Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 10/19/12
AREA FORECAST DISCUSSION
NWS LITTLE ROCK AR
207 PM CDT WED OCT 17 2012
.DISCUSSION...
MAIN CONCERNS THIS FORECAST CYCLE ARE FIRST PERIOD CONVECTION WITH
SEVERE POTENTIAL. ELEVATED WINDS TODAY AND ON THURSDAY. ELEVATED
FIRE CONCERNS ON THURSDAY DUE TO WINDS AND LOWER RH VALUES. A
FIRE DANGER STATEMENT WILL PROBABLY BE ISSUED.
SEVERE STORM POTENTIAL REMAINS IN PLACE FOR LATER THIS AFTERNOON
TO EVENING. KLZK 18Z SOUNDING SHOWS SOME CAPPING IN 5K TO 10K
FT...WHILE WINDS MAINLY UNIDIRECTIONAL FROM THE S TO SW. PRECIP
WATER VALUE WAS 1.09 INCHES...MARGINAL INSTABILITY WITH LI OF
-1.0...WHILE HELICITY OF 362 M2/S2. CAPE WAS 360 J/KG. IF THE CAP
ERODES DUE TO MIXING THE CAPE VALUES WILL GO UP.
CLOUD COVER HAS HELD TEMPS DOWN TODAY WHILE MOISTURE LEVELS HAVE
INCREASED WITH DEW POINT TEMPS IN THE 60S OVER AR...WITH THE BEST
SURGE IN SW AR. CURRENTLY A SURFACE LOW HAD FORMED OVER EASTERN
OK...WITH THE OTHER SURFACE LOW IN THE UPPER PLAINS. A COLD FRONT
WAS SOUTH OVER EASTERN KS TO NEAR MO...WHILE TO EASTERN OK. THE
LOW LEVEL JET OF 30-50 KNOTS WAS STILL HELPING PULL MORE MOISTURE
INTO THE AREA. ALOFT THE UPPER TROUGH WAS DEEPENING INTO THE
SOUTHERN PLAINS WITH THE UPPER LOW OVER THE UPPER MID WEST. STRONG
NW UPPER FLOW WAS NOTED.
OVERALL TIMING OF THE FRONT HAS SLOWED JUST A LITTLE WITH AROUND
20Z NEAR NW AR...THEN MOVING AT A GOOD PASS THROUGH THE STATE...
AROUND 00Z TO 03Z IN CENTRAL SPOTS...AND 06Z TO 10Z EAST AND THEN
OUT OF AR BY 12Z. FROM THIS MORNING THERE IS STILL SOME UNCERTAINTY
IF ALL THE FACTORS WILL COME FOR ANY MORE THAN A SLIGHT CHANCE OF
SEVERE STORMS. STILL EXPECTING A SEVERE THREAT WITH THE BEST
CHANCE FOR A SQUALL LINE OF STORMS. SHORT RANGE MODELS SHOW
THIS...ESPECIALLY IN EAST CENTRAL TO EASTERN AR. DAMAGING WINDS
WITH THIS QUICK MOVING LINE ARE EXPECTED...WITH ISOLATED LARGE
HAIL. ISOLATED STRONG TO SEVERE STORMS AHEAD OF THE LINE WILL
REMAIN A POSSIBILITY BUT IS NOT THE FAVORED SCENARIO. AN ISOLATED
TORNADO THREAT WILL ALSO BE PRESENT DUE TO WIND DYNAMICS...ESPECIALLY
OVER SE AR WHERE SURFACE WINDS MAY BE A BIT MORE SE TO INCREASING
VEERING PROFILE. ALL STORMS ARE EXPECTED TO MOVE QUICKLY DUE TO
THE STRONG MID LEVEL STEERING FLOW FROM THE W TO NW.
&&
.SHORT TERM...TONIGHT THROUGH SATURDAY NIGHT
FIRST PERIOD WILL STAY WITH THE HIGH POPS WITH SEVERE STORM
MENTION AS THE CONVECTION OVER EASTERN OK WITH WORK ITS WAY EAST
WITH THE BOUNDARY. HAVE SEEN A PREFRONTAL TROUGH DEVELOP SOME
CONVECTION AND THEN ADDITIONAL LINE ALONG AND WITH THE COLD FRONT.
WRF AND RR MODELS DEPICT THIS SCENARIO. THE CONVECTION SHOULD MOVE
ACROSS THE STATE FAIRLY QUICKLY WITH THE GOOD MID LEVEL WINDS AND
REACH EASTERN AR AROUND 06Z TO 10Z. QPF WITH THIS SYSTEM IS A BIT
UNCERTAIN DUE TO SPEED AND HOW MUCH MOISTURE WILL BE ADVECTED INTO
THE CONVECTION. WENT WITH HIGHEST FROM A 1/4 TO 3/4 INCH WITH A
FEW ISOLATED HIGHER SPOTS. SOME LOCATIONS WILL SEE ONLY SEE A FEW
TENTHS.
ON THURSDAY...THE SURFACE HIGH PRESSURE WILL BUILD IN BEHIND THE
FRONT AND BRING QUITE A DRY AND COOL AIR MASS. WINDS WILL BE
ELEVATED ESPECIALLY OVER NORTHERN AR TO CENTRAL...AND WITH MINIMUM RH
VALUES DROPPING INTO THE 20S...A FIRE WEATHER DANGER STATEMENT
WILL BE NEED. SOIL MOISTURE LEVELS ARE ABOVE CRITICAL VALUES AT
THIS TIME. DUE TO THE STRONG SURFACE AND UPPER SYSTEM...THE COOLER
AIR MASS WILL HOLD OVER THE AREA THROUGH SATURDAY. ANY CLOUDS ON
THURSDAY OVER NORTHERN AR WILL THIN INTO FRIDAY AND MOSTLY SUNNY
SKIES WILL BE SEEN FRIDAY AND SATURDAY. TEMPS WILL BE AT OR BELOW
THROUGH THE PERIOD THEN A WARMING TREND INTO NEXT WEEK.
&&
.LONG TERM...SUNDAY THROUGH WEDNESDAY...
A SOMEWHAT FLAT RIDGE WILL DEVELOP IN THE UPPER LEVEL FLOW ACROSS
THE REGION DURING THE EXTENDED TERM. A FEW SHORTWAVES WILL LIKELY
RIDE OVER THE RIDGE IN THE SWLY FLOW ALOFT. EXTENDED TERM MODELS ARE
IN DISAGREEMENT OVER THE HANDLING OF A SHORTWAVE DURING THIS TIME
FRAME...WITH THE GFS BEING MUCH WETTER AND GENERATING A WIDE AREA OF
PRECIP ACROSS THE NWRN PART OF THE STATE...WITH A DRIER ECMWF AND A
CANADIAN MODEL THAT IS SOMEWHAT IN BETWEEN.
AT THIS TIME I AM LEANING MORE TOWARD THE ECMWF SOLUTION BUT I AM
PUTTING SOME LOW POPS ACROSS THE NORTHERN/NWRN ZONES ON TUESDAY AND
TUESDAY NIGHT PER THE CANADIAN MODEL.
&&
.PRELIMINARY POINT TEMPS/POPS...
BATESVILLE AR 45 69 43 69 / 80 10 0 0
CAMDEN AR 48 76 46 75 / 60 10 0 0
HARRISON AR 41 65 41 64 / 40 10 0 0
HOT SPRINGS AR 46 73 44 72 / 50 10 0 0
LITTLE ROCK AR 47 73 44 71 / 70 10 0 0
MONTICELLO AR 50 75 47 74 / 70 10 0 0
MOUNT IDA AR 45 71 43 70 / 40 10 0 0
MOUNTAIN HOME AR 41 66 41 65 / 60 10 0 0
NEWPORT AR 45 70 43 69 / 80 10 0 0
PINE BLUFF AR 48 74 45 73 / 70 10 0 0
RUSSELLVILLE AR 44 69 41 69 / 50 10 0 0
SEARCY AR 44 70 42 69 / 80 10 0 0
STUTTGART AR 46 72 43 71 / 80 10 0 0
&&
.LZK WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY UNTIL 8 PM CDT THIS EVENING FOR ARKANSAS-
BAXTER-BOONE-BRADLEY-CALHOUN-CLARK-CLEBURNE-CLEVELAND-CONWAY-
DALLAS-DESHA-DREW-FAULKNER-FULTON-GARLAND-GRANT-HOT SPRING-
INDEPENDENCE-IZARD-JACKSON-JEFFERSON-JOHNSON-LINCOLN-LOGAN-
LONOKE-MARION-MONROE-MONTGOMERY-NEWTON-OUACHITA-PERRY-PIKE-POLK-
POPE-PRAIRIE-PULASKI-SALINE-SCOTT-SEARCY-SHARP-STONE-VAN BUREN-
WHITE-WOODRUFF-YELL.
