SOUTH CENTRAL AND SOUTHEAST COLORADO AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PUEBLO
318 AM MDT THU SEP 9 1999
AT OR ABOVE AVERAGE TEMPERATURES AND SMALL CHANCE OF THUNDERSTORMS
FOR FRI STILL LOOK ON TARGET THIS FORECAST PACKAGE.
TDA/TNGT: LATEST WATER VAPOR IMAGERY LOOP SHOWED LARGE CYCLONE OVER
ONTARIO AND EASTERN PACIFIC COMPACT LOW JUST OFF THE CA COAST.
ALSO...HIGH LEVEL MOISTURE HAS MOVED INTO THE GREAT BASIN INTO
EXTREME SOUTHWEST CO. 07Z/09 SURFACE ANALYSIS AND WSR-88D VAD WIND
PROFILE SHOWING LOWER TROP SOUTHERLY FLOW RETURNING TO CWA.
MAIN CHALLENGE OVER THE NEXT 24 HOURS WILL BE CWA TEMPERATURE
MAXIMA/MINIMA. LATEST RUC...THROUGH 18Z/09...AND SHORT RANGE
MODELS INDICATES LARGE UPPER LEVEL ANTICYCLONE WILL REMAIN OVER THE
DESERT SOUTHWEST. LOW IN EASTERN PACIFIC IS EXPECTED TO CONTINUE
MOVING NORTHEASTWARD AND BECOME MORE OF AN OPEN WAVE. RUC HAS MID-
LEVEL SHORTWAVE TROUGH POSITION OVER CA COASTLINE BY 18Z/09. THIS IS
PRETTY CLOSE TO CURRENT ETA SOLUTION. AVN IS SLOWER...WHILE NGM IS
FASTER. NONE THE LESS...MAIN WEATHER FEATURE WILL BE UPPER LEVEL
RIDGING RETURNING TO CO. FOR MUCH OF THE DAY...700-300MB MEAN RH
VALUES EXPECTED TO RANGE FROM 15-25%. HOWEVER...HIGH LEVEL
MOISTURE WILL BE RETURNING TO WESTERN CWA BY LATE THIS AFTERNOON.
700MB TEMPERATURES PROGGED TO BE 10-12 DEG...SO SHOULD SEE WARMER
HIGHS TODAY.
BY TONIGHT...SHORT RANGE MODELS CONTINUE TO OFFER VARIOUS SOLUTIONS
ON THE HANDLING OF EJECTING MID-LEVEL SHORTWAVE TROUGH IN THE WEST.
PLENTY OF SPATIAL AND TEMPORAL PROBLEMS. ETA IS MUCH WEAKER AND
SLOWER WITH THE SYSTEM...WHILE NGM/AVN ARE PRETTY CLOSE IN TIMING.
AVN IS THE STRONGEST WITH THE WAVE...WHICH HAS BEEN CONSISTENT IN
PAST MODEL RUNS. ALL SHORT RANGE MODELS HAVE A WEAK MID-LEVEL
SHORTWAVE...IN GREAT BASIN...PRECEDING THE MAIN WAVE. GIVEN
INCEASING WESTERLY FLOW WOULD THINK MID/HIGH LEVEL MOISTURE WILL
CONTINUE TO ADVANCE INTO CO LATER ON TONIGHT. 700MB THETA-E AXIS
BEGINNING TO MOVE INTO WESTERN CO. WITH THE ABSENCE OF ANY
SYNOPTIC SCALE LIFT AND MOISTURE RETURNING TO CWA AT WRONG TIME OF
DAY...WOULD THINK SHRA/TSRA POP THREAT IS VERY LOW. CURRENT ZFP FOR
TDA/TNGT LOOKS WELL IN HAND...SO WILL MAINTAIN.
FRI: SHORT RANGE MODELS STILL HAVING SPATIAL...TEMPORAL...AND
STRENGTH PROBLEMS ON HANDLING MID-LEVEL SHORTWAVE TROUGH.ETA MUCH
WEAKER OF THE THREE...WHILE AVN IS THE STRONGEST. ETA/NGM APPEARS TO
BE CHANNELING MID-LEVEL SHORTWAVE TROUGH...MAKING IT TOUGH ON
TIMING...WHILE AVN WANTS TO HANG IT BACK IN THE GREAT PLAINS AND LIFT
IT INTO WY BY LATE FRI AFTERNOON. NGM MOISTURE FIELDS ARE TOO WET.
HOWEVER...WOULD THINK WITH ENOUGH MID/HIGH LEVEL MOISTURE AND
AFTERNOON HEATING...AIR MASS WILL DESTABLIZE. IF YOU BELIEVE AVN...
MID-LEVEL SHEAR AXIS DOESN'T MOVE THROUGH CWA UNTIL LATE FRI
NIGHT/SAT MORNING. ONCE AGAIN...WITH MUCH UNCERTAINTY...CURRENT ZFP
LOOKS GOOD WITH 20 POP WORDING FOR ALL BUT THE SOUTHEAST PLAINS.
EXTENDED(SAT-MON): IF LATEST AVN IS CORRECT...SHOULD BE IN
SUBSIDENCE REGION OF MID-LEVEL SHORTWAVE TROUGH ON SAT. THUS...
REDUCING THREAT OF PRECIPITATION. WILL NEED TO KEEP AN EYE ON LOW
PRESSURE MOVING OUT OF CAN INTO NORTHERN PLAINS SAT NIGHT WITH COLD
FRONT HEAD DOWN PLAINS SAT NIGHT/SUN. MUCH COOLER AIR MASS BY MON
WITH PROGGED 700MB TEMPERATURES OF 0 DEG C NEAR KLIC. AIR MASS
SHOULD BE RELATIVELY DRY AND STABLE...SO WILL CONTINUE TO LEAVE
PRECIPITATION OUT OF THE FORECAST DUE TO LOW THREAT. WILL NEED TO
TWEEK TEMPERATURES DOWN FOR MON.
.PUB...NONE.
METZE
FXUS65 KGJT 090908 co
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
815 PM EDT TUE SEP 7 1999
CONVECTION WINDING DOWN ACROSS THE CWA AS THE ATMOSPHERE STABILIZES
AND THE DYNAMICS SHIFT TO THE EAST. 23 UTC SURFACE DATA SHOWS A WEAK
AND ELONGATED LOW ALONG THE SOUTHEAST COAST AND A DECENT THETA-E
BOUNDARY FROM CHA TN TO BHM AL. 12 UTC ETA AND NGM RUNS VERIFIED
VERY NICELY WITH THEIR 00 UTC FORECASTS OF THE AFORE-MENTIONED
SURFACE FEATURES AND QPF. ALL OF THE MODELS CONSOLIDATE THE SURFACE
LOW AND APPROACHING THETA-E BOUNDARY INTO A SINGLE WELL-DEFINED COLD
FRONT. THERE IS...HOWEVER...SOME DISCREPANCY AS TO WHEN AND BY HOW
MUCH THE FRONT WILL CLEAR OUR CWA...A PROBLEM FOR THE MID SHIFT TO
PONDER.
AS FOR THE IMMEDIATE FUTURE...WILL SEND OUT AN UPDATE WORK ZONES
PACKAGE TO LOWER POPS ACROSS MOST OF THE AREA. WILL DROP POPS FOR
SE AL...AND WILL GO SLIGHT MOST EVERYWHERE ELSE. WILL LEAVE CHANCE
POPS IN FOR NORTH FL ZONES. WILL HAVE TO BUMP UP THE WIND/SEAS
FORECAST FOR THE COASTAL WATERS BASED ON CURRENT OBS AND 21 UTC RUC.
LOOKS LIKE THE 12 UTC MODEL RUNS ARE RUNNING TOO LOW ON FORECASTED
SURFACE WINDS OVER THE MARINE AREA.
FOURNIER
FXUS62 KTAE 091900 fl
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSONVILLE FL
230 PM EDT THU SEP 9 1999
ALL MODELS ARE VERY SIMILIAR FOR THE 12Z RUN. THEY ALL PUSH A
PRE FRONTAL TROUGH ACROSS THE NORTHERN CWA WITH A BROAD AREA OF LOW
PRESSURE WHICH WILL REMAIN OVER THE AREA THROUGH THE DAY. JAX 12Z
SOUNDING WAS MUCH DRIER THAN PREVIOUS RUNS WITH PW AT 1.42 IN. THIS
IS ONLY A TEMPORARY SITUATION AND 12Z RUC SHOWED MOISTURE ON THE
INCREASE ACROSS THE AREA BY LATE AFTERNOON. 00Z ETA/AVN BOTH INDICATE
SIGNIFICANT SYNOPTIC LIFT OVER WESTERN CWA...MOVING SE WITH TIME.
ENOUGH DRY AIR ALOFT TO ALLOW DOWNBURST AND LARGE HAIL WITH WBZ AT
12K. MODIFIED CAPE AT 3400. STORMS FROM WEST AND NW FLOW WILL
EVENTUALLY INTERACT WITH EAST COAST SEABREEZE OVER EASTERN COUNTIES.
EXPECT ISOLATED PULSE SEVERE.
FRI/SAT KRISHNAMURTI SUPER ENSEMBLE DEVELOPS AN MCC LIKE FEATURE OFF
THE NE COAST FRI PM TO SATURDAY AM WITH VERY HIGH RAIN RATES. WILL UP
POPS SIGNIFICANTLY IF 00Z RUN IS CONSISTENT.
DID A MINOR REVISION ON THE COASTAL WATERS TO SHIFT WINDS TO THE
NORTHEAST ACROSS THE NORTHERN PORTION OF THE CWA. REMAINDER OF THE
CURRENT PACKAGE LOOKS GOOD.
BLS/PTW
FXUS62 KMLB 091837 fl
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSONVILLE FL
1020 AM EDT THU SEP 9 1999
BROAD AREA OF LOW PRESSURE WILL REMAIN OVER THE AREA THROUGH THE DAY.
JAX 12Z SOUNDING WAS MUCH DRIER THAN PREVIOUS RUNS WITH PW AT 1.42
IN. THIS IS ONLY A TEMPORARY SITUATION AND 12Z RUC SHOWED MOISTURE ON
THE INCREASE ACROSS THE AREA BY LATE AFTERNOON. DID A MINOR REVISION
ON THE COASTAL WATERS TO SHIFT WINDS TO THE NORTHEAST ACROSS THE
NORTHERN PORTION OF THE CWA. REMAINDER OF THE CURRENT PACKAGE LOOKS
GOOD.
BLS
FXUS62 KMLB 091400 fl
STATE FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
1040 AM EDT THU SEP 9 1999
THE CURRENT RUC MODEL SHOWS THAT DEEP MOISTURE OVER MUCH OF EASTERN
AL AND WESTERN GA WILL MOVE SLOWLY EASTWARD TODAY...AS A CUTOFF LOW
AT 500 MB OVER SOUTH CENTRAL CANADA REMAINS BLOCKED. A BROAD BAND OF
RAIN WITH SCATTERED SHOWERS AND A FEW THUNDERSTORMS...MOSTLY OVER
NORTHWEST GA NOW...SHOULD SHIFT OVER NORTHEAST-CENTRAL-SOUTHWEST GA
DURING THE AFTERNOON. THE FIRST ORGANIZED THUNDERSTORMS COULD FORM AT
THE CLOUD-NO CLOUD BOUNDARY ROUGHLY FROM ATHENS TO MACON TO ALBANY.
IN THE AFTERNOON ZONE FORECAST UPDATES...PROBABILITIES OF PRECIP WILL
BE ADJUSTED TO 50-60 PERCENT WITHIN THE BAND...AND HIGH TEMPERATURES
WILL BE ADJUSTED DOWNWARD. OTHERWISE LITTLE CHANGE.
.ATL...NONE.
SCHAUB
ga
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
1030 PM EDT THU SEP 9 1999
MAIN FCST CONCERN OVERNIGHT IS PCPN TREND.
SHRTWVS ROTATING AROUND CUTOFF LOW DOMINATING WEATHER OVER WRN GRT
LAKES. WV LOOP INDICATED ONE SUCH SHRTWV NW OF CYQT ADVANCING TOWARD
LK SUPERIOR SUPPORTING LARGE AREA OF RAIN OVER NE MN THRU WRN LK
SUPERIOR INTO WRN 1/3 OF UPR MI. ANOTHER SHRTWV WAS LOCATED FURTHER
UPSTREAM OVER NW ONTARIO. ONCE AGAIN... THE 18Z MESO-ETA HAD GOOD
HANDLE ON THESE DETAILS...MUCH BETTER THAN 00Z RUC OR ANY OF THE 12Z
MODELS. HOWEVER...IT WAS STILL A BIT SLOW WITH THE PRECIP INTO WRN
UPR MI. GOOD 850-500 QVECTOR CONVERGENCE WITH THESE FEATURES
STRENGTHENS FROM NW TO SE OVERNIGHT...SUPPORTING INCREASE IN PCPN
COVERAGE...CONSISTENT WITH RADAR TRENDS. EVEN WITH QUICKER
PRECIP TREND WL LEAVE ONLY SCT WORDING FOR THE EAST PORTION OF THE
CWA AS QG FORCING TAKES TIL CLOSER TO 12Z TO ADVANCE TOWARD ERY-ISQ.
850 TEMPS TO NEAR 3C WILL KEEP DLT/T TO AROUND 13C...ENOUGH FOR SOME
LAKE ENHANCEMENT. BACKING WINDS TO SW AHEAD OF SFC TROF OVER NERN MN
THOUGH WILL KEEP LAKE ENHANCED PCPN AMOUNTS TO A MINIMUM.
EXPANDED TEMP RANGE A BIT TO ACCOUNT FOR SLIGHTLY WARMER CONDITIONS
NEAR LAKE SUPERIOR WITH CURRENT OBS NEAR LK 3-5F WARMER THAN INLAND.
