AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
935 PM EST THU DEC 9 1999
UA TNGT SHOWING DOUBLE JET STRUCTURE WITH ANTICYLONIC SEGMENT
STRETCHING FM THE WRN GRT LKS TO ONTARIO CANADA...AND THE CYC
PORTION OF JET FM NE TX TO MID MISSISSIPPI VLY. RUC/MESO ETA
AS WELL AS FULL SUITE OF 12Z (THU) DATA SHOWING SEGMENT OF JET
COUPLET ACRS CNTRL KY OVNGT. THIS STRONGLY DIVERGENT PTN ALOFT
...COUPLED WITH DECENT LOW LVL CONVG...WILL LEAD TO WIDESPREAD
RAIN TNGT -- AS SFC/UPR SYS APPROACHES FM THE WEST. CURRENT
FCST HANDLES THIS WELL...ALTHOUGH RECENT PRES CHG PTN SUGGESTS
LOW TRACK A TAD FURTHER SOUTH OF EARLIER 12Z GUIDE.
NEVERTHELESS...SHOT OF RAIN OVNGT INTO FRI MRNG SEEMS LIKE A
PRETTY SURE BET. MINOR TWEEKING OF WNDS TNGT FOR EXPECTED
TRACK OF SFC LOW.
.SDF...NONE
STUREY
FXUS63 KLMK 091944 ky
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS, MI
1025 PM EST THU DEC 9 1999
FORECAST UPDATE ISSUED AT 1010 PM EST TO ADJUST TIMING OF PCPN
ENDING...REMOVE MENTION OF ANY MIX/CHANGEOVER OVERNIGHT...AND TO
SLIGHTLY ADJUST EXPECTED MIN TEMPS NWRN ZONES.
LATEST SATL AND 88-D LOOPED IMAGERY SHOWS SFC FRONT MAKING THE
EXPECTED RAPID PROGRESS ACROSS NRN LAKE MI...MOVING INTO NW LOWER MI
ATTM. FRONTAL PROGRESS MUCH SLOWER SRN LAKE MI INTO NRN IL AS IT
BECOMES MORE PARALLEL WITH UPPER LEVEL FLOW PATTERN. MOST LOCATIONS
AHEAD OF THE FRONT OVER ERN WI AND LAKE SHORE COUNTIES IN LOWER MI
REPORTING LIGHT MEASURABLE RAINFALL THIS EVENING. NRN STREAM
DISTURBANCE RESPONSIBLE FOR ALL PCPN IN MI THIS EVENING. SRN STREAM
SYSTEM NOW SPREADING PCPN NEWD INTO NRN INDIANA AND APPROACHING NW
OH...BUT LOOKS LIKE MOST OF THE PCPN WILL STAY JUST S AND E OF GRR
FORECAST AREA. LATEST RUC II MODEL DATA CONTINUED THE TREND OF
KEEPING SRN STREAM RAINFALL MAINLY SE OF OUR COUNTIES. BUT..GIVEN
CLOSE APPROACH...WILL CONTINUE THE PREVIOUS FORECAST FOR SE COUNTIES
FOR LIKELY PCPN TONIGHT (ASSOC WITH SFC FROPA) AND CHANCE OF
LINGERING LIGHT SHOWERS FRI MORNING (ASSOC WITH SRN STREAM). IT NOW
APPEARS THE PCPN WILL END BEFORE LOWER ATMOSPHERE WILL BE ABLE TO
SUPPORT ANY MIX/CHANGE TO LIGHT SNOW/FLURRIES. NONE REPORTED SO FAR
IN THE STATE. ETA MODEL SOUNDINGS (12Z) SHOWED NO CHANGEOVER
POSSIBLE UNTIL NEAR 12Z IN GRR. PCPN WILL BE WELL E OF THE AREA BY
THEN.
.GRR...NONE.
GREENE
FXUS63 KMQT 092134 mi
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
430 PM EST THU DEC 9 1999
...MAIN FCST CONCERN IS THE RAIN IN THE EAST AND SOME LES TOMORROW.
SYNOPSIS...TWO DISTINCT STREAMS STILL EVIDENT ON THE WV WITH A 130
KT JET STREAK OVER THE CWA ATTM. THE RR QUAD OF THE JET IS ADDING
LIFT NR LK MICHIGAN AND IS AIDING IN THE DEVELOPMENT OF MOSTLY -RA
THIS AFTERNOON. THE UL TROUGH SHOULD PASS OVER THE REGION TONIGHT
AND SFC HIGH PRESSURE WITH SOME COLDER AIR WILL DRIFT DOWN FROM
CANADA AND SETTLE OVER THE U.P. TOMORROW NIGHT. MORE NORTHERN STREAM
ENERGY WILL MOVE IN FOR THE LATTER PART OF THE WEEKEND.
SHORT TERM...STEADY LGT RAIN FALLING OVER THE SE QUARTER OF THE CWA
ATTM. VIS HAS BEEN LOW WITH THE HIGH SFC RH AND LGT WINDS. PER THE
18Z RUC...A WAVE WILL FORM ON THE FRONT OVER SSM THIS EVENING. THIS
WILL PULL DOWN INCREASINGLY COLDER...DRIER AIR FROM THE NORTH AND
MAY CHANGE THE RAIN TO A BIT OF SNOW BEFORE ENDING. AM NOT LOOKING
FOR ANY ACCUMULATIONS AS THE SUPPORT FOR THE SYSTEM IS MOVING
QUICKLY AND THE COLD AIR IS A LITTLE SLUGGISH. PER COORD W/ APX WILL
END THE PRECIP AFTER MIDNIGHT IN THE EASTERN ZONES. DELTA T'S ARE
MARGINAL OF FLURRIES ALONG THE LAKE AND KEPT THEM IN ON THE KEWEENAW
AND AT MQT LATER TONIGHT. SOME LINGERING QG FORCING COULD HELP THE
FLURRIES GET GOING EARLIER THAN NORMAL. AT THIS POINT DELTA T'S
DON'T LOOK BIG ENOUGH TO WARRANT FLURRIES OVER NIGHT IN THE EAST.
ON FRIDAY THE MAIN CONCERN WILL BE LES. THE LIMITING FACTOR WILL BE
THE DELTA T'S. AT THE MOST IT WILL BE 12C IN THE WEST AND 14C IN THE
EAST. WITH RELATIVELY LOW 850 RH VALUES AND 4K INVERSION HGTS...WILL
LEAN TOWARD FLURRIES WITH ONLY LOW POP SNOW SHOWERS IN MQT AND EAST.
THE SFC HIGH MOVES OVER FRIDAY NIGHT. ON THE VIS IMAGERY...THERE ARE
PLENTY OF LOW CLOUDS UNDERNEATH THE HIGH IN CANADA. WITH THE ADDED
MOISTURE FROM THE LAKES...AM EXPECTING THE LOW CLOUDS TO BE STUBBORN
OVER THE U.P. FRIDAY NIGHT. ETA SOUNDINGS SHOW 90% RH UNDER THE 3K
INVERSION SO WILL WORD SOME CLEARING LATE IN THE MQT ZONE AND THAT
MAY BE GENEROUS.
