP FROM NORTHERLY FLOW/SUBSIDENCE. ELSEWHERE
SKY IS CLOUD FREE. H85 TEMPS ARE FCST TO BE THE SAME OR MAYBE A DEG
COOLER THAN YESTERDAY WITH LITTLE H5 HEIGHT CHANGE TODAY. ONSHORE
FLOW IS A STRONGER THAN YESTERDAY AND WITH THAT IN MIND MAX TEMPS
SHUD BE A LITTLE COOLER TODAY...HOWEVER MARINE EFFECT MAY BE MINIMAL
WITH DEPTH SO SHALLOW AND WE MAY MIX OUT. AT THIS TIME TEMPS ARE
RUNNING THE SAME TO 2F COOLER COMPARED TO THURSDAY. CURRENT FCST
LOOKS ON TRACK. MORE HEIGHT FALLS OCCUR TONIGHT AS MAIN TROF/SHORT
WAVE SINKS OVER THE PACIFIC NORTHWEST WITH 60KT JET ON ITS BACKSIDE.
THIS WILL CREATE STRONGER ONSHORE FLOW TOMORROW...HOWEVER SUBSIDENCE
BEHIND THIS SHOULD SHIFT SURFACE/LOW LEVEL WINDS TO THE
WEST-NORTHWEST STARTING SATURDAY MORNING. AIR MASS IS MORE STABLE ON
SATURDAY IN NORCAL.
STO...NONE.
TARDY
FXUS66 KHNX 131608 ca
INTERIOR CENTRAL CALIFORNIA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
905 AM PDT FRI AUG 13 1999
STRONG SHORT WAVE LIFTING RAPIDLY NE OUT OF NORCAL THIS MORNING AS
UPPER LOW CONTS TO MOVE SOUTH TOWARD WA COASTLINE. ETA/NGM CONT TO
DEEPEN UPPER TROUGH ALONG WEST COAST DURING THE NEXT 24 HOURS AS LOW
SHIFTS INTO PAC NW. PROGS THEN DIVERGE SAT/SUN WITH ETA MAINTAINING
STRONGER TROUGH OVER CA WHILE NGM DAMPENS FLOW AFTER LOW/S EASTWARD
EJECTION. ALTHOUGH MOISTURE WILL REMAIN MINIMAL AT THIS LATITUDE...
WILL AWAIT FULL ARRIVAL OF AVN TO ASSESS IMPACT ON TEMPS ACROSS THE
REGION.
IN THE INTERIM...ETA/NGM/RUC INDICATE LITTLE ADDITIONAL CHANGE IN
HEIGHTS FROM 12Z THIS MORNING TO 00Z THIS EVE WITH BOUNDARY
THICKNESSES AT 00Z CLOSE TO THURSDAY/S LEVELS. WITH WEAK MARINE PUSH
LAST NIGHT RELATIVELY SHALLOW AND CENTRAL/SOUTHERN SJ VALLEY SURFACE
TEMPS RUNNING CLOSE THURSDAY AT THIS TIME...WILL MAKE A FEW
ADJUSTMENTS TO TEMPS ACROSS THE CWA FOR TODAY. CURRENT WIND
FORECASTS LOOK GOOD...HOWEVER...AS ONSHORE GRADS AGAIN TIGHTEN AHEAD
OF UPPER LOW. ALL POPS ZERO.
.HNX...NONE.
FAT UU 089/060 086/058 085 96000
BFL UU 087/059 084/057 083 96000
YNP UU 084/050 079/049 077 96000
NESMITH
FXUS66 KMTR 131600 ca
EAST CENTRAL FLORIDA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MELBOURNE FL
745 PM EDT FRI AUG 13 1999
CURRENTLY...BETTER MOISTURE CONVERGENCE WAS TO THE NORTH DUE TO
SURFACE TROUGH...AND TO THE SOUTH DUE TO LOW LEVEL CYCLONIC
CIRCULATION DEPICTED BY THE LATEST RUC. IN BETWEEN...DRY AIR ALOFT
WORKED ACROSS FROM THE EAST AND KEPT MOST OF THE AREA PRECIP FREE.
OVERNIGHT...LITTLE PROSPECTS FOR RAINFALL NORTHERN TWO THIRDS AS
DEEP LAYER DRYING PREVAILS. LOW LEVEL CYCLONIC CIRCULATION PROGGED TO
MOVE WEST WITH HIGH PRESSURE RIDGE BUILDING TO OUR SOUTH. THIS WILL
RESULT IN WINDS BECOMING SOUTH TO SOUTHWEST WHICH SHOULD KEEP MOST
NOCTURNAL ATLANTIC CONVECTION OFFSHORE SOUTHERN SECTIONS. THEREFORE
THE EVENING UPDATE WILL LIKELY NOT HAVE POPS IN ANY ZONES.
MARINE...WILL GO WITH 10 KT S TO SW WINDS OVER SOUTHERN SECTION AS
PER MAPS ANALYSIS AND 21Z RUC. WITH THE PROXIMITY OF THE DEEPER
LAYER MOISTURE AND SOME CLOUD LINES EVIDENT ON SATELLITE...WILL
INDICATE WIDELY SCATTERED SHOWERS/STORMS OVER THE SOUTHERN LEG.
.MLB...NONE.
LASCODY
FXUS62 KMLB 131914 fl
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAMPA BAY-RUSKIN FL
1030 AM EDT FRI AUG 13 1999
LOW LEVEL SUBSIDENCE IS WORKING ACROSS THE CENTRAL PART OF THE
STATE...THE RUC HAS IT CONFINED TO THE CENTRAL PORTION OF THE STATE
AND BREAKING DOWN SOMEWHAT BY AFTERNOON. A 30 POP LOOKS GOOD FOR
MOST OF OUR CWA. BUT IN THE NORTH...TLH SOUNDING HAS PWATS IN THE 2
INCH RANGE...RUC ALLOWS THIS TO FILTER INTO THE NORTHERN ZONES. I
PLAN TO BREAK THE CITRUS AND LEVY COUNTY ZONE INCLUDING CITRUS WITH
THE ZONES TO THE SOUTH AND INCREASE THE POP IN LEVY COUNTY TO MATCH
THAT OF DIXIE...40 PERCENT. OTHERWISE NO CHANGES ARE PLANNED FOR
THE MORNING UPDATE.
SOBIEN
FXUS62 KMLB 131409 fl
SOUTHEAST IDAHO AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE POCATELLO/IDAHO FALLS ID
910 PM MDT FRI AUG 13 1999
EVENING DOPPLER RADAR SHOWING A FEW LINGERING VIRGA SHOWERS OVER THE
SNAKE RIVER PLAIN BUT NO SIGNIFICANT WEATHER IN FCST/A. SAT IR IMAGE
SHOWING NICE JET STREAK (80KT 3H JET) CIRRUS CLOUDS RACING ACROSS SE
ID THIS EVENING. THIS FEATURE (LF QUAD OF JET) RESPONSIBLE FOR THE
ACTIVE TSTMS THIS AFTERNOON ACROSS NORTHWEST FCST/A. ANOTHER WAVE
APPEARS TO BE SLIDING NE ACROSS E OREGON BUT SHOULD REMAIN WELL WEST
OF FCST/A TONIGHT.
REMAINDER OF TONIGHT...WILL REMOVE POPS OR LOWER TO 10 PERCENT. RUC
MODEL SHOWING A BULLSEYE OF NVA SLIDING ACROSS AREA. FOR SATURDAY...
ACTIVE AFTN TSTMS WILL LIKELY DEVELOP ONCE AGAIN NORTH OF JET AXIS IN
AREA OF HIGHER DEWPTS (SAWTOOTH MTNS AND BIG/LITTLE WOOD RIVER
REGION). FURTHER SOUTH AND EAST...ETA FCSTING LITTLE IF ANY CAPE.
WEDGE OF DRY AIR WILL CONTINUE TO SLIDE NORTHEAST FROM NV INTO SE ID
KEEPING MOST OF SE FCST/A IN DRY AND MORE STABLE AIRMASS.
UPDATED ZONES WILL BE OUT SHORTLY.
WINTHER
TEMPERATURES/POPS ARE UNOFFICIAL AND FOR COORDINATION ONLY...
BYI 055/087 053/080 123
.KSFX WSR-88D...OPERATIONAL...VCP 11.
.PIH...NONE.
PIH BB 048/085 047/076 048 03124
IDA BB 046/082 045/074 047 03135
FXUS65 KBOI 140256 id
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE/WASHINGTON
1000 AM EDT FRI AUG 13 1999
VIS LOOP INDICATING A STRATUS DECK ACROSS THE SOUTHEASTERN CORNER OF
CWA.. MOVING SLOWLY NORTHWARD WITH STRENGTHENING SSELY FLOW. SOME
DEBRIS CIRRUS FROM CONVECTION TO THE WEST HAS BEEN SPREADING INTO
WESTERN MD AND THE WV PANHANDLE. KLWX RADAR SHOWING AN AREA OF LIGHT
SHOWERS EXTENDING FROM SCNTRL PA TO NEAR CBE... WHILE KRLX/KPBZ RADARS
HAVE SOME SCATTERED CONVECTION OVER CENTRAL AND NORTHERN WV.
13Z SURFACE ANALYSIS HAS A WEAK TROUGH EXTENDING FROM EASTERN OHIO
THROUGH WV AND NORTHERN VA.. AND DOWN TOWARD THE TIDEWATER. 00Z AND
12Z RUC DEVELOPED A SURFACE TROUGH DURING THE DAY TODAY AND MOVED IT
ACROSS THE CENTRAL AND EASTERN SECTIONS OF THE FA... AND THE LATEST
SURFACE ANALYSIS MAY BE SHOWING SIGNS OF THAT. DEW POINTS HAVE SLIMBED
UP TO NEAR 70 FOR THE WESTERN HALF OF THE AREA... AND IN THE MID TO
UPPER 70S CLOSER TO THE BAY. AREAS THAT SEE A GOOD DEAL OF SUN WILL
LIKELY CLIMB INTO THE MID 90S PER 12Z SOUNDING... AND CAPES SHOULD THEN
EXCEED 3500. QUESTION IS AMOUNT OF SUNSHINE FOR THIS AFTERNOON. CIRRUS
IS THIN ENOUGH THAT TEMPS ARE CLIMBING FAIRLY WELL. STRATUS SEEMS TO
BE A PROBLEM.. BUT WITH STRONG SUMMERTIME SUN WOULD THINK THAT THIS
WOULD THIN OUT AS THE AFTERNOON WENT ON.
WILL BREAK UP ZONES A LITTLE BIT TO ACCOUNT FOR MORE PERSISTENT
CLOUDINESS. PLAN TO ADD A 30 POP ACROSS THE AREA FOR THE AFTERNOON AS
POTENTIAL EXISTS WITH WEAK SURFACE FEATURE AND HIGHLY UNSTABLE AMS.
HAVE MADE NO REAL CHANGES TO TEMPS... HEAT ADVISORY CRITERIA WILL BE
APPROACHED BUT AFTER A HOT SUMMER IT DOES NOT APPEAR THAT THIS EVENT
WILL BE ENOUGH TO WARRANT A HEADLINE.
.LWX...NONE.
MARGRAF!
md
AREA FORECAST DISCUSSION..PRIMARY UPDATE PGH 09Z RUC..
NATIONAL WEATHER SERVICE TAUNTON MA
626 AM EDT FRI AUG 13 1999
...VERY WARM AND HUMID WX NEXT 72 HRS MAY YIELD EXCESSIVE RAINFALL
AND A SML SCALE FF SOMEWHERE IN SNE...
TELCON COORD OKX AND MESH PRODUCTS WITH ADJACENT OFFICES.
MARINE: MAY HAVE ISO G 25 KTS THIS AFTN CLOSE TO LAND OTRW BEST
CHC GRAD 25 KTS SHUD B SAT THO WITH CNV DVLPG S COAST TNGT
...MAY SEE 25 KTS THERE TWD DAWN. FOR NOW CONFINED PRIMARY
SCA THREAT TO SAT.
SVR: ETA/RUC IB THROWS QUITE A BIT OF CONVECTION INTO SNE MIDDAY AND
AFTN. SWEAT INDEX RATHER HIGH AND THERE IS SOME HELICITY. MAY
HAVE ISO SVR THIS AFTN BUT NOT WRITING SPS FOR IT..JUST MENTION
POSSIBLE STG GUSTY WINDS INTERIOR SNE.