HOWEVER...CLOUDS AND PCPN WILL KEEP DIFFERENCE SMALLER THAN ON A GOOD
RADIATIONAL COOLING NIGHT.
.MQT...NONE.
JLB
FXUS63 KAPX 100228 mi
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
1025 PM EDT THU SEP 09 1999
APX 88D SHOWING SCATTERED SHOWERS MOVING NORTHEASTWARD OVER UPPER
MICHIGAN AND NORTHERN LOWER MICHIGAN. THE SHOWERS ARE IN RESPONSE TO
AN UPPER LEVEL LOW MOVING TOWARD WESTERN LAKE SUPERIOR AND LAKE INDUCED
SURFACE TROFS OVER THE NORTHERN GREAT LAKES. AN AREA OF PRECIPITATION
...CURRENTLY OVER MN AND WESTERN WI...IS IN RESPONSE TO LIFT SUPPLIED
AT THE BASE OF AN UPPER LVL TROF AS NOTED BY THE 700/500 MB QVECTOR
CONVERGENCE AND DPVA. THE LATEST RUC SHOWS THIS AREA OF FORCING TO MOVE
EASTWARD TOWARD THE GREAT LAKES OVERNIGHT.
RUC RELATIVE HUMIDITY TIME SECTIONS SHOWING PLENTY OF LOW LEVEL
MOISTURE LINGERING OVER NORTHERN LOWER AND EASTERN UPPER MICHIGAN
OVERNIGHT... AT LEAST 80 PERCENT THROUGH 850 MB. DUE TO THE LATEST
STLT AND RADAR TRENDS...COMBINED WITH THE EASTWARD ADVANCING UPPER
LOW... WILL KEEP SCATTERED SHOWERS IN THE FORECAST OVERNIGHT ALL
ZONES.
.APX...NONE.
SWR
FXUS63 KGRR 100200 mi
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
950 PM EDT THU SEP 9 1999
...UPDATED ZONES TO DROP POP SRN 1/2 CWA...
SO FAR THIS HAS BEEN A RATHER UNDERWHELMING EVENT IN TERMS OF LAKE
EFFECT SHOWERS AND COLDER TEMPERATURES. THE LATEST LOOPS OF THE
RADARS NEAR LAKE MI AND THE COMPOSITE RADARS SHOW SHOWER ACTIVITY
DECREASING OVER ERN WI AND LK MI. THE SHOWERS CONTINUE TO DEVELOPED
OVER THE NW PART OF THE GRR CWA... MOSTLY N OF MKG. HOWEVER... THERE
GENESIS POINT HAS MOVED INLAND SINCE 00Z. IR LOOPS SHOW LARGE
BREAKS IN CLDS OVER WRN LK MI AND WITH COLD TROF ALMOST TO LK
MICHIGAN... HAVE A HUNCH THE BEST OF THE RAINFALL IS ALREADY OVER.
ALL MODELS AND LATEST RUC SUPPORT COLDEST AIR OVERHEAD AROUND 06Z
OVER WRN LWR MI. AFTER THAT...WAA BEGINS BELOW 700 MB. THIS
RESULTS IN INCREASING STRENGTH TO SUBSIDENCE INVERSION... WHICH BY
12Z WILL BE BETWEEN 850 AND 700 MB OVER THE SRN PART OF THE CWA AND
A LITTLE HIGHER OVER THE NRN PART OF THE CWA. SO... ONCE AGAIN...
TWO THINGS STAND OUT... SRN PART OF CWA HAD AS STILL HAS DRIER AIR
(AS PER RUC SOUNDINGS) AND NRN PART OF CWA WAS AND WILL REMAIN MORE
MOIST BELOW 700 MB. BEYOND THAT... SFC TEMPS OVER WI AT 00Z IN THE
15C RANGE... NOT MUCH COLDER THEN LAKE MI. SO EVEN THROUGH 850 MAY
GIVE 15C LAKE TO 850 TEMP DIFFERENCE... THE LACK OF SFC COLD AIR AND
THE DRY NATURE OF THE AIR OVER THE SRN PART OF THE LAKE ARE KEEPS
MUCH FROM HAPPENING.
SO... SINCE WE HAVE BEST SUPPORT FOR SHOWERS NOW... AND NOT MUCH
HAPPENING... HAVE SCALED BACK ON PCPN OVER CWA. HAVE DROPPED PCPN
FROM SRN 1/3 OF CWA. OVER CNTL THIRD PUT CHC OF SPRINKLES AND OVER
NRN 1/3 HAVE SCATTERED SHOWERS SINCE AFTER COLD TROF MOVES THROUGH
AMOUNT OF SHOWERS SHOULD DECREASE MORE THEN IT CURRENTLY IS AND THIS
IS NOT MUCH NOW!
HAVE LEFT SPECIAL MARINE WARNING IN EFFECT OVERNIGHT FOR NRN 1/2 OF
NEAR SHORE DUE TO NUMEROUS REPORTS DURING THE DAY AND SINCE COLDEST
AIR IS OVERHEAD NOW AND WILL NOT WARM TILL FRIDAY DURING THE DAY.
.GRR...NEAR SHORE MARINE WARNING MKG TO MBL FOR WATERSPOUTS
OVERNIGHT.
WDM
FXUS63 KDTX 100154 mi
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1017 AM EDT THU SEP 9 1999
NO MAJOR CHANGES PLANNED TO THE GOING FORECAST... WITH THINGS
PROGRESSING ABOUT AS ANTICIPATED. LINE OF TOWERING CU WITH SOME
EMBEDDED SHOWERS IS PROGRESSING EAST THROUGH THE FORECAST AREA. A
LIGHTNING RETURN WAS NOTED RECENTLY WITH THIS ACTIVITY OVER NORTHERN
LOWER. THIS BAND OF ACTIVITY IS BEING SUPPORTED BY THE VORT MAX
CURRENTLY MOVING THROUGH THE AREA... AS SEEN ON GOES SOUNDER BAND 11
IMAGERY. HOWEVER... ACTIVITY IS NOT VERY IMPRESSIVE OR WIDESPREAD AT
THIS POINT... SINCE IT IS WORKING WITH LIMITED MOISTURE AND
COMPETING WITH DECENT ISENTROPIC DOWNGLIDE WHICH IS STILL PRESENT
OVER THE AREA.
WITH MOISTURE INCREASING THIS AFTERNOON... AND BOUNDARY LEVEL
MOISTURE INCREASING... STILL FEEL WE WILL HAVE A BETTER CHANCE FOR
SHOWERS LATER THIS AFTERNOON AS ANOTHER VORT LOBE SWINGS INTO THE
AREA. GIVEN THE FACT THAT THERE HAS ALREADY BEEN LIGHTNING THIS
MORNING... MAY NEED TO THROW IN THE MENTION OF AN ISOLATED
THUNDERSTORM FOR THIS AFTERNOON OVER THE NORTHWEST PART OF THE
FORECAST AREA. THIS IS SUPPORTED BY LAKE INDUCED CAPE VALUES OF OVER
1000 J/KG... AS INDICATED ON BUFKIT BY THE 03Z ETA. OTHERWISE...
THE GOING FORECAST OF BECOMING MOSTLY CLOUDY SHOULD WORK OUT FINE...
AND MAY JUST DROP THE BECOMING WORDING DEPENDING ON WHERE THINGS
STAND AT ISSUANCE. THE ONLY EXCEPTION WILL BE OVER THE SOUTH AND
SOUTHEAST... WHERE THING SHOULD TAKE A BIT LONGER TO CLOUD UP.
TEMPERATURES LOOK ABOUT RIGHT... BUT MAY MAKE A FEW MINOR DOWNWARD
ADJUSTMENTS TO LINE UP MORE WITH MODIFIED SOUNDINGS AND THE LATEST
LAMP AND RUC GUIDANCE.
COLD ADVECTION AND DECENT WINDS WILL CONTINUE TO BUILD WAVES ON LAKE
MICHIGAN THIS AFTERNOON... WITH 4 TO 6 FOOT WAVES A LIKELIHOOD BY
EVENING. THE GLERL RESEARCH WAVE MODEL SUPPORTS THIS AS WELL... WITH
4 TO 5 FOOT WAVES PROGGED BY 22Z. THE STEEP LAPSE RATE ABOVE THE
LAKE WILL ALSO CREATE CONDITIONS CONDUCIVE TO WATERSPOUT
DEVELOPMENT... SO AN ISOLATED WATERSPOUT IS A POSSIBILITY LATER THIS
AFTERNOON. A WATERSPOUT WAS OBSERVED OVER SOUTHERN LAKE MICHIGAN IN
SIMILAR CONDITIONS A FEW WEEKS AGO.
ZONES WILL BE ISSUED BY 1100 AM.
.GRR...NONE.
TRH
FXUS63 KMQT 090849 mi
FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
1010 AM CDT THU SEP 9 1999
MORNING ANALYZES AND 12Z RUC SUPPORT DRYING OUT TREND AS 40+
DEWPOINT DEPRESSIONS OVERSPREADING THE AREA IN MID LEVELS.
MOISTURE CONVERGENCE IN THE LOW LEVELS LIMITED TO SERN MS
THROUGH MID AFTERNOON BUT THEN PUSHES OFFSHORE SO WILL KEEP
SMALL POPS IN THE SE FOR A FEW MORE HOURS. PROFILERS ALSO
INDICATING 925MB WINDS OF 20-30KTS WHICH SHOULD SUPPORT SURFACE
GUSTS TO AT LEAST THAT RANGE. ZONE UPDATE WILL BE OUT SHORTLY
WITH MOSTLY MINOR ADJUSTMENTS.
.JAN...
MS...NONE.
LA...NONE.
AR...NONE.
FXUS74 KJAN 090851 ms
SOUTHWEST AND NORTH CENTRAL MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
840 PM MDT THU SEP 9 1999
...UPDATE PLANNED FOR ZFP/SFP...
LATEST WV/IR SATELLITE IMAGERY SHOWS SLUG OF MID LEVEL MOISTURE MOVING
NORTHEAST ACROSS WESTERN MT AT THIS TIME AHEAD OF SHORTWAVE/COLD FRONT
APPROACHING FROM PACIFIC NW. MSX/TFX 88-D ALSO SHOWING PATCHY ECHOES
APPROACHING 28 DBZ INDICATING AT LEAST SOME VIRGA AND ISOLATED SHOWERS
AT SURFACE ALONG AND WEST OF DIVIDE. BTM CARRYING VIRGA AT 0153Z. 10/00Z
ETA AND RUC ALSO SHOWING PRETTY DECENT H8-H7 MOISTURE CONVERGENCE EAST
OF DIVIDE THRU 12Z. EXTRAPOLATION ON WV IMAGERY BRINGS SHORTWAVE JUST
OVER DIVIDE BY 12Z WITH NORTH PORTION OF SHORTWAVE ALONG CANADIAN BORDER
MOVING FASTER. THIS LEADS ME TO BELIEVE CLOUDS AND ISOLATED SHOWERS WILL
PROBABLY LINGER ACROSS CWA THRU 12Z. WILL RAISE TEMPS A TAD ACROSS CWA
AS A RESULT OF THE CLOUD COVER. WITH VIRGA AND ISOLATED LIGHT SHOWER
ACTIVITY...WILL INTRODUCE A LOW POP AT LWT ALSO. SCHMIDT
GTF 1366 HLN 1321 HVR 1234
FXUS65 KBYZ 092042 mt
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
945 PM EDT THU SEP 9 1999
.DISCO...KENX WSR 88D AND RGN LPS INDICATE SHRAS SLOLY MVG NEWD INTO
THE SWRN CATSKILLS. THESE APPEAR 2B THE RESULT OF A TD DISCONTINUITY
BNDRY THAT WAS SEEN NICELY ERLIER ON SAT VSB PIXS. THIS IS PROVIDING
THE LO LVL CONVERGENCE. MEANWHILE...RR QUAD OF A JETLET MVG S OF KALB
WHICH IS GIVING UVM. ALSO A VORT MAX IN THE MID ATLANTIC AREA HELPG
THE CAUSE.
CONVECTION MAINLY CONFINED TO NE PA BUT HAS RECENTLY MVD INTO SWRN
PTN OF CATSKILLS. THIS AREA IF ANYTHING IS EXPANDG AS INDICATED BY
IFR. CLDS TOPS ARE COOLG.
THIS WOULD GIVE CREDENCE TO THE MESO ETA/ETA IDEA OF QPF. BLV THE RUC
IS 2 FAR W AND THE NGM 2 DRY. BASED ON CURRENT TRNDS HV REARRANGED A
FEW ZNS. WL GO CAT IN CATSKILLS (WHERE I THINK BEST RAFL WL BE). WL
GO SCT UP IN NWR RGN WHERE I THINK FORG WB WEAKEST. EVRYWHERE ELSE I
GO LKLY. ALMOST WENT 50 POP IN KALB AREA DUE TO DWNSLPG SWRLY
BRZ...BUT FEEL IT IS TOO CLS A CALL. WL HV CHC OF THUNDER. HISTORY HS
BEEN FOR THESE CELLS 2 PUT DWN A LOT RAFL DUE TO TROPICAL AMS. WL ADD
HVY QUALIFIER BFR ISSUG ZNS.
TEMPS LK REASONABLE AND WB LFT ALN. EXCEPT FOR SOME MINOR WORDG...HV
LFT LTR PDS PRTY MUCH ALN.
WL SEND OUT A FINAL WRKZNS IN MOMENTS FOLLOWED BY THE REAL THING.
BYE!
HWJIV
FXUS61 KBUF 100124 ny
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
1030 AM EDT THU SEP 9 1999
CDFNT MAKING ITS WAY THRU GEORGIAN BAY TO CNTRL OH AT 13Z...LTG
DETECTION SYSTEM ALREADY DETECTING STRIKES NR 20S CYYZ-40S KERI
AND SATPIX HAVE EXTENSIVE RGN OF ST/FG ALG MHKVLY...HDSVLY AND
TRIBS. WL NEED TO TWEAK TO MORE PESSIMISTIC CLD/HIR POP FCST FOR
ADRNDCKS AND MID MHKVLY PER SATPIX/RUC FNTL POSITION FCST THIS AFTN.