ON SATURDAY THE WIND TURNS INTO THE SOUTH WHICH MEANS AN OPPORTUNITY
FOR LOW CLOUDS FROM LK MICHIGAN IN THE EAST SO HAVE WORDED LTD SUN
THERE AND PS ELSEWHERE AS HIGH CLOUDS ROLL IN ON THE FAST NRN STREAM
JET.
SUNDAY THE NEXT WK TROUGH APPROACHES. MOISTURE IS VERY LIMITED AND
AVN QPF'S ARE LOW. WILL WORD FLURRIES IN ALL ZONES BECAUSE OF
ONGOING QG FORCING SATURDAY THROUGH SUNDAY.
EXTENDED...THE MRF AND ECMWF KEEPS THE TWO STREAMS SEPARATE THROUGH
THE PERIOD AND BASED ON PERSISTENCE...THAT LOOKS LIKE A GOOD IDEA.
SO...SHRTWVS WILL PASS BY TO THE SOUTH LEAVING THE U.P. HIGH AND
DRY. COLDER AIR IS SHOWN BY BOTH MODELS TO THE NORTHWEST BY
THURSDAY...SO WILL ALLOW COLDER AIR AND SNOW SHOWERS IN FOR THURSDAY.
.MQT...NONE.
ALTOE
FXUS63 KAPX 092053 mi
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
1130 AM EST THU DEC 9 1999
MAIN FCST CONCERN THIS AFTERNOON IS PCPN POTENTIAL.
WV IMAGERY INDICATED NRN STREAM SHRTWV INTO NW MN AND MORE POTENT
SRN STREAM SHRTWV OVER NRN TEXAS. AREA OF COOLING CLOUD TOPS FROM LK
SUPERIOR TO WI WAS ASSOCIATED WITH GOOD UPR LVL DIVERGENCE AHEAD OF
UPR LVL TROF AXIS. MODERATE TO STRONG 850-500 QVECTOR CONVERGENCE
ALSO FCST OVER AREA THIS AFTERNOON ASSOCIATED WITH THE SHRTWV.
HOWEVER SFC REPORTS INDICATE RAIN ONLY OVER ERN IA INTO SRN WI SO
FAR. RADAR RETURNS OVER WRN UPR MI ONLY ALOFT WITH HIGH CLOUDS AND
VIRGA. 12Z GRB SNDG ALSO INDICATED SUBSTANTIAL DRY LYR FROM 800-600
MB TO OVERCOME.
15Z SFC ANALYSIS INDICATED FRONT FROM SE IA THROUGH WI TO
NEAR THE STRAITS AREA. BEST MOISTURE TO SUPPORT PCPN SHOULD REMAIN
IN THE VCNTY OF THE FRONTAL BNDRY. THIS AREA ALSO IN PROXIMITY TO
BEST 290-295K ISENTROPIC LIFT AND LOWEST COND PRES DEF...PER 12Z ETA
AND RUC. WITH INCREASING UPR LVL SUPPORT...EXPECT SOME DEVELOPMENT
OF SCT -SHRA OVER SE 1/3 OF UPR MI BY LATE AFTERNOON. CURRENT
TEMP/DEWPOINT AND ETA/RUC SNDGS AND 1000-850 THICKNESS FCST SUGGEST
RAIN.
16Z TEMPS GENERALLY IN MID 30S. WITH CLOUD COVER
AND LITTLE IN THE WAY OF WAA TEMPS SHOULD NOT CLIMB MUCH THIS
AFTERNOON. SO...FCST GENERALLY ON TRACK WITH ONLY A FEW MINOR
ADJUSTMENTS NEEDED.
.MQT...NONE.
JLB
FXUS63 KGRR 091622 mi
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS, MI
1120 AM EST THU DEC 9 1999
LRG CLR AREA HAS OPENED UP OVER SRN LWR MI AND WILL NEED TO UPDATE
TO BE MORE OPTIMISTIC WITH SKY COVER. LATEST RUC/ETA INDICATE MAIN
MSTR PUSH COMES AFTER 00Z SO WL GO WITH MOSUNNY IN THE SRN AND ERN
ZONES (AZO-LAN-JXN). WILL KEEP THE NW GROUP (MKG/LUD) MOCLDY WITH
CHC POP AS THIS AREA IS CLOSER TO SFC FNT AND NOSE OF THE LOW LVL
MSTR SURGE. FOR CENTRAL ZONE GROUP (SOUTH HAVEN-GRR-MOP)... HAVE
OPTED FOR PTLY SUNNY AND NO POP TIL TNGT. HAVE ALSO BUMPED HIGH TEMPS
UP A NOTCH BASED ON EXPECTED SUNSHINE.
.GRR...NONE.
MEADE
FXUS63 KDTX 091456 mi
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
955 AM EST THU DEC 9 1999
PLAN TO UPDATE CURRENT ZONE FORECAST IN SOUTHEAST GROUP TO INFER
MORE SUNSHINE AND RAISE FORECAST MAX.
RECENT RUC FORECAST HAS A GOOD HANDLE ON THINNING AND EXITING HIGHER
LEVEL CLOUDS. IN ADDITION IT CONTINUES TO KEEP THE BETTER LOWER
LEVEL MOISTURE SURGING NORTH THROUGH SOUTHERN OH ATTM TO THE
SOUTHEAST. WITH THE LOWER LEVEL MOISTURE TO THE WEST STAYING MAINLY
OVER THE NORTHWEST COUNTIES. THUS...MORE SUNSHINE EXPECTED OVER
SOUTHERN COUNTIES WHICH SUPPORTS A WARMER TEMPERATURE
FORECAST...FAVORING 14Z LAMP GUIDANCE MAXES.
UPDATE SHORTLY AFTER 15Z.
.DTX...NONE.
STRUBLE
mi
WESTERN NEVADA AND EASTERN CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
845 AM PST THU DEC 9 1999
CURRENTLY...SATELLITE DATA SHOWS FRONT THROUGH THE NORTHERN PORTION ON
THE FORECAST AREA...WITH STRONGEST ENHANCEMENT FROM LAKE TAHOE SOUTH.
OROGRAPHICS STILL HELPING KEEP THE SNOW GOING OVER THE SIERRA WITH
ONLY A COUPLE OF INCHES REPORTED THUS FAR THIS MORNING. COLDER AIR IS
EVIDENT ON THE BACK SIDE OF THE TROUGH. AM PLANNING ON UPDATING THE
FORECAST TO TAKE DOWN THE ADVISORIES...EVEN SOUTH THE MAIN PORTION IS
DRAGGIN SOUTHWARD. QUICK LOOK AT THE MODELS...ETA AND RUC...SHOW THE
VORTICITY MAXIMUM STAYING ON THE WESTERN SIDE OF THE SIERRA THROUGH
THE DAY. EXPECT TO KEEP SNOW SHOWERS AROUND AS MOISTURE AND COLD AIR
ARE HERE...BUT THE MAIN PORTION OF PRECIPITATION IS OVER. WINDS HAVE
NOT BEEN DOING MUCH IN THE LOWER ELEVATIONS... AND HAVE BEGUN TO
DECREASE UP ON TOP SOME. WILL CHECK A FEW MORE SENSORS BUT FEEL THAT
WIND ADVISORY FOR MONO AND MINERAL CAN BE DROPPED ALSO.