09Z RUC LOOKS RIGHT ON AS SMALL SHOWERS POPPING OVR NJ AND S OF LI
SINCE 0930Z (DIX/OKC CLEAR AIR MODE) IN VERY HI PW AIR. CLEARLY
DEFINED TE AXIS AND CONV ZONE DVLPG ALONG THE COAST. BLV AM REMISS
IN NOT HAVING WORDED RW+ TDY IN CT RI AND BLV POPS WILL HAVE TO
RAISED ON NEXT UPDATE.
T AFT:RAISING NGM POPS 10-50 PCT E TO W ACRS FA THIS AFTN PER 03Z
ETA/06Z RUC FCST AND ETA FCST VERIFYING MUCH BETTER THAN NGM IN
OFFSHR INSTABILITY. PREDICTED CONV TEMP MOST FAV FOR OUTBURST CT
ARD 83 AND NEAR 87 BOS AREA. NGM TEMPS LOOK GOOD TDY. MAY TOUCH 90
AGAIN CEF.
TNGT: S COAST MAY GET HAMMERED WITH VERY HEAVY CONVECTION AS SW LLJ
DVLPS THERE WITH CONVECTION DEPARTING ARD 15Z SAT. GEM/SEF
WORLDS APART AS ARE NGM/ETA. QUESTIONS ARE...WILL ETA B
CORRECT AND IF SO...HOW FAR INLAND WILL TRW+ OCCR. RIGHT NOW
BLV MOST OF THE HEAVY CONVECTION CONFINED TO A HFD-NZW LN
SOUTHWARD TO S COAST. CUD SEE ISO 3-4 INCH RAIN THERE SINCE PW
IS FCST IN EXCESS OF 1.8 INCHES WITH TRAINING EXPECTED. CANT
RULE OUT ISO SVR EARLY SAT S COAST AND SUSPECT MAY NEED SMW
WITH WIND FIELDS AT 2K NR 33 KTS. NGM TEMP FINE TNGT.
SAT: CUD DRY OUT ALOFT QUITE A BIT IN THE AFTN THEN THE REGEN OF
HEAVY CONVECTION SHUD B UPSTREAM IN NYS AND ROLL INTO NW
FRINGE FA AFTER 20Z. NGM TEMPS TOMORROW USED. ETA HAS HEAVY
R1 RH AND BLV THAT MAY B OVERDONE WITH BL WIND OF 210DEG. ALSO
NGM TEMP FCST IS WITH SOLID OVC. NOTICED AVN/NOGAPS DRY OUT LOW
LVLS A BIT SAT AFTN. IF SO...WITH 16-17C OVHD IN A 574 TKNS...
TEMPS WILL RUN WARMER. KEY IS HOW MUCH SS? BLV NGM HAS BEEN
FOR WHAT ITS WORTH...AVN CAN RUN EASILY 5F TOO COLD ON MAX TEMPS
PROVIDED PARTIAL OR MOSTLY SUNNY SKIES. AVN WAS 5-9F SHORT FOR BDL
4 CONSEC CYCLES AND FMR 10-12F TOO COLD IN CYCLES LEADING UP TO YDY
AND SHORT CHANGED BOS/PVD TO LESSER EXTENT IN 2ND-5TH CYCLES PRIOR
TO YDY. THIS IS BECOMING A VERY WARM AND HUMID AIRMASS WITH OCEAN AIR
TEMPS S OF LONG ISLAND AT 07Z 75-79F! THAT ALLOWS FOR CLOUDS BUT ALSO
IN WARM TKNS CAN HEAT UP PRETTY DECENT....EVEN CAPE COD...
LONG RANGE: SUSPECT HEAT WONT B TOO FAR BEHIND THE DEPARTURE OF THIS
WKND TROF. MAY BE FCSTG NR 90 TUE OR WED IN THE
INTERIOR. MCS COMPLICATIONS CUD ARISE IF RDG DOESNT BULGE
FURTHER NE THAN THE 13/00Z MRF SUGGESTS.
.BOX...SCA MAY BE REQ SAT ALL WATERS.
DRAG
ma
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
953 PM EDT FRI AUG 13 1999
KAPX 88D INDICATES MEASUREABLE PRECIPITATION HAS PUSHED OUT OF THE AREA
AS MID LEVEL DRYING EVIDENT IN WV IMAGERY/00Z APX RAOB HAS OVERSPREAD
NORTHERN MICHIGAN. JUST SOME PATCHY DRIZZLE/SPRINKLES LEFT ACROSS
CENTRAL LOWER DOWNWIND OF HIGHER TERRAIN AREAS. FLOW IS QUICKLY
BECOMING ANTICYCLONIC IN THE LOW LEVELS...AND 925MB ANALYSIS AND RUC
FORECASTS IMPLY STRONGEST LOW LEVEL CAA ALREADY SOUTH OF THE AREA. 12Z
ETA AND SUBSEQUENT RUC 925MB RH FORECASTS CONTINUE TO PROG DRYING SOUTH
ACROSS THE FORECAST AREA OVERNIGHT...WITH FOG LOOPS SHOWING CLEARING
PROGRESSING NICELY THROUGH THE STRAITS AND AS FAR SOUTH AS AN MBL-
ROGERS CITY LINE. GIVEN DEEP-LAYER SUBSIDENCE AND CURRENT SATELLITE
TRENDS...PLAN TO GO WITH A MOSTLY CLEAR FORECAST FOR EASTERN UPPER AND
THE STRAITS...AND PUSH THE TREND OF DECREASING CLOUDS AS FAR SOUTH AS
HTL-OSC. FORECAST MINS LOOK GENERALLY ON LINE GIVEN CURRENT DEW POINTS
AND EXPECTATION THAT WINDS WILL STAY UP OVERNIGHT.
.APX...NONE.
JPB
FXUS63 KDTX 140118 mi
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
118 PM EDT FRI AUG 13 1999
UPDATED TO PUT CHANCE POPS BACK IN TO PORTIONS OF NW CWA. RADAR
INDICATES WIDELY SCATTERED ACTIVITY OVER NORTHERN ZONES WILL
CONTINUE THORUGH THE AFTERNOON AS BROAD FRONTAL SYSTEM MOVES ACROSS
THE CWA. UPWARD MOTION ON RUC INDICATES BEST CHANCE FOR TSTMS IN
THE FORECAST AREA ARE IN THE SE BETWEEN 21 AND 00Z BUT PVA FROM
18-21Z AND CURRENT RADAR INDICATES THAT MOISTURE DIVERGENCE HAS NOT
MOVED INTO AREA AS RAPIDLY AS PREVIOUSLY ANTICIPATED.
.GRR...NONE
MWH
FXUS63 KGRR 131514 mi
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1111 AM EDT FRI AUG 13 1999
WILL UPDATE TO REFRESH WORDING...ALSO TO SLIGHTLY ADJUST
POPS...WINDS AND TEMPERATURES MOST GROUPS FOR THIS AFTERNOON.
INSTABILITY CUMULUS SCHEME AND CURRENT VISIBLE LOOPS INDICATE
LIKELIHOOD OF JUST A FEW BREAKS IN CLOUD COVER THIS AFTERNOON...SO
CURRENT WORDING SHOULD WORK FINE. CLOUD COVER WILL HELP KEEP HIGHEST
TEMPERATURES DOWN...TOWARD LOW END OF CURRENT RANGES. NEWEST RUC
SHOWS COLD FRONT INTO FAR SOUTHEAST LOWER BY 00Z...WITH SOUTHWEST
WINDS OF 10 TO 20 MPH VEERING TO WEST BY DARK AHEAD OF IT OVER MOST
OF CWA. BIGGEST QUESTION WILL BE CONVECTIVE POTENTIAL. PLENTY OF
CAPE...APPROACHING 2500 JOULES THIS AFTERNOON...WILL PROBABLY BE
REALIZED IF CAN GET ENOUGH HEATING INTO MID 80S...BUT THAT IS A BIT
DOUBTFUL. NEVERTHELESS...WITH AID OF ANY SUNSHINE AT ALL...A FEW
STRONG TO POSSIBLY SEVERE STORMS COULD COULD OFF...WITH HELICITY
DECREASING THIS AFTERNOON BUT SHEARS...MAINLY SPEED SHEAR...STILL
RESPECTABLE. THIS IN LIGHT OF LIS AS LOW AS -6 TO -8...RELATIVELY
STEP MID LEVEL LAPSE RATES AND PRESENCE OF FAVORABLE MODEST
DYNAMICS. LOCATION WITHIN DRY SLOT ALOFT WILL ENHANCE DAMAGING WIND
GUST POTENTIAL IN ANY STORMS.
.DTX...NONE.
DWD
FXUS63 KMQT 131452 mi
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
1050 AM EDT FRI AUG 13 1999
MAIN FCST CONCERN FOR THE UPDATE IS WHAT TO DO W/ THE CLRG POTL AND
TEMPS.
14Z MSAS SHOWS THE CENTER OF THE LOW N OF GRAND TRAVERSE BAY. CD
FNT XTNDS FM THE LOW SWD THRU LAKE MICH...W/ ANOTHER SFC TROF FM THE
LOW ACRS CNTRL WISC. LINGERING PCPN ACRS ERN UPPER TIED TO THE UPR
VORT...THE AXIS OF WHICH WAS FM THE CNTRL U.P. TO SWRN WISC. THIS
PCPN WL BE OUT OF THE MQT CWA BY MIDDAY AS THE VORT SWINGS E...AND WL
LET SHORT TERM FCSTS HANDLE THE TIMING.
BACK EDGE OF THE CLDS IS APPROX 5 TO 10 MILES OFF W END OF THE U.P.
AND JUST ABT PERFECTLY PARALLEL TO THE SHORELINE. WATER VAPOR IMAGE
SHOWG DRYING IN THE WAKE OF THE VORT MAX. 12Z RUC MAINTAINS THE ETA
FCST OF IMPRESSIVE SUBSIDENCE AND ISENT DOWNGLIDE AND DRYING THIS
AFTN AT BOTH THE 305 AND 310 LVLS. WL LOOK FOR CLDS TO START TO
BREAK UP ON THE FAR WRN U.P. ARND NOON. AT THE SAME TIME...COOLING
OF 3 TO 4 DEGS AT H85 FCST FOR THIS AFT OUGHT TO ALLOW SOME CU TO
DVLP...SO THE EFFECT WL BE TO SLOW THE CLG TREND OVR WHAT THE
SYNOPTIC SUBSIDENCE MGT ALLOW.
IN THE N CNTRL U.P...WNDS STL FM THE N WL KEEP LOW CLDS IN UPSLOPE
AREAS THIS AFTN...W/ THE CONT THREAT OF DRZL AND FOG THRU ERLY AFTN.
OVR IN THE EAST AND S CNTRL...SUBSIDENCE WL STILL TAKE A WHILE TO
ARRIVE...SO STL MO CLDY.
GRADIENT WNDS HAVE SLACKENED A BIT OVR THE VRY FAR WEST...BUT THEY
WL RMN GUSTY W/ CAA. PROXIMITY OF THE LOW HAS FAR ERN FA WNDS
RELATIVLY LGT ATTM...BUT AS LOW CONTS TO THE EAST... WNDS SHALL PICK
UP AGAIN. LCL GDNCE FOR ESC SUGGESTS ARND 20 KNOTS. WL NEED ONLY TO
TWEAK WNDS SLIGHTLY.
A FEW OF THE ERN CNTYS APR TO BE AT OR NEAR THEIR FCST HIGHS FOR
THIS AFTN. WITH THICK CLDS AND COOLER N WINDS...WL HAVE NEARLY STDY
TEMPS. MIGHT EVEN GO W/ A FALG TEMPS FCST...WL SEE AFT THE 11 AM EDT
OBS. WRN ZONES MAY BE A TOUCH WARM. WL ADJUST A FEW DEGS DOWN.
.MQT...NONE.