&&
$$
SHORT TERM...59 / LONG TERM...53
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
1015 AM EDT WED OCT 17 2012
.DISCUSSION...
CURRENT...AXIS OF WELL DEFINED MID LEVEL SHORT WAVE TROUGH LIES FROM
CTRL GA INTO THE NERN GOMEX. FEATURE IS MOVING RAPIDLY EWD...AND HAS
PRODUCED LARGE SHIELD OF MULTILAYERED CLOUDS OUT AHEAD OF IT. VISIBLE
SATELLITE IMAGERY SHOWS SOME SLIGHT THINNING OF THE HIGH CLOUD DECK
FROM ABOUT OSCEOLA/BREVARD COS SOUTH ALTHOUGH UPSTREAM CLOUD TRENDS
INDICATE THAT ANY GLIMPSES OF FILTERED SUNSHINE OVER THE SOUTH WILL
LIKELY BE SHORT-LIVED.
MORNING RAOBS SHOW A PRONOUNCED DRY LATER BETWEEN ABOUT H80-H50...
SO STRATIFORM PRECIP SHIELD HAS SOME WORK TO DO SATURATING THE MID
LEVELS IN ORDER TO GET DOWN TO THE SURFACE. IN ADDITION...EXTENSIVE
NATURE OF MID/HIGH CLOUD CANOPY WILL LIMIT SURFACE HEATING ESPECIALLY
ACROSS THE NORTHERN HALF OF THE CWA...WHICH IN TURN WILL MINIMIZE
POTENTIAL INSTABILITY FOR CONVECTION THERE. RUC ANLYS FIELDS SHOW H25
JET DIVERGENCE OVERHEAD IS MODEST...BUT A LITTLE MORE RESPECTABLE
ACROSS SOUTH FL AND UPSTREAM OVER THE GOMEX. MID LEVEL TEMPS NORTH
AND WEST OF THE CWA ARE FAIRLY COOL...ABOUT -10C (TBW) TO -12C (JAX)
ACCORDING TO THE RAOB DATA...ABOUT -7 (MFL) TO -9C (XMR) FARTHER TO
THE SOUTH AND EAST. OVERALL...IT APPEARS THE POTENTIAL FOR STORMS
WILL BE LIMITED TO THE SOUTHERN CWA...BUT IF ANY DO GET GOING THERE
THEY COULD BECOME STRONG.
MADE SOME MINOR TWEAKS TO POPS...CAPPING THEM AT 50 OVER THE SOUTH
AND LIMITING THUNDER TO ALONG/SOUTH OF A LAKE KISM-KCOF LINE. GIVEN
CURRENT METAR OBS...MAXES IN THE L80S OVER ALL BUT THE SERN CWA
(NEAR 85F) LOOKS FINE.
&&
.AVIATION...CURRENT RAOB MOISTURE PROFILE ARGUES FOR CLOUD LAYERS
AOA 18KFT AND AOB ABOUT 6KFT ATTM. METARS BEAR THIS OUT...ALTHOUGH
WE SHOULD SEE A LITTLE MORE "TOP-DOWN" MOISTENING THROUGHOUT THE DAY.
12Z TAFS REMOVED VCTS AND TEMPO TS GROUPS GIVEN LOWER TS PROBS...
HOWEVER WILL KEEP A CLOSE EYE ON THE MLB-SUA CORRIDOR GIVEN THAT
THE THINNING HIGH CLOUD DECK SEEN ON VIS IMAGERY IS ALLOWING FOR A
LITTLE MORE SURFACE HEATING ATTM.
&&
.MARINE...LOCAL BUOY OBSERVATIONS INDICATE THAT A MODERATE SWELL
CONTINUES TO PRODUCE COMBINED SEAS 4-5FT NEAR SHORE AND ABOUT 7FT
WELL OFFSHORE...WHICH IS RIGHT ON TOP OF THE ONGOING FORECAST. NO
CHANGES NEEDED TO THE CWF...WITH A CAUTIONARY STATEMENT FOR SEAS
REMAINING IN PLACE AREAWIDE. HWO/G-HWO CONTINUES TO HIGHLIGHT HIGH
THREAT FOR DANGEROUS RIP CURRENTS...GIVEN THE LONG PERIOD (12-14SEC)
SWELLS ARE PILING UP WATER BEHIND THE SAND BAR.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM/AVIATION...CRISTALDI
LONG TERM/IMPACT WX....VOLKMER
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
329 AM EDT WED OCT 17 2012
.DISCUSSION...
TODAY-TONIGHT...A WEAK HI PRES RIDGE OVER THE DEEP SOUTH AND THE FL
PENINSULA WILL DISSOLVE AS IT MOVES OFF THE ATLC COAST TODAY. A MUCH
DRIER AIRMASS ASSOCD WITH THE RIDGE WILL MODIFY RAPIDLY AS A STRONG
ZONAL FLOW PATTERN OVER THE GOMEX/SRN CONUS PULLS A MID LVL IMPULSE
ACRS FL. EVEN SO...PWAT VALUES ARE QUITE LOW OVER THE N HALF OF
FL...RANGING FROM 0.4" AT KJAX/KTAE TO 1.0" AT KTBW. MOISTURE IS A
BIT HIGHER OVER S FL WITH KMFL MEASURING 1.5" PWAT ON THEIR 17/00Z
SOUNDING... MAINLY IN THE H100-H70 LYR.
MOISTURE ASSOCD WITH THE LEADING EDGE OF THE IMPULSE IS LARGELY
MID/UPR LVL DEBRIS CLOUDS THAT WILL MODIFY THE DRY AIR FROM THE TOP
DOWN. THIS WILL LIMIT SFC HEATING AND LOW LVL DESTABILIZATION OVER
MUCH OF CENTRAL FL TODAY. INDEED...LATEST SAT OBS SHOW SUBSTANTIAL
DEBRIS CLOUDS ALREADY PUSHING ACRS THE PANHANDLE AND MOST OF THE
CENTRAL/NRN PENINSULA...BUT RADAR OBS SHOW LITTLE IF ANY RAINFALL.
DESPITE SOME FAVORABLE DYNAMIC LIFTING MECHANISMS...STRONG/SVR WX
POTENTIAL WILL BE QUITE LOW TODAY. LATEST RAP ANALYSIS SHOWS
RESPECTABLE MID LVL LAPSE RATES BTWN 5.5-6.5C/KM...BUT RIDING AHEAD
OF THE DEEPER MOISTURE. A MID LVL THERMAL TROF OVER THE FL
PANHANDLE/NE GOMEX WILL BRIEFLY DROP H50 TEMPS TO BTWN -10C AND -12C
ALONG AND N OF THE I-4 CORRIDOR THIS MORNING...BUT WILL LIFT OUT BY
MIDDAY BEFORE THE AIRMASS CAN FULLY MODIFY. STRONG UPR LVL
DIVERGENCE AND RESPECTABLE MID LVL VORTICITY WILL BE PRESENT AS A
90KT H30-H20 JET STREAK RACES ACRS THE NRN GOMEX. HOWEVER...THESE
WILL BE HAMPERED BY WEAK SFC/LOW LVL INSTABILITY DUE TO THE INCOMING
DEBRIS CLOUDS.
BEST RAINFALL CHANCES WILL BE OVER THE SRN CWA WHERE LOW LVL
MOISTURE IS THE HIGHEST AND MID/UPR LVL DEBRIS CLOUDS ARE THINNEST.