LWR POPS TO E FOR AMS CONVECTION WL BE LEFT AS IS. KALY 12Z SOUNDING
DOES HAVE A 1 THSD FT DP INVRSN BASED ARND 85 HND FT...THUS PCPN
ACRS ERN DIST MAY HOLD TO SHWRS...THOUGH H7 CAA SHOULD HELP
DESTABILIZE SITUATION. WITH HEATING...EHI DOES RISE TO 0.1 TO 0.25
AND HODOGRAPH GETS MORE ELONGATED AS BULGING EDGE OF H4 JET CORE
TRANSLATES NEWD INTO NW DIST. MCKINLEY/GEW
.ALY...NY ERN/VT EXTRM SRN/MA EXTRM WRN/CT NW...NONE.
FXUS61 KOKX 091404 ny
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BINGHAMTON NY
950 AM EDT THU SEP 9 1999
OTHER THAN SOME MINOR HI TEMP TWEAKS THIS AFTN...FCST LEFT MUCH THE
SAME.
VSBL SAT/RADAR LOOPS SHOW BAND OF THICKER CLDS/SCTD CONVECTION FROM WRN
PA NWD THRU EXTREME WRN NYS AND INTO ONT ATTM. MUCH OF THE CURRENT
PCPN APPEARS TO BE ASSOCD WITH UL SPEED MAX/SHRT WV SEEN W/I BEND OF
"S" SHAPED SIG ON WATER VAPOR IMAGERY OVER LK ERIE AND SWRN ONT. THIS
FEATURE SHUD SLIDE NEWD AND PRIMARILY MISS OUR CWA TDY. HOWEVER...A
PRE-FRNTL TROF IS ALSO EVIDENT ACRS WRN PA AND WV THIS MRNG...PERHAPS A
SFC REFLECTION OF ANOTHER WK S/WV AXIS. THE LATEST RUC OUTPUT SEEMS TO
PICK UP ON THIS SECOND VORT LOBE AS IT BRINGS SOME 5H PVA AND A LL
BNDRY INTO CNTRL NY LTR THIS AFTN. A 3H JET MAX IS ALSO PROGGED TO BE
NEAR YYZ BY 21Z WITH DVLPG UL DIV JUST GETTING INTO OUR WRN ZNS AT THAT
TIME. PROXIMITY OF THESE SOURCES FOR LIFT SHUD BE ENUF TO SPARK SCTD
SHWRS/TSTMS IN A FAIRLY UNSTABLE ENVIR BY LT AFTN (MODIFIED SNDGS GIVE
LI/S OF -5 TO -7 WITH CAPES NEAR 2000). 40 POPS SEEM REASONABLE FOR
NOW. ALTHO THEY SLOWLY IMPROVE WITH TIME...WIND FIELDS AREN/T
PARTICULARLY STG OVER THE RGN TDY (40 KT AT 5H JUST IMPINGES ON OUR WRN
ZNS TWDS 00Z). AS A RESULT...THINK BEST CHC FOR ANY SVR (AN OUTSIDE
CHC AT THAT) WUD BE OUR FAR WRN/NRN ZNS LT IN THE DAY. SINCE THERE/S A
MARGINAL THREAT AND AREA IS IN SLGT RISK ON LATEST SPC OTLK...WILL SEND
AN UPDATED HAZ WX OTLK WITH THIS PACKAGE.
MAX TEMPS WERE BUMPED UP TO THE MID 80S MOST AREAS BASED ON MRNG RAOB
INPUT.
WRK ZNS OUT. FINAL RELEASE COMING SOON.
.BGM...NONE.
JUREWICZ
ny
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
959 AM EDT THU SEP 9 1999
ZFP: WIDESPREAD PCPN OFF THE COAST IS ASSOCIATED WITH AN INVERTED
TROUGH AND A WEAK IMPULSE SEEN IN THE WATER VAPOR. MSAS SHOWS THE
TROUGH AND THERE IS A HINT OF A WEAK LOW SOUTHEAST OF LITTLE RIVER
IN THE RADAR IMAGERY AND COASTAL OBS.
MORNING SOUNDINGS THIS MORNING SHOW PW JUST UNDER 2.0 INCHES AND
MODIFIED CAPES SHOWING 2000-2500 FOR THIS AFTERNOON. 09Z RUC
MODEL SHOW S/W OFF THIS COAST THIS MORNING AND THE NEXT ENERGY
ASSOCIATED WITH THE FRONTAL SYSTEM TO THE WEST WILL BE OVER WESTERN
PORTION OF THE CAROLINAS AT 21Z. THE COASTAL AREAS APPEAR TO BE
UNDER THE INFLUENCE OF NVA EARLY THIS AFTERNOON BUT EXPECT WITH
MOISTURE AND INSTABILITY THAT CONVECTION LATER IN THE DAY AS
EASTERLY TO SOUTHEASTERLY FLOW WILL PROVIDE A BOUNDARY INLAND FOR
CONVECTION TO OCCUR.
IT APPEARS THAT THE LOW LEVEL EASTERLY FLOW IS BEGINNING TO CLEAR
LOW LEVEL CLOUDS OVER THE WESTERN PORTION OF THE CWA AND WITH
DAYTIME HEATING THE LOW CLOUDS CLOUDS TO THE WEST OF THE AREA WILL
DECREASE IN COVERAGE.
CWF: OVER THE COASTAL WATERS WEAK LOW HAS CHANGED THE WINDS A BIT
THIS MORNING AND PLANE TO UPDATE THE WINDS DIRECTIONS. OTHERWISE NO
CHANGES PLANNED.
ILM...NONE.
DRH
FXUS62 KMHX 091334 nc
FORECAST DISCUSSION FOR EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS
859 PM CDT THU SEP 9 1999
LATEST SATELLITE IMAGERY SHOWS CLOUD COVER VERY GRADUALLY SHIFTING EAST
THIS EVENING. THIS TREND WELL HANDLED BY 0Z RUC WHICH SHOWS MOST OF ERN
ND TO BE OUT OF THE CLOUDS BY 9Z. ALTHOUGH SKIES CLEARING ATTM OVER DVL
AREA...CONCERN IS THAT TEMPS WILL NOT COOL AS MUCH AS CURRENTLY
FORECAST AS DRIEST AIR FURTHER WEST PER LATEST SFC ANALYSIS AND WITH
RUC KEEPING SFC DEWPOINTS NEAR 40 F THROUGH 12Z. NOT MUCH DROP OFF IN
DEWPOINTS NOTED UPSTREAM AS WELL. THUS WILL BUMP LOWS UP IN THIS AREA
AND REMOVE MENTION OF FROST. LATEST LAMP GUIDANCE ALSO KEEPING TEMPS
WARMER THAN CURRENT FORECASTS OVER MUCH OF THE REMAINDER OF THE
FA...AND WITH LINGERING CLOUD COVER AS WELL AS DEWPOINTS HOLDING A BIT
HIGHER WILL ADJUST TEMPS UP A BIT OVER THE REMAINDER OF THE FA.
THE RUC ALSO SHOWS A SECOND VORT MAX SWINGING THROUGH FAR NE ZONES
OVERNIGHT SO EXPECT SOME LIGHT PCPN TO CONTINUE THERE. THIS AGREES WELL
WITH CURRENT ZFP SO NO ADJUSTMENTS NEEDED THERE. WILL ALSO TWEAK WINDS
TO REFLECT CURRENT TRENDS.
.FGF...NONE.
RT
FXUS63 KBIS 092004 nd
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
1004 AM EDT THU SEP 9 1999
UPPER TROUGH AND ASSOCIATED MSTR FCST TO APPROACH THE MIDLANDS/CSRA
THIS AFTERNOON. LOW CLOUDS ALREADY BEGINNING TO DISSIPATE..SO WE SHOULD
SEE A LITTLE SUN BEFORE CLOUDS MOVE IN LATER THIS AFTERNOON. RUC HAS
MOISTURE DECREASING SOMEWHAT AS AREA MOVES INTO THE MIDLANDS THIS
AFTERNOON. HOWEVER, WITH INCREASING SURFACE MOISTURE CONVERGENCE AND
UNSTABLE AIRMASS..THERE SHOULD BE SOME CONVECTION THIS AFTERNOON AND
EVENING. PLAN TO CONTINUE CURRENT FORECAST FOR THE AFTERNOON.
.CAE...NONE.
LM
FXUS62 KCHS 091334 sc
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
930 AM EDT THU SEP 9 1999
12Z SFC ANALYSIS SHOW COLD FRONT POSITION JUST E OF CROSSVILLE TN
WITH IR SATELLITE SHOWING CYCLOGENESIS IN THE VICINITY OF THE UPPER
JET ENTRANCE REGION LOCATED OVER THE FRONT. FRONTAL PROGRESS MAY
SLOW SOMEWHAT BUT 09Z RUC STILL SHOWS SFC MOISTURE CONVERGENCE OVER
THE WRN CAROLINAS STARTING AT 15Z. THIS CONVERGENCE SHOULD BE THE
MAIN FORCING FOR AFTERNOON THUNDERSTORMS ALONG THE FRONT. WITH SOLID
BODY OF PRECIP OVER ERN TN...MAY NEED A SLIGHT UPWARD ADJUSTMENT TO
POPS...ESPECIALLY MTNS.
WILL ADJUST WESTERN ZONES TO MOSTLY CLOUDY AND ERN ZONES TO
INCREASING CLOUDS. WILL THUS NEED A SLIGHT DOWNWARD ADJUSTMENT FOR
WEST PARTS..WITH 80 TO 85 MTNS..85 TO 90 FOOTS AND SRN PIEDMONT AND
UPPER 80S TO AROUND 90 FAR ERN PIEDMONT.
GSO SOUNDING SHOWS 3500 CAPE WHEN MODIFIED TO MAX TEMP..EVEN 2500
WITH SOME MIXING OUT OF DEWPOINTS BEFORE CONVECTION. MAY NEED A
SEVERE WEATHER OUTLOOK TO ADDRESS POTENTIAL FOR HAIL WITH WET BULB
ZERO 9 TO 10 KFT AND GUSTY WINDS WITH 30+ THETA E LAPSE..MAINLY NRN
PART.
.GSP...NONE.
HG
sc
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MORRISTOWN TN
1043 AM EDT THU SEP 9 1999
LIGHT SHOWERS CONTINUE TO MOVE EAST ACROSS SOUTHERN PORTION OF CWA
AND CLOUD TOPS CONTINUE TO WARM. NORTH SIDE OF PRECIPITATION IS
EVAPORATING AWAY. MESOETA AND NEW RUC GIVE ME LITTLE REASON TO
EXPECT NEW THUNDERSTORM DEVELOPMENT THIS AFTERNOON IN OUR CWA...AND
WILL UPDATE ZONES TO ACCOUNT FOR THIS.
.MRX...NONE.
SP
FXUS64 KMEG 090838 tn
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MIDLAND TX
248 PM CDT THU SEP 9 1999
CURRENT VIS SATELLITE LOOP SHOWS LOTS OF CU STREETS HAVE FORMED OVR
CWA...PARTICULARLY S AND W. FRONT HAS PRETTY MUCH WASHED OUT TO
THE S...AND REMNANTS KICKED OFF POPCORN CELLS IN ITS WAKE.
ALSO...RUC ADVERTISING CONVERGENCE ALONG S NM/TX BORDER AND A FEW
CELLS FIRING THERE AS WELL. MODELS ALL INITIALIZED FAIRLY IN
SYNCH--WAY TOO WET. GUIDANCE POPS REFLECT THIS AS WELL.
W/REMNANTS OF FRONT WELL TO THE S...AND HIGHEST POPS TO THE NW...
CAN ONLY JUSTIFY MODELS THINKING IN LIEU OF SHORTWAVE CURRENTLY
FORMING OVR NV/AZ/UT BORDER. GIVEN MODELS POOR INITIALIZATION...
CONFIDENCE IN THEM IS LOW ATTM. WILL TREAT THIS AS AN UPPER
NW/LOWER SE FLOW SCENARIO...I.E...UPSLOPE CONVECTION BLEEDING OUT
ONTO THE ADJACENT SLOPES/PLAINS.
BIG QUESTION HERE HAS BEEN OVER THE EXTENDED W/TIMING/STRENGTH OF
NEXT FRONT DUE IN LATE SUN. LOWERING THICKNESSES AND INCREASED
CLOUD COVER SUN SEEM TO BE THE BEST BET FOR NOW FOR COOLER HIGHS BY
ABOUT A CAT FROM MONDAY...AS MRF ADVERTISING FROPA SOMETIME LATE
AFTERNOON. FRONT ADVERTISED TO BE STRONGEST ONE YET THIS FALL...
AND IS CALLING FOR TEMPS DROPPING INTO THE 40S SOME AREAS MON
MORNING AND SOME AREAS NOT BREAKING OUT OF THE 70S MON AFTERNOON.
FOR NOW...WILL PUT THESE TEMPS ONLY IN MOUNTAIN AREAS. DO NOT WANT
TO SET OFF THE FALL BELLS AND WHISTLES THIS FAR OUT UNTIL ANOTHER
RUN OR TWO. AFP IN SHORTLY.
THE PRELIMINARY GUIDANCE BELOW IS FOR COORDINATION PURPOSES ONLY.
OFFICIAL FORECASTS ARE CONTAINED WITHIN THE WEST TEXAS/SOUTHEASTERN
NEW MEXICO ZONE FORECAST.