DESROSIERS
FXUS63 KAPX 131215 mi
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
200 AM EDT FRI AUG 13 1999
...FORECAST FOCUS IS SFC LO EXITTING CWA TODAY
NOW...AT 06Z 999MB SFC LO VCNTY OF AUW IN N WISCONSIN PER ASOS/MSAS
ANALYSIS...WITH WARM FRONT EXTENDNG NEWRD TO JUST S OF ERY. ETA
CLEARLY HAS BEST HANDLE ON TIMING AND LOCATION OF LO...WITH NGM
VERIFYING ABOUT 75SM TOO FAR SW AS OF 06Z. NGM ERROR ALSO EVIDENT IN
500MB INITIALIZATION/SHORTWV STRENGTH PER ABERDEEN'S 00Z RAOB. STRONG/SVR
CONVECTION FOCUSED TO S OF CWA...OVR E WI IN CORE OF THETA-E RIDGE
AND INSTABILITY...WITH SHOWALTER INDICES NR -6C. 03Z RUC DEPICTS
NOSE OF 342K 850 THETA-E RIDGE CLIPPING E CWA 06-15Z THIS
MORNING...IN ADVANCE OF SFC LO. WILL MONITOR CONVECTION CLOSELY OVR
NE WI NEXT SEVERAL HRS GIVEN SVR HISTORY OF TSRA IN WI...AND
FAVORABLE LOW LEVEL SHEAR PROFILES. GREATEST THREAT WILL BE E OF A
IMT-MUNISING LINE.
TODAY/TONIGHT...ETA MOVES SFC LO TO VCNY OF MACKINAW BRIDGE BY 18Z AND INTO
SE ONTARIO BY 00Z. CONSIDERABLE CAA ENSUES IN WAKE OF SFC LO TODAY
OVER UPR GREAT LAKES WITH INCREASING QVECTOR 700-300MB DIV. 310K SFC
DEPICTS INCREASING ISENTROPIC DECENT DEVELOPING FROM W TO E AFT 18Z.
THIS SHOULD RESULT IN GRADUAL CLEARING OVR SW CWA THIS AFT...WITH
CEILINGS PROBABLY PERISTING OVR NC UPR MI...WHERE FETCH OFF LK
SUPERIOR WILL UPSLOPE TERRAIN. TIGHT PRS GRADIENT WILL RESULT IN
GUSTY WINDS 15-30KTS. TONIGHT SFC HI PRS BUILDS E FROM PLAINS AND
PRESSURE GRADIENT RELAXES. COOLEST MIN TEMPS WILL BE SW CWA WHERE
WINDS BECOME LIGHT BY MORNING.
SAT...IMBEDDED SHORTWV APPROACHES IN WNW UPR FLOW AS SFC HI BUILDS
OVR REGION AND RIDGE BUILDS OVR CENTRAL CONUS. WHILE QVECTOR CONV
INCREASES OVR CWA...ETA RH CROSS SECTION FOR MQT SUGGEST ONLY
MODEST INCREASE IN MOISTURE ABV 500MB. COOL AND TRANQUIL NIGHT ON
TAP SATURDAY NIGHT WITH SFC HI OVR HEAD AND SUPERB RADIATIONAL
COOLING SCENARIO. THUS...MIN TEMPS BELOW FWC GUIDANCE LIKELY.
EXTENDED...NEW AVN SUPPORTS DRY FCST SUNDAY WITH RISING HEIGHTS AND
RETURN FLOW DEVELOPING ON BACK SIDE OF HI. NEW FAN GUIDANCE
POPS/TEMPS SUPPORT GOING FCST PACKAGE...SO WILL NOT ALTER ATTM.
COORD WITH APX.
.MQT...NONE.
WOLF
mi
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBUQUERQUE NM
850 PM MDT FRI AUG 13 1999
ADJUSTMENTS MADE TO FIRST PERIOD FORECASTS BASED ON TRENDS FROM
IMAGERY AND LATEST RUC OUTPUT. SHOULD BE A 3 TO 6 HOUR EAST TO
SOUTHEAST CANYON WIND EVENT MID RIO GRANDE VALLEY LATE THIS EVENING
INTO THE PREDAWN HOURS. 38
.ABQ...NONE.
FXUS65 KABQ 132101 nm
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC
855 PM EDT FRI AUG 13 1999
SEA-BREEZE CONVECTION PRETTY MUCH GONE AND LATEST RUC AND MESO-ETA
SHOW LITTLE SUPPORT FOR NOCTURNAL ACTVTY. THUS WILL DROP POPS.
CONVECTIVE DEBRIS CLOUDS SHOULD DISSIPATE NEXT FEW HOURS AND MSTLY
CLR SHOULD WORK FOR MOST OF AREA. MID TO UPPER 70S FOR MINS EXCEPT
AROUND 80 OUTER BANKS.
CWF: TIGHTER GRADIENT NRN SECTIONS RESULTING IN 15-20 KT WINDS
THERE...REST OF AREA 15 OR LESS. CURRENT FCST IN GOOD SHAPE.
.MHX...NONE.
JBM
FXUS62 KILM 140025 nc
FORECAST DISCUSSION FOR EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
900 PM CDT FRI AUG 13 1999
FORECAST CHALLENGE FOR UPDATE CONCERNS TEMPS. SC FROM VIS/IR LOOP
ABOUT DONE FOR WITH LOSS OF DAYTIME HEATING. REMAINING IS SCT AC/CI
FROM WK VORTS RIDING OVR RIDGE HANDLED PRETTY WELL BY RUC ALONG WITH
CONVECTIVE DEBRIS FROM STORMS OVR E MT. NOT ENOUGH CLOUD COVER
HOWEVER TO HAMPER MOCLR FORECAST. SFC RIDGE AXIS APPROACHING RRV
ATTM FROM SFC ANALYSIS. ENSUING RETURN FLOW CONFINED TO E ND WITH WK
WAA. CURRENT TEMPS RUNNING INLINE WITH GUIDANCE AND WITH DEWPOINTS
RUNNING AROUND 50F CURRENT FCST SEEMS IN LINE. AS A RESULT WITH
CURRENT FCST IN GOOD SHAPE NO UPDATE PLANNED.
.FGF...NONE.
VOELKER
FXUS63 KBIS 132037 nd
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON OH
845 PM EDT FRI AUG 13 1999
COLD FRONT HAS GOTTEN MORE ACTIVE THIS EVE...ESPLY NORTH OF I-70
WHERE DYNAMICS/INSTABILITY ARE A LTL BETTER. DRY MID LVL AIR MAKING
FOR DECENT WIND PRODUCERS...ALTHOUGH MOSTLY BLO SVR LIMITS SO FAR.
FRONT CURRENTLY ON A CVG-MNN LIN MAKING GUD PROGRESS EAST...WITH
PCPN CUTTING OFF QUICKLY BEHIND. RADAR MOSAIC DOES INDC SOME NEW
SHRA DVLPMNT OVER NORTHERN INDIANA ASSOCIATED WITH MAIN SHORT
WAVE...SO PREV IDEA OF KEEPING POPS GOING IN THE NW STILL LKS GD.
WL PRBLY EXPAND CHC POPS INTO THE DAYTON AREA AS WELL AS LATEST RUC
ROTATES DEEPER MSTR IN LATE TNGT. OTHW WL WAIT TIL ISSUANCE TIME TO
DECIDE WHERE TO CUT OFF POPS...BUT WL LIKELY BE ABLE TO REMOVE FROM
AT LEAST THE SW.
PREV TEMP FCSTS LK RSNBL...NO CHGS XPCTD.
.ILN...NONE.
JOHNSTONE
FXUS61 KILN 131902 oh
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON OH
957 AM EDT FRI AUG 13 1999
OVERNIGHT CONVECTION CONTINUES TO WEAKEN AS IS MOVES INTO MORE
STABLE AIR MASS OVER THE FA.
00Z MODELS SHOWING GOOD SET UP FOR CONVECTION TO DEVELOP ACROSS
INDIANA AND MOVE EAST INTO FA. DEWPOINTS ACROSS INDIANA ARE IN THE
UPPER 60S AROUND 70. LI DROP TO -4 TO -8 WITH CAPES TO 1500 TO 2500
AHEAD OF COLD FRONT. ETA IS THE QUICKEST WITH PUSHING THE
INSTABILITY INTO THE FA...BY 18Z. THE NGM IS A LITTLE SLOWER. WITH
ALL THE INSTABILITY...00Z ETA AND NGM DONT PRODUCE ANY QPF.
THE 03Z MESO-ETA LOOKS MORE REASONABLE...BUT STILL A LITTLE FAST...
FORMING QPF OVER INDIANA AROUND 15Z AND BRINGING IT IN AROUND 18Z.
RUC IS SLOWER AND A LITTLE WEAKER.
WITH ALL THAT SAID...WILL CONTINUE WITH CURRENT POPS. CANT SEE WHY
CONVECTION WONT FIRE. SATELLITE ALREADY SHOWING BREAKS IN THE
CLOUDS ACROSS INDIANA.
WITH LESS CLOUD COVER EXPECTED THICKNESSES ARE SUPPORTING HIGHS ABOUT A
CATEGORY HIGHER THAN EXPECTED.
.ILN...NONE.
SITES
FXUS61 KCLE 131333 oh
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
903 PM EDT FRI AUG 13 1999
WV IMAGERY LOOP SHOWS SHORT WAVE UPPER MISS VALLEY MOVING EASTWARD.
LATEST RUCII RUN INDICATES THAT SHORT WAVE WILL CONTINUE TO FLATTEN
UPPER RIDGE OVERNIGHT. MODELS BRING PVA AND AT LEAST WEAK UPWARD LIFT TO
SOUTH CAROLINA SAT AFTN THRU SUN. LOW POPS DURING THE PERIOD STILL OK.
PATCHY FOG DEVELOPED FRI MORNING AND EXPECT IT AGAIN...WILL SAY PATCHY
FOG TOWARD DAWN IN OVERNIGHT PERIOD. ALSO...WILL GIVE NORTHERN PART OF
CAE CWA SAME LOWS AS SOUTHERN PART...LOWER 70S INSTEAD OF MIDDLE 70S.
OTHER THAN TAKING OUT MENTION OF TSTMS TONIGHT...NO MORE CHANGES.
.CAE...NONE.
TTH
FXUS62 KGSP 140108 sc
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
907 PM EDT FRI AUG 13 1999
KGSP RADAR SHOWS A FEW TSRA MOVING OVER THE SRN NC MOUNTAINS AT 01Z...
WHILE REMNANTS OF CONVECTION EAST OF THE MOUNTAINS HAVE ALL BUT
DISSIPATED. COULD YET SEE SOME PULSE SEVERE STORMS WITH THE ACTIVITY
MOVING INTO THE MOUNTAINS. 21Z RUC AND 18Z ETA KEEP MOST OF THE FORCING
FOR ADDITIONAL CONVECTION JUST TO OUR W OVERNITE...ALTHO RUC SHOWS AN
AREA OF MOISTURE FLUX CONVERGENCE EAST OF THE MOUNTAINS THRU 06Z.
CURRENT SET OF ZONES SEEMS TO HAVE THE SITUATION IN HAND. BEST CHANCE
FOR OVERNITE CONVECTION WOULD APPEAR TO BE ACROSS THE MOUNTAINS. FOR
EVENING UPDATE...WILL PLAN ON LEAVING CHANCE OF TSRA ACROSS THE
MOUNTAINS...BUT WILL REMOVE PRECIP E OF MOUNTAINS. TEMPS LOOK OK.
.GSP...NONE.
MOORE
FXUS62 KCHS 140100 sc
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
213 PM EDT FRI AUG 13 1999
THUNDERSTORMS FORMING ALONG SFC CONVERGENCE AXIS STRETCHING FROM SRN
W VA ACROSS NC/GA MTNS INTO CENT AL. 15Z RUC ALSO SHOWED A WEAK S/W
MOVING ACROSS NC MTNS...WHICH COULD BE HELPING TO ENHANCE
CONVECTION. AS STORMS MOVE SLOWLY EAST THERE IS STILL SOME QUESTION
AS TO THEIR ABILITY TO SURVIVE IN THE SUBSTANTIALLY LOWER DWPTS (LOW
TO MID 60S) IN THE IMMEDIATE FOOTHILLS REGION. HOWEVER...WILL ALSO BE
WATCHING THE ERN HALF OF CWA LATE THIS AFTN WHERE SHARP SFC DWPT
DISCONTINUITY EXISTS.