THIS AFTERNOON WILL TAKE A LOOK AT THE TEMPERATURES AND WINDS FOR
POSSIBLE WIND CHILL ADVISORY. WINDS WILL BE BRISK...AND WITH
DECREASED TEMPERATURES THIS MIGHT BE A CONCERN FOR TOMORROW. CAIRNS
.REV...EASTERN CALIFORNIA...NONE.
WESTERN NEVADA...NONE.
FXUS65 KVEF 091209 nv
FORECAST DISCUSSION FOR EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
940 AM CST THU DEC 9 1999
...CLOUD TRENDS/TEMPS AFTERNOON FORECAST CONCERNS...
WK SFC LO NR CYWG THIS AM WITH ACCOMPANYING TROF NEARING RRV. W/V
LOOP SHOWS VORT MAX SPIRALLING INTO NE ND WITH BATCH OF MID-LEVEL
MOISTURE AND FEW -SHSN IN A BAND FROM JUST N OF FAR AND THEN NE INTO
NW MN. SUM ECHOES ON KMVX 88D...BUT SFC OBS REPORTING -SN HAVE BEEN
SPARSE. STILL BELIVE FEW MORE FLAKES THRU AM IS POSSIBLE ESP NE
ZONES SO WILL WORD FLURRIES/-SHSN ENDING THERE WITH PARTIAL SUN
LATER...AS XPCT LOWER CLOUD THAT LINGERED ALL NIGHT TO FINALLY
ADVECT OUT AS WINDS GO W.
APPEARS TRACK OF VORT LOBE IS A BIT FASTER THAN PRVSLY
PROGGED...WHICH SHUD LEAD TO MORE SUNSHINE ACRSS CWA THIS AFTN. 12Z
RUC PULLS THE H7 MOISTURE EAST OF NW MN BY 18Z AND THEN ONLY CONCERN
WUD BE LOWER CIGS LAGGING BHND IN SRN MB AND SUM FROM DVL NW.
APPEARS BULK OF THIS CLOUD AND STRONGEST CAA WILL SKIRT BORDER
COUNTIES THIS AFTN SO WILL IMPROVE THE BCMNG MCLDY TO PSUNNY FAR N.
XPCT EVEN MORE SUN TO THE S FOR ALMOST COMPLETE SUN MAYVILLE-LISBON
AND EVENTUALLY FAR TO FFM IN SUBSIDENT SW SIDE OF VORT. THEREFORE
SUNNY OR BCMNG SUNNY WILL WORK THERE.
MODEL SOUNDINGS HINT AT LESSENING INVERSION THRU AFTN IN WEAK CAA
PATTN. THIS SHUD HELP MIX DOWN FROM BTWEEN H85-H9 AND BOOST TEMPS TO
ARND FRZNG S AND MID/UPPER 20S N. WILL BUMP UP NUMBERS JUST A TAD IN N WITH
MORE INSOLATION NOW XPCTED WITH LITTLE CHANGE ELSWHRE.
.FGF...NONE.
SOROKA
nd
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
943 AM EST THU DEC 9 1999
DISC: 14Z SFC ANALYSIS SHOWS HI PRES TRYING TO HANG ON ALONG THE
ERN PTNS OF THE CAROLINAS. LOW PRES ALNG TX/OK BORDER.
MORNING VSBY SATELLITE LOOP SHOWS CLOUDINESS ACRS THE WRN PTN OF THE
STATE SLOWLY SPREADING EWD. ALSO CLDS ALNG THE S CST EXTENDING OFSHR
TRYING TO PUSH W AND NW TOWARD THE SERN PTN OF THE CWA. WL DIVIDE UP
AREA AS PER CLOUD COVER. THIS WILL ALSO AFFECT TEMPS...ESP WHERE
MORE CLDS ARE PERSISTANT. SFC OBS EVEN SHOWING A FEW SPRINKLES ACRS
GA AND PER GSPAFD. 00Z ETA RUN AND MORNING RUC SHOWING MOISTURE TO
OUR W...WL SLOWLY PUSH EWD DURING THE AFT. MAY NEED TO ADJUST TEMPS
SOME PER CLD COVER...BUT WL MONITOR THRU ISSUANCE TIME.
.CAE...NONE.
LCV
FXUS62 KGSP 091430 sc
AREA FORECAST DISCUSSION FOR CENTRAL/NORTHCENTRAL AND NORTHEAST
SOUTH DAKOTA AND WEST CENTRAL MINNESOTA
NATIONAL WEATHER SERVICE ABERDEEN SD
910 PM CST THU DEC 9 1999
FORECAST CONCERN THIS EVENING DEALS WITH FOG FORMATION...YES OR NO.
LOOKING AT LATEST RUC 850 AND 925 MB RH FIELDS...DRYING MOVES IN
FROM WEST THROUGH 06Z. VERY DRY AIR SEEN AT 850MB...WITH RH BY 06Z
ON ORDER OF 15-25%. AT 925MB...RH BIT HIGHER...45-55%...BUT LOW
CLOUD EDGE IN ND IS CLOSE TO 75% RH LINE. EVEN THOUGH LOW LEVEL
WINDS WILL BE LIGHT FROM THE NORTH OVERNIGHT...DRY AIR PUSHING INTO
REGION AHEAD OF 500MB RIDGE AXIS WILL HELP TO ERODE CLOUDS. LOOKING
AT FOG IMAGE...LOW CLOUDS IN RRV ARE ERODING QUICKLY AS THEY MOVE
SOUTH. WILL PULL MENTION OF FOG OUT OF ERN CWA ZONES. WINDS IN THE
KMBG AND KPIR AREAS ARE ALREADY TURNING SOUTHEAST...SO WILL NEATEN
UP WIND FORECAST AS WELL. REMAINDER OF FORECAST LOOKS OK. UPDATES
OUT SHORTLY.
.ABR...NONE.
HINTZ
FXUS63 KFSD 100153 sd
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE MEMPHIS TN
805 PM CST THU DEC 9 1999
SFC LOW ACROSS NE AR THIS EVENING W/ LINEAR MCS EXTENDING FROM
CENTRAL ILLINOIS SOUTH INTO CENTRAL MISSISSIPPI. STORMS IN NRN MS
HAVE SHOWN OCCASIONAL LOW/MID LEVEL MESO FEATURES...OTRW NOT MUCH
GOING ON RIGHT NOW. 40-50KT LLJ STILL EVIDENT ON KNQA RADAR W/ 80 KT
MID LEVEL JET ON OKOLONA PROFILER. CURRENT PLANS ARE TO DROP
COUNTIES OUT OF WATCH FROM WEST TO EAST AS WRN EDGE OF MCS PASSES
THROUGH. HOWEVER...SFC ANALYSIS AND REGIONAL COMPOSITE DOES SHOW
SOME WRAPAROUND SHOWERS W/ OCCASIONAL LTG ACROSS NW AR ATTM. GIVEN
CURRENT TRENDS AND THE FACT THAT RUC KEEPS LIGHT PRECIP IN OUR WRN
ZONES OVNT WILL LIKELY KEEP A LOW POP WHEN UPDATE IS ISSUED.
.MEM...TORNADO WATCH NORTH CENTRAL AND NORTHEAST MS UNTIL 1 AM...
TORNADO WATCH UNTIL 10 PM ELSEWHERE.
