AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
900 AM PST MON NOV 29 1999
LITTLE SURFACE FORCING EVIDENT IN WIND OBSERVATIONS OVER NORTHERN CA
THIS MORNING...WITH PRESSURE FALLS FOCUSED ALONG PACIFIC
NORTHWEST/VANCOUVER COASTLINE UNDER CLASSIC COUPLED JET STREAK
PATTERN. IN FACT..HAVE YET TO SEE ANY PRESSURE FALLS OF NOTE SOUTH OF
THE OREGON BORDER. THESE LIGHT WINDS TOGETHER WITH SIGNIFICANT CLOUD
COVER WILL ALLOW VALLEY FOG TO PERSIST PAST NOON TODAY. IF
PROGRESSION OF FRONT AND ASSOCIATED WINDS SLOWS...WILL BE LOOKING AT
ANOTHER DAY LIKE FRIDAY IN THE LOWER VALLEY...WHERE FOG REFORMS
RAPIDLY WITH EVENING COOLING.
NO UPDATES AT THIS TIME...ONLY CHANGE WOULD BE TO RAISE INITIAL SNOW
LEVELS OVER THE SIERRA/SOUTHERN CASCADES AND SLOW THE LOWERING OF
SAID LEVELS OVER THE NEXT 8 HOURS. ETA AND RUC MODEL SOUNDINGS
PLOTTED FOR THE SIERRA BOTH INDICATE WET BULB ZERO HEIGHTS OF 8000
FEET TODAY...FALLING ONLY TO 6000-7000 FEET THIS EVENING. MOST
SIGNIFICANT LOWERING OF SNOW LEVELS WILL OCCUR..AS THE FLOW VEERS
SLIGHTLY LATER TONIGHT...WITH SNOW SHOWERS LINGERING INTO THE MORNING
HOURS DOWN TO 3000-3500 FEET. THUS...THE NEW 24 HOUR CHANGE IS
COVERED WELL IN WSW. SJC
.STO...WINTER STORM WATCH TONIGHT...FOR THE MOUNTAINS OF SHASTA
COUNTY INCLUDING BURNEY BASIN SOUTHWARD TO THE MOUNTAINS OF
NORTHERN LAKE COUNTY AND FOR THE NORTHERN SIERRA NEVADA...
FXUS66 KHNX 291731 ca
AREA FORECAST DISCUSSION...UPDATED MARINE DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
935 PM EST MON NOV 29 1999
SATELLITE AND UPPER AIR DATA SHOW JET DIVING INTO BASE OF DEEP UPPER
TROUGH OVER THE ERN USA WITH STRONG SUBSIDENCE MOVING S INTO NRN
MS/AL. SURFACE DATA SHOW ASSOCIATED COLD FRONT MAKING RAPID PROGRESS
INTO OUR NW CWA AT THIS TIME. KMXX WSR-88D INDICATES 35-40 KT NNE
FLOW BEHIND FRONT WITHIN A FEW KFT AGL...BUT LOCAL METARS STILL IN
THE 10 KT RANGE. SEE NO NEED TO MODIFY FORECAST WINDS OR
TEMPERATURES AT THIS TIME. BRISK WINDS SHOULD KEEP TEMPERATURES FROM
GETTING TOO LOW TONIGHT...BUT WEDNESDAY MORNING LOOKS RIPE FOR A
FREEZE WARNING. MIDNIGHT SHIFT WILL HAVE TO MONITOR.
FIRE WEATHER: RED FLAG WARNING WILL LIKELY BE NEEDED FOR FL ZONES
TUESDAY AFTERNOON BASED ON LOW HUMIDITY CRITERION.
MARINE: BASED ON OBSERVED POST-FRONTAL BOUNDARY LAYER WINDS AND RUC
PROGS...WILL ISSUE SMALL CRAFT ADVISORY FOR COASTAL ZONES WITH THE
EXPECTATION THAT WINDS WILL INCREASE SIGNIFICANTLY AFTER MIDNIGHT.
FEEDBACK ALWAYS WELCOME.
.TLH...WIND CHILL ADVISORY TUE MORNING FOR FL BIG BEND AND
INLAND ZONES OF ERN FL PANHANDLE...
RED FLAG WARNING FL ZONES TUE AFTN.
TJT
FXUS62 KTAE 300222 fl
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO IL
300 PM CST MON NOV 29 1999
CLD SURG OF AIR DWN LM THIS AFTN HAS STRTD LK SNW IN NWRN IN. VPZ
RTPNG SNW ATTM WITH SAT/88D IMGRY INDC ANUDR BND BTWN GYY AND VPZ.
SNW BND ASSOCD WITH N-S SFC RDG ALNG MS RVR. STIL SUM DIFFS IN HNDLG
MVMT OF HI AND ULTMATLY END OF SNW IN NWRN IN AND SCT CLDS IN CHI.
NGM APPRS TO BE ODD MAN OUT. ETA/AVN/RUC MV CNTR OF HI TO VCNTY UIN
BY 06Z SO THAT SFC WNDS RMN NWLY AND KP SNW AND CLDS TO E OF CHI BUT
IN ERN CTYS IN CWA. BY TUES AM RDG LN NEWD OVR LM WIL PUT END TO SNW.
AFTR CLD NITE WITH TMPS INTO TEENS SLY FLO TUE WILL PSH MAXS BCK TO
NR SNSL MRK. DP TROF OFF E CST SLOES EWD MVMT OF H5 RDG AND POSTPNS
ARVL OF NXT WX SYS TO LT IN WK.
MOS GDNC CLS AND IN LN WITH CURNT FCSTS.
.CHI...NONE
SOMREK
FXUS63 KILX 292041 il
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
247 PM EST MON NOV 29 1999
LATEST SAT AND 18Z SFC DATA SHOW SW TROF ROTATING ACRS LWR MI WITH
SFC TROF REFLECTION ALG ORD TO DAY LINE. SC/LK EFFECT SNSH DVLPG
IN EARNEST BEHIND THIS FTR AS CAA INTENSIFIES. KIWX REF LOOP
INDICATING NR 35 DBZ ECHOES ALG MKG TO SBN LINE. RUC MODEL ALG
WITH UW AND LAST EVENING MM5 RUN ALL POINTING TO SHORE PARALLEL SNOW
BAND PERSISTING ALG E SHORE OF LM FOR BETTER PART OF TONIGHT.
ALREADY SOME LOCALES IN SW MI/NW IN DOWN TO 1/4SM +SN AT TIMES.
12Z MODELS CONT AGREEABLE TREND WITH SYN FTRS THRU FCST PD. PRIMARY
ISSUE OVERNIGHT ARE POTENTIAL SNOW ACCUMS ACRS LAPORTE...BERRIEN AND
ST JOE IND COUNTIES. WILL RELY ON RUC/UW/MM5 IN SHORT TERM AND
ETA/AVN BLEND AFT THAT. LK EFFECT PROGGED TO SHUT OFF AS LOW LVL
FLW BEGINS TO TURN ANTICYCLONIC BY 12Z TUE BUT UNTIL THEN PERSISTENT
CVRG PROGGED FM MKG TO SBN THRU 09Z. DROPPING TEMPS AFT SS WILL MAKE
ROADS MESSY AND FEEL THIS COMBINED WITH XPC GENERAL ACCUMS OF 2-3
INCHES WITH LOCAL 4 WILL THEN NEED TO HOIST ADVY FOR BERRIEN...