WILL GO WITH 60 POPS AROUND THE LAKE OKEECHOBEE REGION...DECREASING
TO 30 POPS OVER VOLUSIA AND NRN LAKE COUNTY TODAY. SUFFICIENT
MOISTURE WILL REMAIN IN PLACE AFT SUNSET TO KEEP 20-40 POPS IN THE
FCST FOR THE FIRST HALF OF THE OVERNIGHT PD...AGAIN BEST CHANCES
WILL BE OVER THE SRN CWA DUE TO THE MOISTURE PROFILE. CLOUDS/RAIN
WILL KEEP MAX TEMPS IN THE U70S/L80S. LINGERING CLOUDS AND LIGHT
SRLY FLOW OVERNIGHT WILL KEEP MIN TEMPS IN THE M/U60S OVER MOST OF
ECFL...L70S ALONG THE IMMEDIATE COAST S OF SEBASTIAN INLET.
THU-SAT...WEATHER FOR MUCH OF THE EASTERN HALF OF THE NATION WILL BE
INFLUENCED BY A LARGE VORTEX AT MID/UPPER LEVELS AS IT TREKS FROM
MIDWEST ACROSS THE GREAT LAKES DURING THE LATE WEEK. EC FL WILL BE
LOCATED IN RELATIVELY WARM SWLY FLOW THURS AND FRI BEFORE A WEAK
COLD FRONT PASSES ON SATURDAY. MOISTURE WILL BE FAIRLY LIMITED IN
THIS TIMEFRAME. LOW POPS MAINLY CONFINED TO SOUTHERN SECTIONS ON
THURSDAY. A LOW POP MENTIONED FOR ALL AREAS ON FRI WITH A SLIGHT
UPTICK IN MOISTURE. WITH FRONT MOVING THROUGH ON SATURDAY LOW
MENTIONABLE POPS WILL BE MAINLY CONFINED TO AREAS NEAR AND SOUTH OF
THE FRONTAL BOUNDARY. HIGH TEMPS MID/UPPER 80S INLAND AND LOW/MID
80S COAST. OVERNIGHT LOWS MID/UPPER 60S EXCEPT NEAR 70/LOWER 70S
ALONG THE COAST SOUTH OF THE CAPE.
SUN-WED...SURFACE HIGH PRESSURE TO THE NORTH BUILDING ALONG THE
EASTERN SEABOARD AND RIDGE ALOFT BUILDING ACROSS THE STATE FROM THE
GULF OF MEXICO. THIS WILL BRING ONSHORE FLOW REGIME TO EC FL WITH
SLOW INCREASE IN MOISTURE AND TEMPS MODERATED BY THE ONSHORE FLOW.
WILL KEEP POPS BELOW MENTIONABLE VALUES FOR NOW...BUT SOME LOW POPS
FOR COASTAL SHOWERS MAY BECOME WARRANTED.
&&
.AVIATION...THRU 17/17Z...VFR ALL SITES...CIGS AOA FL120. BTWN
17/17-17/23Z... NMRS MVFR SHRAS/SCT IFR TSRAS S OF KVRB-KBOW...SCT
MVFR SHRAS/ISOLD IFR TSRAS N OF KVRB-KBOW...PREVAILING CIGS BTWN
FL080-100. AFT 17/23Z...CHC MVFR SHRAS S OF KOMN-KISM...SLGT CHC
MVFR SHRAS N OF KOMN-KISM...PREVAILING CIGS BTWN FL100-120.
&&
.MARINE...TODAY-TONIGHT...A WEAK HI PRES RIDGE OVER THE DEEP S AND
MID ATLC COAST WILL WEAKEN AS IT PUSHES INTO THE W ATLC. GENTLE TO
MODERATE E/NE BREEZE TODAY WILL VEER TO THE S OVERNIGHT AS A NEW
FRONTAL TROF PUSHES THE LWR MS VALLEY AND INTO THE DEEP SOUTH. LONG
PD SWELL FROM T.C. RAFAEL WILL IMPACT THE LCL ATLC AND MAINTAIN SEAS
BTWN 4-6FT HIGHER THAN WHAT THE CURRENT SFC/BNDRY LYR WINDS WOULD
SUPPORT.
BUOY010 MEASURING 8-9FT SEAS...BUOY MEASURING 6-7FT SEAS...BOTH
WITH DOMINANT PDS BTWN 12-14SEC. HOWEVER...PGRAD IS EXPECTED TO
SLACKEN AS THE RIDGE WEAKENS...RESULTING IN SFC/BNDRY LYR WINDS AOB
10KTS. THIS TREND IS ALREADY PLAYING OUT AT BUOY012 WHERE SFC WNDS
HAVE DIMINISHED FROM ARND 15KTS LAST NIGHT TO ARND 10KTS EARLY THIS
MRNG. WILL HOLD OFF ON AN ADVISORY BUT WILL GO WITH A CAUTIONARY
STATEMENT AREAWIDE TO ACCOUNT FOR THE SWELL.
THU-MON...LINGERING SWELLS FROM RAFAEL WILL DECREASE LATE WEEK INTO
THIS WEEKEND. WINDS RELATIVELY LIGHT THU-FRI WITH HIGH PRESSURE IN
CLOSE PROXIMITY. WINDS WILL PICK UP OUT OF THE NNE-NE SAT AS FRONT
MOVES DOWN THE WATERS. ONSHORE FLOW REGIME DEVELOPING BEHIND THE
FRONT SUNDAY INTO EARLY PART OF NEXT WEEK WITH HIGH PRESSURE TO THE
NORTH BUILDING ALONG THE EASTERN SEABOARD.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 79 66 85 67 / 30 30 10 10
MCO 81 65 86 67 / 40 20 10 10
MLB 79 69 84 70 / 50 30 10 10
VRB 81 70 86 69 / 50 30 10 10
LEE 80 64 86 66 / 30 20 10 10
SFB 80 65 86 67 / 40 20 10 10
ORL 81 66 86 67 / 40 20 10 10
FPR 81 71 85 69 / 60 40 20 10
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM/AVIATION...BRAGAW
LONG TERM....GLITTO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1014 PM CDT THU OCT 18 2012
.DISCUSSION...
925 PM CDT
A MASSIVE STACKED LOW PRESSURE CONTINUES TO PIVOT ACROSS THE UPPER
MIDWEST AND WESTERN GREAT LAKES TONIGHT. TO EXPRESS HOW
IMPRESSIVELY DEEP THIS LOW IS...THIS SYSTEM HAS DIPPED THE
TROPOPAUSE DOWN TO NEAR 400 MB ON AREA RAOBS...WITH 250 MB
TEMPERATURES 13C DEGREES WARMER IN THE CENTER OF THE CIRCULATION
/DUE TO STRATOSPHERIC FOLDING/. MULTIPLE MID AND LOW-LEVEL
CIRCULATIONS CONTINUE TO TWIRL AROUND EACH OTHER. SEVERAL SUCH
MID-LEVEL IMPULSES ARE IN A WRAPAROUND TONGUE OF MOISTURE AND
GRADUAL ASCENT OVER THE AREA THIS EVE. THIS IS FORECAST TO
CONTINUE ON RAP ISENTROPIC FIELDS INTO OVERNIGHT AND GRADUALLY
SHIFT EAST AS THE LOW CENTER EXPANDS INTO THE NORTHWEST FORECAST
AREA. GENERAL DRIZZLE WITH NUMEROUS TO WIDESPREAD SHOWERS HAVE BEEN
THE PREVAILING RAIN MODE. EARLIER PRIOR TO SUNSET THERE WERE A
FEW 40 DBZ ECHOES NEAR THE FREEZING LEVEL...AND A FEW PUBLIC
REPORTS OF GRAUPEL WERE REPORTED IN ROCKFORD. FOR THE REMAINDER OF
TONIGHT THE PRECIP TYPE SHOULD BE DRIZZLE AND LIGHT TO MODERATE
SHOWERS. ON FRIDAY THE POTENTIAL FOR GRAUPEL WILL AGAIN RE-
INCREASE. IN ADDITION...WITH THE LOW CENTER AND A DIMINISHING WIND
FIELD APPROACHING LAKE MICHIGAN...ANY POTENTIAL CONVERGENCE AREA
WILL LIKELY SERVE AS FOCI FOR WATERSPOUTS...INCLUDING NEAR THE
SHORES.