CBD
FXUS64 KMRX 100135 tn
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BURLINGTON VT
901 PM EST THU DEC 9 1999
HI PRESS RIDGE TO MOVE EAST OF THE FA AND OUT TO SEA OVRNITE TONITE.
MEANWHILE...ONE (NORTHERN STREAM) STORM SYS TO MOVE NE ACRS ONT
TONITE AS A SECOND (SOUTHERN STREAM) LOW PRESS SYS MOVES DOWN THE OH
VLY. THE NORTHERN STORM WILL BE MOVING ACRS SOUTHERN QUE ON FRI AS
THE SOUTHERN STORM TRACKS ACRS THE MID-ATLANTIC REGION. UPR TROF TO
MOVE EAST ACRS THE GREAT LKS REGION DURING THE DAY ON FRI.
IR SAT PIX/FOG PRODUCT SHOWS CLOUDINESS MOVING NE ACRS WESTERN NY
ATTM. -RA NOTED AT IAG AT AROUND 01Z. FEEL THAT THIS AREA OF PCPN
WILL STAY TO THE WEST OF THE FA (IN ONT) OVRNITE. THE CLOUDINESS IS
ASSOCIATED WITH SOME WK H85 WAA AND A FEW WK H5 VORT MAXES THAT WILL
BE MOVING NE ACRS THE FA OVRNITE TONIGHT. TRACKING THESE CLDS IN THE
IR SAT PIX HAS THEM INTO THE ST LAW VLY BY AFT 05Z...INTO THE
ADIRONDACKS/SRN VT BY AROUND 08Z...AND ELSEWHERE ACRS THE FA BY
AROUND 11Z OR SO. WILL BRING IN A FEW CLDS INTO THE CHAMP VLY/RUT
COUNTY ZONE GROUPING BY EARLY FRI MORNING.
21Z RUC HOLDS OFF PCPN THROUGH 09Z AND HAS 2M TEMPS GETTING DOWN
INTO THE M-U20S IN NE/NC VT...THE L-M30S IN THE ST LAW VLY...AND
AROUND 30 ELSEWHERE. WILL BUMP OVRNITE TEMPS UP A TAD IN THE
ADIRONDACKS DUE TO CURRENT OBS TRENDS AND THE FACT THAT THEY/LL BE
CLOUDING OVER OVRNITE.
ETA MODEL SOUNDINGS SHOW ANY PCPN THAT FALLS IN THE ST LAW VLY
DURING THE MORNING HOURS OF FRI MAY FALL AS -FZRA. THIS ESPECIALLY
TRUE UP TOWARDS MSS-LAND WITH WK NE FLOW OVRNITE. GOING FORECAST HAS
THIS COVERED.
ONLY MINOR COSMETIC CHANGES TO ANY LATER PERIODS. WORK ZONES AWAY.
NO LAMP DATA IN AWIPS/N-AWIPS. FINAL ISSUANCE IN A BIT.
.BTV...NONE.
MURRAY
FXUS61 KBTV 092005 vt
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SHREVEPORT LA
255 AM CST FRI DEC 10 1999
FIRST CONCERN TODAY IS THE LINGERING SC DECK OVER ALL BUT THE FAR S.
ALL OF THE MODELS...INCLUDING THE LATEST RUC...ARE INSISTENT THAT
THIS DECK SHOULD BE ERODING AWAY QUICKLY THIS MORNING...BUT WE HAVE
YET TO SEE ANY EVIDENCE OF THAT. WILL PROBABLY NEED A LITTLE
INSOLATION TO GET RID OF THEM SO WILL WORD THE 1ST PERIOD FOR CLOUDY
EARLY THEN DECREASING CLOUDS.
MODELS HAVE SOME SLIGHT DIFFERENCES ON THIS RUN WITH RESPECT TO
THE NEXT SYSTEM THAT CAUSES US SOME DIFFICULTY IN THE LATTER PERIODS
AND EXTENDED PART OF THE FORECAST. NGM...ETA AND AVN ALL AGREE ON
DIGGING THE SYSTEM CURRENTLY COMING ONSHORE IN CALIFORNIA AND
EVENTUALLY CUTTING IT OFF NEAR THE MEXICAN BORDER. BY 12/00Z...THE
AVN IS FASTEST AND FARTHEST N OF THE THREE...ETA IS SLOWEST AND
FARTHEST S...NGM IS BETWEEN THE TWO BUT ALSO STRONGER THAN THE
OTHERS. HOWEVER...THE NGM BY FAR HAS THE BEST RUN-TO-RUN CONSISTENCY
SO WILL FAVOR IT. THIS MEANS WE WILL BE LOOKING FOR MOISTURE TO
SPREAD INTO OUR AREA A BIT SLOWER THAN THE AVN SHOWS...AND ALSO
SLOWER THAN OUR CURRENT FORECAST. THIS SEEMS LIKE A REASONABLE TREND
FOR A CUTOFF SYSTEM.
FWC TEMPS LOOK OK...ESP IN THE 1ST COUPLE OF PERIODS WHERE THEY
AGREE VERY WELL WITH THE ETA 2M TEMPS. 3RD PERIOD MAY BE A BIT TOO
COOL ON THE FWC AT MOST LOCALES. IF THE APPROACHING SYSTEM IS A BIT
SLOWER...LIKE THE ETA SHOWS...THEN WE WOULD BE CONSIDERABLY WARMER ON
SATURDAY. MAY USE A RANGE OF TEMPS ON SATURDAY TO COVER THAT
POSSIBILITY.
05
PRELIMS...
SHV 61/41/58/52 0024
MLU 58/40/58/50 0013
TXK 60/41/55/48 0024
TYR 59/43/56/50 0035
LFK 62/43/60/52 0046
.SHV...NONE.
FXUS64 KLCH 100856 la
EXTREME SOUTHWESTERN CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
435 AM PST FRI DEC 10 1999
A PACIFIC STORM IS MOVING EAST ACROSS SOUTHERN CALIFORNIA TODAY.
PRECIPITATION AMOUNTS HAVE BEEN RATHER LIGHT WITH THE SNOW LEVEL
DROPPING TO 4000 FEET. MORE SIGNIFICANT IS THE THREAT DAMAGING HIGH
WINDS FOLLOWING THE STORMS PASSAGE. HIGH WIND WARNINGS AND WIND
ADVISORIES ARE IN EFFECT FOR MOST OF SOUTHWEST CALIFORNIA FOR TODAY
THROUGH SATURDAY AFTERNOON. BREEZY CONDITIONS MAY CONTINUE INTO
SUNDAY...OTHERWISE FAIR WEATHER SHOULD RETURN AND CONTINUE
INTO THE MIDDLE OF THE COMING WEEK.
WHERE TO BEGIN...PRECIPITATION STARTED WITH THE POST FRONTAL INSTABILITY
SHOWERS AROUND 130 AM...AMOUNTS SO FAR LESS THAN A TENTH OF AN INCH.