LAPORTE...ST JOE IN. FOR TUE...FEEL LK EFFECT CLDS TO HOLD IN BETTER
PART OF DAY PER TIME HGT CROSS SECTIONS WHICH INDICATE TRAPPED MOIST
UNDER DROPPING INVERSION. IN ADDITION VRY WK FLW UNDER SFC RIDGE AXIS
WILL NOT PROVIDE ANY MIXING TO SPEAK OF AND WILL THEREFORE PLAY IT
PESSIMISTIC. AS SFC RIDGE WORKS E ACRS FA TUE...ROBUST WAA BEGINS TUE
NIGHT AND CONTS WED. LOOKS LIKE PLENTY OF MID LVL CLD DVLPMT IN
ASSOCD/W STRONG WAA IN 850-700MB LYR WED WITH 850 TEMPS WARMING ABV
0. SUBSTANTIAL MIXING PROGGED AS WELL AND TEMPS TO WARM CONSIDERABLY
EVEN WITH PLENTY OF CLD CVR. THERMAL RIDGE CONTS TO BUILD INTO EARLY
PART OF THE EXTDD AS PROGRESSIVE EPAC TROF THIS AM MARCHES E INTO
CENTRAL/SOUTHERN PLAINS. MED RANGE MODELS CONT TO DISPLAY SIG
DIFFERENCES WITH HANDLING OF THIS SYS. CLIMATOLOGY WOULD DICTATE WKNG
LEAD SW TO AFFECT AREA LATE THU-FRI WITH POTENTIALLY MORE SIG SYS
SAT-SUN TIME FRAME DEPENDENT UPON HOW SYS EVOLVES/TRACKS. WIL BEAR
WATCHING.
GUIDANCE TEMPS CLOSE FIRST HALF WITH NGM SOMEWHAT COOLER LTR HALF.
WILL SIDE AGAIN WITH FAN AS IT HAS NOT DONE TOO BAD LATELY. WORK
ZONES OUT SHORTLY.
.IWX...LE SNOW ADVY TONIGHT FOR MIZ077...INZ003>004.
TEH
FXUS63 KIND 291930 in
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GOODLAND KS
809 PM MST MON NOV 29 1999
ATTM LOW LVL CLOUD COVER CONTS TO DISSIPATE AS DRIER AIR ADVECTS
NORTHWARD INTO THE CWA. THE LATEST RUC DOES HINT AT A RETURN OF
BOUNDARY LAYER MOISTURE LATER TONIGHT THEREFORE...I WILL LEAVE THE
MENTION OF PATCHY FOG ACRS ALL ZONES. ALSO...WITH TMPS ACRS ALL ZONES
IN THE LOWER 30S ALREADY...AND WITH THE PARTLY CLOUDY SKIES OF
TONIGHT...I HAVE LOWERED OVERNIGHT TMPS ACRS ALL ZONES. THE REMAINDER
OF THE FORECAST APPEARS ON TRACK.
.GLD...NONE.
VPAPOL
FXUS63 KICT 292137 ks
AREA FORECAST DISCUSSION...UPDATE
NATIONAL WEATHER SERVICE GOODLAND KS
1115 AM MST (1215 PM CST) MON NOV 29 1999
WL HAVE TO MAKE ADJUSTMENTS TO TEMPS AND CLD COVER BASED ON LATEST
SATL TRENDS AND LATEST RUC/MESOETA/ETA. CLEARING OF STRATUS IS
OCCURRING FM SE TO NW WITH LTL TO NO CHANGE IN CONDITIONS OVR THE
NW HALF OF CWFA. FOG IS EVEN HANGING ON STILL IN NW HALF AS WELL.
THIS A LTL DIFFERENT FM CURRENT PACKAGE. SE PTN OF CWFA LOOKS IN
GOOD SHAPE SO WL MAKE LTL IF ANY CHANGE THERE WHERE WARMEST TEMPS AND
MOST SUN WL BE. SO WL HAVE BCMG MSUNNY SE. THEN WL HAVE FOG EARLY
AND BCMG PTSUN TO MCLDY NRN AND WRN SECTIONS AND LWR TEMPS ANYWHERE
FROM 5 TO 15 DEGREES.
.GLD...NONE.
FXUS63 KGLD 290914 ks
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
1053 PM EST MON NOV 29 1999
CURRENT APX RADAR DATA SHOWING A ONCE DISORGANIZED LAKE EFFECT SNOW
BAND CROSSING INTO NORTHWEST LOWER MICHIGAN... HAS NOW BECOME A WELL
ORGANIZED BAND EXTENDING FROM JUST SOUTH OF NAUBINWAY IN SOUTHERN
MACKINAC COUNTY TO LITTLE TRAVERSE BAY TO GRAYLING. THIS LAKE EFFECT
SNOW BAND HAS AN EMBEDDED AREA OF 28 DBZ OR GREATER RETURNS THAT IS 70
NM LONG AND 8 NM MILES WIDE CURRENTLY OVER NORTHWEST LOWER MICHIGAN.
RECENT SPOTTER SNOWFALL REPORTS AROUND LITTLE TRAVERSE BAY SHOWED
SNOWFALL RATES TO ONE HALF INCH PER HOUR WITH EVENING SNOW ACCUMULATIONS
ALREADY NEAR 3 INCHES IN SOME LOCATIONS. THE LATEST MESO ETA AND RUC
DATA SUGGEST ANOTHER 3 TO 4 HOURS OF GOOD LAKE EFFECT SNOW CONDITIONS...
WITH INVERSION HEIGHTS TO 6000 FEET...DELTA T'S AROUND 15 TO 17 AND 80
PERCENT OR GREATER RH EXTENDING TO ABOVE 850 MB.
DRIER AIR AND A WIND SHIFT TO THE NORTH WILL TAKE PLACE OVER NORTHERN
LOWER MICHIGAN SHORTLY AFTER 2AM... WHICH SHOULD BEGIN TO DIMINISH THE
AREAL COVERAGE AND INTENSITY OF THE LAKE EFFECT SNOW. HOWEVER...WITH
GOOD LAKE EFFECT SNOW CONDITIONS FOR THE NEXT 3 OR 4 HOURS AND ASSUMING
AN AVERAGE SNOWFALL RATE AROUND ONE HALF INCH PER HOUR...EXPECT ANOTHER
2 OR 3 INCHES POSSIBLE FOR THE LAKE MICHIGAN SNOWBELT TONIGHT.
THEREFORE WILL ISSUE A LAKE EFFECT SNOW ADVISORY FOR LOCATIONS AROUND
GAYLORD...GRAYLING...MANCELONA AND CHARLEVOIX.
.APX...LAKE EFFECT SNOW ADVISORY...TONIGHT...MIZ016-019-021-022-028.
SWR
FXUS63 KMQT 300303 mi
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
800 PM EST MON NOV 29 1999
CURRENT APX 88D SHOWING LAKE EFFECT SNOW BANDS AFFECTING MUCH OF
NORTHWEST LOWER MICHIGAN AND EAST UPPER MICHIGAN... WITH SEVERAL
LOCATIONS NORTH OF M-55 AND WEST OF US-131 WITH +28 DBZ RETURNS. THE
LAKE EFFECT SNOW BANDS OVER NORTHWEST LOWER HAVE BEEN SHIFTING DURING
THE PAST HOUR...WITH THE BANDS BEGINNING TO SHOW MORE OF A NORTHWEST
ORIENTATION INSTEAD OF THE NORTH/SOUTH ORIENTATION NOTED EARLIER THIS
EVENING. THE LATEST MESOETA PICKED UP ON THE WIND SHIFT TO THE
NORTHWEST THIS EVENING... PLACING THE BEST LAKE EFFECT SNOW POTENTIAL
NOW OVER ANTRIM...OTSEGO...CHARLEVOIX...KALKASKA AND CRAWFORD COUNTIES.
RECENT SPOTTER REPORTS FROM THE TVC AREA INCLUDING ELK RAPIDS AND
ALDEN... SHOW AROUND ONE HALF INCH PER HOUR SNOWFALL RATES UNDER THE
HIGHER 28 DBZ RETURNS.
THE MESOETA AND RUC MODEL TIME SECTIONS AND SOUNDINGS SUGGEST THE BEST
LAKE EFFECT SNOW GENERATION PERIOD WILL BE BETWEEN NOW AND 06Z.