MAF 66/88/68/92 2---
LSA 63/90/62/92 2---
E41 65/89/67/91 2---
6R6 74/88/76/93 2---
MRF 59/85/59/86 2222
CNM 66/93/66/94 2111
.MAF...
TX...NONE.
NM...NONE.
44
FXUS64 KSJT 091948 tx
UTAH AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UTAH
1020 AM MDT THU SEP 9 1999
SYNOPSIS...HIGH PRESSURE OVER UTAH WILL WEAKEN TODAY AS MOISTURE
SPREADS INTO THE STATE FROM THE WEST. A SERIES OF WEATHER
DISTURBANCES MOVING ACROSS THE AREA TONIGHT AND FRIDAY WILL RESULT IN
SCATTERED SHOWERS AND THUNDERSTORMS.
DISCUSSION...TREND FROM YESTERDAY IN OVERNIGHT MODELS AND CONTINUING
THIS MORNING HAS BEEN TO SPEED UP THE TIMING OF THE DYNAMIC FEATURES
MOVING ACROSS THE AREA. 12Z RUC BRINGS A 300MB VORTICITY LOBE INTO
WESTERN UT BY EARLY AFTERNOON WHICH COULD BE ENOUGH TO START
TRIGGERING SOME HIGH LEVEL THUNDERSTORMS. LOWER LEVELS REMAIN VERY
DRY TODAY SO LITTLE RISK OF RAIN REACHING THE GROUND IN THE VALLEYS
BUT SOME MAY IN THE MOUNTAINS ESPECIALLY IN THE SOUTH. CAMERA AT
ST. GEORGE HAS BEEN SHOWING CONSIDERABLE VIRGA AT TIMES AND
SATELLITE IMAGERY SHOWS A NICE NOTCH IN THE BACK EDGE OF THE CLOUDS
OVER SOUTHERN NV INDICATING A WAVE MOVING NORTHEAST OVER THAT AREA
HELPING PRODUCE A LITTLE ADDED LIFT HEADED FOR SOUTHWEST UT IN THE
NEXT FEW HOURS. SO HAVE MADE MOSTLY MINOR ADJUSTEMENTS TO MANY
ZONES. TOOK OUT THE REFERENCE TO LATE AFTERNOON BECAUSE OF THE
INCREASED SPEED OF THE HIGH LEVEL FEATURES. ADDED A THREAT OF
THUNDERSTORMS THIS AFTERNOON TO SOME OF THE EASTERN ZONES AND ADDED
A THREAT OF SHOWERS INTO THE SOUTHERN MOUNTAINS TODAY. AS THE LOWER
LEVELS GRADUALLY MOISTEN THE TREND TORWARD A CHANCE OF VALLEY
SHOWERS TONIGHT/FRIDAY STILL LOOKS GOOD.
SLC 123 CDC 233 SANDERS
.SLC...NONE.
FXUS65 KSLC 090946 ut
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
842 PM EDT THU SEP 9 1999
SHOWERS DYING DOWN IN THE VA/NC PIEDMONT AS RAIN COOLED AIR HAS
STABLIZED THE ATMS. CD FNT AT 23Z WAS LOCATED FROM WRN PA SOUTH INTO
ERN KY AND E TN. MORE SHRA/TSRA FIRING JUST AHEAD OF THIS FNT ATTM
GETTING READY TO MOVE INTO WRN CWA. MSAS DATA SHOWING CAPES CLOSE TO
1000 J/KG IN WV. EXPECT THIS ACTIVITY TO CONTINUE EWD INTO THE MTNS
THIS EVENING...WITH FNT MAKING IT TO NEW RIVER VALLEY BY 06-09Z.
WILL CONTINUE POPS INTO THE LATE NIGHT OVER ALL BUT FAR WRN CWA.
18Z MESOETA/21Z RUC SHOWING VORT SPINNING UP FROM SE NC NORTH INTO
COASTAL PLAIN OF NC TONIGHT AND INTO ERN VA BY 12Z FRI. THE ADDED
DYNAMICS WILL HELP KEEP THE AIR SOMEWHAT UNSTABLE.
WILL SEE A DECREASE IN CLDS IN WV/WRN VA/NW NC ZONES OVERNIGHT BUT
WILL KEEP MC ELSEWHERE. PLAN ON LOWERING MINS A LITTLE IN THE
PIEDMONT AS TEMPS THERE ALREADY COOLED INTO THE UPPER 60S.
REST OF FORECAST LOOKS ON TRACK. UPDATE OUT BY 02Z.
COMMENTS/SUGGESTIONS WELCOME.
.RNK
VA...NONE.
WV...NONE.
NC...NONE.
WHP
FXUS61 KAKQ 091923 va
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
1005 AM EDT THU SEP 9 1999
SFC ANLYS INDICATES CD FRONT MOVG THRU CNTRL KY/TN ATTM WITH RESIDU
TROF HANGING ACROSS CNRTL VA THIS MORN. RADAR SHOWING SCT SHRA DVLPG
OVER WVA WELL IN ADVANCE OF THE FRONT...ASSOCD WITH WEAK S/W ENERGY
SLIDING NE ALONG THE BNDRY THRU KY PER GEOST ANLYS. QUESTS THIS AFTN
WITH TSRA CVRG PTNL/STRENGTH AS VORT TAIL PASSES ACROSS THE MTNS AND
PRE-FRONTAL CNVRGNC LINGERS OUT E OF THE RIDGES. MODIFIED MORN RAOBS
PRODUCE GOOD INSTAB WITH 2-4K CAPES BUT GOOD UVM APRS LMTD A BIT FAR
W BY LACK OF DEEP RH AND EARLY CLDNS/SHRA. 12Z 85H THETAE ANLYS
GNRLY CLOSER TO LATEST RUC WHICH HAS BEST LOW LVL MCON INTO NW NC
EARLY THIS AFTN. OTRW THINK STRONGEST ACTIVITY(PSBL LN) LKLY ACRS THE
N/W WHERE BEST DYNAMICS HEAD THIS AFTN...THEN JUMPING INTO THE
PIEDMONT PER BETTER PWAT...ALTHO TSRA OVER ERN NC MAY ROB GOOD SFC
CVNRGNC LTR ON. BASED ON CURRENT CVRG WILL BUMP UP POPS/CLDNS WEST
AND PSBLY SRN TIER LOOKING AT SFC-85H THETA GRAD. LOW WBZ'S AND DRY
AIR ALF ALSO SUGGEST A CONTD SVR PTNL ESPCLY ALONG AND E OF THE BLUE
RDG WHERE HIER CAPES AND MORE HEATING WILL EXIST. CLDNS LOOKS TO
OFFSET WARM THICKNESS VALUES SO MAY TWEAK TEMPS DOWN OUT W OTRW OK.
.RNK
VA...NONE.
WV...NONE.
NC...NONE.
JH
va
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON WV
930 AM EDT THU SEP 9 1999
RUC AND MESO ETA MODELS SHOW MORE MOISTURE IN LOWER LEVELS THEN
EXPECTED PREVIOUS SHIFT. WILL INCREASE THE CLOUDS FOR THIS
AFTERNOON AND SHADE DOWN THE HIGH TEMPERATURES SOME. THE BEST
SUPPORT FOR PRECIPITATION STILL LOOKS BEST TO THE EAST THIS
AFTERNOON.
.RLX...
WV...NONE.
VA...NONE.
KY...NONE.
OH...NONE.
.END / AAR
wv
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
848 PM CDT THU SEP 9 1999
UPDATED ZONES TO REFLECT CLOUD AND WIND TRENDS.
SRN EDGE OF CLOUD DECK ERODED SOME WITH LOSS OF DAYTIME HEATING...
PUTTING SW COUNTIES IN THE CLEAR FOR A TIME. BUT ANOTHER IN A SERIES
OF VORT MAXES AND WK SFC TROFS ROTATING AROUND LOW IN SRN CANADA...
SPINNING CLOUDS BACK ACROSS SWRN SECTIONS OF CWA BY MIDNIGHT. REST OF
CWA WILL STAY M CLDY THRU THE NIGHT.
EDGE OF CLD COVER ON IR IMAGES ALIGNS WELL WITH 21Z RUC 60 PCNT RH
AT 700 MB. RUC BRIEFLY LIFTS THE EDGE OF THIS FIELD INTO EXTRM SRN
WI...THEN DROPS IT BACK SOUTH AROUND 06Z. 12Z ETA H5 TEMPS
OF -15C TO -16C AND H7-H8 LAYER RH OF 70 PCNT OR HIER ALSO DEPICTED
BNDRY OF CLOUD COVER WELL. THESE FIELDS HOVER OVR RGN THRU NIGHT TIME
HOURS. ALSO TOUCHED UP WNDS AS THEY HAVE DIMINISHED PER PREVIOUS
FCST.
.MKX...NONE.
REM
FXUS63 KMKX 092027 wi
SOUTH CENTRAL AND SOUTHEAST COLORADO AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PUEBLO
305 AM MDT FRI SEP 10 1999
...SIGNIFICANT COOL DOWN STILL IN THE OFFING FOR SUN/MON...
MAIN FORECAST CHALLENGE OVER THE NEXT 24-36 HOURS IS THE TIMING...
STRENGTH...AND POSITION OF MINOR MID-LEVEL SHORTWAVE TROUGHS MOVING
THROUGH WESTERLY FLOW.
TDA/TNGT: ONE...WAA DRIVEN...TSRA HAS FORMED OVER CHEYENNE COUNTY
AND SHOULD CONTINUE TO MOVE INTO KS...IF IT HOLDS TOGETHER. LATEST
WATER VAPOR IMAGERY REVEALED MID-LEVEL CYCLONIC SHEAR AXIS MOVING
THROUGH CENTRAL UT. PLENTY OF HIGH LEVEL MOISTURE WITH IT PER
SATELLITE IMAGERY AND 00Z/10 UPPER AIR ANALYSIS. TIMING OF THIS
FEATURE WILL BE THE KEY TO TDA'S FORECAST. ETA/AVN/NGM ALL HAVE
VARIOUS TEMPORAL AND SPATIAL DIFFERENCES OVER THE NEXT 12 HOURS.
HOWEVER...THE LATEST RUC INDICATES MID-LEVEL SHORTWAVE TROUGH WILL BE
IN WESTERN CO BY 18Z/10...WHICH IS MUCH SLOWER THAN THE OTHER SHORT
RANGE MODELS. OTHER FEATURE NOTED ON THE WATER VAPOR IMAGERY IS
RELATIVELY DRYING OF HIGH LEVELS PUSHING INTO WESTERN CO. ALSO...
CONCERNED ABOUT THE ABOUT OF DOWNSLOPE DRYING AROUND THE I-25
CORRIDOR PER RUC/ETA THIS AFTERNOON. 700MB RH VALUES PROGGED TO BE
20-30%. GIVEN DAYTIME HEATING...STILL COULDN'T RULE OUT SOME
CONVECTIVELY DRIVEN HIGH-BASED SHRA/TSRA...OR VIRGA...LATE THIS
MORNING/AFTERNOON. OVERALL COVERAGE STILL A HEAD SCRATCHER. PLAN TO
CARRY 20 POP WORDING FOR MOUNTAINS AND ISOLATED IN ADJACENT
PLAINS/VALLEYS. EASTERN SAN JUAN MOUNTAINS AND SAN LUIS VALLEY
PRECIPITATION THREAT MAY ONLY BE THIS MORNING/EARLY AFTERNOON AS
RELATIVELY DEEP DRIER AIR FILTERS INTO THE REGION. NOT REAL CONFIDENT
ON SHRA/TSRA OCCURRENCE THIS EVENING IN THE PLAINS. WILL DEPEND ON
TIMING OF THE AFOREMENTIONED MID-LEVEL SHORTWAVE TROUGH. PLAN TO
CARRY "EARLY EVENING" WORDING IN SOUTHEAST MOUNTAINS AND PLAINS.
WESTERN PORTION OF CWA MAY BE PRECIPITATION-FREE THIS EVENING.
CURRENT ZFP TEMPERATURE FORECAST LOOKS GOOD.
SAT: LOTS OF UNCERTAINTY FOR SAT'S FORECAST. MODELS USUALLY HAVE
PROBLEMS WITH WESTERLY FLOW MID-LEVEL SHORTWAVE TROUGH MIGRATION
AND THIS PERIOD...INCLUDING THE PAST FEW RUNS...IS NO DIFFERENT.
CURRENT SHORT RANGE MODEL RUNS...IF YOU WANT TO BELIEVE THEM...
HINTING AT ANOTHER MID-LEVEL SHORTWAVE TROUGH MOVING ACROSS CO SAT.
ETA/NGM ARE WEAKER WITH THIS FEATURE...WHILE AVN REALLY PUMPS IT
UP. ALSO...AVN/NGM ARE MUCH FASTER WITH THE WAVE. SYSTEM COMING
OUT OF CAN WILL BE ENTERING NORTHERN PLAINS LATE SAT AFTERNOON WITH
ASSOCIATED COLD FRONT STILL NORTH OF CO. AVN/NGM A TAD STRONGER
WITH THIS FEATURE. STILL ENOUGH MID/HIGH LEVEL MOISTURE TO WORK
WITH DURING THE AFTERNOON FOR CONVECTIVELY DRIVEN SHRA/TSRA. WITH SO
MUCH UNCERTAINTY ON ANY ORGAINZED LIFTING MECHANISM...WILL GO WITH
"SILENT" 10 POPS IN CCF AND MAINTAIN ZFP CONTINUITY FOR SAT.
EXTENDED(SUN-TUE): 60-72HR AVN STILL HAVING GOOD CONTUINTY WITH COLD
FRONT SWEEPING THROUGH CWA SAT NIGHT/SUN MORNING AS PARENT LOW MOVES
INTO NORTHERN PLAINS/UPPER MIDWEST. MRF HAS SERIES OF MID-LEVEL
SHORTWAVE TROUGHS MOVING INTO THE NORTHERN AND CENTRAL PLAINS
MON/TUE...WHICH SHOULD RE-ENFORCE COOLER AIR OVER THE PLAINS.