UPSTREAM KVBG SOUNDING AND AVAILABLE RAWS STATIONS TEMPERATURE TREND
WOULD INDICATE SNOW LEVEL LOWERING TO 4000 FEET WITH TEMPERATURES
FALLING THROUGH THE DAY OVER THE SAN DIEGO COUNTY MOUNTAINS. THE THREAT
OF MOST SHOWERS SHOULD END AS THE TROUGH AXIS MOVES ACROSS...WHICH
APPEARS TO BE SOMETIME BETWEEN 18Z AND 00Z DEPENDING ON WHETHER THE AVN
MODEL IS USED OR THE NGM/ETA/RUC MODELS. SATELLITE WATER VAPOR IMAGERY
LOOPS YIELDED A ESE 33 KT MOVEMENT TO THE TROUGH AXIS WHICH SUPPORTS THE
FASTER AVN MODEL...SO LEFT THE IDEA OF AFTERNOON CLEARING ALONE. NOW ON
TO THE WIND PROBLEM... UNLIKE MY FIASCO LAST WEEK...WENT AGAINST INITIAL
IMPRESSION AND UPGRADED HIGH WIND WATCH TO WARNING AND ISSUED WIND
ADVISORIES/ADDITIONAL WATCHES FOR SURROUNDING MOUNTAINS/DOWNSTREAM
ZONES. SUPPORT FOR THIS FOUND IN THE 300-200 MB RUC 100 KT PLUS
NORTHERLY WINDS ALONG 125 WEST LONGITUDE AXIS SHIFTING EAST TO 120W BY
18Z...AVN MODEL EVEN FURTHER EAST...TIME HEIGHT CROSS SECTIONS OF THE
MESOETA MODEL SHOWING DOWNWARD VERTICAL VELOCITIES OF -8 UMB BEGINNING
SHORTLY THEREAFTER AND INCREASING TO -16 BY 11/12Z...OFFSHORE PRESSURE
GRADIENT BETWEEN KTPH AND KSAN INCREASING FROM -5 MB AT 11/00Z TO -10 TO
-16 MB BY 11/12Z DEPENDING AGAIN ON WHICH MODEL IS USED...AND JUST TO
PUT THE ICING ON THE CAKE...LOCAL WIND FORECAST SCHEME YIELDING 65 TO
77 MPH FOR THIS AFTERNOON AND 94 TO 106 MPH WIND GUSTS FOR
TONIGHT/SATURDAY BELOW CAJON PASS AND THROUGH SANTA ANA RIVER VALLEY.
MEDIUM RANGE MODELS WERE IN GOOD AGREEMENT THROUGH AT LEAST NEXT 5 DAYS
WITH TROUGH/CLOSED LOW MOVING EAST ACROSS SRN ARIZONA/NRN MEXICO...RIDGE
BUILDING OVER CALIFORNIA/NEVADA THROUGH MONDAY THEN RETROGRADING WEST AS
DEEP LOW MOVES OFF THE KAMCHATKA PENINSULA AND SHORT WAVE DROPS DOWN
THROUGH NW CANADA. EITHER WAY FAIR WEATHER PREVAILS WITH DRY NORTHWEST
FLOW ALOFT. IDEA OF RETURNING MARINE LAYER BY MID WEEK REASONABLE BUT
NOT FULLY EXPLORED DUE TO SHORT TERM PROBLEMS/TIME CONSTRAINTS.
SAN 300
.SAN...HI WIND WARNINGS/WATCHES/WIND ADVISORIES THRU 230 PM SAT...REFER
TO LATEST LAXNPWSAN.
SMALL CRAFT ADVISORY...REFER TO LAXCWFSGX
ABOVE NORMAL SURF...REFER TO LATEST LAXMWSSAN AND LAXOMRSGX
BALFOUR
FXUS66 KHNX 101145 ca
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
1030 AM EST FRI DEC 10 1999
...LES EVOLUTION IS MAIN UPDATE CONCERN...
FCST AREA CURRENTLY UNDERGOING STRONG NDPA/QVECTOR DIV IN WAKE OF
DEPARTING UPR SHORTWV OVER N LOWER MI. PURE LES UNDERWAY OVER
SUPERIOR WITH RUC DEPICTING 850MB THERMAL TROF OVER W LAKE SUPERIOR
ATTM. 12Z RAOBS (ESPECIALLY KINL) IMPLY RUC HAS WARM BIAS BY
1-2C...SO DELTA T'S ARE 16-18C. NEVERTHELESS IR IMAGERY DEPICTING
WARMING TOPS OVER E LAKE SUPERIOR LAST FEW HOURS WITH MAX 88D
REFLECTIVITIES STILL NR 28DBZ FROM E MQT COUNTY-ALGER COUNTY.
UPSTREAM YWPL SOUNDING AND NGM SFC-850MB PARCEL TRAJECTORIES IMPLY
DRY AIR ADVECTION AND LOWERING SUBSIDENCE INVERSION LAKE THIS
AFTERNOON. IR/VIS IMAGERY ALREADY DEPICTING SOUTHWARD PROGRESSING
BACK EDGE OF LOW CLDS APPROACHING N LAKE SUPERIOR ATTM. CMX ASOS
DEPICTS SN HAD ENDING WITH P6SM. ANY LINGERING -SHSN OVER KEEWENAW
AND W LK SUPERIOR WILL TAPER TO ONLY FLURRIES THIS AFT WITH
CONTINUED DRY AIR ENTRAINMENT FROM N AND LOWER SUBSIDENCE
INVERSION...SO I WILL CANCEL ADVISORY WITH NO ADDITIONAL ACCUM.
E OF MQT...LES SHOULD GRADUALLY DIMINISH IN INTENSITY AS INVERSION
HEIGHT CONTINUES TO LOWER. WILL GO AN ADDITIONAL 1-3 INCHES THIS
AFTERNOON...WITH LITTLE ADDITIONAL ACCUM EXPECTED AFTER SUNSET.
ALSO ISSUED GALE WARNING FOR E LAKE SUPERIOR PER 2 SHIP REPORTS OF
35-45KT WINDS.
.MQT...LK EFFECT SN ADVY DISCONTINUED MIZ001>003.
LK EFFECT SN ADVY THIS AFTERNOON MIZ006-007 AND NRN PART
MIZ014.
GALE WARNING E LAKE SUPERIOR.
WOLF
FXUS63 KMQT 101613 mi
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
950 AM EST FRI DEC 10 1999
PLAN AN UPDATE TO ADJUST CLOUD COVER AND TEMPERATURE FORECAST FOR
TODAY.
CURRENT SHORT WAVE ENERGY ROTATING THROUGH HELPING TO AID IN SNOW
SHOWERS NORTHERN LOWER. CONSIDERABLE SUBSIDENCE FOLLOWS THIS WAVE IN
ADDITION TO FALLING INVERSION HEIGHTS. HOWEVER...WITH THE LOWER
CLOUDS CONTINUING TO PROPAGATE SOUTHEAST...AND RUC SHOWING THE SAME
THROUGH THE AFTERNOON WILL KEEP MORE CLOUDS NORTHWEST AND ADD
MENTION OF FLURRIES. FOR THE SOUTHERN MOST COUNTIES EXPECT THE
STRONG SUBSIDENCE TO INHIBIT TOO MUCH CLOUD DEVELOPMENT.
TEMPERATURES HAVE FALLEN OFF IN THE CAA FIELD...BUT SOME SUNSHINE
WILL HELP TO HOLD THEM UP A LITTLE. CURRENTLY FAVORING THE LAMP
FORECAST TEMPERATURE SCHEME. WILL ALSO BUMP UP THE WIND
FORECAST...WITH INCREASED SUBSIDENCE HELPING TO BRING DOWN THE
STRONGER WIND SPEEDS.