INVERSION HEIGHTS DURING THIS PERIOD WILL BE BETWEEN 4000 AND 7000 FEET
WITH ABUNDANT LOW LEVEL MOISTURE EXTENDING UP INTO A -12C AIRMASS AND
NORTHWEST FLOW AND DELTA T'S GREATER THAN 17C. WITH BANDS STILL
SHIFTING ACROSS NORTHWEST LOWER AS WINDS TURN FROM 360 TO 320...LAKE
EFFECT SNOW ACCUMULATIONS WILL BE DISTRIBUTED OVER A GOOD PORTION OF
NORTHWEST LOWER UNTIL AROUND 900 PM... BEFORE THE MORE DOMINATE 320 WIND
SETS UP.
THEREFORE WILL UPDATE NORTHWEST LOWER AND INCLUDE TOTAL EVENING
SNOWFALL ACCUMULATIONS OF GENERALLY 2 TO 4 INCHES.
.APX...LAKE EFFECT SNOW ADVISORY...THIS EVENING...MIZ008-015.
SWR
FXUS63 KGRR 292358 mi
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS
1205 PM EST MON NOV 29 1999
...UPDATED TO INCREASE HIGH TEMPS / DECREASE SNOW SHOWER TO FLURRIES
GRR AREA...
SHORE PARALLEL BAND CONTINUES TO DOMINATE THIS EVENT AS OF NOON
TODAY. BASED ON MSAS DATA SHOWING CONVERGENCE MOSTLY OVER LK MI AND
HIGHEST SFC DWPTS NEAR LAKE SHORE...PLUS NEW ETA/RUC SHOWING SFC TO
850 MOISTURE HIGHEST RH STAYING WITHIN 70 MILES OF THE LAKE SHORE
AND FACT THAT NOT MUCH DEVELOPING EAST OF US-131... HAD DECIDED TO
DECREASE SCATTERED SNOW SHOWERS TO FLURRIES I-96 SOUTH... AND US-131
EAST THIS AFTERNOON. MODELS ALSO SHOW BETTER 700 MOISTURE OVER NW
LWR MI AND THAT MATCHES BETTER SNOW SHOWER ACTIVITY IN THAT AREA BUT
THAT DOES NOT GET INTO GRR CWA. EVEN SO... CLOSE ENOUGH TO KEEP SCT
SNOW SHOWERS N OF I-96 THIS AFTERNOON. THIS IS ALSO SEEN ON AWIPS
88D MOSAIC.
BASED ON PHONE CALLS TO AREAS ALONG LAKE SHORE THAT HAVE HAD 35DBZ
SHOWERS PASS OVERHEAD... SNOW MELTING AS IT FALLS SO FAR. SO WILL
KEEP THE LOCALLY 1 TO 2 INCHES WITH OCCASIONAL SNOW SHOWERS IN LAKE
SHORE AREAS. GROUND TO WARM YET... AND SNOW BAND IS MOSTLY OFF
SHORE ANYWAY.
INCREASED HIGH TO 35 TO 40 OVER SRN 1/2 OF CWA SINCE MOST TEMPS IN
THE 35 TO 37 RANGE AT NOON... SO 35 TO 40 SHOULD BE SAFE GIVEN
DEVELOPING MDT CU AND COLDER AIR MOVING IN FROM N AT THE SFC.
.GRR...NONE.
WDM
FXUS63 KDTX 291626 mi
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
1105 AM EST MON NOV 29 1999
LAKE EFFECT SNOW IS MAIN CONCERN.
LAKE EFFECT BANDS HAVE BECOME MORE ORGANIZED THIS MORNING FOLLOWING
A WIND SHIFT TO MORE NORTHERLY DIRECTION...AROUND 340 DEGREES. 4
MAIN BANDS EVIDENT ON 88-D NOW ORIENTED N-S... WITH THE DOMINANT
BANDS OVER EASTERN MARQUETTE/WESTERN ALGER COUNTIES AND OVER EASTERN
ALGER COUNTY. SCATTERED AREAS OF >28DBZ RETURNS WITHIN THESE BANDS.
VWP SHOWS CONVECTIVE TOPS AROUND 9K FEET...LOWER THAN LAST NIGHT...
BUT STILL GOOD FOR MOD/HVY SNOW.
ONE SHORTWAVE HAS PUSHED SOUTH OF FA PER WV IMAGERY AND RUC
ANALYSIS. ANOTHER WEAK VORT MAX LOCATED NW OF LAKE SUPERIOR PUSHING
SOUTHWARD IN N FLOW. THIS MAY SLIGHTLY ENHANCE LES EARLY AFTERNOON
BEFORE RIDGE BUILDS IN FROM WEST. SFC ANALYSIS SHOWS N-S AXIS OF
HIGH PRESSURE FROM WESTERN ONTARIO TO NORTHERN MISSOURI. LAKE
ENHANCED SFC TROF A LITTLE LESS EVIDENT THAN DURING THE OVERNIGHT
HOURS. RUC INITIALIZED SFC FEATURES AND 850MB TEMPS WELL. EXPECT
LAKE/850MB DELTA T/S TO REMAIN IN 15-20 C RANGE. RUC SOUNDINGS SHOW
LOWERING INVERSION LEVEL OVER WESTERN COUNTIES AROUND 900MB THIS
AFTERNOON. THIS IS IN GOOD AGREEMENT WITH 12Z KINL SOUNDING...WHICH
SHOWED INVERSION AROUND 875MB. CWPL SOUNDING UPSTREAM ALSO SHOWS
SUBSIDENCE INVERSION AT 800MB WITH SATURATED CONDITIONS BELOW 800MB.
RUC IS NOT TOO QUICK IN DEVELOPING INVERSION OVER CENTRAL AND
EASTERN COUNTIES THIS AFTERNOON. GIVEN PURE LES NATURE OF CURRENT
CONDITIONS...WILL MAKE ONLY MINOR CHANGES TO GOING FORECAST. WILL
ADJUST FOR ADDITIONAL AFTERNOON ACCUMULATIONS OF 3 TO 6 INCHES IN
WARNING AREAS...HIGHEST IN HIGHER TERRAIN. HIGHEST SPOTTER REPORT SO
FAR OF 7 INCHES WAS IN ALGER COUNTY. WILL ALSO MAINTAIN ADVISORY FOR
MARQUETTE COUNTY... WHERE LES HAS PERSISTED EAST OF MQT AND
FAVORABLE NNW FETCH SHOULD CONTINUE. ANOTHER WEAK BAND ALSO OVER
WESTERN MQT COUNTY LIKELY PRODUCING LIGHT TO MODERATE SHSN BASED ON
RADAR RETURNS.
COORD WITH APX.
.MQT...LAKE EFFECT SNOW WARNING THIS AFTERNOON ALGER/LUCE/NORTHERN
SCHOOLCRAFT
LAKE EFFECT SNOW ADVISORY THIS AFTERNOON MARQUETTE COUNTY.
JS
FXUS63 KAPX 291601 mi
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DULUTH MN
1008 AM CST MON NOV 29 1999
15Z SFC ANALYSIS HAD SFC HIGH OVER WEST CENTRAL MN WITH RIDGING INTO
NE MN. VIS LOOP SHOWS SC DECK OVER NE MN WITH SOME HOLES BEGINNING
TO APPEAR. THIS DECK MATCHES WITH 60 PERCENT 925 MB RH CONTOUR FROM
THE 14Z RUC. WITH SUBSIDENCE EXPECT CLOUDS TO BREAK UP EVEN MORE
WITH ADDED SOLAR. WILL MAKE SOME ADJUSTMENTS TO WORDING AND TAKE A
CLOSER LOOK AT TEMPS.
.DLH...NONE.