AS FOR TEMPERATURES...THEY SHOULD REMAIN NEARLY STEADY...DROPPING
ONLY ABOUT 2-4 DEGREES THE REMAINDER OF TONIGHT. SOME LIGHT FOG IS
POSSIBLE TOWARDS THE ROCKFORD AREA AS THE WINDS BECOME LIGHT LATE.
MTF
//PREV DISCUSSION...
341 PM CDT
MAIN FORECAST CONCERNS CONTINUE WITH SHOWERS/POSSIBLE THUNDER THIS
AFTERNOON...AND SHOWERS TO PERSIST THROUGH FRIDAY.
LATEST WATER VAPOR IMAGERY SHOWING LARGE CLOSED UPPER LEVEL SYSTEM
OVER THE MIDWEST THIS AFTERNOON...WITH SEVERAL STRONG MID LEVEL
FEATURES WRAPPING AROUND THIS SYSTEM. THIS FORCING IN THE PRESENCE
OF STEEP LAPSE RATES...PER AMDAR SOUNDINGS AND RAP ANALYSIS...HAS
ALLOWED SHOWERS TO BLOSSOM ACROSS NORTHERN ILLINOIS. ISOLATED
CONVECTIVE ELEMENTS HAVE ALSO BEGUN TO DEVELOP OUT AHEAD OF THIS
MAIN PRECIP SHIELD ACROSS NORTHEAST ILLINOIS AND NORTHWEST INDIANA
WHERE STEEPER LAPSE RATES CURRENTLY RESIDE. EXPECT THESE
CONVECTIVE ELEMENTS TO BE THE MORE NORM THROUGH THE REMAINDER OF
THE AFTERNOON AS MAIN PRECIP SHIELD CONTINUES TO SHIFT ACROSS THE
AREA. ITS IN THESE CONVECTIVE ELEMENTS THAT HEAVIER SHOWERS AND
LOWER VIS COULD OCCUR...AND ALSO WHERE THE POSSIBILITY OF
THUNDER/SMALL HAIL STILL MAY OCCUR.
UPPER LEVEL LOW WILL CONTINUE TO SLOWLY MEANDER TO THE EAST
OVERNIGHT...WITH PRECIP EXPECTED TO PERSIST FOR MUCH OF THE CWA
TONIGHT. ALTHOUGH WITH MID LEVEL FEATURES/FORCING SHIFTING
EASTWARD TONIGHT...MAIN AXIS OF PRECIP SHOULD ALSO SHIFT.
NEVERTHELESS...EXPECT AT LEAST LIGHT SHOWERS OR DRIZZLE TO
CONTINUE OVERNIGHT ACROSS THE ENTIRE CWA WITH TEMPS SLOWLY
LOWERING TO AROUND 40 ACROSS NORTHERN ILLINOIS AND THE LOWER 40S
FOR THE REMAINDER OF THE CWA...AS EXPANSIVE CLOUD SHIELD REMAINS
OVERHEAD. UPPER LEVEL LOW CENTER AND COLDEST TEMPS WILL BE
OVERHEAD ON FRIDAY...WITH A SIMILAR SETUP EXPECTED ONCE AGAIN.
SHOWERS WILL BE POSSIBLE ALONG WITH A SLIGHT CHANCE FOR
THUNDERSTORMS/SMALL HAIL ONCE AGAIN IN THE AFTERNOON...WHEN LAPSE
RATES ARE ONCE AGAIN EXPECTED TO BE THE STEEPEST. TEMPS WILL
STRUGGLE TO CLIMB MUCH AS THIS CLOUD SHIELD WILL REMAIN
OVERHEAD...WITH TEMPS IN THE UPPER 40S TO AROUND 50 EXPECTED.
GUIDANCE IN FAIR AGREEMENT WITH TAKING THIS UPPER LEVEL LOW EAST
OF THE AREA BY FRIDAY NIGHT AND EARLY SATURDAY MORNING. SO
CONTINUED TREND OF LOWERING POPS THROUGH FRIDAY NIGHT BUT WITH
THESE SYSTEMS GENERALLY MOVING SLOWER THAN MODEL GUIDANCE...WASNT
TOO AGGRESSIVE WITH LOWERING THE POPS AS STRAY SHOWERS MAY
LINGERING WITH CYCLONIC FLOW STILL IN PLACE.
AS UPPER LEVEL SYSTEM CONTINUES TO DRIFT EAST ON SATURDAY...HEIGHT
RISES ON THE BACKSIDE OF THIS SYSTEM WILL SET THE STAGE FOR A
PERIOD OF UPPER LEVEL RIDGING. WHAT THIS WILL MEAN FOR THE
REMAINDER OF THE WEEKEND WILL BE CLEARING SKIES AND QUIET WEATHER
WITH AN INCREASE IN TEMPS. EXPECT WINDS TO FLOP BACK TO THE
SOUTH/SOUTHWEST LATE SATURDAY WITH WAA USHERING IN SOME WARMTH
ACROSS THE REGION. THIS WAA AND SUNNY SKIES WILL HELP TEMPS RISE
WITH FORECAST HIGHS EXPECTED TO BE IN THE UPPER 60S TO LOW 70S ON
SUNDAY. THIS WARMTH WILL CONTINUE ON MONDAY WITH A SLIGHT INCREASE
IN TEMPS...AS THEY RISE TO THE LOW TO MID 70S. ALTHOUGH WITH THE
RIDGE AXIS OVERHEAD...THIS WILL BRING A SETUP FOR STEERING FLOW TO
BRING ABOUT SOME MID LEVEL ENERGY AND ACTIVE WEATHER FOR NEXT
WEEK.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 03Z...
* PERIODS OF -SHRA.
* TIMING OF 1500 FT MVFR CIGS THIS EVENING.
* POTENTIAL FOR IFR CIGS OVERNIGHT INTO FRIDAY MORNING.
KJB
//DISCUSSION...UPDATED 00Z...
THE MAIN FORECAST CONCERNS WILL BE CIGS AND PERIODS OF SHOWERS
THROUGH THE PERIOD.
A POTENT AUTUMN SEASON STORM SYSTEM WILL CONTINUE TO IMPACT THE
REGION THROUGH THE PERIOD AS IT SLOWLY PUSHES ACROSS THE GREAT LAKES
REGION. WINDS CONTINUE TO BE GUSTY OUT OF THE SOUTH EARLY THIS
EVENING AND THESE WINDS SHOULD ABATE LATER TONIGHT AS THE SURFACE
LOW MOVES ACROSS THE AREA.
THE MAIN CONCERNS WILL BE TIMING THE LOWER CIGS...AS IT APPEARS WE
WILL SEE A DOWNWARD TREND THROUGH THE EVENING. LOWER END MVFR CIGS
AROUND 1,200 TO 1,500 FT AGL LOOK TO DEVELOP SOMETIME AFTER 02 UTC
AT THE NORTHEASTERN ILLINOIS TERMINALS AND THEN POTENTIALLY DROP
DOWN AROUND OR JUST BELOW 1,000 FT FOR A PERIOD LATER TONIGHT. A
SLOW IMPROVEMENT IN IS EXPECTED DURING THE MORNING ON FRIDAY AS CIGS
SHOULD RISE ABOVE 2,000 FT BY EARLY AFTERNOON.
SCATTERED LIGHT SHOWERS ARE ALSO EXPECTED...ESPECIALLY TONIGHT.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 03Z...
* MEDIUM TO HIGH CONFIDENCE IN CIGS LOWERING TO AROUND 1500 FT
OVER THE NEXT COUPLE OF HOURS.
* LOW-MEDIUM CONFIDENCE IN CIGS LOWERING TO IFR LATER TONIGHT.
KJB
//OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z...
* SATURDAY AND SUNDAY...VFR. WX NIL.
* MONDAY THROUGH WEDNESDAY...CHANCE OF TSRA/SHRA.
KJB
&&
.MARINE...