MID/UPR TROUGH TO MOVE EAST FROM MIDWEST AND DEVELOP A FAIR AMOUNT
OF AMPLITUDE ALONG THE EAST COAST BY SATURDAY NIGHT. PLUME OF DEEPER
MOISTURE EVIDENT ON WV LOOP WILL CROSS CWA TONIGHT...WITH
SIGNIFICANT MID/UPR VEVEL DRYING AFTER 12Z SAT. SFC COLD FRONT WILL
BE EDGING INTO MTNS SAT MORNING AS WELL. CORE OF THE DYNAMICS WILL
PASS WELL NORTH OF THE AREA...BUT MODELS DO INDICATE A FAIR AMOUNT
OF DPVA ASSOCIATED WITH A COUPLE OF SPOKES OF ENERGY TO PASS OVER
THE REGION SATURDAY AND SATURDAY NIGHT...ALONG WITH COOLING MID
LEVELS. UNFORTUNATELY...THE TIME WHEN ALL THE INGREDIENTS COME
TOGETHER FOR PRECIPITATION IS THE LEAST DIURNALLY FAVORABLE TIME OF
DAY...SAT AM.
ETA HANGS FRONT UP IN MTNS AND FORECASTS IT TO MOVE INTO PIED BY SUN
MORNING. NGM FASTEST AND COLDEST. FELT THAT ETA WOULD DO A BETTER
JOB IN THE LOWER LEVELS...SO AM LEANING TOWARD ITS SOLUTION.
SO...WITH FRONT STILL IN MTNS FOR MUCH OF SAT...LOW-LEVEL MOISTURE
WILL REMAIN HIGH ACROSS MOST OF CWA AND BOUNDARY LAYER MOISTURE
CONVERGENCE WILL BE GOOD. WITH COOLER TEMPS MOVING IN
ALOFT...ATMOSPHERE WILL BECOME RATHER UNSTABLE AGAIN. HOWEVER...VERY
DRY MID/UPR LEVELS WILL LIMIT STORM DEVELOPMENT TO THE SCATTERED
DIURNAL VARIETY. WITH SUCH HIGH THETA-E LAPSES THOUGH...ANY STORMS
THAT DO DEVELOP WILL HAVE THE POTENTIAL TO BE SEVERE. SINCE
FRONT/TROUGH WILL BE OVER OR EAST OF ERN CWA SUNDAY...WILL KEEP CHC
POPS THERE FOR SUN AFTN.
TEMPS WILL BE SLIGHTLY COOLER WITH A DECREASE IN THICKNESSES.
BUT...WILL CONTINUE TEMPS ABOVE NORMAL OUTSIDE OF MTNS.
IN THE EXTENDED...HIGH PRESSURE ALOFT BUILDS EAST AS LONGWAVE TROUGH
EXITS EAST COAST. SFC HIGH ALSO DOMINATES THE REGION. TEMPS APPEAR
TO WANT TO STAY WELL IN THE 90S.
AVL 67/85/64/83 4431
CLT 73/93/70/90 3433
GSP 72/94/70/91 4432
.GSP...NONE.
MOYER
FXUS62 KCAE 131436 sc
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
1029 AM EDT FRI AUG 13 1999
EXPECT WIDELY SCATTERED TSTMS TO DEVELOP ALONG THE WEAK SURFACE TROUGH
THAT EXTENDS THROUGH THE CENTRAL PART OF THE CWA. COVERAGE SHOULD BE
LIMITED BY CAPPING. THE ANALYSIS AND RUC SUPPORT H7 TEMPERATURES
REMAINING 10 TO 11 THIS AFTERNOON. MODIFYING THE FFC RAOB WITH FWC
TEMPERATURES/DEW POINTS SHOWS TOTAL TOTALS REACHING 54 AT CAE.
HOWEVER...THE RUC KEEPS THE H5 COLD POOL NEAR FFC WEST OF THE CWA SO DO
NOT EXPECT THIS MUCH INSTABILITY. ADAP DOES SHOW LI/S ALREADY
APPROACHING -8 IN THE EAST PART OF THE CWA SO A FEW PULSE SEVERE TSTMS
APPEAR POSSIBLE. THE MAIN THREAT APPEARS TO BE WIND AND NOT LARGE HAIL.
BUFKIT SHOWS WET BULB ZERO HEIGHTS ABOVE 13000 FEET THIS AFTERNOON.
LOW-LEVEL MOISTURE HAS INCREASED TODAY COMPARED TO YESTERDAY AND EXPECT
HIGHER HEAT INDEX VALUES. PLAN TO INCREASE THE HEAT INDEX FORECAST FROM
105 TO NEAR 110.
.CAE...HEAT ADVISORY THIS AFTERNOON SCZ015-016-018-020>022-025>031-
035>038-041-GAZ040-063>065-077.
RJL
FXUS62 KGSP 131413 sc
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1012 AM EDT FRI AUG 13 1999
CURRENT SATL TRENDS SHOW THIN CIRRUS AROUND THE SOUTHEAST.
PRE-FRONTAL CONVECTIVE BAND FALLING APART IN MISS VALLEY. SHOULD SEE
PLENTY OF SUNSHINE THIS AFTERNOON WHICH WILL BOOST TEMPS WELL INTO
THE 90S AND LOWER 100S. SEVERAL SITES SAW TEMPS 100 TO 102 YESTERDAY
ACROSS THE UPSTATE AND SRN FOOT/PIED OF NC. 850 THERMAL RIDGE IS
ALIGNED RIGHT ACROSS THE AREA TODAY. MAY NEED TO TWEAK TEMPS UP A
BIT...DEPENDING ON CLOUD TRENDS CLOSER TO ISSUANCE. DWPTS NOT AS
HIGH AS IN ERN CAROLINAS...AND SFC TROUGH SHOULD PROHIBIT THEM FROM
PUSHING THIS FAR INLAND. HOWEVER...THE HEAT INDEX MAY FLIRT WITH 105
FROM TIME TO TIME IN FOOT/PIED.
AIRMASS STARTING OFF VERY UNSTABLE THIS MORNING WITH CAPES RANGING
FROM 1700 AT GSO TO 3000 AT FFC. NO DOUBT CAPES WILL ONLY INCREASE
THROUGH THE DAY. ALTHOUGH STILL RELATIVELY DRY...DWPT DEPRESSIONS AT
700 MB ARE NOT AS GREAT AS PREVIOUS DAYS. 09Z RUC ALSO AGREES IN
SHOWING AT LEAST 70% RH FROM THE SFC TO 700 MB THROUGH THE DAY. AS
MID/UPR LEVEL TROUGH AND SFC FRONT EDGE EAST TODAY...THINK THAT MTNS
WILL HAVE THE GREATEST CHC AT SEEING SOME CONVECTION WITH THE
INCREASED DYNAMICS AND MOISTURE. THETA-E LAPSES OF 25 TO 30 HEIGHTEN
THE AWARENESS OF MICROBURST POTENTIAL. INTERESTING 50 KT JET IN THE
TN VALLEY SHOULD STAY TO THE NW OF CWA.
PLAN TO KEEP CHC POPS IN MTNS AS WELL AS NRN FOOTHILLS OF NC. WOULD
NOT BE SURPRISED TO SEE ISOLATED TSTMS OUTSIDE OF MTNS...BUT TOO
SMALL OF A CHC TO MENTION IN ZONES.
.GSP...NONE.
MOYER
FXUS62 KCHS 131401 sc
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
830 PM MDT FRI AUG 13 1999
THE 02Z SURFACE ANALYSIS SHOWED A LOW OVER CENTRAL WY WITH
BOUNDARY/WARM FRONT INTO SOUTHWEST SD. 00Z UPPER AIR ANALYSIS SHOWS
INCREASING WARM AIR ADVECTION HEADING OUR WAY AHEAD OF SHORTWAVE
NOTED FROM WESTERN MT INTO EASTERN ID. JET STREAK ASSOCIATED WITH
THE DISTURBANCE DISTINCT PER IR LOOP. EXTENT OF CONVECTION IS MAIN
CONCERN THIS EVENING.
00Z RUC2 INITIALIZED ALRIGHT AND NEAR 03Z IT REPRESENTED REALITY.
SHORTWAVE WILL MOVE INTO EASTERN MT/WESTERN ND OVERNIGHT.
COMBINATION OF LOW LEVEL JET TO 30KTS...LOW LEVEL THERMAL
BOUNDARY...7-8C/KM 700-500MB LAPSE RATES...AND QG-FORCING WILL
SUPPORT CONVECTION MAINLY NORTH OF A LINE FROM KGCC TO KD07.
THICKNESS DIFFLUENCE SUPPORTS ANY CONVECTION SYSTEM TO MOVE EASTERLY
AS IT ROUNDS TOP OF 500-700MB RIDGE OVER THE PLAINS.
MINOR WORDING CHANGES PLANNED FOR UPDATE. GIST OF FORECAST INTACT.
.UNR...NONE.
HELGESON
FXUS63 KFSD 140202 sd
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1005 AM CDT FRI AUG 13 1999
GOING FCST ON TRACK. COOL AIR WL CONT TO FEED INTO CWA THIS AFTN
WITH LLVL NRLY FLOW. HOWEVER RUC DOES PROG A DECREASE IN WNDS...AS
925MB WINDS DECREASE FM AROUND 25KTS TO 10KTS LATE THIS AFTN. IN
ADDN...SAT PIX SHOWS THE STRATUS CONTINUING TO ERODE FM THE NORTH
AND WEST. RUC MSTR PROGS SHOWS ENTIRE CWA IN THE CLEAR BY MID
AFTN...WITH AREAS FM MJQ TO SLB THE LAST TO CLEAR OUT.
.FSD...NONE
FUHS
FXUS63 KUNR 130902 sd
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NASHVILLE TN
925 PM CDT FRI AUG 13 1999
COOL FRONT APPEARS TO BE ALONG A LEXINGTON TO BOWLING GREEN TO JACKSON
LINE MOVING EASTSOUTHEATS AT 15 MPH. WILL UPDATE TO REDUCE THE
THREAT OF RAIN GENERALLY AND POSSIBLY REMOVE IT FROM THE NW MIDDLE
TENNESSEE ZONES.
TEMPS LOOK OK. RUC BRINGS 925MB CLD DECK OVER MO/SRN IL SEWD TO KY
TN BORDER BUT BEGINS TO THIN IT OUT BY MORNING SO WILL RETAIN THE
MOSTLY SUNNY FOR SAT.
18
JLM
FXUS64 KMEG 140154 tn
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NASHVILLE TN
1256 PM CDT FRI AUG 13 1999
...CURRENT WEATHER...
1700 UTC SURFACE PLOT SHOWS FRONT LOCATED ACROSS CENTRAL ILLINOIS AND
SOUTHEAST MISSOURI. PRIMARY CLOUD BAND IS LOCATED ALONG A PRE-FRONTAL
TROUGH LOCATED NEAR THE CUMBERLAND PLATEAU. SURFACE DEW POINTS REMAIN
BETWEEN 70 AND 75 DEGREES AGAIN TODAY WITH TEMPERATURES APPROACHING
"CAP BUSTER" VALUES.
1700 UTC LAPS ANALYSES SHOW BEST INSTABILITY NEAR WAVERLY IN
NORTHWEST MIDDLE TENNESSEE...SO EXPECT STORMS TO BEGIN FIRING OVER
THIS AREA DURING THE AFTERNOON.
...MODEL DISCUSSION...
ETA AND NGM ARE ONCE AGAIN IN GOOD AGREEMENT REGARDING THE SURFACE
SYSTEM. NGM IS VERIFYING A LITTLE BETTER WITH PLACEMENT OF THE PRE-
FRONTAL TROUGH...AND IS A LITTLE SLOWER THAN THE ETA AND MORE IN
LINE WITH THE LATEST RUC MODEL. AVN ONCE AGAIN MISSES WITH THE
IMPORTANT MESOSCALE FEATURES...SO WILL DEFER TO THE NGM THIS
FORECAST.
FRONT WILL PASS NASHVILLE BY 0600 UTC SATURDAY AND WILL BE FOLLOWED
BY STRONG NORTHWESTERLY FLOW AND RAPID MID LEVEL DRYING. HIGH
PRESSURE WILL SLOWLY BUILD INTO THE REGION FROM THE NORTHWEST. LOW
LEVEL THICKNESS FIELDS SUGGEST GOOD TEMPERATURE DROP BEHIND THE
FRONT.
...FORECAST DISCUSSION...