GSF
FXUS63 KDLH 290945 mn
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
1000 PM CST MON NOV 29 1999
BASED ON TRENDS OF STLT (11-3.9U) ANIMATION AND MOST RECENT RUC 925MB RH
OUTPUT THRU EARLY MORNING HOURS...FEEL POTENTIAL FOR DVLPMNT OF WDSPREAD
LOW CLDS REST OF NITE HAS DECREASED AND HAVE UPDATED ZONES TO REFLECT.
.OMA...NONE
GW
FXUS63 KGID 300325 ne
AREA FORECAST DISCUSSION...UPDATED...
NATIONAL WEATHER SERVICE GREENVILLE/SPARTANBURG SC
1030 AM EST MON NOV 29 1999
VISIBLE SATELLITE IMAGERY SHOWS MORE MID LEVEL CLOUDINESS THAN
EXPECTED. CURRENT SET OF ZONES FEATURES MOSTLY SUNNY WORDING IN MOST
PLACES. BOTH THE 06Z ETA AND THE 09Z RUC SHOW THE MID LEVEL CLOUDS
MOVING E OF THE AREA AROUND 18Z OR SO AS MID LEVEL DRYING SEEN ON UPPER
AIR ANALYSIS ADVECTS IN FROM THE NW. THUS...IT WOULD APPEAR THAT THE
WEATHER SHOULD CATCH UP TO THE FORECAST IN A FEW HOURS...SO WILL ONLY
MAKE MINOR TWEAKS TO THE WORDING. CURRENT TEMPS ARE NOT FAR FROM FCST
HIGHS...BUT WITH COLD ADVECTION OCCURRING THROUGHOUT THE DAY...THINK WE
ARE STILL IN DECENT SHAPE.
ONE CHANGE THAT WILL HAVE TO BE MADE IS THE HIGH TEMP ACROSS THE
SOUTHERNMOST ZONES AS GRD HAS ALREADY REACHED 60 DEGREES. WILL SPLIT
OFF THE SOUTHERN ZONES TO RAISE TEMPS ONE CATEGORY.
.GSP...NONE.
MOORE
FXUS62 KCAE 291528 sc
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1010 AM CST MON NOV 29 1999
MAIN PROBLEM IS CLOUD COVER...AND RESULTANT EFFECTS ON TEMPERATURES
ACROSS THE CWA. SATELLITE LOOPS SHOW SOME EROSION TO PORTION OF SC
DECK EXTENDING INTO NW IA...BUT BROAD AREA SEEMS TO BE HANGING TOUGH
OVER WESTERN COUNTIES. GIVEN PERSISTENCE OF LOW CLOUDS SOUTHWEST OF
THE RIDGE AXIS OVER WESTERN SD YESTERDAY...HAVE TO THINK A SIMILAR
PERSISTANCE MIGHT OCCUR OVER JAMES VALLEY AREA TODAY. THIS THOUGHT
IS SUPPORTED BY LATEST SHORT TERM MODELS /RUC AND 06Z MESOETA/...
WHICH KEEP 70%+ LOW LEVEL RH OVER WESTERN CWA MOST OF THE DAY. ONLY
CONCERN WITH THIS SCENARIO IS PIREPS AND VISUAL OBSERVATION HERE AT
FSD SHOW CLOUD DECK IS FAIRLY THIN /200 FT E OF MORVR/...SO ANY
ATTEMPT AT MIXING COULD BE SUCCESSFUL AT BREAKING IT UP. WILL GO
WITH PERSISTANCE IDEA IN FARTHEST WEST AREAS...WHILE KEEPING AREAS
CURRENTLY ON THE EDGE BECOMING PARTLY CLOUDY. AS A RESULT...WILL
HAVE TO LOWER TEMPS A NOTCH OR SO IN WESTERN COUNTIES FROM CURRENT
MID-UPPER 40S. WILL LET EASTERN AREA TEMPS RIDE FOR NOW.
.FSD...NONE
HAMEN
FXUS63 KABR 291554 sd
AREA FORECAST DISCUSSION FOR CENTRAL/NORTHCENTRAL AND NORTHEAST
SOUTH DAKOTA AND WEST CENTRAL MINNESOTA
NATIONAL WEATHER SERVICE ABERDEEN SD
955 AM CST MON NOV 29 1999
CONCERNS THIS MORNING DEAL WITH CLOUD COVER...AND WHEN OR IF IT WILL
BURN OFF TODAY. LOOKING AT RUC...CURRENT CLOUD SHIELD LINES UP
REALLY WELL WITH THE 60% 1000MB-850MB LINE. THE RUC HAS THIS LINE
ADVANCING SLOWLY EAST DURING DAY...WITH MUCH OF THE CWA AT 70% OR
GREATER RH AT LOW LEVELS. LAMP GUIDANCE SHOWS KABR IN LOW CLOUDS ALL
DAY...WITH KMBG AND KPIR BREAKING OUT LATE THIS AFTERNOON. KATY MAY
SEE A FEW BREAKS AS WELL THIS AFTERNOON SINCE THEY ARE ON THE FAR
EDGE. SFC WINDS IN THE WRN CWA SHOULD TURN MORE SOUTHERLY AS THE DAY
WEARS ON IN RESPONSE TO WARM FRONT BEGINNING TO ADVANCE INTO AREA.
WILL TWEAK CLOUD COVER ALL AREAS...AND WITH THE INCREASE IN CLOUD
COVER...WILL HAVE TO LOWER HIGHS A NOTCH...ESPECIALLY KABR AND KATY
AREAS. NO OTHER CHANGES PLANNED TO FORECAST
.ABR...NONE.
HINTZ
FXUS63 KUNR 290952 sd
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NASHVILLE TN
930 AM CST MON NOV 29 1999
SPRAWLING CANADIAN HIGH PRESSURE NOW BLEEDING SWD OUT OF IOWA AND
MINNESOTA, PUTS MIDDLE TN IN A STABLE AND VERY COOL AIR MASS.
BASED ON LATEST RUC, WHICH SHOWS SGFNTLY COOLER 1000MB TEMPS TDY THAN
DID PREV (00Z) MODELS, WILL PROBABLY UPDATE AFTERNOON TEMPS FOR SOME
AREAS AND GO MORE WITH A NW-SE TEMP GRADIENT (RATHER THAN CURRENT
N-S SET-UP).
.BNA...NONE.
19
FXUS64 KMRX 291546 tn
COASTAL BEND FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE CORPUS CHRISTI TX
905 PM CST MON NOV 29 1999
WINDS STILL HAVING A HARD TIME COMING UP. MSAS SHOWS BEST GRADIENT
REMAINING TO THE NORTH...BUT SLOWLY MOVING TO THE SOUTH. PRESSURE
RISES BEHIND WEAK FRONTAL BOUNDARY NOT TERRIBLY IMPRESSIVE. CURRENT
TRENDS AND MODEL DATA (LONG TERM AND RUC) INDICATE THE BETTER
GRADIENT TO MAKE IT INTO CWFA TONIGHT (KVCT NOW AT 9KTS) SO WILL
CONTINUE TO HOLD OFF ON LOWERING WINDS FOR A WHILE LONGER AS CURRENT
WIND FORECAST STILL IN LINE WITH CURRENT TRENDS. HOWEVER...IF WINDS
NEED TO BE LOWERED...TEMPS WILL NEED TO BE LOWERED AS WELL AS PER
PREVIOUS AFD.
NO ZFP ISSUED ATTM.
.CRP...NONE.