253 PM CDT
A LARGE UPPER LEVEL LOW WILL CONTINUE TO SPIN OVER OVER SOUTHERN
WISCONSIN AND SOUTHERN LAKE MICHIGAN TONIGHT AND FRIDAY BEFORE
GRADUALLY SHIFTING OFF TO THE EAST INTO SATURDAY. ONE AREA OF LOW
PRESSURE CONTINUES TO SPIN OVER THE ARROWHEAD OF MINNESOTA WITH A
SECONDARY CIRCULATION OVER WEST CENTRAL WISCONSIN. THE TWO LOWS WILL
MERGE AND WEAKEN TONIGHT AND THEN MOVE EASTWARD ACROSS SOUTHERN LAKE
MICHIGAN FRIDAY AND FRIDAY NIGHT. IN THE MEANTIME...THE PRESSURE
GRADIENT REMAINS STRONG LEADING TO 30 KT SOUTH TO SOUTHWEST WINDS
ACROSS THE LAKE...WITH SOME 35 KT GALES OCCURRING AT TIMES LATE THIS
AFTERNOON AND POSSIBLY EARLY THIS EVENING. SPEEDS LOOK TO REMAIN
STEADY THROUGH THE EVENING BUT THEN BEGIN TO SLOWLY DIMINISH AS THE
LOW BROADENS AND WEAKENS RESULTING IN A WEAKER PRESSURE GRADIENT.
THE DOWNWARD TREND SHOULD CONTINUE FRIDAY WITH WIND DIRECTION
BECOMING MORE COMPLEX AS THE LOW CROSSES THE SOUTHERN PART OF THE
LAKE. SOUTHWEST WINDS WILL OCCUR TO THE SOUTH OF THE LOW WHILE WINDS
TURN SOUTHEAST...THEN EAST...THEN NORTHEAST NORTH OF THE LOW ACROSS
THE NORTHERN HALF TO TWO-THIRDS OF THE LAKE FRIDAY. ONCE THE LOW
SHIFTS EAST FRIDAY EVENING NORTH TO NORTHWEST WINDS WILL TAKE OVER
WITH SOME MODEST INCREASE IN SPEEDS LIKELY AS THE PRESSURE GRADIENT
RECOVERS BUT THE LOW ITSELF WILL REMAIN IN A WEAKENED STATE. IN
ADDITION...WITH THE UPPER LOW PRESENT AND COLDER AIR ACROSS THE
LAKE...THERE WILL BE A GOOD CHANCE FOR WATERSPOUTS THROUGH
FRIDAY...WITH A FEW THUNDERSTORMS POSSIBLE AS WELL.
THE NORTHWEST WINDS WILL CONTINUE INTO INTO SATURDAY BEFORE TURNING
WESTERLY THEN SOUTHWESTERLY SATURDAY EVENING AS A RIDGE OF HIGH
PRESSURE BUILDS FROM SOUTHERN LAKE MICHIGAN INTO WESTERN WISCONSIN.
THE RIDGE SHIFTS EAST MONDAY ALLOWING WINDS TO TURN SOUTHEASTERLY AS
LOW PRESSURE SPREADS ACROSS THE CENTRAL AND NORTHERN PLAINS FOR THE
MIDDLE PART OF THE WEEK. SOUTH TO SOUTHEAST WINDS WILL LIKELY
INCREASE AS THE PRESSURE GRADIENT STRENGTHENS AS THE LOW TRACKS
NORTHEAST ACROSS THE UPPER MISSISSIPPI RIVER VALLEY AND LAKE
SUPERIOR. BEYOND THAT A FRONTAL BOUNDARY SHOULD CROSS THE LAKE AND
BRING A RETURN TO NORTHERLY WINDS FOR LATE WEEK.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 5 AM FRIDAY.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS CHICAGO/ROMEOVILLE IL
926 PM CDT THU OCT 18 2012
.DISCUSSION...
925 PM CDT
A MASSIVE STACKED LOW PRESSURE CONTINUES TO PIVOT ACROSS THE UPPER
MIDWEST AND WESTERN GREAT LAKES TONIGHT. TO EXPRESS HOW
IMPRESSIVELY DEEP THIS LOW IS...THIS SYSTEM HAS DIPPED THE
TROPOPAUSE DOWN TO NEAR 400 MB ON AREA RAOBS...WITH 250 MB
TEMPERATURES 13C DEGREES WARMER IN THE CENTER OF THE CIRCULATION
/DUE TO STRATOSPHERIC FOLDING/. MULTIPLE MID AND LOW-LEVEL
CIRCULATIONS CONTINUE TO TWIRL AROUND EACH OTHER. SEVERAL SUCH
MID-LEVEL IMPULSES ARE IN A WRAPAROUND TONGUE OF MOISTURE AND
GRADUAL ASCENT OVER THE AREA THIS EVE. THIS IS FORECAST TO
CONTINUE ON RAP ISENTROPIC FIELDS INTO OVERNIGHT AND GRADUALLY
SHIFT EAST AS THE LOW CENTER EXPANDS INTO THE NORTHWEST FORECAST
AREA. GENERAL DRIZZLE WITH NUMEROUS TO WIDESPREAD SHOWERS HAVE BEEN
THE PREVAILING RAIN MODE. EARLIER PRIOR TO SUNSET THERE WERE A
FEW 40 DBZ ECHOES NEAR THE FREEZING LEVEL...AND A FEW PUBLIC
REPORTS OF GRAUPEL WERE REPORTED IN ROCKFORD. FOR THE REMAINDER OF
TONIGHT THE PRECIP TYPE SHOULD BE DRIZZLE AND LIGHT TO MODERATE
SHOWERS. ON FRIDAY THE POTENTIAL FOR GRAUPEL WILL AGAIN RE-
INCREASE. IN ADDITION...WITH THE LOW CENTER AND A DIMINISHING WIND
FIELD APPROACHING LAKE MICHIGAN...ANY POTENTIAL CONVERGENCE AREA
WILL LIKELY SERVE AS FOCI FOR WATERSPOUTS...INCLUDING NEAR THE
SHORES.
AS FOR TEMPERATURES...THEY SHOULD REMAIN NEARLY STEADY...DROPPING
ONLY ABOUT 2-4 DEGREES THE REMAINDER OF TONIGHT. SOME LIGHT FOG IS
POSSIBLE TOWARDS THE ROCKFORD AREA AS THE WINDS BECOME LIGHT LATE.
MTF
&&
.PREV DISCUSSION...
341 PM CDT
MAIN FORECAST CONCERNS CONTINUE WITH SHOWERS/POSSIBLE THUNDER THIS
AFTERNOON...AND SHOWERS TO PERSIST THROUGH FRIDAY.
LATEST WATER VAPOR IMAGERY SHOWING LARGE CLOSED UPPER LEVEL SYSTEM
OVER THE MIDWEST THIS AFTERNOON...WITH SEVERAL STRONG MID LEVEL
FEATURES WRAPPING AROUND THIS SYSTEM. THIS FORCING IN THE PRESENCE
OF STEEP LAPSE RATES...PER AMDAR SOUNDINGS AND RAP ANALYSIS...HAS
ALLOWED SHOWERS TO BLOSSOM ACROSS NORTHERN ILLINOIS. ISOLATED
CONVECTIVE ELEMENTS HAVE ALSO BEGUN TO DEVELOP OUT AHEAD OF THIS
MAIN PRECIP SHIELD ACROSS NORTHEAST ILLINOIS AND NORTHWEST INDIANA
WHERE STEEPER LAPSE RATES CURRENTLY RESIDE. EXPECT THESE
CONVECTIVE ELEMENTS TO BE THE MORE NORM THROUGH THE REMAINDER OF
THE AFTERNOON AS MAIN PRECIP SHIELD CONTINUES TO SHIFT ACROSS THE
AREA. ITS IN THESE CONVECTIVE ELEMENTS THAT HEAVIER SHOWERS AND
LOWER VIS COULD OCCUR...AND ALSO WHERE THE POSSIBILITY OF
THUNDER/SMALL HAIL STILL MAY OCCUR.
UPPER LEVEL LOW WILL CONTINUE TO SLOWLY MEANDER TO THE EAST
OVERNIGHT...WITH PRECIP EXPECTED TO PERSIST FOR MUCH OF THE CWA
TONIGHT. ALTHOUGH WITH MID LEVEL FEATURES/FORCING SHIFTING
EASTWARD TONIGHT...MAIN AXIS OF PRECIP SHOULD ALSO SHIFT.