UPDATE PLANNED SHORTLY AFTER 15Z.
.DTX...GALE WARNING LAKE HURON THIS AFTERNOON AND EVENING.
STRUBLE
FXUS63 KGRR 101427 mi
MOJAVE DESERT/SOUTHERN GREAT BASIN AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAS VEGAS NV
455 AM PST THU DEC 9 1999
SYNOPSIS...SKIES WILL BEGIN TO CLEAR OUT TODAY AS AN UPPER LEVEL
DISTURBANCE MOVES SOUTHEAST INTO SOUTHERN ARIZONA. MEANWHILE HIGH
PRESSURE WILL BUILD INTO NORTHERN NEVADA...ALLOWING BRISK NORTH WINDS
TO DEVELOP ACROSS MUCH OF THE SOUTHERN GREAT BASIN AND MOJAVE DESERT.
DISCUSSION...WATER VAPOR IMAGERY INDICATES MAIN MID LEVEL VORTICITY
CENTER OVER BFL AREA WITH SECONDARY CIRCULATION VCNTY DRA. PATTERN
PROBABLY RESEMBLES AVN EVOLUTION MOST CLOSELY. SOME SHALLOW MOISTURE
REMAINS IN THE 800-600MB LAYER ACCORDING TO THE DRA SOUNDING BUT BEST
FORCING IS SHIFTING SE SO PRECIP SHOULD CONTINUE TO DIMINISH NEXT FEW
HOURS AS SUGGESTED BY RADAR AND SATELLITE TRENDS.
FORECAST PROBLEM FOR TODAY WILL BE WINDS. ALL MODELS ARE CONSISTENT
IN BUILDING SFC HIGH OVER GREAT BASIN BUT THERE ARE SOME SIGNIFICANT
DIFFERENCES IN STRENGTH AMONG THEM. NGM IS DEPICTING A VERY STRONG
PRESSURE GRADIENT ACROSS THE ENTIRE CWA THIS AFTERNOON AND SUGGESTING
SOME AREAS WILL GET WARNING LEVEL WINDS. BUT THE NGM HAS ADVERTISED
THIS SYSTEM AS BEING COLDER AND STRONGER THAN IT REALLY IS WITH A
TRAJECTORY TOO FAR NORTH. THE OFF-TIME ETA AND RUC SEEM TO HAVE THE
BEST HANDLE ON THE SURFACE PRESSURE/LO LVL THERMAL GRADIENTS. SO
AFTER SOME SERIOUS WAFFLING...I DECIDED TO GO WITH A WIND ADVOSIRY
FOR THIS AFTERNOON ACROSS EASTERN CALIFORNIA...AND WORDING THAT
SUGGESTS WIND ADVISORY-TYPE GUSTS IN EXTREME SOUTHERN NEVADA FOR THIS
EVENING. HOPEFULLY THE SITUATION WILL BECOME MORE CLEAR FOR THE DAY
SHIFT AND THEY CAN EITHER GO AHEAD AND HOIST THE ADVISORY OR BE IN A
BETTER POSITION TO TRIM THE WORDING BACK FOR THE AFTERNOON PACKAGE.
RUNK
.LAS...WIND ADVISORY HAS BEEN ISSUED FOR INYO AND SAN BERNARDINO
COUNTIES...CA ZONES 26/27/28. PLEASE SEE THE LATEST RNONPWLAS
STATEMENT FOR DETAILS.
FXUS65 KREV 101101 nv
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC
948 AM EST FRI DEC 10 1999
COLD FRONT NOW RIPPING THROUGH WRN CAROLINAS AT 30 KTS. AT THIS CLIP
DEEP MSTR RECOVERY MAY PROVE DIFFICULT IN DRY MID LVLS ALG COAST AS
SEEN IN 12Z MHX RAOB. GSO SNDG WETTER ALOFT SO LIKE CURRENT POP
DISTRIBUTION FOR ZNS...HIGHER N AND W LOWER S. THIS COINCIDES WITH
PROJECTED OMEGA PLOTS. RUC AND ETA QPF FLDS SIMILAR IN POINTING TO
SCT POP CVRG. OVRHD AND UPSTREAM DRY H7-H5 AIR STILL ALLOWING BOUTS
OF SUN SO WILL LIKELY WORD MOSTLY OR CONSDRBLY CLOUDY.
ALREADY 69 F HERE AT MHX. CURRENT METARS AND CLOUD COVER SUGGESTS
SOME SLGT ADJUSTMENTS UPWARD NEEDED. COUPLE STRIKES LTG SEEN IN NC
MNTNS AND WITH INCREASED LOW AND MID LVL DESTAB FROM ADDITIONAL
INSOLATION LIKE MENTION OF PSBL TSTM INLAND ZONES EVEN THOUGH K
INDEX MARGINAL AND LIS UNIMPRESSIVE THERE.
MARINE: GRADIENT TIGHTENES AS SECONDARY SFC LOW TRACKS NE THROUGH
APPALACHIA. NEARLY UNIFORM CONSENSUS IN MODEL WIND COMPARISON IN
DEPICTING S 20 KTS THIS AFTN GOING SW 25 TO 30 AROUND DUSK.
THUS WILL HOIST SMALL CRAFT ADVSRY IN THIS UPDATE.
.MHX...SCA CSTL WTRS AND SNDS.
MJC
FXUS62 KILM 101448 nc
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
957 AM EST FRI DEC 10 1999
DISC: 14Z SFC ANALYSIS SHOWS CDFNT PUSHING INTO THE UPSTATE.
RADAR COMPOSITE SHOWS LINE OF SHRA AHEAD OF FRONT MOVG EWD FROM THE
UPSTATE INTO THE MIDLANDS THIS MORNING. SATELLITE SHOWS PTLY CLDY
SKIES OVR THE ERN PTN OF THE AREA AND CLDY W WITH SHRA. 00Z ETA AND
MORNING RUC SIMILIAR IN PUSHING CDFNT ITO THE MIDLANDS BY MIDDAY.
MODELS SHOW LINE OF MOISTURE OUT AHEAD OF SFC FRNT AND E OF THE AREA
BY EARLY AFT. WL LIKELY SEE SOME CLEARING BEHIND THE CDFNT AS SHRA
MOVE BY. WL WORD FCST FOR SHRA EARLY WITH SOME CLEARING DURING THE
AFT. AS FAR AS TEMPS GO...TEMPS RISING NICELY ACRS AREAS SEEING
SUNSHINE...SHOULD TOP OFF NEAR FCST MAXES. NOT EXPECTING MUCH IN THE
WAY OF PCPN WITH SYS...RADAR ESTIMATES ONLY SHOWING UP TO ONE
QUARTER OF AN INCH. WL ADJUST WIND SPEEDS AND DIRECTION SLIGHTLY FOR
AFT. WINDS A BIT BREEZY HERE AT CAE...15 TO 20 G 25.
.CAE...NONE.