86/GW
EOD
FXUS64 KHGX 300253 tx
DEEP SOUTH TEXAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BROWNSVILLE TX
815 PM MON NOV 29 1999
ALTHOUGH HIGH PRESSURE AT THE SFC AND ALOFT ARE DOMINATING THE WX IN
DEEP S TX...LLVL CONVERGENCE OF WINDS ALONG THE SEABRZ FNT MAY TOUCH
OFF SHRAS TUE. CURRENT ERLETA METEOGRAM IS SHOWING ISOLATED PCPN IN
THE VLY TUE WITH LLVL WIND FLOW INCREASING FM THE NE AT 20 KTS. MSTR
DEEPENS FM SFC TO 750MB TUE NOONISH...BUT PWATS PROGD TO MAX AT ONLY
1.1 INCH WITH LI'S STAYING POSITIVE. RUC2 ALSO SHOWS MSTR CONVERGING
IN DEEP S TX LATE TUE MRNG WITH DEEPENING AND INCREASING NE FETCH IN
LLVLS.
BOTH NGM AND ETA DO INFER LOW POPS TUE. CURRENT KBRO REF AND STLT
SHOW MSTR OVR ADJ GULF...-RA TO RA AND SUM ISOLATED SHRAS DID FORM
MON OVR PORTIONS OF THE VLY. WL ALLOW CURRENT DRY FCST TO CONTINUE
AND ANOTHER RUN OF MDL DATA.
NO CHANGES TO CURRENT ZFPBRO WITH MINOR CHANGE OF CWF FOR WAVE
HEIGHTS. SYN...PHILO 58/HMT...MARTINEZ
.BRO...NONE.
FXUS64 KFWD 292317 tx
TEXAS/OKLAHOMA PANHANDLES AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE AMARILLO TX
1025 AM CST MON NOV 29 1999
UPDATED ZNS TO CLEAN UP WORDING FOR FOG. PATCHY FG REMAINING ACROSS
NRN ZNS AND WILL HANDLE WITH NOWS UNTIL IT BURNS OFF. WENT MOSTLY
SUNNY THIS AFTN AS SATL SHOWS LITTLE IN WAY OF CIRRUS UPSTREAM. 15Z
RUC BRINGS WINDS TO S/SE ACROSS FA THIS AFTN AS SFC HIGH CENTER MVS
SE INTO OH VALLEY. HIGH TEMPS TODAY LOOK REASONABLE GIVEN LATEST
GUIDANCE.
.AMA...
TX...NONE.
OK...NONE.
COBB
FXUS64 KMAF 291604 AMD tx
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
1014 AM EST MON NOV 29 1999
NO MAJOR CHANGES NEEDED TO ZONES THIS UPDATE. 12Z SOUDINGS SUPPORT
CURRENT FCST HIGHS. MESOETA/RUC SHOWING GOOD COVERGENCE/SUBSIDENCE
ON THE E SIDE OF THE MOUNTAINS THIS AFTN AND TNGT. WINDS SHUD BEGIN
TO INCREASE ARND 21Z. THIS WL BE THE BEGINNING OF STG CAA.
.RNK
VA...NONE.
WV...NONE.
NC...NONE.
AMS
FXUS61 KAKQ 291500 va
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA...UPDATED FOR HEADLINES
845 PM PST MON NOV 29 1999
WHERE IS THE RAIN AND SNOW YOU SAY? WELL THE FACT REMAINS THAT MUCH
OF THE VALLEY AND TO AN EXTENT THE REGION USUALLY RECEIVES LITTLE
PRECIPITATION FROM PRE-FRONTAL/WARM AIR ADVECTION EFFECTS. 00Z KOAK
SOUNDINGS HELPS SHOW THIS WITH A DRY ATMOSHPERE SEEN BETWEEN
800-600MB. BLUE CANYON ASOS SHOWS A DEWPOINT OF -8C INDICATIVE OF
THE DRY AIR. RADAR CONTINUES TO SHOW LOW LEVEL MOISTURE IN THE
REGION AND THIS IS EVIDENT IN LIGHT FOG AND LOW ALTOCUMULUS. CLOUD
STRUCTURE LATE THIS AFTERNOON SHOWED STRONG TURBULENCE WITH MAMMATUS
TEXTURE. UPWARD MOTION IS THERE BUT DEEP MOISTURE IS LACKING. VAD
WIND PROFILE SHOWS 50 KNOTS FROM THE SOUTH AT 10KFT AT THIS TIME.
THE RAIN...OCNLLY HEAVY...EXTENDS FROM THE NORTHERN SAC VALLEY TO THE
NORTH BAY. ITS SPREADING INTO WESTERN PLUMAS CTY NOW. UP TO 1.5
INCHES HAS FALLEN IN TRINITY COUNTY ALPS. OVERNIGHT IT WILL BE
LOCALLY WINDY ESPECIALLY IN NORTHERN ZONES.
00Z MODELS INCLUDING THE RUC SHOW A NARROW AREA OF H7 MOISTURE AND
DECENT OMEGA PUSHING THRU THE CENTRAL VALLEY BETWEEN 06 AND 12Z. THE
RIGHT REAR QUAD OF THE H2 JET MAX OF 120+ KTS WILL SAG OVER THE
REGION HOWEVER VORTICITY ASSOCIATED WITH SYSTEM WILL BE STRETCHED
WITH MOST ENERGY LIFTING NORTH OF THE REGION...BUT A WEAK SECONDARY
VORT MAX OVERHEAD BY 15Z. AROUND ONE INCH PRECIPITABLE WATERS ARE
FEEDING THIS SYSTEM AS SEEN ON SSM/I PRODUCTS AND H85 MOISTURE CONVERGENCE
ALONG THE COLD FRONT WILL BRING A PERIOD OF RAIN TO ALL OF OUR CWA.
ITS PASSAGE WILL RESULT IN A BREAK IN PRECIPIATION ON TUESDAY.
PRECIPITATION AMOUNTS WILL NOT BE SIGNIFICANT BUT NORTHERN HALF OF
ZONES SHOULD GET DECENT AMOUNTS WITH GOOD S-SW FLOW. SAC AREA SHOULD
SEE A PERIOD OF RAIN. SAN JOAQUIN VALLEY MAY EVEN BE MISSED AS
SOUTHERN END OF FRONT IS WEAK. SNOW LEVELS WILL LOWER OVERNIGHT TO
NEAR 5500 FEET BY THE TIME PRECIPITATION ENDS IN THE SIERRA.
CONCERNED ABOUT THE CURRENT WINTER STORM WARNING FOR THE SIERRA
ABOVE 7000FEET. WINDS WILL VERIFY BUT A FOOT OF SNOW MAY NOT HAPPEN.
WINTER WEATHER ADVISORY WILL COVER STRONG WINDS IN SHASTA COUNTY
WITH A REPORT OF GUSTS NEAR 60 MPH AT 830 PM.
ANOTHER STRONGER SHORT WAVE NOW SEEN ON WATER VAPOR NEAR 41N AND
135W IS DIVING QUICKLY TOWARDS NORCAL. THIS SYSTEM WILL HAVE A
LITTLE LESS MOISTURE (PW'S NEAR 0.9 INCH) BUT SNOW LEVELS WILL BE MUCH
LOWER AND THE OROGRAPHIC COMPONENT WILL BE MORE WESTERLY SUPPORTIVE
OF GOOD UPSLOPE. A GOOD AREA OF H7-5 QVEC CONVERGENCE AND H7 OMEGA
WILL TARGET THE NORTHERN SIERRA NEAR 06Z. RAIN SHOULD QUICKLY RETURN
TO THE SAC CWA BETWEEN 20Z AND 02Z...THEN TAPER OFF TOWARDS 12Z
AS WINDS VEER TO THE NORTH AND SUBSIDENCE TAKES OVER. THIS WILL BE A
QUICK SHOT OF DECENT PRECIP...BUT DEFINITELY GRANTS THE WINTER STORM
WATCH WITH UP TO A FOOT OF POWDER POSSIBLE FOR NRN SIERRA. SNOW
LEVELS SHOULD GET AS LOW AS 3000 FEET WEDNESDAY MORNING WITH H7
TEMPS NEAR -10C BEFORE PRECIP ENDS. ENOUGH LOW LEVEL MOISTURE
LINGERS FOR STRATOCUMULUS/CUMULUS DEVELOPMENT.