NEVERTHELESS...EXPECT AT LEAST LIGHT SHOWERS OR DRIZZLE TO
CONTINUE OVERNIGHT ACROSS THE ENTIRE CWA WITH TEMPS SLOWLY
LOWERING TO AROUND 40 ACROSS NORTHERN ILLINOIS AND THE LOWER 40S
FOR THE REMAINDER OF THE CWA...AS EXPANSIVE CLOUD SHIELD REMAINS
OVERHEAD. UPPER LEVEL LOW CENTER AND COLDEST TEMPS WILL BE
OVERHEAD ON FRIDAY...WITH A SIMILAR SETUP EXPECTED ONCE AGAIN.
SHOWERS WILL BE POSSIBLE ALONG WITH A SLIGHT CHANCE FOR
THUNDERSTORMS/SMALL HAIL ONCE AGAIN IN THE AFTERNOON...WHEN LAPSE
RATES ARE ONCE AGAIN EXPECTED TO BE THE STEEPEST. TEMPS WILL
STRUGGLE TO CLIMB MUCH AS THIS CLOUD SHIELD WILL REMAIN
OVERHEAD...WITH TEMPS IN THE UPPER 40S TO AROUND 50 EXPECTED.
GUIDANCE IN FAIR AGREEMENT WITH TAKING THIS UPPER LEVEL LOW EAST
OF THE AREA BY FRIDAY NIGHT AND EARLY SATURDAY MORNING. SO
CONTINUED TREND OF LOWERING POPS THROUGH FRIDAY NIGHT BUT WITH
THESE SYSTEMS GENERALLY MOVING SLOWER THAN MODEL GUIDANCE...WASNT
TOO AGGRESSIVE WITH LOWERING THE POPS AS STRAY SHOWERS MAY
LINGERING WITH CYCLONIC FLOW STILL IN PLACE.
AS UPPER LEVEL SYSTEM CONTINUES TO DRIFT EAST ON SATURDAY...HEIGHT
RISES ON THE BACKSIDE OF THIS SYSTEM WILL SET THE STAGE FOR A
PERIOD OF UPPER LEVEL RIDGING. WHAT THIS WILL MEAN FOR THE
REMAINDER OF THE WEEKEND WILL BE CLEARING SKIES AND QUIET WEATHER
WITH AN INCREASE IN TEMPS. EXPECT WINDS TO FLOP BACK TO THE
SOUTH/SOUTHWEST LATE SATURDAY WITH WAA USHERING IN SOME WARMTH
ACROSS THE REGION. THIS WAA AND SUNNY SKIES WILL HELP TEMPS RISE
WITH FORECAST HIGHS EXPECTED TO BE IN THE UPPER 60S TO LOW 70S ON
SUNDAY. THIS WARMTH WILL CONTINUE ON MONDAY WITH A SLIGHT INCREASE
IN TEMPS...AS THEY RISE TO THE LOW TO MID 70S. ALTHOUGH WITH THE
RIDGE AXIS OVERHEAD...THIS WILL BRING A SETUP FOR STEERING FLOW TO
BRING ABOUT SOME MID LEVEL ENERGY AND ACTIVE WEATHER FOR NEXT
WEEK.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* GUSTY SOUTH WINDS THROUGH EARLY THIS EVENING.
* PERIODS OF SHRA.
* TIMING OF 1500 FT MVFR CIGS THIS EVENING.
* POTENTIAL FOR IFR CIGS OVERNIGHT INTO FRIDAY MORNING.
KJB
//DISCUSSION...UPDATED 00Z...
THE MAIN FORECAST CONCERNS WILL BE CIGS AND PERIODS OF SHOWERS
THROUGH THE PERIOD.
A POTENT AUTUMN SEASON STORM SYSTEM WILL CONTINUE TO IMPACT THE
REGION THROUGH THE PERIOD AS IT SLOWLY PUSHES ACROSS THE GREAT LAKES
REGION. WINDS CONTINUE TO BE GUSTY OUT OF THE SOUTH EARLY THIS
EVENING AND THESE WINDS SHOULD ABATE LATER TONIGHT AS THE SURFACE
LOW MOVES ACROSS THE AREA.
THE MAIN CONCERNS WILL BE TIMING THE LOWER CIGS...AS IT APPEARS WE
WILL SEE A DOWNWARD TREND THROUGH THE EVENING. LOWER END MVFR CIGS
AROUND 1,200 TO 1,500 FT AGL LOOK TO DEVELOP SOMETIME AFTER 02 UTC
AT THE NORTHEASTERN ILLINOIS TERMINALS AND THEN POTENTIALLY DROP
DOWN AROUND OR JUST BELOW 1,000 FT FOR A PERIOD LATER TONIGHT. A
SLOW IMPROVEMENT IN IS EXPECTED DURING THE MORNING ON FRIDAY AS CIGS
SHOULD RISE ABOVE 2,000 FT BY EARLY AFTERNOON.
SCATTERED LIGHT SHOWERS ARE ALSO EXPECTED...ESPECIALLY TONIGHT.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* MEDIUM-HIGH CONFIDENCE IN WIND DIRECTION AND WIND GUST TRENDS.
* MEDIUM CONFIDENCE IN CIGS LOWERING TO AROUND 1500 FT THIS
EVENING WITH LOW CONFIDENCE ON TIMING OF LOWERING...
* LOW-MEDIUM CONFIDENCE IN CIGS LOWERING TO IFR LATER TONIGHT.
* MEDIUM-HIGH CONFIDENCE IN SHRA TRENDS THROUGH THIS EVENING.
* MEDIUM CONFIDENCE IN VSBY TRENDS...WITH PRIMARILY VFR VIS
EXPECTED IN THE -SHRA.
KJB
//OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z...
* SATURDAY AND SUNDAY...VFR. WX NIL.
* MONDAY THROUGH WEDNESDAY...CHANCE OF TSRA/SHRA.
KJB
&&
.MARINE...
253 PM CDT
A LARGE UPPER LEVEL LOW WILL CONTINUE TO SPIN OVER OVER SOUTHERN
WISCONSIN AND SOUTHERN LAKE MICHIGAN TONIGHT AND FRIDAY BEFORE
GRADUALLY SHIFTING OFF TO THE EAST INTO SATURDAY. ONE AREA OF LOW
PRESSURE CONTINUES TO SPIN OVER THE ARROWHEAD OF MINNESOTA WITH A
SECONDARY CIRCULATION OVER WEST CENTRAL WISCONSIN. THE TWO LOWS WILL
MERGE AND WEAKEN TONIGHT AND THEN MOVE EASTWARD ACROSS SOUTHERN LAKE
MICHIGAN FRIDAY AND FRIDAY NIGHT. IN THE MEANTIME...THE PRESSURE
GRADIENT REMAINS STRONG LEADING TO 30 KT SOUTH TO SOUTHWEST WINDS
ACROSS THE LAKE...WITH SOME 35 KT GALES OCCURRING AT TIMES LATE THIS
AFTERNOON AND POSSIBLY EARLY THIS EVENING. SPEEDS LOOK TO REMAIN
STEADY THROUGH THE EVENING BUT THEN BEGIN TO SLOWLY DIMINISH AS THE
LOW BROADENS AND WEAKENS RESULTING IN A WEAKER PRESSURE GRADIENT.
THE DOWNWARD TREND SHOULD CONTINUE FRIDAY WITH WIND DIRECTION
BECOMING MORE COMPLEX AS THE LOW CROSSES THE SOUTHERN PART OF THE
LAKE. SOUTHWEST WINDS WILL OCCUR TO THE SOUTH OF THE LOW WHILE WINDS
TURN SOUTHEAST...THEN EAST...THEN NORTHEAST NORTH OF THE LOW ACROSS
THE NORTHERN HALF TO TWO-THIRDS OF THE LAKE FRIDAY. ONCE THE LOW
SHIFTS EAST FRIDAY EVENING NORTH TO NORTHWEST WINDS WILL TAKE OVER
WITH SOME MODEST INCREASE IN SPEEDS LIKELY AS THE PRESSURE GRADIENT
RECOVERS BUT THE LOW ITSELF WILL REMAIN IN A WEAKENED STATE. IN
ADDITION...WITH THE UPPER LOW PRESENT AND COLDER AIR ACROSS THE
LAKE...THERE WILL BE A GOOD CHANCE FOR WATERSPOUTS THROUGH
FRIDAY...WITH A FEW THUNDERSTORMS POSSIBLE AS WELL.