FAN/FWC TEMPERATURES ARE IN GENERALLY GOOD AGREEMENT...AND THESE
VALUES ARE ONCE AGAIN IN LINE WITH THOSE GIVEN BY THE MASSIE/ROSE
LOW LEVEL THICKNESS SCHEME. WILL LEAVE IN 30 POP FOR MIDDLE TENNESSEE
EARLY PERIOD 1...40 POP FOR THE PLATEAU.
BNA UU 069/086 064/090 067 08300
CSV UU 065/083 058/085 061 08400
.BNA...NONE.
$$
08
FXUS64 KMEG 131427 tn
AREA FORECAST DISCUSSION - UPDATED
NATIONAL WEATHER SERVICE EL PASO TX/SANTA TERESA NM
603 PM MDT FRI AUG 13 1999
DISCUSSION...
ISOLATED THUNDERSTORMS HAVE CROSSED THE RIVER INTO HUDSPETH COUNTY
OF TEXAS. ALSO SIERRA MADRE CELLS ARE LAPPING AT THE BOOTHEEL. WILL
UPDATE ZONES TO CORRECT TEXAS 2-3 PERIOD POPS, AND SEPARATE. WILL
ALSO MENTION AN ISOLATED CHANCE FOR HUDSPETH AND HIDALGO COUNTIES.
18Z RUC SAYS THE PARTY IS OVER BY 03Z...BUT ORIGINATOR OF HUDSPETH
CONVECTION IS A GOOD OUTFLOW BOUNDARY MOVING NW TOWARDS EL PASO AND
SOUTHERN OTERO. EVENING SOUNDING SHOWS A GOOD SUBSIDENCE INVERSION
CAP, SO WILL LEAVE POPS OUT OF THOSE ZONES.
.ELP...NONE
06 RAMEY
N
FXUS64 KFWD 132249 AMD tx
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN ANGELO TX
307 PM CDT FRI AUG 13 1999
SURFACE COLD FRONT SHOWING GOOD SOUTHWARD PROGRESS INTO THE BIG
COUNTRY AT THIS TIME WITH BOTH DYS DOPPLER AND SATELLITE IMAGERY
SHOWING THE WELL DEFINED BOUNDARY. CONVECTION ALREADY BEGINNING TO
DEVELOP IN ADVANCE OF THE FRONT ALONG THE NORTHERN PORTIONS OF THE
CONCHO VALLEY. DIFFICULT PART OF FORECAST WILL BE TO DETERMINE
SOUTHERN EXTENT OF THE FRONTAL MOVEMENT. MSAS PRES CHG FIELD IN
SUPPORT OF A CONTINUATION OF THE SOUTHERLY MOVEMENT ALONG WITH A GOOD
NORTHERLY SURFACE WIND AND UPPER LEVEL PUSH BEHIND THE FRONT. BOTH
AVN AND ETA SHOWING AN ACCURATE 6 HR POSITIONING OF THE FRONT AT 18Z
THIS AFTERNOON. BOTH MODELS PLACE THE FRONT ACROSS CENTRAL SECTIONS
OF THE CWA BY SUNRISE SATURDAY. FOLLOWING THIS...THE FRONT WEAKENS
AND SOUTHEASTERLY SURFACE FLOW TAKES OVER. DIRECTIONAL AND SPEED
CONVERGENCE AT 850 WILL OCCUR JUST NORTH OF THE SURFACE BOUNDARY THUS
SUPPORTING THE 00Z LIFT ACROSS THE NORTH HALF OF THE CWA. TURNING
TOWARD THE RUC...SUPPORT IS INDICATED WITH THE PROGRESS OF THE FRONT
INTO CENTRAL AREAS. IN ADDITION...SOME SHORTWAVE ENERGY MAY ENHANCE
ACTIVITY ACROSS THE BIG COUNTRY THIS EVENING. WILL LEAN TOWARD 30
PERCENT FOR POPS ACROSS THE BIG COUNTRY AND CENTRAL AREAS WITH LESS
THAN 20 ELSEWHERE. STRONG/GUSTY WINDS WILL ALSO BE POSSIBLE WITH THE
CONVECTIVE ACTIVITY AS WARM TEMPS COMBINE WITH THE DRY MID LEVELS TO
PRODUCE DOWNBURST POTENTIAL.
FOR TOMORROW...FRONT WASHES OUT WITH THE ONLY REMAINING DYNAMICS
BEING THAT OF A WEAK UPPER LEVEL IMPULSE ACROSS THE NORTH AND THE
POTENTIAL RESIDUAL BOUNDARIES/MOISTURE ACROSS THE CENTRAL AND NORTH.
WILL COOL TEMPS A BIT FROM TODAYS HIGHS AND KEEP 20 POPS IN FOR THE
CONCHO VALLEY NORTHWARD.
SATURDAY NIGHT...SURFACE HIGH BUILDS ACROSS THE AREA WITH SLIGHTLY
LOWER WIND SPEEDS AND THICKNESSES. A TASTE OF THE UPPER 60S WOULD BE
POSSIBLE WITH THIS SCENARIO BUT NEAR 70 MAY BE A BETTER FORECAST
EXCEPT FOR THE JUNCTION AREA WHERE COOLER DRAINAGE CONDITIONS WILL
PREVAIL.
IN THE EXTENDED...THE MRF HAS BEEN CONSISTENTLY DRAGGING AN EASTERLY
WAVE ACROSS THE AREA FOR MID WEEK. A CLOSER LOOK AT TUES AND
WEDNESDAY DOES INDICATE THAT THIS FEATURE WILL IMPACT THE AREA AS
EARLY AS TUESDAY AFTERNOON. WILL WORD THE EXT AS PC FOR TUES AND
INTRODUCE A SLIGHT CHANCE OF SHRS/TSTMS FOR WEDNESDAY. TEMPS NEAR
SEASONAL WITH SLIGHTLY BELOW NORMAL MAX TEMPS ON WEDNESDAY AS THE
WAVE APPROACHES.
ABI 071/094 071/095 3210
SJT 070/097 070/097 32-0
JCT 071/097 067/096 1-00
.SJT...NONE.
21
FXUS64 KFWD 132000 tx
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE FORT WORTH TX
1113 AM CDT FRI AUG 13 1999
SURFACE COLD FRONT CONTINUES TO SLIDE SOUTH ACROSS THE RED RIVER.
FAIRLY STRONG PUSH BEHIND THE FRONT IN OKLAHOMA WITH 3 TO 4 MB
PRESSURE RISES AT 15Z. ALSO...NORTH WINDS OF 15 TO 25 MPH WITH SOME
HIGHER GUSTS NOTED ACROSS NORTHERN AND CENTRAL OKLAHOMA AND SOUTHERN
KANSAS. FAIRLY CONFIDENT THAT THIS FRONT WILL SLIDE ACROSS THE
NORTHERN ZONES LATE AFTERNOON AND REACH THE METROPLEX THIS EVENING.
THIS IS SUPPORTED BY LAMP AND RUC SOLUTIONS.
THE INCREASED CLOUD COVER AND PRECIPITATION DEVELOPING ACROSS THE
AREA WILL KEEP AFTERNOON HIGH TEMPERATURES DOWN A BIT. WILL TREND
THE NORTHERN HALF OF THE AREA IN THE 95 TO 100 DEGREE RANGE.
HOWEVER...THE HIGH DEWPOINTS ACROSS THE AREA WILL STILL KEEP THE
HEAT INDEX VALUES BETWEEN 105 AND 110 DEGREES. WILL KEEP THE HEAT
ADVISORY GOING THROUGH THIS AFTERNOON ONLY.
WILL UP POPS A CATEGORY OR TWO ACROSS THE NORTHERN HALF DUE TO FAIRLY
HIGH INSTABILITIES AND MOISTURE CONVERGENCE NEAR THE FRONT.
WILL MAKES SOME OTHER MODIFICATIONS TO WINDS AND CLOUD COVER IN THE
NORTH. 79
.FTW...CONTINUE HEAT ADVISORY FOR ALL OF NORTH CENTRAL TEXAS TODAY.
AVIATION DISCUSSION...
INVERTED-V ON 12Z FWD SOUNDING WITH SIGNIFICANT POSITIVE ENERGY ABOVE
THE CAPPING INVERSION SUGGESTS THE POTENTIAL FOR DRY MICROBURSTS
LATER TODAY. GOOD PRESSURE RISES BEHIND INVADING COLD FRONT NOT
EXPECTED TO RESULT IN NORTHEASTERLY WIND SHIFT DFW METROPLEX UNTIL
MID TO LATE EVENING UNLESS OUTFLOW ACCELERATES PROGRESS OF FRONTAL
BOUNDARY. WILL INDICATE CBS IN 18Z TAFS WITH BEST CONVECTIVE
POTENTIAL DURING THE EVENING HOURS. OUTSIDE OF THUNDERSTORM ACTIVITY
EXPECT VFR CONDITIONS TO PREVAIL. ...48...
FXUS64 KEWX 131450 tx
EASTERN WASHINGTON AND NORTH IDAHO AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WASHINGTON
315 AM PDT FRI AUG 13 1999
HAVE TWO FORECAST PROBLEMS AGAIN THIS MORNING. THE FIRST IS A BIT
TRICKY...AND DEALS WITH THE FAIRLY SIGNIFICANT UPPER WAVE OVER
NORTHERN CALIFORNIA. A JET STREAK IS CLEARLY VISIBLE (ON WATER VAPOR
IMAGERY) ON THE SOUTH SIDE OF THIS WAVE. GOES HIGH DENSITY/CLOUD
TRACK WINDS INDICATE THIS JET STREAK HAS A MAGNITUDE OF 80-100 KTS.
IMAGERY SHOWS THAT THE JET STREAK IS NOW LIFTING EAST AHEAD OF THE
WAVE. IF THIS JET STREAKS LIFTS EAST...THE WILL NOT BE ANYTHING TO
REINFORCE SPIN - SO THE WAVE WILL NOT INTENSIFY ANY.
ANOTHER FEATURE OF INTEREST IS A PIECE OF THE LOW OVER VANCOUVER
ISLAND WHICH HAS BROKEN OFF AND IS NOW OVER 130W/40N. THE REASON
THIS FEATURE IS IMPORTANT IS THAT IT WILL LIKELY FORCE THE NORTHERN
CALIFORNIA WAVE FURTHER NORTH THAN THE MODELS INDICATE. ANOTHER
TRICKY THING IS THAT THE ETA AND MESO-ETA ACTUALLY SPLIT THIS WAVE
INTO TWO DISTINCT PIECES - BOTH REMAINING RATHER INTENSE. ONE PIECE
SHOOTS RIGHT OVER THE EASTERN THIRD OF WASHINGTON...AND THE OTHER
HEADS IN TO THE SOUTHERN HALF OF NORTHERN IDAHO AND THEN INTO WESTERN
MONTANA. NONE OF THE OTHER MODELS SHOW THIS SPLIT. THE 0900 UTC RUC
(WHICH NORMALLY DOES VERY WELL WITH VORTICITY FIELDS) DOES NOT SHOW
THIS SPLIT EITHER - AND IN FACT WEAKENS THE WAVE AND KEEPS IT A BIT
FURTHER SOUTH THAN THE OTHER MODELS. AFTER A THOROUGH INSPECTION OF
SATELLITE IMAGERY WE CAN'T SEE ANYTHING TO SUPPORT THE IDEA OF A
MAJOR SPLIT IN THE WAVE. THE REASON THIS DIFFERENCE IS IMPORTANT IS
THAT THE ETA AND MESO-ETA QPF FIELDS SHOW LARGE AMOUNTS OF
PRECIPITATION - WHILE ALL THE OTHERS SHOW ALMOST NONE. SO FEEL THE
BEST WAY TO HANDLE THIS IS TO INCLUDE A CHANCE OF AFTERNOON SHOWERS
AND THUNDERSTORMS OVER THE EASTERN THIRD OF THE CWFA.
THE FINAL FORECAST PROBLEM IS THE MAJOR UPPER LOW WHICH IS ADVERTISED
TO BE OVER THE AREA BY MIDDAY SATURDAY. THERE HAS BEEN A REAL
TENDENCY BY THE MODELS TO MOVE THESE FEATURES INLAND TOO FAST. OUR
FEELING THE SAME IS TRUE WITH THIS...AND MAYBE LATE SATURDAY
AFTERNOON IS A BETTER TIME-FRAME FOR THE CENTER OF THAT LOW TO BE
OVER THE CENTER OF THE CWFA. WHEN THIS LOW DOES GET HERE IT WILL
BRING A GOOD COLD POOL AND DYNAMICS. BY ALL ACCOUNTS SATURDAY
AFTERNOON AND EVENING LOOK TO BE ACTIVE...WITH SCATTERED SHOWERS AND
THUNDERSTORMS.