WILL LIKELY UPDATE TO WORK ON PRECIPIATION WORDING,BEEF UP WINDS ETC.
SHORT WAVE RIDGING ON WEDNESDAY THEN ANOTHER SYSTEM IS ONLINE FOR
THURSDAY...BUT IS PROGGED TO TAKE A COURSE FURTHER NORTH. WAA
ADVECTION CLOUDS RETURN AS EARLY AS WEDNESDAY NIGHT WHICH SHOULD
HELP PREVENT DENSE FOG.
.STO...WINTER STORM WARNING TONIGHT ABOVE 7000 FEET FOR WESTERN
PLUMAS COUNTY
...WINTER WEATHER ADVISORY TONIGHT FOR NW SHASTA
COUNTY AND THE MOUNTAINS OF SOUTHWESTERN SHASTA TO
NORTHERN LAKE COUNTIES ABOVE 5500 FEET AND THE NORTHERN
SIERRA NEVADA AND WESTERN PLUMAS COUNTY ABOVE 6000 FEET
...WIND ADVISORY FOR EASTERN SHASTA COUNTY TONIGHT...
...WINTER STORM WATCH FOR TUESDAY NIGHT FOR SIERRA
NEVADA...SHASTA COUNTY/SOUTHERN CASCADES INCLUDING BURNEY
BASIN AND NORTHERN COASTAL RANGE ABOVE 4000 FEET
TARDY
FXUS66 KHNX 300512 ca
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
405 AM TUE NOV 30 1999
CONTINUING THREAT OF LAKE EFFECT SNOW ACROSS NORTHEAST THUMB
HEADLINES THIS MORNING/S FORECAST.
SHORT TERM MODELS...RUC AND 6KM ETA...INDICATE LOW LEVEL FLOW TO
VEER TO THE NORTH BETWEEN 09Z AND 15Z THIS MORNING. THROUGHOUT THIS
EVENT LAKE EFFECT BAND HAS LINGERED PRIMARILY OFFSHORE WITH THE
OCCASIONAL EXCURSION INLAND...PRODUCING NOTHING MORE THAN A
DUSTING. WITH FLOW VEERING TO THE NORTH THIS MORNING...LAKE EFFECT
BAND LIKELY TO MOVE ONSHORE ACROSS HURON AND SANILAC COUNTIES...WITH
BEST ACTIVITY ACROSS HURON COUNTY. APART FROM WIND DIRECTION...OTHER
LAKE EFFECT PARAMETERS STILL SUPPORTIVE THROUGH 15Z WITH INVERSION
HEIGHTS RUNNING BETWEEN 750 AND 800 MB...LAKE AIR DELTA/S AROUND
20C...AND 850 MB RH 50 PERCENT PLUS. WITH ADVISORY UP WILL CONTINUE
THROUGH MID MORNING. AT THIS POINT...MAY BE HARD PRESSED TO FIND A 3
INCH REPORT...BUT WITH FIRST EVENT OF THE SEASON WILL KEEP IN PLACE.
REPORTS FROM COUNTY OFFICIALS THIS MORNING INDICATED CAR ACCIDENTS
OCCURRING EVEN WITH ONLY DUSTING. ONE OTHER NOTE ON LES EVENT...6 KM
ETA SUGGESTS THAT SOME SHSN ACTIVITY COULD SNEAK INTO ST CLAIR
COUNTY SO WILL BREAK OFF THAT COUNTY FOR 20 PERCENT POPS THIS
MORNING.
FOR REMAINDER OF CWA THIS MORNING WILL HAVE TO DEAL WITH CLOUDS AND
FLURRIES. KDTX 88D CLEARLY INDICATES FLURRY ACTIVITY OVER CWA.
ALTHOUGH RECENT TRENDS INDICATE IT WANING ACROSS CWA. HOWEVER...
WOULD BE HARD PRESSED TO DISCERN ANY ACTIVITY VIA MTR REPORTS AS ALL
STATIONS REPORTING DRY CONDITIONS. WITH CYCLONIC FLOW ESSENTIALLY
OUT OF CWA BY 15Z...WILL WORD FORECASTS FOR CLOUDS/FLURRIES THROUGH
MID MORNING...THEN BECOMING PARTLY SUNNY.
FINAL FORM SUBJECT TO CHANGE JUST BEFORE 445 AM PRESS TIME.
TONIGHT ATTENTION TURNS TO LOW TEMPERATURES. FWC AT DTW PRINTING
16...WHILE FAN OFFERS 21...AND ETA 2M TEMP AT 25. TEMPERATURES
UNDER STRONG HIGH THIS MORNING ARE INTO LOW 20S AND UPPER TEENS WITH
CONSIDERABLE COOLING TO GO. HIGH PRESSURE RIDGE WILL BE EAST OF CWA
BY 12Z WEDNESDAY...ALTHOUGH ETA INDICATES GRADIENT TO BE WEAK THROUGH
12Z. FWC TEMP OF 16 LOOKS TO BE RESULT OF VERY DRY AIR. BELIEVE THAT
DTW FWC TEMP PROBABLY TOO LOW...BUT NOT BY MUCH. THEREFORE WILL GO
WITH UPPER TEENS ENTIRE CWA...EXCEPT NORTHEAST THUMB WHERE WILL OPT
FOR AROUND 15...BASED PRIMARILY ON ASSUMPTION THAT SOME SNOW
WILL BE ON THE GROUND THERE TONIGHT. IF NOT...THEN UPPER TEENS
PROBABLY OK THERE TOO. NGM SHOWS CI AROUND TONIGHT. FOR THE MOST
PART...THE CI LOOKS TO BE TRANSPARENT...SO WENT WITH MOSTLY CLEAR.
ON WEDNESDAY...DAY STARTS OFF MOSTLY SUNNY...BUT MORE SIGNIFICANT CI
BEGINS TO STREAM INTO NORTHERN CWA BY LATE IN THE AFTERNOON...
PRODUCING PARTLY SUNNY SKIES...WHILE SOUTH STAYS MOSTLY SUNNY.
FWC/FAN TEMPS NEARLY IDENTICAL...AND SEE NO REASON TO QUIBBLE.
WEDNESDAY NIGHT EXTENDED LOOKS GOOD WITH DENSE CI PROVIDING MOSTLY
CLOUDY SKIES AND FAN TEMPS IN FORECAST RANGE...SO NO CHANGE.
.DTX...LAKE EFFECT SNOW ADVISORY...THROUGH MID MORNING TODAY...
OKEEFE
FXUS63 KMQT 300858 mi
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
650 AM CST TUE NOV 30 1999
WILL UPDATE ZONES IN THE CWA TO REFLECT MID LEVEL CLOUD DECK
MOVING IN FROM WEST. CLOUDS SEEM TO BE ASSOCIATED WITH LEADING FAIRLY
STRONG WAA/ISENTROPIC LIFT BETWEEN 850 AND 700 MB. 00Z MODELS SEEM TO
MISS THE BOAT ON THIS ONE...BUT 09Z RUC THIS MORNING HAS IT HANDLED
WELL AND KEEPS 65 TO 7O RH MOVING ACROSS CWA DURING THE DAY. WILL LOWER
TEMPS AT LEAST A CAT EVEN THOUGH WE WILL SEE SOUTHERLY WINDS WHICH WILL
HELP OFFSET CLOUD EFFECTS.
.DVN...
IA...NONE.
IL...NONE.