THE NORTHWEST WINDS WILL CONTINUE INTO INTO SATURDAY BEFORE TURNING
WESTERLY THEN SOUTHWESTERLY SATURDAY EVENING AS A RIDGE OF HIGH
PRESSURE BUILDS FROM SOUTHERN LAKE MICHIGAN INTO WESTERN WISCONSIN.
THE RIDGE SHIFTS EAST MONDAY ALLOWING WINDS TO TURN SOUTHEASTERLY AS
LOW PRESSURE SPREADS ACROSS THE CENTRAL AND NORTHERN PLAINS FOR THE
MIDDLE PART OF THE WEEK. SOUTH TO SOUTHEAST WINDS WILL LIKELY
INCREASE AS THE PRESSURE GRADIENT STRENGTHENS AS THE LOW TRACKS
NORTHEAST ACROSS THE UPPER MISSISSIPPI RIVER VALLEY AND LAKE
SUPERIOR. BEYOND THAT A FRONTAL BOUNDARY SHOULD CROSS THE LAKE AND
BRING A RETURN TO NORTHERLY WINDS FOR LATE WEEK.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 5 AM FRIDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
625 PM CDT THU OCT 18 2012
.DISCUSSION...
341 PM CDT
MAIN FORECAST CONCERNS CONTINUE WITH SHOWERS/POSSIBLE THUNDER THIS
AFTERNOON...AND SHOWERS TO PERSIST THROUGH FRIDAY.
LATEST WATER VAPOR IMAGERY SHOWING LARGE CLOSED UPPER LEVEL SYSTEM
OVER THE MIDWEST THIS AFTERNOON...WITH SEVERAL STRONG MID LEVEL
FEATURES WRAPPING AROUND THIS SYSTEM. THIS FORCING IN THE PRESENCE
OF STEEP LAPSE RATES...PER AMDAR SOUNDINGS AND RAP ANALYSIS...HAS
ALLOWED SHOWERS TO BLOSSOM ACROSS NORTHERN ILLINOIS. ISOLATED
CONVECTIVE ELEMENTS HAVE ALSO BEGUN TO DEVELOP OUT AHEAD OF THIS
MAIN PRECIP SHIELD ACROSS NORTHEAST ILLINOIS AND NORTHWEST INDIANA
WHERE STEEPER LAPSE RATES CURRENTLY RESIDE. EXPECT THESE
CONVECTIVE ELEMENTS TO BE THE MORE NORM THROUGH THE REMAINDER OF
THE AFTERNOON AS MAIN PRECIP SHIELD CONTINUES TO SHIFT ACROSS THE
AREA. ITS IN THESE CONVECTIVE ELEMENTS THAT HEAVIER SHOWERS AND
LOWER VIS COULD OCCUR...AND ALSO WHERE THE POSSIBILITY OF
THUNDER/SMALL HAIL STILL MAY OCCUR.
UPPER LEVEL LOW WILL CONTINUE TO SLOWLY MEANDER TO THE EAST
OVERNIGHT...WITH PRECIP EXPECTED TO PERSIST FOR MUCH OF THE CWA
TONIGHT. ALTHOUGH WITH MID LEVEL FEATURES/FORCING SHIFTING
EASTWARD TONIGHT...MAIN AXIS OF PRECIP SHOULD ALSO SHIFT.
NEVERTHELESS...EXPECT AT LEAST LIGHT SHOWERS OR DRIZZLE TO
CONTINUE OVERNIGHT ACROSS THE ENTIRE CWA WITH TEMPS SLOWLY
LOWERING TO AROUND 40 ACROSS NORTHERN ILLINOIS AND THE LOWER 40S
FOR THE REMAINDER OF THE CWA...AS EXPANSIVE CLOUD SHIELD REMAINS
OVERHEAD. UPPER LEVEL LOW CENTER AND COLDEST TEMPS WILL BE
OVERHEAD ON FRIDAY...WITH A SIMILAR SETUP EXPECTED ONCE AGAIN.
SHOWERS WILL BE POSSIBLE ALONG WITH A SLIGHT CHANCE FOR
THUNDERSTORMS/SMALL HAIL ONCE AGAIN IN THE AFTERNOON...WHEN LAPSE
RATES ARE ONCE AGAIN EXPECTED TO BE THE STEEPEST. TEMPS WILL
STRUGGLE TO CLIMB MUCH AS THIS CLOUD SHIELD WILL REMAIN
OVERHEAD...WITH TEMPS IN THE UPPER 40S TO AROUND 50 EXPECTED.
GUIDANCE IN FAIR AGREEMENT WITH TAKING THIS UPPER LEVEL LOW EAST
OF THE AREA BY FRIDAY NIGHT AND EARLY SATURDAY MORNING. SO
CONTINUED TREND OF LOWERING POPS THROUGH FRIDAY NIGHT BUT WITH
THESE SYSTEMS GENERALLY MOVING SLOWER THAN MODEL GUIDANCE...WASNT
TOO AGGRESSIVE WITH LOWERING THE POPS AS STRAY SHOWERS MAY
LINGERING WITH CYCLONIC FLOW STILL IN PLACE.
AS UPPER LEVEL SYSTEM CONTINUES TO DRIFT EAST ON SATURDAY...HEIGHT
RISES ON THE BACKSIDE OF THIS SYSTEM WILL SET THE STAGE FOR A
PERIOD OF UPPER LEVEL RIDGING. WHAT THIS WILL MEAN FOR THE
REMAINDER OF THE WEEKEND WILL BE CLEARING SKIES AND QUIET WEATHER
WITH AN INCREASE IN TEMPS. EXPECT WINDS TO FLOP BACK TO THE
SOUTH/SOUTHWEST LATE SATURDAY WITH WAA USHERING IN SOME WARMTH
ACROSS THE REGION. THIS WAA AND SUNNY SKIES WILL HELP TEMPS RISE
WITH FORECAST HIGHS EXPECTED TO BE IN THE UPPER 60S TO LOW 70S ON
SUNDAY. THIS WARMTH WILL CONTINUE ON MONDAY WITH A SLIGHT INCREASE
IN TEMPS...AS THEY RISE TO THE LOW TO MID 70S. ALTHOUGH WITH THE
RIDGE AXIS OVERHEAD...THIS WILL BRING A SETUP FOR STEERING FLOW TO
BRING ABOUT SOME MID LEVEL ENERGY AND ACTIVE WEATHER FOR NEXT
WEEK.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* GUSTY SOUTH WINDS THROUGH EARLY THIS EVENING.
* PERIODS OF SHRA.
* TIMING OF 1500 FT MVFR CIGS THIS EVENING.
* POTENTIAL FOR IFR CIGS OVERNIGHT INTO FRIDAY MORNING.
KJB
//DISCUSSION...UPDATED 00Z...
THE MAIN FORECAST CONCERNS WILL BE CIGS AND PERIODS OF SHOWERS
THROUGH THE PERIOD.
A POTENT AUTUMN SEASON STORM SYSTEM WILL CONTINUE TO IMPACT THE
REGION THROUGH THE PERIOD AS IT SLOWLY PUSHES ACROSS THE GREAT LAKES
REGION. WINDS CONTINUE TO BE GUSTY OUT OF THE SOUTH EARLY THIS
EVENING AND THESE WINDS SHOULD ABATE LATER TONIGHT AS THE SURFACE
LOW MOVES ACROSS THE AREA.
THE MAIN CONCERNS WILL BE TIMING THE LOWER CIGS...AS IT APPEARS WE
WILL SEE A DOWNWARD TREND THROUGH THE EVENING. LOWER END MVFR CIGS
AROUND 1,200 TO 1,500 FT AGL LOOK TO DEVELOP SOMETIME AFTER 02 UTC
AT THE NORTHEASTERN ILLINOIS TERMINALS AND THEN POTENTIALLY DROP
DOWN AROUND OR JUST BELOW 1,000 FT FOR A PERIOD LATER TONIGHT. A
SLOW IMPROVEMENT IN IS EXPECTED DURING THE MORNING ON FRIDAY AS CIGS
SHOULD RISE ABOVE 2,000 FT BY EARLY AFTERNOON.