IN THE EXTENDED...THE CURRENT MRF AND ECMWF ARE VERY SIMILAR TO THE
PREVIOUS DAYS. TROUGHY CONDITIONS SATURDAY AND SUNDAY - WHICH SPELLS
COOLISH CONDITIONS WITH A CHANCE OF SHOWERS/THUNDER. ON MONDAY A
RIDGE BEGINS BUILDING INTO THE AREA FOR GRADUAL IMPROVING CONDITIONS.
DRIFE/MOORE
...THE INFORMATION IN THIS PRODUCT CONCERNING WARNINGS AND FORECASTS
IS VALID ONLY AT THE TIME OF ISSUANCE. THE LATEST WARNING AND
FORECAST INFORMATION WILL BE FOUND IN THE APPROPRIATE PRODUCTS...
GEG 074/052/070 344
CQV 077/050/073 335
S86 074/049/069 335
COE 073/052/071 345
WWP 074/049/068 555
LWS 076/056/074 534
MOS 074/051/070
EAT 077/056/075 133
.GEG...NONE.
FXUS66 KSEW 130939 COR wa
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
235 PM CDT FRI AUG 13 1999
PRIMARY FORECAST CONCERNS...LOWS TONIGHT...THEN RETURN FLOW AND WARM AIR
ADVECTION ON SUNDAY.
VISIBLE SATELLITE IMAGERY INDICATED LARGE AREA OF CLOUDS OVER THE UPPER
MISSISSIPPI VALLEY IN CYCLONIC FLOW ASSOCIATED WITH DEPARTING GREAT
LAKES LOW PRESSURE. EDGE OF CLOUDS CORRESPONDS GENERALLY WITH THE 925
MB 70 PERCENT RELATIVE HUMIDITY IN THE LATEST RUC AND 12Z ETA AND NGM.
DUE TO THE CLOUD COVER AND COLD AIR ADVECTION...TEMPERATURES IN THE
FORECAST AREA WERE AUTUMN-LIKE WITH READINGS IN THE MIDDLE TO UPPER 60S.
12Z MODELS SHOWED THE LOW LEVEL MOISTURE CONTINUES PULLING OUT OF THE
AREA THIS EVENING AS DRIER NORTH FLOW FILTERS IN. CLOUDS DEPARTING THIS
EVENING...ALLOWING FOR A CLEAR SKY OVERNIGHT. UPSTREAM DEWPOINTS IN THE
MIDDLE 40S TO LOWER 50S...SO SATURDAY MORNING LOWS SHOULD DIP TO SIMILAR
VALUES. THIS AGREED WITH FWC AND FAN TEMPERATURE GUIDANCE. SINCE
TEMPERATURE/DEWPOINT SPREADS CLOSE...PATCHY FOG STILL A POSSIBILITY
OVERNIGHT AND EARLY SATURDAY MORNING...ALTHOUGH DRIER NORTH WIND FLOW
SHOULD PRECLUDE SIGNIFICANT AREAS OF DENSE FOG.
SURFACE HIGH PRESSURE SETTLES OVER THE UPPER MISSISSIPPI VALLEY
SATURDAY...BRINGING NICE DAY...THEN DRIFTS EASTWARD BY SUNDAY.
ATTENTION THEN TURNS TO SOUTH WIND FLOW AND WARM AIR ADVECTION PATTERN
DEVELOPING AHEAD OF LOW PRESSURE OVER THE PLAINS. ALL MODELS SHOWED 30
TO 40 KNOT LOW LEVEL JET...WITH ETA MODEL BRINGING 850 MB DEWPOINTS INTO
THE MID TEENS.
CURRENTLY...WE HAVE A DRY FORECAST GOING FOR SUNDAY AND WOULD PREFER TO
LEAVE AS SUCH WITH UNCERTAINTY OF TIMING MOISTURE RETURN AND WARM AIR
ADVECTION AHEAD OF NEXT SYSTEM. THEREFORE...EXPECTING A PARTLY SUNNY
DAY WITH MID AND HIGH LEVEL CLOUDS AS SHOWN BY TIME/HEIGHT CROSS
SECTIONS.
COORDINATED WITH MPX...DMX AND DVN.
.LSE...NONE.
THOMPSON
FXUS63 KMKX 131855 wi
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
1059 AM CDT FRI AUG 13 1999
CURRENT FORECASTS UPDATED TO REMOVE MORNING SHOWER MENTIONS...AND
DROP TEMPERATURES SLIGHTLY FOR THE AFTERNOON. GOES VISIBLE SATELLITE
AND LATEST RUC INDICATE GOING FORECASTED CLOUD TRENDS GOOD WITH NO
APPRECIABLE CLEARING EXPECTED UNTIL TONIGHT. PATCHY DRIZZLE
CONTINUES ALONG THE RIDGETOPS AND OVER ADAMS/JUNEAU COUNTIES SO WILL
KEEP IN FOR THE AFTERNOON HOURS. NEW ZONES WILL BE SENT AT 1100 AM.
.LSE...NONE.
DEVOIR
FXUS63 KARX 131559 wi
SOUTHWEST ARIZONA/SOUTHEAST CALIFORNIA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
250 AM MST SAT AUG 14 1999
.SYNOPSIS...
HIGH PRESSURE ALOFT WILL BE CENTERED OVER THE SOUTHERN PLAINS THIS
WEEKEND...ALLOWING FOR INCREASING SOUTH TO SOUTHEAST WINDS ALOFT TO
FLOW INTO ARIZONA. THIS WIND FLOW WILL BRING INCREASING MONSOON
MOISTURE INTO THE STATE...LEADING TO AN UPSWING OF SHOWERS AND
THUNDERSTORMS OVER SOUTH CENTRAL ARIZONA THIS WEEKEND...AND ACROSS
SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA BY EARLY NEXT WEEK.
.DISCUSSION...
IT APPEARS THAT WE WILL BE IN STORE FOR AN UPSWING IN THUNDERSTORMS
THE NEXT FEW DAYS. ALREADY...THUNDERSTORMS IN SE AZ PRODUCED AN
OUTFLOW BOUNDARY THAT BROUGHT 30 MPH SOUTHEASTERLY WINDS THROUGH THE
PHX AREA...RAISING DEW POINTS FROM THE UPPER 40S LATE THIS AFTERNOON
TO THE MID 60S DURING THE NIGHT. GOOD STEERING WINDS FROM THE SOUTH
AND SOUTHEAST AROUND THE SOUTHERN PLAINS HIGH IS FORECAST TO BRING
MORE MOISTURE INTO THE STATE THIS WEEKEND BY ALL THE MODELS. THE ETA
IS MORE AGGRESSIVE WITH THIS INCREASE WHILE THE AVIATION APPEARS TO
BE A LITTLE MORE CONSERVATIVE. THE NGM IS IN BETWEEN BUT CLOSEST TO
THE ETA. ALONG WITH THE MOISTURE INCREASE DOES APPEAR TO BE SOME
DYNAMICS. BOTH THE ETA AND NGM...ALONG WITH THE RUC...DO SHOW A
COUPLE VORT MAXIMUMS ROTATING INTO THE STATE FROM THE SOUTH AND
SOUTHEAST. THE FIRST VORT MAX WILL BE ROTATING NORTH OF THE REGION
THIS MORNING. THE SECOND VORT MAX WILL ROTATE INTO SE AZ BY LATE SAT
NIGHT AND TOWARDS CENTRAL AZ SUN. THE AVN IS VERY WEAK OR NONEXISTANT
WITH THESE FEATURES. ANOTHER FORCING MECHANISM MAY BE INCREASING
DIVERGENCE ALOFT AS 300MB WINDS INCREASES OVER NORTHERN ARIZONA. THIS
RESULTS IN THE WINDS COMING AROUND THE HIGH INTO SOUTHEAST ARIZONA TO
INCREASE AS IT MOVES NORTH AND NORTHEASTWARD INTO CENTRAL AND
NORTHERN ARIZONA. THIS SHOWS UP QUITE NICELY ON THE NGM CROSS SECTION
FOR PHOENIX AND A LITTLE LESS DEFINED ON THE ETA. THIS FEATURE NOT
QUITE AS OBVIOUS OVER THE WESTERN CWA.
THE EXTENDED PERIODS LOOKS AS IF THE MONSOON PATTERN WILL CONTINUE.
THE LATEST MRF KEEPS THE HIGH CENTER TO THE EAST THROUGH THE EXTENDED
KEEPING THE MONSOON FLOW OVER US. BERKOVITZ
FXUS65 KFGZ 140937 az
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON KY
240 AM EDT SAT AUG 14 1999
MODELS IN VERY CLOSE AGREEMENT THIS MORNING IN MOVING THE FRNT ACRSS E
KY BY 12Z...AND WITH THE OTHER FEATURES AS WELL. FROPA HERE AT THE
OFFICE AROUND 1 AM AND BNDRY IS EXPECTED TO CLEAR THE CWA BEFORE 12Z.
BNDRY THEN EXPECTED TO SLOW DOWN OVER THE VA S DURING THE DAY. HIGH
PRESSURE TO SLOWLY BUILD INTO THE REGION TODAY AND TOMORROW WITH MUCH
COOLER TEMPS IN STORE FOR THE AREA.
FCST PROBLEMS TDY INCLUDE TEMPS, DEGREE OF SKY COVER AND SLIGHT CHC
OF AFTERNOON SPRINKLES. WITH STRONG 8H CAA...CYCLONIC FLOW
ALOFT...UPSLOPE FLOW...A WEAK POST FRONTAL TROFF AND THE MAIN 7H TROFF
NOT PROGGED TO PASS THRU UNTIL LATE AFTERNOON...CLOUD COVER IS IN
QUESTION. MOS GOING CLR TO SCT WHILE I THINK SCT V BKN AT LEAST WILL BE
MORE LIKE IT..MAYBE EVEN OVC AT TIMES. ERGO THINKING PARTLY SUNNY OR
EVEN MC SKIES TODAY...WITH DECR CLOUDS POSSIBLE IN THE LATE AFTERNOON
OR BY EVENING. TEMPERATURE WISE...WITH FROPA JUST GETTING HERE AND THE
COOLER AIR JUST STARTING TO TRICKLE IN AND WITH TEMPS STILL AROUND 70
OR SO...MOS NUMBERS MIGHT NOT BE TOO BAD THEREFORE WONT DEVIATE TOO
FAR...HIGHS AROUND 80 NORTH OR IN THE LOWER 80S.
NONE OF THE MODELS ARE GOING FOR ANY QPF TODAY...BUT WITH PEAK HEATING
AND SOME LINGERING INSTABILITY...TROFFINESS AND UPSLOPE FLOW THIS
AFTERNOON...I THINK SPRINKLES ARE POSSIBLE..BUT CONFIDENCE IN THIS IS
LOW SO WILL NOT INCLUDE THIS IN ZONES ATTM. WE CAN HANDLE SPRINKLES IN
THE NOWCASTS I GUESS. WILL TAKE A LAST MINUTE LOOK AT 03Z MESO-ETA AND
06Z RUC WHEN AVAILABLE THOUGH.
FOR TONIGHT CLRING SKIES WITH A LOW AROUND 60 LOOKS REASONABLE. MS ON
SUNDAY WITH TEMPS A LITTLE WARMER...PROBABLY MIDDLE 80S.
MODELS ARE PERSISTENT IN BLDG BIG 5H RIDGE THRU THE EXTENDED
PERIOD...SPELLING HOTTER AND MORE HUMID WX. WILL STICK WITH CURRENT
EXTENDED FCST.
WORK ZONES WILL BE ISSUED SHORTLY UNDER AFOS HEADER SDFOZFJKL. COMMENTS
WELCOME.
THANKS TO SDF FOR COORDINATION.
.JKL...NONE
HALL
FXUS63 KJKL 140056 ky
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
315 AM EDT SAT AUG 14 1999
SFC COLD FRONT SOUTH OF THE STATE OF MI CURRENTLY...WITH NORTHERLY
FLOW IN ITS WAKE BRINGING IN DRIER AIR. 50S DEW POINTS NOW IN PLACE
ACROSS THE FCST AREA. CLEARING TRYING TO WORK ITS WAY THROUGH THE
FCST AREA WITH LEADING EDGE OF PARTIAL CLEARING ON A MKG TO MT.