CROSBIE
FXUS63 KDVN 300907 COR il
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CARIBOU ME
939 AM EST TUE NOV 30 1999
SYNOPSIS:
A LARGE RIDGE OF HIGH PRESSURE EXTENDING FROM THE OHIO VALLEY
NORTHEAST INTO EASTERN CANADA...WILL CONTINUE TO BRING COLD AND DRY
CONDITIONS TO THE REGION THIS AFTERNOON INTO THURSDAY. A DEVELOPING
STORM SYSTEM SOUTHEAST OF THE AREA WILL TRACK NORTHEAST TOWARD NOVA
SCOTIA BY WED NIGHT. THIS WILL BRING THE THREAT OF SNOW AND WIND TO
DOWNEAST MAINE WEDNESDAY INTO EARLY THURSDAY.
TECHNICAL DISCUSSION:
CAN/T SEE ANY REASON TO CHG TO MUCH W/PRVS PKG AS HIGH PRES WILL
HOLD STG. CWFA STILL UNDER CYCLONIC FLOW. RUC HAS DECENT AMT OF NVA
OVER THE AREA THRU LATE AFTN. SHOULD SEE SCU DVLPMENT W/COLD AIR &
ENUF LLVL RH STILL IN PLACE. DOWNEAST & TO THE CST WILL SEE
SOME AC-CI ADVECT INTO THE RGN LATE FM THE OPEN WTRS W/DVLPG LOW E
OF NJ.
FOR TEMPS...I LIKE 25-30 FOR ZNS1-10. 12Z CAR SNDG GIVES CLOSE TO 30
DEGS. A FLURRY IS PSBL THIS AFTN...BUT NOT SIGNIFICANT. CAN LEAVE
OUT IF YOU WISH. PS WILL WORK ESP NRN ZNS.
COASTAL WATERS...NE WINDS ATTM AVGG 20-25. SEAS @ 5 FT. MIGHT WANT
TO PUSH RNG TO 5 TO 7 FT THIS AFTN. WILL REMOVE SHSN IN THIS UPDATE.
GLW CRITERIA LOOK TO BE IN ORDER TNGT.
.CAR...GLW.
JOE
FXUS61 KCAR 300838 me
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE/WASHINGTON
1005 AM EST TUE NOV 30 1999
IR/VIS LOOPS SHOWING BKN SC ALONG AND WEST OF THE BLUE RIDGE.. WITH
MAINLY CLEAR SKIES ACROSS THE REST OF THE CWA. KLWX RADAR INDICATING
SOME VERY LIGHT RETURNS FROM N OF CHO TO NEAR OKV.. AND SUSPECT THAT A
FEW FLURRIES OR SPRINKLES MAY BE FALLING ACROSS THIS AREA.
DEVELOPING CUT-OFF LOW TO OUR EAST AND HIGH PRESSURE BUILDING IN FROM
THE WEST WILL RESULT IN STRONG NNWLY FLOW ACROSS THE AREA TODAY. SOME
CLOUDS AND SCATTERED FLUURIES WILL CONTINUE TO SPILL OVER THE
MOUNTAINS EARLY THIS AFTERNOON.. BUT MAY BEGIN TO TAPER OFF AS THE FLOW
SHIFTS TO MORE OF A NORTHERLY DIRECTION. HAVE BROKEN OUT A FEW
COUNTIES FROM OKV TO SHD TO ADD A MENTION OF A FEW FLURRIES OR
SPRINKLES EARLY.
MODIFIED 12Z IAD SOUNDING ALONG WITH MODEL SOUNDINGS FROM THE 06Z ETA
AND 09Z RUC SHOW VERY STEEP LOW LEVEL LAPSE RATES THIS AFTERNOON.. AND
EXPECT THAT SCT-BKN SC WILL BEGIN TO FORM IN THE NEXT COUPLE OF HOURS.
A LITTLE MORE MOISUTRE AVAILABLE IN THE WEST.. AND V/C FORECAST THERE
APPEARS IN LINE. WILL CONTINUE WITH PSUNNY WORDING FOR THE EAST.
NNWLY FLOW AND MODERATE COLD ADVECTION TODAY SHOULD KEEP TEMPS FROM
CLIMBING MORE THAN 4 OR 5 DEGREES FROM CURRENT READINGS. TEMPS IN THE
30S FOR THE WEST APPEAR GOOD... BUT WILL TWEAK MAX TEMP FORECASTS UP TO
AROUND 40 FOR THE EAST AS 15Z TEMPS ARE ALREADY UP IN THE 35-37 RANGE.
KLWX VAD WIND PROFILE SHOWING 20-25 KNOT WINDS JUST OFF THE SURFACE...
WHICH SHOULD MIX DOWN IN THE NEXT COUPLE OF HOURS. WILL CONTINUE WITHE
BLUSTERY WORDING IN ZONES.. AND SCA WILL REMAIN UP FOR MARINE AREA.
.LWX...SCA MD PTN BAY AND TIDAL POTOMAC
MARGRAF!
FXUS61 KLWX 300802 md
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
1100 AM EST TUE NOV 30 1999
CLOUDS AND WINDS ARE THE FORECAST CONCERNS THIS MORNING.
14Z SFC ANALYSIS SHOWS RIDGE AXIS JUST EAST OF THE UP...WITH RETURN
FLOW PATTERN BEGINNING TO SET UP OVER WESTERN AND CENTRAL COUNTIES.
VIS IMAGERY SHOWS MOST OF THE UP CLOUD FREE. SOME RESIDUAL CLOUDS IN
THE EASTERN COUNTIES CONTINUE TO DIMINISH...ALTHOUGH LATEST IMAGES
SHOW SOME CLOUDS BEGINNING TO MOVE IN FROM LAKE MICHIGAN TOWARD
NEWBERRY. I THINK THESE WILL SKIRT NEWBERRY AS S/SW WINDS PICK
UP...SO WILL LEAVE MOSTLY SUNNY WORDING ALONE. LOCAL 12Z SOUNDINGS
SHOW SUBSIDENCE INVERSION AT 900MB (KGRB)...850MB (KMPX AND KINL)
AND 800MB (KAPX). VIS IMAGERY AND METARS ALSO INDICATE CLOUDS JUST
TO THE WEST OF THE UP RUNNING ANYWHERE FROM OVC030 TO OVC060. KINL
AND KMPX SOUNDINGS SHOW THIS MOISTURE TRAPPED BELOW SUBSIDENCE
INVERSION. THESE CLOUDS ARE SLOWLY DRIFTING EASTWARD. THIS MOISTURE
PICKED UP BY RUC 900MB RH FIELD...AND FORECAST TO BRUSH THE WESTERN
COUNTIES AS MAIN CORE OF MOISTURE PUSHES NORTH OF THE CWA. GIVEN
SATELLITE TREND...THINK THESE CLOUDS WILL AT LEAST GRAZE WESTERN
GOGEBIC AND ONTONAGON COUNTIES...SO WILL ADJUST WORDING FOR
INCREASING CLOUDS THERE. WILL LEAVE MOSTLY SUNNY WORDING ALONE FOR
REMAINING COUNTIES.
SOUTH WINDS EXPECTED TO INCREASE AS PRESSURE GRADIENT TIGHTENS THIS
AFTERNOON. RUC WIND FORECAST KEEPS WINDS ON THE LIGHTER SIDE...BUT
ITS ALREADY UNDERDOING THE WINDS IN MN UNDER THE TIGHTER GRADIENT.
WILL THEREFORE KEEP WORDING OF INCREASING WINDS THIS AFTERNOON WITH
BRISK CONDITIONS WEST AND CENTRAL COUNTIES.
TEMPS LOOK ON TRACK SO FAR...SO WILL LEAVE ALONE.
.MQT...GALE WARNING LAKE SUPERIOR.
JS
FXUS63 KAPX 301539 mi
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1000 AM CST TUE NOV 30 1999
CLOUDS ERODING FROM WEST ON SATELLITE...RUC FORECASTS DECREASE OF
LOW LEVEL RELATIVE HUMIDITY TO LESS THAN SATURATION OVER ALL BUT W
CENTRAL WI ZONES. FORECASTS HAVE BEEN UPDATED TO REFLECT
THIS...OTHERWISE EARLY MORNING ZONES HOLDING WELL.