QUALITY OF DEEP MOISTURE TO WORK WITH STILL IN QUESTION FOR
SIGNIFICANT PRECIPITATION COVERAGE. HOWEVER...WITH PROLONGED
EASTERLY LOW LEVEL FLOW COULD HAVE SOME STRATUS/DRIZZLE MON/TUE...
BUT TOO FAR OUT TO PIN DOWN AND IS A NON-ACCUMULATING EVENT ANYWAY.
KEY FEATURE WILL BE BELOW AVERAGE TEMPERATURES AND POTENTIAL FOR
SCATTERED FROST...IF THE SKY IS CLEAR. CURRENT EFP LOOKS GOOD...SO
NO CHANGES.
.PUB...NONE.
METZE
FXUS65 KPUB 092041 co
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
400 AM EDT FRI SEP 10 1999
MAIN FORECAST CHALLENGE THIS FORECAST PERIOD REVOLVES AROUND
PRECIPITATION CHANCES THROUGH TONIGHT WITH UPPER TROUGH MOVING EAST
AND NORTH.
SHORT TERM MODELS FAIRLY SIMILAR IN SHOWING THE UPPER LOW OVER THE
WESTERN GREAT LAKES TODAY...THEN PULLING EAST AND NORTH TONIGHT.
SHORT WAVE ENERGY WILL CONTINUE TO PIVOT AROUND THIS UPPER LOW. IT
WILL BE THIS SHORT WAVE ENERGY...AS SEEN IN WATER VAPOR IMAGERY
COUPLED WITH LAKE ENHANCEMENT THAT WILL POSE THE POTENTIAL FOR
PRECIPITATION AND CLOUD COVER. BEST SHORT WAVE ENERGY IS PROGGED TO STAY
NORTH OF THE REGION...THUS BEST LIFT FOR SHOWER ACTIVITY TO THE
NORTH AS WELL. ONE SHORT WAVE CAN BE SEEN IN THE WATER VAPOR IMAGERY
PASSING THROUGH SOUTHERN WI. THIS WILL DO LITTLE MORE THAN INCREASE
CLOUD COVER LATE THIS MORNING...NEXT STRONGER SHORT WAVE WILL PIVOT
THROUGH IN THE AFTERNOON WITH BETTER ENERGY TO THE NORTH.
LAKE EFFECT SHOWER POTENTIAL IS BEST THIS MORNING...WITH LITTLE...IF
ANY CURRENTLY TAKING PLACE OFF LAKE MI. WITH THE THERMAL TROUGH
MODIFYING SOMEWHAT AS IT DROPS INTO SOUTHERN MICHIGAN TODAY...NOT
EXPECTING MUCH LAKE ENHANCEMENT TODAY FOR PRECIPITATION...AS INVERSION HEIGHTS
WILL LOWER. WILL LIMIT MENTION OF PRECIPITATION TO NORTHERN
COUNTIES...WHICH WILL BE INFLUENCED BY BETTER UPPER ENERGY...AS WELL
AS ANY LAKE ENHANCEMENT. 06Z RUC HAS BEST HANDLE ON CLOUD COVER AT
THE MOMENT...SO WILL FOLLOW IT FOR CLOUD WORDING IN THE FIRST 12
HOURS. ESSENTIALLY WILL SEE CLOUDS WORKING FROM NORTH TO SOUTH
ACROSS FORECAST AREA INTO THE AFTERNOON.
TEMPERATURES ARE A BIT TRICKY FOR TODAY...WITH THE ETA AND NGM
PROVIDING WARMER SOLUTIONS FOR TODAY FROM THIS RUN THAN THE ONE FROM
LAST NIGHT. HOWEVER...EXPECTED CLOUD COVER IN THE COLD ADVECTION
PATTERN SHOULD ACT TO KEEP READINGS AT LEAST A FEW DEGREES COOLER
THAN FWC/S NORTH. SOUTHERN TIER OF COUNTIES COULD SEE ENOUGH
SUNSHINE TO REACH PROGGED MAXES.
FOR TONIGHT...UPPER LOW PULLS OUT...WITH BETTER SHORT WAVE ENERGY
EXITING BY 06Z. WITH RIDGING BUILDING IN...AND MOIST LAYER BECOMING
MORE SHALLOW...EXPECT MOST CLOUDS TO DISSIPATE OVERNIGHT...LEAVING
ONLY ENOUGH LOW LEVEL MOISTURE IN THE LOW LEVELS FOR A FEW CU ON
SATURDAY. WITH SUNSHINE EXPECTED ON SATURDAY...UNDER BUILDING HIGH
PRESSURE...FWC MAXES LOOK REASONABLE.
.DTX...NONE.
STRUBLE
FXUS63 KGRR 100739 mi
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
1030 PM EDT THU SEP 9 1999
MAIN FCST CONCERN OVERNIGHT IS PCPN TREND.
SHRTWVS ROTATING AROUND CUTOFF LOW DOMINATING WEATHER OVER WRN GRT
LAKES. WV LOOP INDICATED ONE SUCH SHRTWV NW OF CYQT ADVANCING TOWARD
LK SUPERIOR SUPPORTING LARGE AREA OF RAIN OVER NE MN THRU WRN LK
SUPERIOR INTO WRN 1/3 OF UPR MI. ANOTHER SHRTWV WAS LOCATED FURTHER
UPSTREAM OVER NW ONTARIO. ONCE AGAIN... THE 18Z MESO-ETA HAD GOOD
HANDLE ON THESE DETAILS...MUCH BETTER THAN 00Z RUC OR ANY OF THE 12Z
MODELS. HOWEVER...IT WAS STILL A BIT SLOW WITH THE PRECIP INTO WRN
UPR MI. GOOD 850-500 QVECTOR CONVERGENCE WITH THESE FEATURES
STRENGTHENS FROM NW TO SE OVERNIGHT...SUPPORTING INCREASE IN PCPN
COVERAGE...CONSISTENT WITH RADAR TRENDS. EVEN WITH QUICKER
PRECIP TREND WL LEAVE ONLY SCT WORDING FOR THE EAST PORTION OF THE
CWA AS QG FORCING TAKES TIL CLOSER TO 12Z TO ADVANCE TOWARD ERY-ISQ.
850 TEMPS TO NEAR 3C WILL KEEP DLT/T TO AROUND 13C...ENOUGH FOR SOME
LAKE ENHANCEMENT. BACKING WINDS TO SW AHEAD OF SFC TROF OVER NERN MN
THOUGH WILL KEEP LAKE ENHANCED PCPN AMOUNTS TO A MINIMUM.
EXPANDED TEMP RANGE A BIT TO ACCOUNT FOR SLIGHTLY WARMER CONDITIONS
NEAR LAKE SUPERIOR WITH CURRENT OBS NEAR LK 3-5F WARMER THAN INLAND.
HOWEVER...CLOUDS AND PCPN WILL KEEP DIFFERENCE SMALLER THAN ON A GOOD
RADIATIONAL COOLING NIGHT.
.MQT...NONE.
JLB
FXUS63 KAPX 100228 mi
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
355 AM CDT FRI SEP 10 1999
SATELLITE LOOP SHOWS BACK EDGE OF CLOUDS...ASSOCIATED WITH THE COLD
CYCLONIC FLOW ALOFT...ALONG AND EAST OF THE 300 MB JET AXIS AS
DEPICTED BY THE ETA MODEL. THIS UPPER LEVEL JET AXIS IS FORECAST BY
THE RUC MODEL TO SHIFT EAST THROUGH MOST OF OUR COUNTY WARNING AREA
BY EARLY AFTERNOON. EXPECT OUR SOUTHWEST COUNTIES WILL BE IN THE
CLEAR TODAY. SUBSIDENCE EXPECTED TO WORK ACROSS OUR AREA TONIGHT AND
THIS SHOULD COMPLETE THE CLEARING TREND. SURFACE RIDGE EXPECTED TO
REACH CENTRAL MINNESOTA TONIGHT. OVERNIGHT LOWS SHOULD BE QUITE COOL
WITH 850 MB TEMPERATURES FORECAST TO RANGE FROM 3 DEGREES OVER WEST
CENTRAL WISCONSIN TO 8 DEGREES SOUTH OF THE MINNESOTA RIVER VALLEY.
WILL KEEP A CHANCE OF SHOWERS MENTIONED OVER PORTIONS OF WEST
CENTRAL AND SOUTHWEST MINNESOTA LATE SUNDAY. THE MIDDLE LEVEL
RELATIVE HUMIDITY IS FORECAST TO INCREASE BEHIND THE 700 MB RIDGE
AND LIFT IS IMPLIED FROM THE 700 OMEGA AND Q VECTOR FIELDS. AT 48
HOURS...THE LOW LEVEL CONVERGENCE IS FORECAST TO REMAIN ALONG A
BOUNDARY SOUTH OF OUR AREA AND 850 MB THETA E AXIS IS JUST BEGINNING
TO NUDGE INTO NORTHWEST MINNESOTA SO MAIN PRECIPITATION THREAT
SHOULD HOLD OFF UNTIL SATURDAY NIGHT.
.MSP...NONE.
WH
FXUS63 KDLH 100837 mn
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
3 AM CDT FRI SEP 10 1999
...FORECAST CHALLENGES...TIMING PRECIP/TEMPS.
...SYNOPSIS...SFC HI PRES WAS OVER NEB WITH SFC LO PRES STRETCHING
FM MT TO CO. 00Z SNDINGS SHOWS SOME MOISTURE AROUND 6K AT OAX AND
9K AT TOP. LNK REPORTING A MID DECK AND THE LTST IR STLT HAS SOME
PATCHY CLDS IN THE SE WITH MORE WDSPRD CLDS IN SW NEB. DDC HAD A
DEWPOINT OF 7 DEG C AT ARND 745MB WITH FLO AT AND BLO THIS LVL FM
THE SW. RECENT PROFILERS SHOW H85 FLO FM THE SW OVR SW KS AND NW
FLO AT H70 IN NEB AND THE NE HALF OF KS.
...FORECAST...THERE ARE TWO WX SYSTEMS OF CONCERN OVR THE NEXT
COUPLE OF DAYS...WHICH WILL BRING A RISK OF PRECIP TO THE FCST
AREA. THE FIRST WX SYSTEM IS A SHRTWV OVR UT. THE ETA/RUC TRACK
THIS SYS E INTO CO THIS AM AND KS THIS AFT. WITH THE APPROACH OF
THE SHORTWV...LO AND MID LVL MOISTURE RETURNS. THE ETA/NGM ARE
SIMILAR...WITH THE AVN A BIT MORE AGRESSIVE ON THE PRECIP H20.
ETA/AVN COMPR AS STLT SHOWING MONSOONAL MOISTURE WILL BE AVAILABLE.
GOES SNDRS WERE NOT AVAIL...HOWEVER RUC PRECIP H20 OVR KS ARND AN
INCH AND INCREASING.
AS LO AND MID LVL MOISTURE INCREASE AND SHRTWV MOVES ACRS KS...SOME
UVV DOES MAKE IT INTO SE NEB. LAPSE RATES STEEPEN WITH RELATIVELY
COOL AIR ALOFT AND WRMING H85 TEMPS SOME 4 DEG C TO AROUND 15 0R 16
FOR THE FCST AREA. GUID TEMPS AND CURRENT FCST OF 75 TO 80 RSNBL.
RUC DOES HAVE SOME PRECIP IN THE FAR SE IN ITS 12HR FCST AND THE NGM
AND AVN HAS A CHC FM 18-00Z. WITH WAA/INSENTROPIC LIFT/RETURN OF
DEEPER MOISTURE...AND SHRTWV...SLT CHC OF PRECIP FOR SRN
ZONES...WITH BETTER CHC IN KS. SPC HAS SLT RISK FOR SVR OVR KS/OK.
OVERNIGHT AND SAT AM...WAA/LLVL JET INCREASES ACRS THE FCST AREA.
AGAIN...WITH STEEP LAPSE RATES AND HIGHER RH SCT TSRA POSSIBLE. THE
NGM IS MUCH STGR WITH THE NRN SHRTWV THAT DROPS DOWN FM CANADA INTO
THE NRN AND CNTRL PLNS SAT. MODELS HAVE SLOWED THEIR TIMING...WITH
THE AVN THE SLOWEST...AND ALL SHOW PRECIP BY SAT AFT. WILL ADJUST
POPS LOWER FOR SCT ERLY SAT AND HIGHER POPS SAT AFT/SAT NIGHT.
TEMPS TOUGHER FOR SAT. NGM MUCH WRMR ON H85 TEMPS WITH STGR S FLO
AHD OF THE CDFNT. CLDCVR WILL MAKE A BIG DIFFERENCE AND WITH SOME
SUNSHINE EXPECTED...WILL UP TEMPS FOR SAT FROM PREVIOUS FCST.
CURRENT EXTENDED LOOKS O.K.
.OMA...NONE
ZAPOTOCNY
FXUS63 KGID 100758 ne
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
224 AM EDT FRI SEP 10 1999
SAT PIX SHOW SKIES CLEARING ACROSS CWFA ATTM. THIS IS HELPING FOG
FORMATION OUTSIDE OF THE MTNS WITH VSBYS FALLING IN THESE LOCATIONS.
DENSE FOG PATCHY ATTM BUT WILL PROBABLY NEED TO MENTION IN ZONES.
WILL WATCH OBS TO SEE IF DENSE FOG ADVISORY WILL BE NEEDED.
MUCH DRYER DEW POINTS HAVE ALREADY FILTERED INTO THE MTNS AND DRY
AIR SHOULD CONTINUE TO MAKE A SLOW BUT STEADY PUSH EAST. RUC...ETA
AND AVN ALL DRY THE ATMOS BY 18Z...WHILE THE NGM HOLDS ON TO LOW
LEVEL MOISTURE THRU THE DAY. LINGERING MOISTURE WOULD BE SIGNIFICANT
BECAUSE OF SECONDARY SHORT WAVE ROTATING THRU THE AREA TODAY.