LCV
FXUS62 KCAE 100841 sc
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE MEMPHIS TN
930 AM CST FRI DEC 10 1999
MRNG VIS IMAGERY SHOWS CLEARING LINE ALONG A MARTIN-OSCEOLA-WYNNE
LINE MOVING ESE AT AROUND 30KT. AT THIS RATE...ALL BUT THE EXTREME
SOUTH AND SERN COUNTIES WILL BE CLEAR BY EARLY AFTN. NOT SURE HOW
MUCH SUN (IF ANY) OUR SERN COUNTIES WILL SEE TODAY W/ ETA/RUC
KEEPING SFC-925MB LAYER SATURATED THROUGH AROUND LATE AFTN. ALL IN
ALL...CURRENT ZONES HAVE THIS HANDLED WELL. NO MAJOR CHANGES TO
TEMPS ARE PLANNED ATTM W/ DECENT CAA AND LOW SUN ANGLE LEADING TO
ONLY A CAT OR TWO CLIMB IN TEMPS. AN UPDATE WILL BE ISSUED BY 17Z TO
REMOVE MORNING WORDING AND TO MAKE MAINLY COSMETIC CHANGES.
.MEM...NONE.
CBD
FXUS64 KMRX 101457 tn
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
900 PM PST FRI DEC 10 1999
COLD MORNING WITH MOUNTAIN TEMPERATURES IN THE 20S AND 30S AND VALLEY
TEMPERATURES IN THE 30S. STRONG VALLEY INVERSION CURRENTLY KEEPING
AIRPORT WIND OBSERVATIONS BELOW ADVISORY CRITERIA...AND MAY KEEP MOST
VALLEY WINDS TEMPERED UNTIL THIS AFTERNOON...ACCORDING TO RUC
SOUNDINGS. STRONGEST MID LEVEL SUBSIDENCE HEADS SOUTH
TONIGHT...KEEPING STRONG OFFSHORE/SANTA ANA CONDITIONS GOING DOWN
THERE. BREEZY CONDITIONS WILL PERSIST IN THE MOUNTAINS UNDER
NORTHEASTERLY FLOW SATURDAY WITH BLOCKING UPSTREAM RIDGE DEFLECTING
160KT+ PACIFIC JET INTO WESTERN CANADA.
PATCHY FOG AT BEST IS EXPECTED IN THE SAN JOAQUIN VALLEY SATURDAY
MORNING AS DEW POINTS ARE NOT EXPECTED TO RECOVER SIGNIFICANTLY.
THIS SHOULD ALLOW SCATTERED FROST TO DEVLOP IN THE REST OF THE WIND
SHELTERED AREAS OF THE VALLEY. MOUNTAINS AND FOOTHILLS WILL ENJOY
SIGNIFICANT WARMING SATURDAY AS ETA FORECASTS 850 MB TEMPERATURES UP
3 TO 5 DEG.
NEXT SPEED MAX MANAGES TO ERODE RIDGE SLIGHTLY SUNDAY
NIGHT...BRINGING CLOUDS AND A CHANCE FOR PRECIPITAION SUNDAY NIGHT
AND MONDAY TO THE NORTHERN ZONES. SJC
.STO...WIND ADVISORY FOR TODAY THROUGH THIS EVENING FOR THE CENTRAL
SACRAMENTO VALLEY...SOUTHERN SACRAMENTO VALLEY...CARQUINEZ
STRAIT AND DELTA...AND NORTHERN SAN JOAQUIN VALLEY
FXUS66 KSGX 101717 ca
WESTERN COLORADO & EASTERN UTAH AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
925 AM MST FRI DEC 10 1999
12Z SOUNDING SHOWS EVAPORATIVE COOLING ABOVE 650MB...AS OFTEN
HAPPENS IN WARM ADVECTION. WEAK 90KT JET IN NORTHERN NEW MEXICO
ENHANCED CIRRUS OVER THE SAN JUANS BUT APPARENTLY PRODUCED NO
SIGNIFICANT PRECIP...PERHAPS SOME HIGH MTN -SN. NORTHERN SPLIT OF
TROF PRODUCING SNOW ACROSS NORTHERN ZONES. 14Z RUC AND 12Z ETA/NGM
FORECAST SOUNDINGS SHOW LOWER DRY LAYER MOISTENS UP BY 00Z THIS
AFTERNOON...WITH BEST CHANCE OF SNOW TONIGHT. ETA PRECIP FIELD
LOOKS OVERBLOWN CONSIDERING THE LACK OF FORCING...AND ACTUALLY
PREFER THE NGM FCST FOR NOW (APOLOGIES TO YOUNGER FORECASTERS).
TROF AXIS PASSES LATE TONIGHT WITH COLD ADVECTION NORTH FLOW SATURDAY
EXPECTED TO SHUT DOWN PRECIP FOR ALL BUT MTN FLURRIES ON NORTH
SLOPES...ESPECIALLY NEAR THE CONTINENTAL DIVIDE. NO SURPRISES IN
EXTENDED WITH NEXT OPEN PACIFIC TROF PRECIP STILL TIMED FOR LATE
MONDAY NORTHERN ZONES...TUESDAY ELSEWHERE. NEW MRF NO SHOWING
SIGNS OF SPLITTING THIS SYSTEM TOO. 99/RAMEY
FXUS65 KBOU 101021 co
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
215 PM EST FRI DEC 10 1999
AT 19Z CLOUDS HAD CLEARED ALL OF THE FORECAST AREA WEST OF A LINE
FROM LEXINGTON TO BOWLING GREEN. RUC DATA INDICATED THAT THE EXTREME
EASTERN COUNTIES SHOULD CLEAR BY 6 PM.
AFTER SUCH A LONG PERIOD UNDER DROUGHT CONDITIONS IT IS NICE TO LOOK
AT AN ACTIVE SOUTHERN STREAM JET. JUST AS ONE SYSTEM EXITS THE STATE
WE HAVE ANOTHER TROUGH AND S/W TO DEAL WITH AT THE END OF THIS
FORECAST PERIOD. IN THE MEAN TIME COOL HIGH PRESSURE WILL BUILD INTO
THE REGION. WE EXPECT CLEAR SKIES OVERNIGHT. THERE WILL BE SOME
CIRRUS SPILLING OVER THE RIDGE AXIS ON SATURDAY BUT THIS WILL BE THIN
AND MOSTLY SUNNY SKIES LOOK GOOD. AFTER ONE DAY OF COLD AIR
ADVECTION WINDS WILL SHIFT TO THE SOUTHWEST AND WARMER AIR AND
MOISTURE WILL RETURN TO THE STATE. THE NGM IS SLOWER THAN THE ETA OR
AVN ON BRINGING RAIN BACK INTO THE FORECAST AREA AND WE FEEL THIS IS
THE MODEL OF CHOICE SINCE IT DID A BETTER JOB ON TIMING THE LAST
SYSTEM ACROSS KENTUCKY. WITH THAT IN MIND WE WILL NOT MENTION
PRECIPITATION ON SUNDAY.