PLEASANT LINE. HIGH PRESSURE BUILDS IN THROUGH THE SHORT TERM PERIOD
BOTH AT THE SFC AND ALOFT. FCST CONCERNS RATHER MINIMAL TODAY
THROUGH SUNDAY...BUT MAINLY PERTAIN TO CLOUD COVER TODAY. MODELS
FAIRLY SIMILAR IT TERMS OF MI/S WEATHER.
FOR TODAY...STRATOCU IN THE WAKE OF THE FRONT MOVING FROM NORTH TO
SOUTH ACRS THE AREA ATTM. CLEARING AS STATED ABOVE MAKING PROGRESS
TO THE SOUTH. QUESTION IS HOW FAR SOUTH WILL THE CLEARING MAKE IT BY
DAYBREAK. RUC RH PROGS FROM 925 AND 850 MB/S SHOW THE DRYING TREND
CONTINUING THROUGH 12Z. BY 12Z...THE CLEARING SHOULD HAVE MADE IT
THROUGH THE MAJORITY OF THE FCST AREA...THE EXCEPTION BEING THE FAR
SOUTHEAST TOWARD JXN. IN THE WAKE OF THE STRATOCU TODAY...PLENTY OF
CUMULUS DEVELOPMENT ANTICIPATED...WITH THE 850MB THREMAL TROF
OVERHEAD. THERMAL TROF COMBINED WITH AUGUST SUNSHINE WILL LEAD TO
PLENTY OF CU. WILL GO ON THE OPTIMISTIC SIDE OF THINGS HOWEVER AND
WORD FCST AS PARTLY SUNNY. YESTERDAY/S VIS PICS FROM UPSTREAM SHOWED
QUITE A FEW BREAKS...THEREFORE THE PARTLY SUNNY FCST. 850 TEMPS
TODAY YIELD HIGHS IN THE LOW 70S. A BLEND OF THE AVN AND NGM
GUIDANCE TEMPS ALSO COME UP WITH THE SAME RANGE.
TONIGHT...CU SHLD DISSIPATE THROUGH THE EVENING...WITH SKIES
BECOMING CLEAR. POSSIBILITY OF SOME CIRRUS ADVECTING IN LATE...BUT
SHLD NOT PRECLUDE A CLR OVERNIGHT FCST. SFC HIGH PRESSURE SITUATED
ACRS THE FCST AREA TONIGHT...WITH A GOOD RADIATIONAL COOLING SETUP.
GUIDANCE TEMPS IN THE BALLPARK TONIGHT WITH UPR 40S FROM BALDWIN TO
CLARE AND DOWN TO LAN. AROUND 50 ELSEWHERE SHLD WORK FOR MORNING
LOWS.
CIRRUS DEBRIS FROM PLAINS CONVECTION WILL WORK ITS WAY INTO THE FCST
AREA ON SUNDAY. WILL RUN WITH AN INCREASING HIGH CLOUDS FCST TO
ACCOUNT FOR THIS. WILL STAY CLOSE TO THE WARMER NGM MOS NUMBERS FOR
HIGHS GIVEN THE STRENGTH OF THE 850MB WAA. HIGHS AROUND 80 SHLD WORK
FOR THE MAJORITY OF THE AREA.
DUKESHERER
.EXTENDED DISCUSSION...
ONLY CHANGE PLANNED TO EXTENDED FORECAST IS TO BUMP UP EXPECTED MAX
TEMPS FOR MONDAY BY A FEW DEGREES. LATEST ECMWF AND UKMET MESH WELL
WITH AVN FOR SUNDAY NIGHT/MONDAY PERIODS. SIGNIFICANT PATTERN CHANGE
ADVERTISED IN THE EXTENDED AS UPPER RIDGE BUILDS OVER THE CENTRAL
U.S. AND SWRLY FLOW IN THE LOWER LEVELS BRINGS THE HEAT AND HUMIDITY
BACK INTO THE SRN GREAT LAKES REGION. ECMWF CONTINUES TO SHOW LEAD
SHORTWAVE BRUSHING UPPER AND NRN LOWER MI TUESDAY...WILL THEREFORE
LEAVE MENTION OF A SLIGHT CHANCE FOR CONVECTION TUESDAY AFTERNOON.
MUCH BETTER CHANCE FOR WEDNESDAY AS SECOND SHORTWAVE TROUGH WILL
DEEPEN AS IT APPROACHES THE WRN GREAT LAKES. AS FOR TEMPS ON
MONDAY...AVN WARMS H85 TEMPS TO 21-22C BY 00Z WITH 1000-850 MB
THICKNESS VALUES WARMING TO 1410-1415M. LOCAL TEMP SCHEME YIELDS
MID-UPPER 80S WITH PARTLY CLOUDY CONDITIONS. WILL PLAY IT
CONSERVATIVELY AND GO MID 80S WITH SWRLY LAKE BREEZE KEEPING WRN
AREAS A FEW DEGREES COOLER.
GREENE
.GRR...NONE.
FXUS63 KDTX 140230 mi
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
953 PM EDT FRI AUG 13 1999
KAPX 88D INDICATES MEASUREABLE PRECIPITATION HAS PUSHED OUT OF THE AREA
AS MID LEVEL DRYING EVIDENT IN WV IMAGERY/00Z APX RAOB HAS OVERSPREAD
NORTHERN MICHIGAN. JUST SOME PATCHY DRIZZLE/SPRINKLES LEFT ACROSS
CENTRAL LOWER DOWNWIND OF HIGHER TERRAIN AREAS. FLOW IS QUICKLY
BECOMING ANTICYCLONIC IN THE LOW LEVELS...AND 925MB ANALYSIS AND RUC
FORECASTS IMPLY STRONGEST LOW LEVEL CAA ALREADY SOUTH OF THE AREA. 12Z
ETA AND SUBSEQUENT RUC 925MB RH FORECASTS CONTINUE TO PROG DRYING SOUTH
ACROSS THE FORECAST AREA OVERNIGHT...WITH FOG LOOPS SHOWING CLEARING
PROGRESSING NICELY THROUGH THE STRAITS AND AS FAR SOUTH AS AN MBL-
ROGERS CITY LINE. GIVEN DEEP-LAYER SUBSIDENCE AND CURRENT SATELLITE
TRENDS...PLAN TO GO WITH A MOSTLY CLEAR FORECAST FOR EASTERN UPPER AND
THE STRAITS...AND PUSH THE TREND OF DECREASING CLOUDS AS FAR SOUTH AS
HTL-OSC. FORECAST MINS LOOK GENERALLY ON LINE GIVEN CURRENT DEW POINTS
AND EXPECTATION THAT WINDS WILL STAY UP OVERNIGHT.
.APX...NONE.
JPB
FXUS63 KDTX 140118 mi
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAMPA BAY-RUSKIN FL
1005 AM EDT SAT AUG 14 1999
ALTHOUGH THE CENTRAL PORTION OF THE FA HAS A LITTLE MORE MOISTURE
TODAY THAN YESTERDAY...RELATIVE TO THE REST OF THE STATE WE ARE MUCH
DRIER. I LIKE THE WAY THE RUC HANDLED EVERYTHING
YESTERDAY...UNFORTUNATELY WITH THE CRAY CRASHING WE HAVE NOT BEEN
ABLE TO GET A 09Z RUC. THE 06Z RUN KEEPS A DRY SLOT OVER THE
CENTRAL FLORIDA AREA THROUGH 18Z AND ALL OF THE HAZE AROUND CONFIRMS
THAT WE REMAIN CAPPED. ONCE AGAIN MODELS HAVE MOISTURE SPREADING
NORTH INTO THE AREA THIS AFTERNOON. SO...I WILL LEAVE THE 30 AND 40
POP OVER MOST OF THE AREA. THE FAR NORTH AND SOUTH WILL LIKELY GET
DRENCHED...I WILL LEAVE THE 50 POP IN THE SOUTH AND INCREASE THE POP
FOR LEVY TO 50. DEWPOINT REMAIN HIGH PLUS WE WILL HAVE PLENTY OF
SUN...SO I WILL HIT A LITTLE HARDER ON THE HIGH INDICES.
SOBIEN
FXUS62 KTAE 141400 fl
AREA FORECAST DISCUSSION..UPDATED
NATIONAL WEATHER SERVICE TAUNTON MA
655 AM EDT SAT AUG 14 1999
...SULTRY AFTN WILL PROBABLY GIVE TO WAY SCT SVR OR FF THIS EVE...
CRAY CRASHED AT NCEP AND NO 09Z RUC AND DELAYED 06Z AVN. HOPING TO
GET 12Z MODELS STARTED ON TIME.
ZONES PROB TO B UPDATED A BIT ARD 730 AM. RELIED ALMOST ENTIRELY ON
ETA/NGM FIRST 36 HRS THEN BLENDED AVN/EC INTO THE FCST 48-120 HRS. NO
REVIEW OF GEM/SEF/NOGAPS OR NEW MRF FOR THE EARLY ZFP RELEASE.
TDY: OFFICIAL DAY HEAT WAVE POSSIBLE BDL/CEF AS SULTRY HEAT LIKELY TO
RETURN THIS AFTN WITH MAX TEMP POSSIBLY REACHING 94F. ATTM PLAY
IT CONSERVATIVE BASED ON 03Z ETA T1 FCST BUT AM CONCERNED THAT
THIS SHWR/TSTM SYSTEM IN SNE ATTM LEAVES A LITTLE EARLIER AND
ALLOWS MORE RAPID RTN TO SS TODAY. AIRMASS IS POTENTIALLY HOT
AND ALL WE NEED IS ABT 4-5 HRS OF P/S TO GET TO 90F. WITH SFC TD
NR 75 THIS AFTN THE CT RVR VLY ESPECIALLY HAS A GOOD CHC OF A
HEAT INDEX ARD 100 AT 3-4P. IF PS IS LESS THAN 3 HRS AND TEMPS
MAX NR 87 AS FCST BY NGM (BLV NGM MOS HAS TOO MUCH OVC AND NOT
ENUF HEAT ALLOWED ON SW LOW LVL FLOW IN SUMMER AND THEREFORE
TOO COOL) THEN THE THREAT OF SVR WOULD BE LESS THAN CURRENTLY
FCST. WE DO REALIZE OUTFLOW BOUNDARY HAS SLIPPED DOWN INTO S NJ
AND THAT MAY ALSO MITIGATE THREAT. DRY SLOT BTWN OUR SYSTEM
AND W NYS WILL PROBABLY ALLOW RECOVERY.
WE ARE NOTING RW+ DVLPG E PA NJ ATTM BEHIND THE INITIAL BAND.
THIS COMPLICATES FCST FOR SE 2/3RDS OF FA TDY.
SVR: WILL ISSUE SPS FOR SW NH/W 2/3 MA AND N CT ARD 7AM. BLV ATMOS
CAN RECOVER AND ALLOW FOR A SIGNIFICANT SVR EVENT FAR W PTN OF
FA. HOWEVER THIS ALL NEEDS REEVALUATION AFTER 12Z.
TNGT: BENEFICIAL RAIN MOST AREAS.
SUNDAY: MUCH COOLER NE MA COAST. OTRW IF SS IN THE AFTN...CAN
EASILY SEE HAILERS AND SLOW MOVING TRW+
LR: MINOR MODIFICATION TO FCST MON-WED PRIMARILY BASED ON EC.
BLV 2 OR 3 MORE DAYS OF 90+ LIKELY BTWN TUE-THU BASED ON
00Z/14 MRF/NOGAPS AND 12Z/13 EC.
BDL TOTAL AOA 90 THRU 8/13 26 SEASONAL NORM 19
HIGHEST SINCE 1991 31
.BOX...SCA ALL WATERS.
DRAG
FXUS61 KBOX 141053 AMD ma
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
1130 AM EDT SAT AUG 14 1999
MINOR UPDATES THIS MORNING FORECAST
SURFACE MAP SHOWS THE CENTER OF THE HIGH OVER IOWA AND SLOWLY
SHIFTING EAST. IMPACTS ON TODAYS FORECAST...DECREASING WINDS OVER
LAKE HURON AND BRINGING A COOL BUT PLEASANT AFTERNOON. A FEW LAKE
CLOUDS OVER THE EASTERN UP ALSO UNDER AN AREA OF SOME PVA.