HOWEVER THIS SHOULD BE MORE OF A PROBLEM TO OUR EAST SINCE
SUBSIDENCE AND SLIGHT DOWNSLOPE WIND COMPONENT SHOULD AID DRYING.
ANOTHER NICE DAY SATURDAY AS DRY AIR MASS REMAINS.
GUIDANCE NUMBERS CLOSE TODAY AND WARMER THAN CURRENT FCST. WILL
TREND THAT WAY GIVEN ALMOST FULL SUN...ONLY SLIGHT DROP IN
THICKNESSES AND SLIGHT DOWNSLOPE WIND COMPONENT. LIKE COOLER FWC
TEMPS TONIGHT GIVEN GOOD RADIATIONAL CONDITIONS. XCPT HAD TO
UNDERCUT SIGNIFICANTLY AT CLT SINCE MOS HAS NOT CAUGHT UP WITH NEW
OBSERVATIONS AND COOP SITES THERE ALSO COOLER THAN GSP IN THESE
TYPES OF SITUATIONS. GUIDANCE CLOSE AND ACCEPTED SATURDAY WITH LOWER
THICKNESSES AND MORE NELY WINDS.
AVL 81/48/78 000
CLT 85/51/82 -00
GSP 86/52/83 000
.GSP...NONE.
RWH
FXUS62 KGSP 100123 sc
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NATIONAL WEATHER SERVICE SIOUX FALLS SD
252 AM CDT FRI SEP 10 1999
UPPR LVL LOW CONTINUES TO SPIN NR CYPL WITH SLOW EWRD DRIFT EARLY
THIS MRNG...WITH ANOTHER LOBE WRAPPING BACK THRU MN. SFC RIDGE
WRN ND THRU CNTRL NEBR...WITH NOT MUCH SFC GRAD REMAINING EXCEPT
SW MN. MAIN CONCERN TDA IS HOW QUICKLY TO BRING PCPN THREAT IN
ON SAT.
SOME MORE SIG DIFFERENCES IN MODEL FIELDS TDA...ETA BEING
LESS AMPLIFIED AND LTL SLOWER WITH STG CLOSED LOW ALG CANADIAN BRDR
BY 00Z SUN...AVN MORE SO...AND NGM DEEPER AND FASTER. SLOWER
SEEMS MORE REASONABLE WITH THE LARGE SCALE AMPLIFICATIONS...SO
WL SIDE MORESO WITH AN ETA/AVN IDEA. HOWEVER...REALIZE POOR LO
LVL TMP FCST...AND WL ADJUST ACCORDINGLY.
GOING ONS MINOR TODAY. ISSUE AT HAND IS TMPS...AND FINE TUNING
TREND IN WIND AS LOW LVL RIDGE AXIS TRAVERSES MOST OF CWA BY 00Z.
LTL LESS FAVORABLE MIXING SUPPORT AGAIN TDA...BY THE TIME BETTER
MIXING SHOULD OCCUR...MOMENTUM AVAILABLE CONTINUES TO DCRS WITH
ONLY 20KTS AT 850 HPA IN HIER GRAD ACRS SW MN. THRU AFTN...WL
SEE BATTLE OF NWLY MIXING AND WK SELY SFC FLOW FOR LGT WNDS IN
MUCH OF SD CWA. WK IMPULSE AND JET DVRG IN WRN PLAINS MAY BRUSH LTL
CI THRU WRN CWA BEFORE FLOW TAKES IT SE...AND A MINOR SC OUTBREAK
MIDDAY FAR NE... OTHERWISE UNTAINTED SUNSHINE EXPECTED TDA.
OVERNIGHT...BIGGEST DIFFERENCE IN ETA IS LACK OF WK IMPULSE CROSSING
NRBY OR JUST TO S ARND 06Z. EVEN IF MISSED...SHUD ONLY BE SOURCE OF
MID TO HIGH CLDS AND LTL SENSIBLE WX. BETTER PCPN GENERATION IN
COUPLED LLJ DIV Q/UPPR JET DIVERGENCE WL REMAIN ACRS WRN INTO CNTRL
SD...SO PLAN ON DRY WITH ONLY INCRS IN CLDS. WITH RELATIVELY STG
STM MOTION VECTORS...WL HAVE TO WATCH FOR WKNG STUFF INTO WRN CWA
TOWARD MORNING...AS WELL AS HINT THAT SOME MIDLVL ACC SHRA MAY SPREAD
TO ALG SRN MO RVR TOWARD MRNG.
HIGHLY CURVED JET WITH UPSTREAM STG TROUGH LOOKS TO ENHANCE WKLY
COUPLED JET ACRS ERN SD SAT...AND EVENTUALLY SW MN AND NW IA LATER
IN THE DAY. DYNAMICS OVERALL FAIRLY IMPRESSIVE...BUT WL HAVE TO
OVERCOME PRETTY DRY ATM. WL DELAY ONSET OF PCPN THREAT E OF JAMES
RVR TO MIDDAY...AND LT IN SW MN AND NW IA...MORE IN LINE WITH DVLPG
LO LVL WAA. SUPRISING AGREEMENT IN ALL MDLS QPF LENDS SOME CERTAINTY
AS WELL.
TEMPERATURE CONCERNS TODAY AGAIN DEPEND ON WHICH MDL TO SIDE WITH...
AND AS YDA...NGM/AVN APPRECIABLY WARMER THAN ETA...2-4C BY 00Z SAT...
AND FOR OTHER REASONS...5-7C WARMER BY 00Z SUN. RUC AGAIN IS MORE
SUPPORTIVE OF NGM 850 HPA TMPS FOR TDA...AND WL TREND THAT DIRECTION.
TMPS SAT LARGELY DEPENDENT ON CLDS PCPN. BOWING OF THERMAL FIELD INTO
LOW LVL FLOW SUGGEST EFFECT OF SIG UPWARD MOTION...AND LKLY NOT
FRONT SHUD NOT REACH CWA YET. WL DOWNPLAY SIG WARMING ON SAT...BUT
HAVE GREATEST POTENTIAL ERN CWA WHERE CLDS WL BE SLOWEST TO INCRS.
.FSD...NONE
CHAPMAN
FXUS63 KUNR 100139 sd
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MORRISTOWN TN
1043 AM EDT THU SEP 9 1999
LIGHT SHOWERS CONTINUE TO MOVE EAST ACROSS SOUTHERN PORTION OF CWA
AND CLOUD TOPS CONTINUE TO WARM. NORTH SIDE OF PRECIPITATION IS
EVAPORATING AWAY. MESOETA AND NEW RUC GIVE ME LITTLE REASON TO
EXPECT NEW THUNDERSTORM DEVELOPMENT THIS AFTERNOON IN OUR CWA...AND
WILL UPDATE ZONES TO ACCOUNT FOR THIS.
.MRX...NONE.
SP
tn
COASTAL BEND FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CORPUS CHRISTI TX
320 AM CDT FRI SEP 10 1999
MODEL X-SCTNS SHOW LINGERING 1000-850MB MSTR TDY. HIER ETA PW
PROBABLY MORE REPRESENTATIVE GIVEN WV IMAGES. VERTICAL WND FIELD
RATHER LGT TDY SO CBRZ SHUD BE EVIDENT. AVN(NGM LESSER EXTENT) SHOW
WEAKLY FAVORABLE 1000-850MB DIV Q/Q VECTOR CONVERGENCE ALG COAST BUT
MNLY N/W CWA AT OTHER LVLS. NGM/ETA ALSO SHOW DECENT SFC MSTR
CONVERGENCE ALG CST TDY. SOME 700-300MB DIVERGENCE IS ALSO
INDICATED. NGM ALSO HAS 850MB THETA RIDGE ACROSS CWA TDY.
THESE ABOVE FACTORS COULD SUPPORT LOW POPS BUT GENERAL SYNOPTIC
SUBSIDENCE WILL ENSURE NEGATION. NGM SOUNDINGS SHOW INVERSION AT
800MB TDY WITH WARMING FURTHER ALOFT. OVERALL ETA SOUNDING MORE
FAVORABLE BUT ALSO SHOWS WARMING FURTHER ALOFT. NGM TIME/HGT SCTN
INDICATES SIGNIFICANT DVM AT 18Z WHEN CBRZ WOULD BECOME PROMINENT.
THUS NO POPS.
DIRTY UPR LVL RIDGE TO OUR W WITH EMBEDDED VOTMAX WILL BRING OCNL CI
DEBRIS FROM CONVECTION. THIS IN COMBINATION WITH LINGERING LLVL MSTR
TDY SO PC SKY. WILL OPT FOR MS TOMORROW AS DRIER ATMOS WILL BE IN
PLACE.
COOLER 850MB TEMPS AND LOWER THICKNESSES TDY AND TOMORROW FAVOR AVN
MOS BUT GENERAL SUBSIDENCE AND DRIER AIR ARGUE TACKING ON A DEGREE
OR TWO. MOS GUIDANCE TEMPS AT NIGHT SEEM REASONABLE AND MAY TWEAK
HERE AND THERE.
SFC RH/DWPT DEP/COND PRES DEF FROM LATEST RUC/MESOETA SUGGEST PTCHY
FG THIS MORNING. THESE FIELDS FROM 03Z MESOETA SUGGESTS AREAS OF FG
LATER TNGT/TOMORROW MORNING.
FORESEE NO PROBLEMS FOR THE MARINE WATERS AS WIND/SEAS REMAIN FLAT.
MRF CONTS TO INDICATE A CD FNTL PASSAGE MON NGT WITH COOLER TEMPS
AS PORTRAYED AT 850MB. X-SCTNS SHOW MARGINAL MSTR PRECEDING ITS
PASSAGE FOR SLGHT CHC. CURRENT ADVERTISED EXTENDED SHOWS TRENDS
WELL.
PRELIMINARY NUMBERS:
CRP BA 092/071 091/071 091 -00
VCT BA 095/068 094/068 094 -00
LRD BA 094/073 096/073 096 -00
.CRP...NONE.
(SYN)...85/BB
(MESO)...76/BL
FXUS64 KSJT 100816 tx
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EL PASO TX/SANTA TERESA NM
148 AM MDT FRI SEP 10 1999
SYNOPSIS...
A HIGH PRESSURE RIDGE OVER NORTHERN MEXICO WILL KEEP MOST OF THE
BORDERLAND DRY THROUGH SATURDAY DESPITE RELATIVELY MOIST AIR NEAR
THE SURFACE. OVER THE GILA AND SACRAMENTO MOUNTAINS WHERE THE
INFLUENCE OF THE HIGH IS LESS AND THE TERRAIN HELPS LIFTING
THUNDERSTORMS WILL BE MORE NUMEROUS. THUNDERSTORMS MAY BE MORE
NUMEROUS LATE SUNDAY OR SUNDAY NIGHT AS A COLD FRONT APPROACHES FROM
THE NORTH. THIS FRONT SHOULD LEAVE US WITH SLIGHTLY DRIER AND COOLER
WEATHER FOR THE FIRST PART OF THE NEXT WEEK.
DISCUSSION...
MORE OF SAME THROUGH SATURDAY. UPPER LEVEL DYNAMICS/INSTABILITY MOST
FAVORABLE WITH N/NW PORTION OF FA NEAR RIGHT ENTRANCE REGION OF JET AND
COOLER TEMPS ALOFT. MORE SURFACE MOISTURE SE BUT WITH 00Z H5 -4C ON
ELP RAOB..UPPER HIGH IS DOING ADEQUATE JOB OF CAPPING OFF ATMOSPHERE.
SOME COOLING ALOFT INDICATED BY RUC2 SOUNDING FOR FRIDAY EVENING
OVER SE BUT STILL EXPECT ONLY WIDELY SCATTERED EVENING THUNDERSTORMS
THERE AT BEST.
NEXT COLD FROPA INDICATED BY AVN FOR LATE SUNDAY NIGHT OR EARLY
MONDAY SO WILL CONTINUE CURRENT EXTENDED WORDING WITH ONLY MINOR
CHANGES DESPITE SOME SKEPTICISM ON TIMING.
EL PASO BB 90/ 66/ 90/ 66/ 93 12121
LAS CRUCES BB 88/ 60/ 88/ 60/ 91 12121
ALAMOGORDO BB 88/ 61/ 88/ 61/ 91 12121
CLOUDCROFT BB 69/ 45/ 69/ 46/ 70 32323
TRUTH OR CONSEQUENCES BB 88/ 61/ 88/ 61/ 91 22222
SILVER CITY BB 85/ 55/ 85/ 55/ 88 32322
DEMING BB 89/ 59/ 89/ 59/ 92 12121
LORDSBURG BB 90/ 60/ 90/ 61/ 94 12121
.ELP...NONE
02
N
FXUS64 KBRO 100734 tx
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
848 PM CDT THU SEP 9 1999
UPDATED ZONES TO REFLECT CLOUD AND WIND TRENDS.
SRN EDGE OF CLOUD DECK ERODED SOME WITH LOSS OF DAYTIME HEATING...
PUTTING SW COUNTIES IN THE CLEAR FOR A TIME. BUT ANOTHER IN A SERIES
OF VORT MAXES AND WK SFC TROFS ROTATING AROUND LOW IN SRN CANADA...
SPINNING CLOUDS BACK ACROSS SWRN SECTIONS OF CWA BY MIDNIGHT. REST OF
CWA WILL STAY M CLDY THRU THE NIGHT.