UNDER CLEAR SKIES TONIGHT TEMPERATURES SHOULD FALL TO BETWEEN 25 AND
30 DEGREES. FAN AND FWC NUMBERS LOOK GOOD FOR SATURDAY AND SUNDAY.
.SDF...NONE
JA
FXUS63 KJKL 101832 ky
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1040 AM CST FRI DEC 10 1999
BOTH 12Z KBIS AND KABR SOUNDING SHOWING HIGH RELATIVE HUMIDITY ABV
10K AHEAD OF PACIFIC WAVE CROSSING INTERMOUNTAIN REGION. MAIN S/W
ENERY IN SRN CA HANDLED WELL BY PREVIOUS MODELS. WV IMAGERY SHOWING
UPSTREAM RDGNG IN ERN PACIFIC AS PLANNED WITH ONSHORE FLOW INTO WRN
CAN...HELPING TO KEEP SPLIT FLOW PROGRESSING EWD ACRS NRN TIER.
IMMEDIATE PROBLEM FOR REST OF DAY IS HIGH TEMPERATURES AND HIGH
CLOUDINESS. BOTH NEW ETA AND LATEST RUC SHOW HIGH RH AT THE MID
LEVELS SPREADING INTO WRN MN ZFA THRU EARLY AFTN WITH HIGH CLDS INTO
ERN MN ZFA LTR THIS AFTN. WITH MANY TEMPS STILL IN TEENS IN WRN
AREAS...WL NEED TO LWR HIGHS SLIGHTLY. HAVE ALREADY RISEN INTO THE
UPR 20S IN ERN AREAS SO TEMPS ON TRACK. COLD AIR ADVECTION SC
BEGINNING TO BREAK UP ACRS WI ZNS 15..16..27.
.MSP...NONE
KAVINSKY
FXUS63 KMPX 100839 mn
AREA FORECAST DISCUSSION...COR TO ADD PRELIM NUMBERS AND TYPO
NATIONAL WEATHER SERVICE JACKSON MS
325 PM CST FRI DEC 10 1999
CHALLENGING FORECAST TODAY WITH SEVERAL ASPECTS TO FOCUS ON. FIRST
IS CLOUDS TONIGHT. EARLIER EROSION ON THE SOUTH SIDE OF CLOUD SHIELD
HAS PRETTY MUCH STOPPED...WHILE A SLOW CLEARING FROM THE N ACROSS
FAR N MS CONTINUES. RUC SHOWS 925 MB FLOW BECOMING EASTERLY BY 03Z
WHICH SHOULD SLOW CLEARING FROM THE N. FURTHERMORE...MODELS CONCUR
ON KEEPING LOW LEVEL MOISTURE RELATIVELY HIGH TONIGHT WHICH MAY
ALLOW FOR REDEVELOPMENT IN AREAS WHICH HAVE SEEN SOME EROSION. WILL
LIKELY KEEP DELTA REGIONS MOSTLY CLOUDY OVERNIGHT WITH PARTLY CLOUDY
OR VARIABLE CLOUDS ELSEWHERE. MENTIONED A LITTLE FOG IN THE S
OVERNIGHT WITH RELATIVELY LOW TEMPERATURE/DEWPOINT SPREADS AT THE
PRESENT TIME AND FAVORABLE LOOKING FOG FORECAST SOUNDINGS. IF ANY
AREAS FARTHER N DO CLEAR FOR A TIME COULD SEE SOME FOG FORM THERE ALSO.
SATURDAY...STRATOCUMULUS SHOULD GRADUALLY ERODE ONLY TO GIVE WAY TO
INCREASING MID/HIGH CLOUDS AHEAD OF NEXT SYSTEM. NEXT SYSTEM BECOMES
THE MAIN FOCUS FROM SATURDAY NIGHT INTO THE EARLY PART OF THE
EXTENDED PERIOD. ETA SHOWS SYSTEM STRONGLY DIGGING INTO NRN MEXICO
BY 12Z SUN WHILE NGM NOT QUITE AS DEEP AND AVN QUITE A BIT MORE
PROGRESSIVE. 12Z AVN IS A MARKED CHANGE FROM 00Z MRF WHICH LOOKED
MUCH LIKE ETA AT 12Z SUN. FURTHERMORE...EXAMINATION OF INITIAL DATA
INDICATES THAT ETA WAS BEST IN THE STRENGTH OF UPPER JET OVER WRN
US/NE PACIFIC RESPONSIBLE FOR STRONGLY DIGGING NATURE OF THE SYSTEM.
WILL GO WITH ETA SOLUTION WHICH AGREES WELL WITH 12Z CANADIAN MODEL
AND NCEP REASONING. THIS SOLUTION MEANS THAT BY SATURDAY NIGHT GULF INFLOW
WILL BE RAPIDLY INCREASING AS SFC CYCLOGENESIS TAKES PLACE OVER S
TX. ETA SHOWS STRONG FRONTOGENETIC FORCING DEVELOPING IN VICINITY OF
NRN AND WRN ZONES BY 12Z SUN. REGION ALSO IN RIGHT ENTRANCE REGION
OF UPPER JET OVER LOWER GREAT LAKES. FURTHERMORE...ELEVATED
CONVECTION PARAMETERS APPEAR INCREASINGLY FAVORABLE FOR SOME
ELEVATED STORMS THIS AREA LATE SAT NIGHT. SHOWALTER INDICES FROM ETA
JUST ABOVE ZERO...BUT ETA OFTEN DOES NOT SHOW ENOUGH ELEVATED
INSTABILITY IN THESE SCENARIOS. HENCE WILL GO AHEAD AND INCREASE
POPS FOR LATE SAT NIGHT MOST AREAS AND MENTION THUNDERSTORMS. WILL
KEEP SW DRY BUT HAVE LOW POPS IN THE SE AS A FEW SHOWERS OFTEN
DEVELOP HERE IN THE INITIAL RETURN FLOW.
00Z MRF/12Z CANADIAN SHOW WIDESPREAD RAIN/STORMS FOR SUNDAY AND
SUNDAY NIGHT AND WILL WORD ZONES ACCORDINGLY. CONSENSUS OF MEDIUM
RANGE MODELS INDICATE DRY SLOT FOR MONDAY BUT WILL PROBABLY MENTION
AT LEAST A CHANCE OF SHOWERS/STORMS THEN AS UPPER LOW MOVES ACROSS
REGION. PRECIPITATION THREAT SHOULD DECREASE INTO MIDWEEK.
QPF DISCUSSION...NONE EXPECTED THROUGH 00Z SUN.
PRELIMINARY NUMBERS...
JAN 042/062 048/067 0-36
MEI 040/066 045/067 0025
.JAN...
MS...NONE.
AR...NONE.
LA...NONE.
08
FXUS64 KJAN 102120 ms
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE JACKSON MS
1110 AM CST FRI DEC 10 1999
SATELLITE DATA INDICATES THAT STRATOCUMULUS DECK OVER FORECAST AREA
IS SOLIDIFYING WHILE PULLING BACK TOWARD THE WEST AS LOW LEVEL FLOW
VEERS AROUND TO A MORE NE DIRECTION. RUC/ETA DATA INDICATE THAT
MOISTURE AROUND 925 MB WILL HOLD IN ACROSS FORECAST AREA THROUGH THE
AFTERNOON. BASED ON ALL THIS...WILL UPDATE ZONES TO DELAY CLEARING
UNTIL TONIGHT. WITH MORE CLOUDINESS...WILL LOWER AFTERNOON HIGHS
ANYWHERE FROM 2 TO 3 CATEGORIES MOST LOCATIONS.
.JAN...
MS...NONE.
AR...NONE.
LA...NONE.
FXUS64 KJAN 100900 ms