.MSP...NONE
SCOTT
FXUS63 KDLH 300939 mn
NORTHEAST MONTANA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
854 AM MST TUE NOV 30 1999
UPDATED PLANNED.
LEE TROF IN CNTRL MT...COOL FRONT SOMEWHERE IN W MT JUDGING BY PRESS
TENDENCIES/WINDS BUTTE/MSO. RUC/ETA PLACES THICKNESS RIDGE OVER E MT
NOW...SWEPT INTO NODAK BY EARLY AFTERNOON WITH SFC TROF. SW/LY SFC
FLOW ACROSS CNTRL MT WITH TEMPS MID 40S TO MID 50S...WILL APPROACH
NEMONT...ESP SW ZONES. WITH OVERNIGHT TEMPS TO 50F IN SW ZONE...MID
50S NOT ENOUGH TO COVER POTENTIAL HEAT BURST FROM DOWNSLOPE FLOW AS
COOL FRONT ORGANIZES AND SWEEPS E/WARD...WILL UPDATE PRIMARILY TO
BOOST MAXIMA SW ZONES. ELSE...CURRENT FCST HANDLES CONDITIONS WELL
WITH SCTD/BKN CI TODAY AS E PAC TROF OPENS AND TRANSLATES E/WARD
INTO GRT BASIN/CNTRL ROCKIES.
GGW 012 052/026/042
GDV 012 055/029/042
SECORA
FXUS65 KBYZ 301540 mt
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE/SPARTANBURG SC
955 AM EST TUE NOV 30 1999
12Z SURFACE ANALYSIS SHOWS HIGH PRESSURE OVER THE MIDWEST...BUILDING
TOWARD THE WESTERN CAROLINAS. VISIBLE SATELLITE IMAGERY SHOWS THE
NEAREST CLOUDS ACROSS THE MOUNTAINS OF WV/VA...WITH A FEW CLOUDS MAKING
IT DOWN TO THE NORTHERN MOUNTAINS OF NC. EXPECT THE CLOUDS TO REMAIN TO
THE N OF THE FORECAST AREA TODAY. A FEW PATCHES OF CIRRUS ARE NOTED
ACROSS THE OH VALLEY...BUT THE 06Z ETA SHOWS THIS CIRRUS HEADING TO THE
WEST OF THE MOUNTAINS LATE TODAY. THE CURRENT SET OF ZONES SEEM TO BE
IN DECENT SHAPE...OTHER THAN SOME MORNING WORDING THAT MUST BE CLEANED
UP. 06Z ETA AND 09Z RUC SHOW COLD ADVECTION CONTINUING THROUGHOUT THE
DAY. TEMP TRENDS LOOK OK FOR THE MOST PART...BUT WILL PROBABLY SPLIT OFF
THE SOUTHERNMOST ZONES AGAIN TO GO SLIGHTLY WARMER.
.GSP...WIND ADVISORY FOR AREA LAKES TODAY FOR ALL ZONES.
MOORE
FXUS62 KCHS 300744 sc
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY...CORRECTED
NATIONAL WEATHER SERVICE RAPID CITY SD
ISSUED BY NWS NORTH PLATTE
1232 PM CST TUE NOV 30 1999
...ISSUED AS SERVICE BACKUP BY WFO NORTH PLATTE...
MADE SEVERAL LATE MORNING UPDATES TO REFLECT CURRENT CONDITIONS.
IN SD ZONES...REMOVED MORNING WORDING FOR FOG AND LOW CLOUDS
MENTIONED IN SEVERAL SD ZONES. SOME FOG...5SM BR...LINGERING AT
PHILIP AT 18Z...BUT EXPECT WINDS TO PICK UP CLEAR OUT FOG BY EARLY
AFTERNOON AND TEMPERATURES TO SHOOT TO NEAR HIGHS TARGETED IN
MORNING FORECAST PACKAGE. IEN SHOT UP RAPIDLY EARLIER THIS MORNING
WITH WINDS MIXING DOWN. DID LOWER HIGHS 5 DEGREES FOR NW SD ZONES
WHERE WIND SHIFT TO SW HAS YET TO TAKE PLACE AND THICK CI LIMITING
INSOLATION.
WINDS MUCH STRONGER THAN INITIALLY FORECAST FOR NE WY ZONES AND
UPDATED TO REFLECT THESE CONDITIONS. STRONG PRESSURE GRADIENT WITH
SURFACE TROUGH BETWEEN GCC AND DGW WILL KEEP WINDS IN WINDY CATEGORY
THROUGH AFTERNOON. LATEST RUC DID NOT PICK UP ON THIS...BUT SUGGEST
NO DECREASE IN WIND SPEED THROUGH REST OF AFTERNOON.
...CORRECTED FOR WORDING SECOND PARAGRAPH...
.UNR...NONE.
SHEETS
FXUS63 KUNR 301833 sd
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
ISSUED BY NWS NORTH PLATTE
1231 PM CST TUE NOV 30 1999
...ISSUED AS SERVICE BACKUP BY WFO NORTH PLATTE...
MADE SEVERAL LATE MORNING UPDATES TO REFLECT CURRENT CONDITIONS.
IN SD ZONES...REMOVED MORNING WORDING FOR FOG AND LOW CLOUDS
MENTIONED IN SEVERAL SD ZONES. SOME FOG...5SM BR...LINGERING AT
PHILIP AT 18Z...BUT EXPECT WINDS TO PICK UP CLEAR OUT FOG BY EARLY
AFTERNOON AND TEMPERATURES TO SHOOT TO NEAR HIGHS TARGETED IN
MORNING FORECAST PACKAGE. IEN SHOT UP RAPIDLY EARLIER THIS MORNING
WITH WINDS MIXING DOWN. DID LOWER HIGHS 5 DEGREES FOR NW SD ZONES
WHERE WIND SHIFT TO SW HAS YET TO TAKE PLACE AND THICK CI LIMITING
INSOLATION.
WINDS MUCH STRONGER THAN INITIALLY FORECAST FOR NW WY ZONES AND
UPDATED TO REFLECT THESE CONDITIONS. STRONG PRESSURE GRADIENT WITH
SURFACE TROUGH BETWEEN GCC AND DGW WILL KEEP WINDS IN WINDY CATEGORY
THROUGH AFTERNOON. LATEST RUC DID NOT PICK UP ON THIS...BUT SUGGEST
NO DECREASE IN WIND SPEED THROUGH REST OF AFTERNOON.
.UNR...NONE.
SHEETS
FXUS63 KABR 301630 sd
TEXAS/OKLAHOMA PANHANDLES AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE AMARILLO TX
1115 AM CST TUE NOV 30 1999
UPDATED ZNS TO REMOVE MORNING CLOUDS/FG. SOME PATCHY STRATUS ALONG
SRN BORDER OF CWA BUT THAT SHOULD BE GONE SOON. INCREASED WIND
SPEEDS IN CENTRAL/NE ZNS AS CURRENT OBS/MESONET SHOWING SPEEDS WELL
INTO 20MPH RANGE. 12Z MODELS/15Z RUC INDICATE PRES GRADIENTS AT SFC
AND H8 TO INCREASE THROUGH THE DAY SO EVEN WITH MIXING...WINDS
EXPECTED TO STAY IN TOP END OF BREEZY CATEGORY. ALSO TWEAKED TEMPS
IN E BASED ON CURRENT TRENDS. SOME CI ON SATL IMAGERY DEVELOPING
ACROSS ERN CO/NM SO MOSUNNY ON TRACK.
.AMA...
TX...NONE.
OK...NONE.
COBB
FXUS64 KMAF 301653 tx