EDGE OF CLD COVER ON IR IMAGES ALIGNS WELL WITH 21Z RUC 60 PCNT RH
AT 700 MB. RUC BRIEFLY LIFTS THE EDGE OF THIS FIELD INTO EXTRM SRN
WI...THEN DROPS IT BACK SOUTH AROUND 06Z. 12Z ETA H5 TEMPS
OF -15C TO -16C AND H7-H8 LAYER RH OF 70 PCNT OR HIER ALSO DEPICTED
BNDRY OF CLOUD COVER WELL. THESE FIELDS HOVER OVR RGN THRU NIGHT TIME
HOURS. ALSO TOUCHED UP WNDS AS THEY HAVE DIMINISHED PER PREVIOUS
FCST.
.MKX...NONE.
REM
FXUS63 KMKX 092027 wi
EAST CENTRAL FLORIDA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MELBOURNE FL
1030 AM EDT FRI SEP 10 1999
MAPS PLACES SURFACE TROUGH ACROSS NORTHERNMOST CWA THIS MORNING WITH
NW FLOW ACROSS N FL AND N WINDS DEVELOPING ACROSS GA. AS S/W MOVES
FROM GULF TO ACROSS PENINSULA TONIGHT/TONIGHT...SURFACE TROUGH DROP
SE THROUGH CWA AND MAJORITY OF COASTAL WATERS. MORNING SOUNDINGS
INDICATE INCREASED DRYING ALOFT OVER C FLORIDA...BUT COMBINED WITH
SLIGHT COOLING...ATMOSPHERE WILL BE A LITTLE MORE UNSTABLE THIS
AFTERNOON COMPARED TO RECENT DAYS. PVA AND INCREASED INSTABILITY
WILL LIKELY COUNTER DRIER COLUMN OF AIR TO RESULT IN SCATTERED
AFTERNOON/EVENING STORMS. MAY ALTER ZFP ACROSS THE NORTHERN COUNTIES
TO VEER WINDS TO N COMPONENT EARLIER...OTHERWISE NO CHANGES PLANNED.
MARINE...LATEST RUC AND MESO-ETA FORECASTS CONSISTENT WITH OBSERVED
TROUGH POSITION AND ASSOCIATED VEERING WIND TO THE NORTH. WILL
ADJUST NORTHERN MARINE LEG FOR LIGHTER OFFSHORE WINDS
INITIALLY...SHIFTING TO NORTH AND INCREASING SLIGHTLY THIS AFTERNOON.
.MLB...NONE.
BORZ/SPRATT
FXUS62 KJAX 101436 fl
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSONVILLE FL
1021 AM EDT FRI SEP 10 1999
09Z RUC SEEMS TO BE CLOSE TO BUT SLOWER THAN CURRENT CONDITIONS SO
FOR THE GEORGIA PORTION OF THE CWA SUGGEST THAT POPS BE DROPPED FOR
THE INLAND ZONES AND A LOW POP CHANCE BE KEPT FOR THE COASTAL ZONES.
THINGS WILL BE CUT CLOSE FOR THE FLORIDA PORTION OF THE CWA BUT
DECIDED TO LOWER POPS SLIGHTLY WITH HIGHER POPS FOR COASTAL AND
SOUTHERN ZONES.
BLS
FXUS62 KJAX 101424 fl
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
403 AM EDT FRI SEP 10 1999
KAPX 88D SHOWING SCATTERED RAIN SHOWERS ACROSS THE TIP OF LOWER MICHIGAN
SPREADING NORTHEAST INTO MACKINAC AND FAR EASTERN CHIPPEWA COUNTIES
ATTM...BEING DRIVEN PRIMARILY BY LAKE INSTABILITY AND ENHANCED BY
NORTHEAST-SOUTHWEST ORIENTED CONVERGENCE AXIS OVER NORTHERN LAKE
MICHIGAN. SUBSIDENCE IN WAKE OF SHORT WAVE WHICH CROSSED LOWER MICHIGAN
LAST EVENING LIKELY STABILIZING THINGS SOMEWHAT ACROSS CENTRAL LOWER...
WITH ETA/RUC MODEL SOUNDINGS SUPPORTING THIS WITH MID LEVEL DRYING AND
SUBSIDENCE INVERSIONS PROGGED THROUGH MID MORNING. RAIN CHANCES THE
MAIN PROBLEM TODAY...ALONG WITH EXTENT OF CLEARING FOR SATURDAY.
WV IMAGERY SHOWING NEXT IN A SERIES OF VORTICITY CENTERS TO ROTATE
THROUGH THE GREAT LAKES LATER TODAY CURRENTY NORTH OF THE MN ARROWHEAD
AS ASSOCIATED SPEED MAX DROPS ACROSS MN/WI. DEEPEST MOISTURE/Q-G
FORCING PROGGED ACROSS THE UPPER PENINSULA TODAY...SO WILL CONTINUE
WITH CATEGORICAL POPS FOR CHIPPEWA/MACKINAC COUNTIES TODAY AND INTO
TONIGHT...WITH LIKELY POPS ALONG/NORTH OF M-32. EVEN WITH SOME
BREAKS IN THE CLOUD COVER AND INSOLATION...SUSPECT THAT MID LEVEL
INVERSION WILL LIKELY CAP INITIAL CONVECTION OVER SOUTHERN PORTION OF
FORECAST AREA UNTIL DESTABILIZING EFFECTS OF APPROACHING SHORT WAVE
ARRIVE LATER TODAY. SO WILL CONFINE RAIN CHANCES TO THIS AFTERNOON FOR
AREAS SOUTH OF M-32.
TONIGHT...UPPER WAVE AND LOW LEVEL RESPONSE SWEEP ACROSS NORTHERN
MICHIGAN...SO RAIN CHANCES CONTINUE. WILL LEAVE POPS OPEN ENDED ACROSS
EASTERN UPPER AND FAR NORTHEAST LOWER WHERE VORTICITY CENTER WILL CROSS
THE AREA...AND WILL HANG ON TO CLOUD COVER ACROSS THE REST AREA THROUGH
THE NIGHT AFTER SOME EVENING SHOWERS. AS FOR EXTENT OF CLEARING
SATURDAY...ETA A LITTLE STRONGER HANGING ONTO CYCLONIC FLOW ACROSS THE
REGION INTO SATURDAY MORNING... PULLING MORE LOW CLOUDS ACROSS ONTARIO
SOUTH INTO THE STATE. NGM/AVN NOT AS AGGRESSIVE WITH THIS IDEA. FOR
NOW...HAVE OPTED TO GO WITH A CLEARING FROM SOUTH-TO-NORTH SCENARIO...
WITH ALL AREAS PARTLY SUNNY AT LEAST BY AFTERNOON ALTHOUGH EXPECT A
FAIR AMOUNT OF CU/SC TO DEVELOP AS LOW LEVEL LAPSE RATES REMAIN STEEP.
OVER LAKE INSTABILITY LED TO A LARGE NUMBER OF WATERSPOUTS THURSDAY...
AND WITH CONDITIONS FAIRLY SIMILAR AT LEAST THIS MORNING...PLAN TO ISSUE
AN SMW IN THE NEARSHORE COVERING POSSIBLE WATERSPOUTS THROUGH THE
MORNING. LOW LEVEL WINDS INCREASING AOA 25 KNOTS OVER THE LAKE THIS
AFTERNOON MAY DIMINISH THE POTENTIAL SOMEWHAT.
COORDINATED WITH GRR/DTX.
.APX...NONE.
JPB
FXUS63 KDTX 100801 mi
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
955 AM EDT FRI SEP 10 1999
WITH CDFNT OVR ERN FINGER LKS AND TROFS IN ADVANCE...ARND SCHOHARIE
VLY...AND BEHIND IT...W OF FINGER LKS...LOOKS LIKE WND DIRECTION
SHOULD SELDOM BE STNRY TDA. RUC H8 THETA-E RDG POSITIONED NR
CYUL-25SW KGFL-KFOK AXIS AT 12Z...RCHG K1V4-40W KGON LN AT 18Z WITH
A SCNDRY THETA-E RDG HANGING BACK ACRS FINGER LKS. LTG DETECTION
SYSTEM HAS TSTMS ACRS SRN CHSPK BAY ATTM AND THAT APPEARS POISED TO
RCH SE DIST LTR TDA. BASED ON RADAR TRENDS...WL NEED TO ISSUE FFS TO
TRIM BACK FFA OUT OF NY...BUT SCT SHWRS WL NEED TO BE MAINTAINED
ACRS WRN DIST THIS AFTN WITH PROXIMITY OF CDFNT AND SCNDRY TROF AND
UPR JET. MCKINLEY/KDL
.ALY...NY ERN...NONE
VT EXTRM SRN...FLOOD WATCH INTO EVNG ZONES 13>14
MA EXTRM WRN...FLOOD WATCH INTO EVNG ZONE 1
CT NW...FLOOD WATCH INTO EVNG ZONE 1
FXUS61 KBGM 101348 ny
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BINGHAMTON NY
940 AM EDT FRI SEP 10 1999
NOT EXACTLY AN EASY FCST THIS AFTN. ALMOST RAZOR SHARP CLRG LN IS
SLOWLY MOVG INTO OUR FAR WRN ZNS ATTM AND SEPARATES MUCH DRIER AIR
UPSTREAM FROM FAIRLY DEEP MOIST AND SHWRS FURTHER E. LATEST TRENDS ON
SAT LOOPS SUGGEST A VERY SLOW EWD PUSH TO THE DRIER AIR THRU THIS AFTN.
THIS IS ALSO SUPPORTED BY THE LATEST RUC OUTPUT...WHICH BRINGS ANOTHER
SFC WV UP THE FRNT DURG THE AFTN HELPING TO RETARD ITS PROGRESS. BASED
ON CURRENT RADAR COVERAGE AND ABV REASONING...WILL EXTEND CHC POPS INTO
THE AFTN FROM OTSEGO CNTY SWD THRU THE WRN CATSK AND POCONOS. GRDL
CLRG IS STILL EVENTUALLY XPCTD IN THESE AREAS...BUT NOT TIL LTR IN THE
DAY.
ACRS WRN SXNS...THINGS AREN/T CLEAR CUT EITHER. ALTHO CLRG SHUD BE
TAKING PLACE OVER THE SHORT TERM...STEEPENING LWR LVL LAPSE RATES AND
SOME LINGERING MOIST UNDER THE INVERSION THIS AFTN CUD WELL MEAN SC
DVLPMT. IN FACT...MODIFIED BUF RAOB WUD INDICATE A SHALLOW...BUT
RELATIVELY "WIDE" AREA OF B+ FROM SFC TO INV BASE ARND 750 MB DURG THE
AFTN THAT CUD LEAD TO SCTD -SHRA FORMATION. FOR NOW...WILL INSERT THE
PSBLTY OF SOME SPRINKLES IN FAR WRN PTNS OF THE FA. STILL FEEL THERE
WILL BE ENUF SUNNY BRKS TO KEEP P/SNY WORDING ACRS THE WRN 2/3 OF THE
RGN DESPITE SC/CU DVLPMT.
MAX TEMPS LOOK OK.
THANKS TO ALY/BUF/PHI FOR THEIR INPUT.
WRK ZNS OUT. FINAL RELEASE BY 10 AM.
.BGM...NONE.
JUREWICZ
FXUS61 KOKX 100731 ny
FORECAST DISCUSSION FOR EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS
920 AM CDT FRI SEP 10 1999
MINOR NEAR TERM UPDATE PLANNED. WEAK WAVE/TROF APPARENT IN CLOUD
FIELD OVR NRN MN. ENHANCED STRATOCU EXTEND INTO SERN MAN. PARTLY
SUNNY FCST OKAY BUT FEW SPRINKLES ALSO EXPECTED. WILL ADJUST FCST
FOR ZONES EAST OF HCO-TVF-PKD LINE. 09Z RUC PICKED UP ON WEAK SFC
TROF AND PRECIP PATTERN. EXPECT CLD LINE TO STEADLY MOVE EASTWARD
UNDER INFLUENCE OF BUILDING RIDGE IN WEST...HOWEVER EXTREME NERN
ZONES WILL STAY UNDER INFLUENCE OF CLD DECK MOST OF DAY.
.FGF...NONE.
GUST
FXUS63 KFGF 100811 nd
AREA FORECAST DISCUSSION FOR CENTRAL/NORTHCENTRAL AND NORTHEAST
SOUTH DAKOTA AND WEST CENTRAL MINNESOTA
NATIONAL WEATHER SERVICE ABERDEEN SD
10 AM CDT FRI SEP 10 1999
THE LATEST RUC SHOWS THE CURRENT FORECAST IS ON TRACK. THEREFORE...NO
UPDATES NEEDED AT THIS TIME.
.ABR...NONE
MOHR
FXUS63 KUNR 100828 sd
COASTAL BEND FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CORPUS CHRISTI TX
320 AM CDT FRI SEP 10 1999
MODEL X-SCTNS SHOW LINGERING 1000-850MB MSTR TDY. HIER ETA PW
PROBABLY MORE REPRESENTATIVE GIVEN WV IMAGES. VERTICAL WND FIELD
RATHER LGT TDY SO CBRZ SHUD BE EVIDENT. AVN(NGM LESSER EXTENT) SHOW
WEAKLY FAVORABLE 1000-850MB DIV Q/Q VECTOR CONVERGENCE ALG COAST BUT
MNLY N/W CWA AT OTHER LVLS. NGM/ETA ALSO SHOW DECENT SFC MSTR
CONVERGENCE ALG CST TDY. SOME 700-300MB DIVERGENCE IS ALSO
INDICATED. NGM ALSO HAS 850MB THETA RIDGE ACROSS CWA TDY.
THESE ABOVE FACTORS COULD SUPPORT LOW POPS BUT GENERAL SYNOPTIC
SUBSIDENCE WILL ENSURE NEGATION. NGM SOUNDINGS SHOW INVERSION AT
800MB TDY WITH WARMING FURTHER ALOFT. OVERALL ETA SOUNDING MORE
FAVORABLE BUT ALSO SHOWS WARMING FURTHER ALOFT. NGM TIME/HGT SCTN
INDICATES SIGNIFICANT DVM AT 18Z WHEN CBRZ WOULD BECOME PROMINENT.