LITTLE NEW MODEL DATA TO LOOK AT DUE TO COMPUTER PROBLEMS AT NECEP.
THE FORECAST QUESTION OF THE DAY IS WHAT TO DO WITH AFTERNOON CLOUD
COVER IN THE UP AND CU IN THE LP. UP CLOUDS APPEAR TO BE MAKING
PROGRESS WITH THE 6Z RUC AND 0Z ETA AND WILL REACH BE IN THE
STRAIGHTS BY 18Z...WL ADJUST WORDING WHERE NEEDED. THE CU IN THE LP
FROM TVC TO MID LAKE MICHIGAN DON/T LOOK TO BE TOO WIDESPREAD AND
WITH MODEL SOUNDINGS SHOWING DRYING TODAY...DON/T BELIEVE THEY WILL
BE TOO MUCH OF A PROBLEM.
...WITH MINOR CHANGES TO CLOUD COVER WORDING THE ONLY OTHER CONCERN
IS DAY TIME TEMPERATURES. 12Z APX SOUNDING IS A COOL ONE AND
TEMPERATURES MAY STRUGGLE AS THEY PRESS ABOVE THE 70 DEGREE MARK.
.APX...NONE.
HIRSCH
FXUS63 KAPX 121921 mi
NORTHERN GREAT BASIN FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ELKO NV
845 AM PDT SAT AUG 14 1999
SATELLITE IMAGERY SHOWING NEARLY CLOUD FREE SKIES OVER NORTHERN
GREAT BASIN THIS MORNING. A COUPLE OF FEATURES OF
NOTE...SUBTROPICAL JET STREAK CIRRUS OVER EAST CENTRAL NEVADA AND
OF COURSE THE CLOUD SHIELD ASSOCIATED WITH PAC NW LOW LIFTING
NORTHEAST OVER EASTERN OREGON. CURRENT TRAJECTORY OF VORT MAX
MATCHES UP VERY WELL WITH LAST NIGHTS ETA RUN (NO 12Z RUN DUE TO
NCEP PROBLEMS). WIND WILL LIKELY BE THE MAIN WEATHER FEATURE TODAY
AS EVEN THE 06Z RUC INDICATED 20-30 KTS AT 700 MB OVER THE FA
TODAY. WILL NOT BE MAKING ANY UPDATES THIS MORNING AS CURRENT
FORECAST HAS THINGS WELL IN HAND.
.EKO...NONE.
DUDLEY
FXUS65 KVEF 141008 nv
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBUQUERQUE NM
850 PM MDT FRI AUG 13 1999
ADJUSTMENTS MADE TO FIRST PERIOD FORECASTS BASED ON TRENDS FROM
IMAGERY AND LATEST RUC OUTPUT. SHOULD BE A 3 TO 6 HOUR EAST TO
SOUTHEAST CANYON WIND EVENT MID RIO GRANDE VALLEY LATE THIS EVENING
INTO THE PREDAWN HOURS. 38
.ABQ...NONE.
FXUS65 KABQ 132101 nm
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
955 AM EDT SAT AUG 14 1999
.DISC...
.SHORT TERM...CDFNT HAS MVD FM ST LWRC VLY TO ABT JST N OF
BTV-UCA-BFD PAST 2 HRS. ITS ABT ON TRACK WITH THE RUC FCST FM 06Z
WHICH WD PUT IT FM GFL-DELAWARE CO BY 19Z. A FEW WK SFC LOWS HV
FORMD ALNG IT PAST HR. AHEAD OF CDFNT MID CLDS BREAKING UP AND TD
RMN ARND 70. NGM PROD CAPES THIS AFTN IN MDLS SNDGS ARND 2500
J/KG...ETA VALUES CLOSR TO 1000 J/KG. SELS PROJ CAPES IN NGM RANGE
BUT SHFTD SLIGHT RISK AREA SLGHTY S TO ONLY INCLUDE ULSTER/DUTCHESS
COS.
BOTH MDLS SHW LTL SHEAR OR HELICITY SO WHAT POT FOR SVR WX WL
LARGELY BE PULSE TYPE WINDS. SCT SHRA HV ORG ALONG AND AHEAD OF
CDFNT BUT NOT TSRA YET. GIVEN FRNTS MVMT WILL DROP TO CHC POPS AND
RMVE TSRA NW OF ALB. FOR MST PART CRNT FCST LKS GOOD ALTHOUGH WL
MODIFY TO VARBLE CLDS OR CLDS MIXED WITH SOME SUN AS MST AREAS WLL
SEE A FEW HRS OF SUN BFR SHRA/TSRA.
.LONG TERM...NO CHNGS ATTM
ALY...NONE
SNYDER
FXUS61 KBGM 141405 COR ny
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
1013 AM EDT SAT AUG 14 1999
NTRANS/MSAS SFC ANALYSIS SHOWS LEE TROF IN PLACE W/ THE CDFNT JUST W
OF THE MTNS. NTRANS UA ANALYSIS SHOWS UPR TROF SET UP TO OUR W. WATER
VAPOR IMAGERY SHOWS UPR JET APPROACHING. NO NEW RUC/MESO-ETA TO LOOK
AT THIS MORNING BUT APPEARS LIFT WILL BE SUFFICIENT THIS AFTN. WEAK
LO-LVL WIND FIELDS SO WE SHOULD GET A RESULTANT BOUNDARY FORM.
MODIFIED 12Z MHX RAOB SHOWS PLENTY OF INSTABILITY (LI -10) & ENERGY
(5+K CAPE) AS WELL AS DECENT MOISTURE (PW 1.7). DEWPTS IN THE MID
70S. ALREADY PUSHING 90 AT ILM & SATELLITE SHOWS MOSTLY CLOUD-FREE
SKIES ACROSS THE CWFA SO HEATING WON/T BE A PROBLEM. WILL CONTINUE
CHC POPS FOR THE AFTN W/ MOST ACTIVITY TO COME AFTER 20Z. LOCAL
SCHEMES GIVE UPR 90S MOST LOCATIONS WHILE LAMP GUIDANCE STAYS IN MID
90S. BUT INCREASED CLOUD COVER THIS AFTN WILL HOLD BACK SLIGHTLY &
WILL STAY W/ GOING FCSTS. WILL STILL HIT HEAT ADVRY CRITERIA.
CWF...WINDS IN 10-15 RANGE THIS MORNING BUT AN INCREASE IS PROGGED
FOR THE AFTN. CONTINUE GOING FCST.
LGE
FXUS62 KRAH 141400 nc
AREA FORECAST DISCUSSION FOR CENTRAL/NORTHCENTRAL AND NORTHEAST
SOUTH DAKOTA AND WEST CENTRAL MINNESOTA
NATIONAL WEATHER SERVICE ABERDEEN SD
1015 AM CDT SAT AUG 14 1999
REMAINS OF MCS STILL DRIFING THROUGH SRN CWA ATTM...WITH WEAK NEW
DEVELOPMENT TAKING PLACE ON BACK SIDE. THIS IS TAKING PLACE ON
LEADING EDGE OF WAA COMING BACK INTO AREA. AFTER THIS CLEARS...WAA
THROUGH ALL LAYERS WILL TAKE PLACE TODAY. UNFORTUNETLY...NO 12Z RUC
TO LOOK AT. WILL HOLD OFF UNTIL 16Z FOR ZONE UPDATE TO SEE IF REMAINING
PCPN ECHOS HAVE CLEARED CWA.
.ABR...NONE.
HINTZ
FXUS63 KUNR 140945 sd
SOUTHEAST IDAHO AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE POCATELLO/IDAHO FALLS ID
232 PM MDT SAT AUG 14 1999
NCEP HAD COMPUTER PROBLEMS TODAY...SO LIMITED MODEL OUTPUT AVAILABLE
TO USERS..COMPUTERS ARE STILL DOWN...SO THEY ARE USING OLDER...MUCH
SLOWER BACKUP COMPUTERS. CERTAIN MODELS (ETA AND RUC) WILL NOT BE
AVAILABLE UNTIL THEY GET THINGS FIXED UP. NGM RUN DID MAKE IT THROUGH
AND WAS CLOSE ON ITS INITIALIZATION OF LOW PRESSURE SLIDING THROUGH
WA/OR TODAY. PLUS 10-12 DEGREE 700 MB CAP IN PLACE THIS AFTERNOON HAS
KEPT SCT CLOUD DEVELOPMENT TO A MINIMUM. MAIN AXIS OF LOW ENERGY AND
ASSOCIATED JET DYNAMICS TO SWEEP PAST THIS EVENING MAKING DECENT
CHANCES OF POPS IN CENTRAL MOUNTAINS AND UPPER SNAKE AREA AND
LINGERING AFFECTS TOMORROW MORNING. REST OF CWA TO HAVE ISOLATED
CHANCES OF THUNDERSTORMS...WITH LITTLE IF ANY PRECIP. DECENT SURFACE
GRADIENT IN PLACE WILL KEEP WINDS UP ESPECIALLY IN SOUTHERN SECTIONS
OF CWA.
ON SUNDAY EXPECT IMPROVING CONDITIONS AND PARTLY TO MOSTLY SUNNY BY
AFTERNOON AS SUBSIDENCE TAKES PLACE...ZERO TO LOW POPS. BIG TREND IS
COOLER TEMPS. SUNDAY NIGHT...PARTLY TO MOSTLY CLEAR...WILL SPELL EVEN
COLDER OVERNIGHT TEMPS IN SOME LOCALS. ANOTHER WEAK SYSTEM TO PUSH
THROUGH MONDAY...BUT MOST DYNAMICS TO REMAIN NORTH. WILL PUT ISOLATED
AFTN BUILDUPS. THICKNESS VALUES INCREASE SO EXPECT A LITTLE WARMER.
AFTER MONDAYS SYSTEM...RIDGE STARTS TO BUILD...BUT WILL RE-INTRODUCE
MONSOONAL FLOW WED INTO THUR...SO POTENTIAL FOR AFTN POPS COMES INTO
PLAY WITH NORMAL TO SLIGHTLY ABOVE NORMAL TEMPS.
PRESTON/HARMON
TEMPERATURES/POPS ARE UNOFFICIAL AND FOR COORDINATION ONLY...
BYI 051/082 050/085 100
.KSFX WSR-88D...OPERATIONAL...VCP 32.
.PIH...RED FLAG WARNINGS FOR FIRE WEATHER ZONES 412 AND 413 THROUGH 9
PM
PIH UB 050/079 045/083 048 03100
IDA BB 048/076 044/082 047 03210
FXUS65 KBOI 141618 COR id
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
1022 AM EDT SAT AUG 14 1999
EXPECT TSTMS WILL DEVELOP IN THE SURFACE TROUGH IN THE WEST PART OF THE
FORECAST AREA AROUND MID AFTERNOON AND MOVE EASTWARD INTO THE REMAINING
AREA LATE THIS AFTERNOON OR EVENING. THE 09Z RUC SHOWED H95 MOISTURE
CONVERGENCE AT 21Z IN THE WEST PART AND THE LATEST ADAP ALREADY SHOWS
WEAK CONVERGENCE JUST WEST OF THE FORECAST AREA. THE H5 SHORTWAVE THE
RUC SHOWS APPROACHING THE AREA SHOULD ALSO HELP WITH INSTABILITY. THE
WATER VAPOR LOOP SHOWS THIS SHORTWAVE APPROACHING. H7 TEMPERATURES STILL
APPEAR WARM(9 TO 10) AND THIS MAY HELP LIMIT COVERAGE. PLAN TO KEEP POPS
IN THE CHANCE CATEGORY. ADAP ALREADY SHOWS LI/S AROUND -8. THE STRONG
INSTABILITY COULD HELP SUPPORT A FEW SEVERE TSTMS. THE WATER VAPOR LOOP
ALSO SHOWS SOME MID-LEVEL DRYING COULD MOVE INTO THE AREA LATE THIS
AFTERNOON OR THIS EVENING WHICH COULD AID DOWNDRAFT POTENTIAL. CURRENT
TEMPERATURES AND DEW POINTS SUPPORT OUR HEAT ADVISORY THIS AFTERNOON.
.CAE...HEAT ADVISORY THIS AFTERNOON SCZ015-016-018>022-025>031-035>038-
041-GAZ040-063>065-077.
RJL
FXUS62 KCHS 141432 COR sc