THUS NO POPS.
DIRTY UPR LVL RIDGE TO OUR W WITH EMBEDDED VOTMAX WILL BRING OCNL CI
DEBRIS FROM CONVECTION. THIS IN COMBINATION WITH LINGERING LLVL MSTR
TDY SO PC SKY. WILL OPT FOR MS TOMORROW AS DRIER ATMOS WILL BE IN
PLACE.
COOLER 850MB TEMPS AND LOWER THICKNESSES TDY AND TOMORROW FAVOR AVN
MOS BUT GENERAL SUBSIDENCE AND DRIER AIR ARGUE TACKING ON A DEGREE
OR TWO. MOS GUIDANCE TEMPS AT NIGHT SEEM REASONABLE AND MAY TWEAK
HERE AND THERE.
SFC RH/DWPT DEP/COND PRES DEF FROM LATEST RUC/MESOETA SUGGEST PTCHY
FG THIS MORNING. THESE FIELDS FROM 03Z MESOETA SUGGESTS AREAS OF FG
LATER TNGT/TOMORROW MORNING.
FORESEE NO PROBLEMS FOR THE MARINE WATERS AS WIND/SEAS REMAIN FLAT.
MRF CONTS TO INDICATE A CD FNTL PASSAGE MON NGT WITH COOLER TEMPS
AS PORTRAYED AT 850MB. X-SCTNS SHOW MARGINAL MSTR PRECEDING ITS
PASSAGE FOR SLGHT CHC. CURRENT ADVERTISED EXTENDED SHOWS TRENDS
WELL.
PRELIMINARY NUMBERS:
CRP BA 092/071 091/071 091 -00
VCT BA 095/068 094/068 094 -00
LRD BA 094/073 096/073 096 -00
.CRP...NONE.
(SYN)...85/BB
(MESO)...76/BL
FXUS64 KSJT 100816 tx
INTERIOR CENTRAL CALIFORNIA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
230 PM PDT FRI SEP 10 1999
WEAK UPPER TROF ACROSS NRN AND CENTRAL CA. FLOW ALOFT OVER CENTRAL
CA IS FROM THE SW...WITH LAST 2 RUC RUNS INDICATING A 70KT 250MB JET
OVERHEAD. THOUGH 700MB MOISTURE FIELDS ARE 40-50 PERCENT...STABILITY
INDICIES TOO HIGH FOR CONVECTION TO INITIATE OVER MTNS. SINCE NOT
MUCH HAPPENING TODAY...PREFER THE MORE STABLE ETA MODEL TO THE AVN
THE NEXT 2 DAYS. WILL KEEP IT DRY WITH JUST SOME AFTERNOON CU OVER
MTNS...SUNNY ELSEWHERE.
PROBLEM OF THE DAY IS WHAT TO DO WITH VALLEY TEMPS NEXT 2 DAYS.
CURRENT 24HR CHANGE SHOWING TEMPS DOWN 3-7 DEGS FM YESTERDAY. THOUGH
ONSHORE GRADS ARE WEAK...A DEEP MARINE LAYER EXISTS ALONG THE COAST
AND IS MIXING IN THRU THE DELTA AND COASTAL PASSES. THERMAL LOW IS
INLAND AT THIS TIME...BUT SHIFTS BACK TOWARD THE COAST BY SUN. WILL
KEEP TEMPS UNDER MOS SAT...THEN WARM UP SEVERAL DEGS SUN.
EXTENDED MODELS DONT SHOW A GREAT DEAL OF CHANGE. SURFACE GRADS
REMAIN WEAK WITH LITTLE CHANGE IN HEIGHTS. DRY WX WITH TEMPS NEAR OR
SLIGHTLY ABOVE NORMAL. ALL POPS ZERO. BINGHAM
.HNX...NONE.
FAT UU 060/092 062/094 063 85000
BFL UU 061/092 062/094 063 85000
YNP UU 053/088 054/089 055 85000
FXUS66 KMTR 102120 ca
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
525 PM EDT FRI SEP 10 1999
...UPDATE TO PUT SCT SHWRS NW PART OF CWA THIS EVENING...
LATEST SAT/RADAR LOOPS SHOW AN AREA OF SHWRS HAS DEVELOPED FARTHER
TO THE SE THEN EXPECTED THIS EVENING. LATEST RUC SHOWS SECONDARY
COLD FRONT AND ASSOC SHTWV TROF SWINGING THROUGH THE AREA THIS
EVENING. BY 03Z 700 MOISTURE IS LOST... THAT IS AROUND THE TIME OF
THE BEST 925 TO 850 CAA IS FCST. IT IS CURIOUS TO NOTE THAT THE 18Z
ETA DID FCST SHWRS DEVELOPING FARTHER SOUTH ALONG NW MI COAST THIS
EVENING AS THE COLD AIR MOVES IN. SO... WILL PUT SCT SHWRS OVER NRN
1/2 OF CWA THIS EVENING. BEST ACTIVITY WILL BE CLOSE TO COAST BUT
WIND STRONG ENOUGH THROUGH 850 TO BRING SHOWERS ACROSS CWA NEXT FEW
HOURS ANYWAY. MOST PLACES WILL GET LITTLE MORE THEN A TRACE OF A FEW
HUNDERTHS BEFORE THINGS DRY OUT ENOUGH.
.GRR...NONE.
WDM
FXUS63 KMQT 102023 mi
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
420 PM EDT FRI SEP 10 1999
CONCERNS IN THIS PACKAGE INCLUDE ENDING PRECIP THIS EVENING AND PRECIP
CHANCES ON SUNDAY INTO MONDAY...
19Z SFC ANALYSIS SHOWS LOW PRESSURE IN SOUTH CENT ONTARIO STARTING
TO EDGE TO THE EAST. LAST SFC TROF IN THE PROCESS OF SWINGING THRU
THE U.P. ATTM. MQT 88D AND SFC OBS FIND THIS TROF KICKING OFF SCT
SHRA FROM THE MN ARROWHEAD DOWN THRU NRN LOWER MI.
TONIGHT...18Z RUC 1000-500MB RH AND Q-VECTOR CONVERGENCE FIELDS SHOW
A SHARP LINE OF DEMARCATION PROGGED TO MOVE INTO THE ERN YOOP AND
OUT OF THE CWA BY 03Z. CLOUDS SHOULD BREAK OVERNIGHT AND ALLOW
TEMPS (ESPECIALLY) IN THE WRN CWA TO APPROACH FROST LEVELS...WL
MENTION SCT FROST IN PLACES IN THE WEST.
SATURDAY AND SAT NIGHT...NGM..ETA..AND AVN ALL HAVE SFC HI PRES MOV
OVR SRN LAKE MI BY 18Z SAT. FCST SOUNDINGS FOR THE PERIOD ALL SHOW
DRYING IN THE 1000-700MB LAYER. HOWEVER...CU MACRO HINTS AT FAIR WX
CU DEVELOPING DURING AFTN MAINLY OVER THE NORTHEAST YOOP. AS A
RESULT WL GO WITH MO SUNNY WEST AND PARTLY SUNNY EAST TMRW. TMRW
NGT...MODELED 700-300MB QVECTORS AND 1000-850MB RH INCREASE WITH
WAA OVER CENTRAL WI INTO ERN U.P. BY SUN...SO CLOUDS WL INCREASE
AFTER MIDNIGHT IN ALL ZONES. MIXING 850 TEMPS DRY ADIABATICALLY
YIELDS TEMPS NEAR MOS...60 TO 65...WARMEST IN THE WEST...COMPARED TO
TDY HIGHS OF 55 WL HIGHLIGHT WARMER IN THE WEST. MOS LOW TEMPS
(AROUND 45) SEEM ON TRACK AS WELL.
SUNDAY AND SUN NIGHT...PER COORD WITH APX WL GO WITH THE NGM AND AVN
SOLN FOR DETAILS ON SUN. FELT THAT THE ETA WAS TOO FAR NORTH W/ THE
SFC LOW DEVLOPMENT AND THAT NGM INTO AVN TRANSITION WAS SMOOTHEST.
WAA ASSOCIATED WITH SFC LOW LOCATED OVR W LK SUPERIOR BY 00Z SUN...
BOISTEROUS OMEGA VALUES IN THE ERN U.P. AND Q-VECTOR CONVERGENCE
OVERTAKING THE ENTIRE CWA ON SUN POINT TO A LIKELY EVENT. SOME
POSSIBILITY OF THUNDER IN THE AFTN DUE TO STRONG UPWARD MOTION
ASSOCIATED WITH RIGHT REAR OF 300MB JET STREAK AND THE
AFOREMENTIONED OMEGA VALUES. RAIN CHANCES CONT THRU SUN NIGHT AS
NEXT MAJOR SHRTWV APPROACHES THE AREA FOR ANOTHER LIKELY EVENT ON
MONDAY.
IN THE EXTENDED...MOST MEDIUM RANGE MODELS AGREE ON DIGGING H5 TROF.
ASSOCIATED CLOSED LOW AND SFC CD FNT TO GLIDE OVER NORTH CENTRAL
CONUS AND MOVE INTO SRN HUDSON BAY BY 12Z TUE. EXCEPTION IS THE
CANADIAN MODEL WHICH FOR THE LAST TWO RUNS IS FASTER WITH THE SYSTEM
AS IT ARRIVES AT HUDSON BAY ONE FULL DAY EARLIER. WL GO WITH
MRF..UKMET..AND ECMWF AS THEY FAVOR THE SLOWER EVOLVING SOLN WHICH
WOULD CARRY SHRA THRU MONDAY NIGHT IN THE U.P. RAIN WL LINGER IN THE
ERN CWA THRU MIDDAY TUESDAY AS CD FNT MOVES EAST. OPERATIONAL MRF IN
THE LATEST ENSEMBLE RUN APPEARS TO BULLISH WITH H5 TROF...THEN
MODIFIES PATTERN TOO QUICKLY.
AFTER LOW EXITS TO NE IT APPEARED THAT A FEW DAYS OF QUIET AND COOL
WX WOULD FOLLOW...HOWEVER NEWEST MRF AND ECMWF WANTING TO DIG
ANOTHER H5 TROF RIGHT OVER WRN GRT LAKES BY 12Z THU WHILE STILL
PROGGING SFC HI PRES OVER SAME AREA...SINCE TWO OUT OF THREE MEDIUM
RANGE FCSTS WENT WITH MAIN TROF EXITING REGION BY WED WL KEEP
CURRENT FCST AS IT IS (DRY) AND WAIT TO SEE NEXT MODEL RUNS...WL
PASS THE IDEA TO EVG/MID SHIFTERS.
COORD WITH GRB AND APX
.MQT...NONE.
JLA
FXUS63 KAPX 101959 mi
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
1055 AM EDT FRI SEP 10 1999
...SHRA COVERAGE/TIMING PROBLEM OF THE AFTERNOON...
CHC OF PCPN DURG THE AFTN IS THE MAIN FCST PROBLEM. COVERAGE IS
FAIRLY SPARSE ATTM...BUT BEST DYNAMICS ARE STILL TO COME PER LAST
EVENINGS RUNS AS WELL AS THE 12Z RUC.
14Z SFC ANALYSIS SHOWS RELATIVELY SHARP TROF SWINGING THRU SRN
ONTARIO AND APRCH NWRN LAKE SUPERIOR. THIS TROF IS THE
REFLECTION OF THE LAST VORT MAX ROUNDING THE UPR LVL LOW. MDLS MIGHT
BE JUST A HAIR FAST W/ THIS VORT BUT NOT BY MUCH. THERE WL BE GOOD
PVA AHD OF THIS WAVE AS WELL AS DIFFERENTIAL DIVERGENCE WHICH SWINGS
ACRS THE YOOP DURG THE AFTN. THUS...WL LOOK FOR SOME INCRS IN PCPN
COVERAGE THIS AFTN AND WL KEEP CURRENT TRENDS.
TEMPS GNRLY IN LINE...WENT A LTL COOLER IN THE FAR WEST WHERE
READINGS STILL ONLY ARND 50 AND NERLY STEADY IN THE NE WHERE TEMPS
ARE ALREADY CLOSE TO FCST HIGH BUT ADTNL WARMING NOT XPCTD GIVEN
CLDS AND IMPENDING PCPN.
.MQT...NONE.
DESROSIERS
FXUS63 KDTX 101459 mi
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
910 AM EDT FRI SEP 10 1999
CLOUDLESS SKY ASSOC WITH DRY SFC HIGH BUILDING EASTWARD WILL ALLOW
FULL SUN CONDITIONS THROUGHOUT. 09Z RUC MODEL SHOWS LOW LEVEL THCK
IN LINE WITH CURRENT TEMP FORECAST FOR THIS AFTERNOON...SO NO
ADJUSTMENTS NEEDED. RUC ALSO HAS UPPER TROF AXIS SWINGING THROUGH
AROUND 21Z...BUT WITH ABSOLUTELY NO MOISTURE TO WORK WITH.
VAD WIND PROFILE SHOWS SOME 20 TO 25 KT JUST OFF THE GROUND ABOVE
THE SURFACE INVERSION. WINDS ARE PRESENTLY LIGHT UNDER THE
INVERSION...BUT BREEZY STILL EXPECTED IN THE MOUNTAINS. FOOTHILLS
AND PIEDMONT WINDS MAY NEED TO BE BUMPED UP TO 10 TO 15 CONSIDERING
PRES GRAD BETWEEN COASTAL LOW AND BUILDING HIGH. WILL WATCH THIS UP
TO ISSUANCE SINCE INVERSION SHOULD DISAPPEAR SHORTLY AFTER 10 AM.
.GSP...NONE.
HG
FXUS62 KCHS 100803 sc