SCATTERED LIGHT SHOWERS ARE ALSO EXPECTED...ESPECIALLY TONIGHT.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* MEDIUM-HIGH CONFIDENCE IN WIND DIRECTION AND WIND GUST TRENDS.
* MEDIUM CONFIDENCE IN CIGS LOWERING TO AROUND 1500 FT THIS
EVENING WITH LOW CONFIDENCE ON TIMING OF LOWERING...
* LOW-MEDIUM CONFIDENCE IN CIGS LOWERING TO IFR LATER TONIGHT.
* MEDIUM-HIGH CONFIDENCE IN SHRA TRENDS THROUGH THIS EVENING.
* MEDIUM CONFIDENCE IN VSBY TRENDS...WITH PRIMARILY VFR VIS
EXPECTED IN THE -SHRA.
KJB
//OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z...
* SATURDAY AND SUNDAY...VFR. WX NIL.
* MONDAY THROUGH WEDNESDAY...CHANCE OF TSRA/SHRA.
KJB
&&
.MARINE...
253 PM CDT
A LARGE UPPER LEVEL LOW WILL CONTINUE TO SPIN OVER OVER SOUTHERN
WISCONSIN AND SOUTHERN LAKE MICHIGAN TONIGHT AND FRIDAY BEFORE
GRADUALLY SHIFTING OFF TO THE EAST INTO SATURDAY. ONE AREA OF LOW
PRESSURE CONTINUES TO SPIN OVER THE ARROWHEAD OF MINNESOTA WITH A
SECONDARY CIRCULATION OVER WEST CENTRAL WISCONSIN. THE TWO LOWS WILL
MERGE AND WEAKEN TONIGHT AND THEN MOVE EASTWARD ACROSS SOUTHERN LAKE
MICHIGAN FRIDAY AND FRIDAY NIGHT. IN THE MEANTIME...THE PRESSURE
GRADIENT REMAINS STRONG LEADING TO 30 KT SOUTH TO SOUTHWEST WINDS
ACROSS THE LAKE...WITH SOME 35 KT GALES OCCURRING AT TIMES LATE THIS
AFTERNOON AND POSSIBLY EARLY THIS EVENING. SPEEDS LOOK TO REMAIN
STEADY THROUGH THE EVENING BUT THEN BEGIN TO SLOWLY DIMINISH AS THE
LOW BROADENS AND WEAKENS RESULTING IN A WEAKER PRESSURE GRADIENT.
THE DOWNWARD TREND SHOULD CONTINUE FRIDAY WITH WIND DIRECTION
BECOMING MORE COMPLEX AS THE LOW CROSSES THE SOUTHERN PART OF THE
LAKE. SOUTHWEST WINDS WILL OCCUR TO THE SOUTH OF THE LOW WHILE WINDS
TURN SOUTHEAST...THEN EAST...THEN NORTHEAST NORTH OF THE LOW ACROSS
THE NORTHERN HALF TO TWO-THIRDS OF THE LAKE FRIDAY. ONCE THE LOW
SHIFTS EAST FRIDAY EVENING NORTH TO NORTHWEST WINDS WILL TAKE OVER
WITH SOME MODEST INCREASE IN SPEEDS LIKELY AS THE PRESSURE GRADIENT
RECOVERS BUT THE LOW ITSELF WILL REMAIN IN A WEAKENED STATE. IN
ADDITION...WITH THE UPPER LOW PRESENT AND COLDER AIR ACROSS THE
LAKE...THERE WILL BE A GOOD CHANCE FOR WATERSPOUTS THROUGH
FRIDAY...WITH A FEW THUNDERSTORMS POSSIBLE AS WELL.
THE NORTHWEST WINDS WILL CONTINUE INTO INTO SATURDAY BEFORE TURNING
WESTERLY THEN SOUTHWESTERLY SATURDAY EVENING AS A RIDGE OF HIGH
PRESSURE BUILDS FROM SOUTHERN LAKE MICHIGAN INTO WESTERN WISCONSIN.
THE RIDGE SHIFTS EAST MONDAY ALLOWING WINDS TO TURN SOUTHEASTERLY AS
LOW PRESSURE SPREADS ACROSS THE CENTRAL AND NORTHERN PLAINS FOR THE
MIDDLE PART OF THE WEEK. SOUTH TO SOUTHEAST WINDS WILL LIKELY
INCREASE AS THE PRESSURE GRADIENT STRENGTHENS AS THE LOW TRACKS
NORTHEAST ACROSS THE UPPER MISSISSIPPI RIVER VALLEY AND LAKE
SUPERIOR. BEYOND THAT A FRONTAL BOUNDARY SHOULD CROSS THE LAKE AND
BRING A RETURN TO NORTHERLY WINDS FOR LATE WEEK.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 5 AM FRIDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
334 PM CDT WED OCT 17 2012
.DISCUSSION...
1230 PM CDT
MAIN FORECAST ISSUES/CONCERNS THIS AFTERNOON ARE WITH
SHOWER/THUNDERSTORM POTENTIAL AND SMALL BUT NOT ZERO CHANCE FOR
SEVERE WEATHER ACROSS THE SOUTHERN CWA...CENTRAL/EAST CENTRAL
ILLINOIS AND NORTHWEST INDIANA.
MADE SOME MINOR EDITS TO THE GRIDS...PRIMARILY WITH RESPECT TO THE
POP/WX GRIDS FOR THIS AFTERNOON SLOWING DOWN THE ONSET OF PRECIP.
WAA WHICH HAS BEEN PROMINENT ALL MORNING HAS BEEN STIFLED WITH THE
APPROACH OF THE LARGE SCALE TROUGH TO THE WEST. ALTHOUGH THIS WAA
HAS WEAKENED...SEVERAL WAVES OF ENERGY CONTINUE TO EJECT OUT
AHEAD OF THIS SYSTEM PROVIDING ENOUGH LIFT TO AID IN EXPANSIVE
CLOUD SHIELD TO THE SOUTHWEST OF THE CWA...TO CONTINUE SPREADING
NORTH AS WELL AS SOME ISOLATED SHOWER AND THUNDERSTORM
DEVELOPMENT. LATEST RADAR IMAGERY DEPICTING AN ISOLATED AREA OF
SHOWERS QUICKLY MOVING NORTHEAST ACROSS COOK COUNTY. AS A NARROW
RIBBON OF INSTABILITY IS POKING NORTH ACROSS NORTHERN
ILLINOIS...PER LATEST RAP ANALYSIS...A FEW LIGHTNING STRIKES HAVE
BEEN REPORTED. ALTHOUGH...AM NOT EXPECTING MUCH TO RESULT FROM
THESE SHOWERS/THUNDERSTORMS OUTSIDE OF BRIEF GUSTY WINDS AND BRIEF
DOWNPOURS. SO...HAVE PULLED BACK POPS ACROSS THE CWA THROUGH EARLY
AFTERNOON WITH THE EXPECTED DELAY IN PRECIP. ALTHOUGH WITH THE
APPROACH OF A FAIRLY STOUT VORT LOBE OUT AHEAD OF THIS DIGGING
TROUGH...FORCING WILL REALLY RAMP UP. THIS WILL HELP AN EXPANDING
AREA OF PRECIP TO SPREAD NORTHEAST ACROSS THE ENTIRE CWA LATE THIS
AFTERNOON THROUGH THE EVENING. SEVERAL FORCING MECHANISMS WILL
COME TOGETHER DURING THIS TIME FRAME AND PROVIDE STRONG FORCING TO
OCCUR OVERHEAD. WITH THIS STRONG FORCING COINCIDING WITH AN
INCREASE IN MOISTURE...LINGERING WEAK INSTABILITY...AND AN
INCREASE IN BULK SHEAR...HAVE BECOME A LITTLE MORE CONCERNED WITH
THUNDERSTORM POTENTIAL. ALTHOUGH THUNDERSTORMS WILL BE POSSIBLE
ACROSS THE ENTIRE CWA THIS AFTERNOON...PREVIOUS THINKING CONTINUES
WITH THE BETTER CHANCES FOR THUNDERSTORMS APPEARING TO BE SOUTH OF
INTERSTATE 80 LATE THIS AFTERNOON AND EVENING WITH A FEW POSSIBLY
BECOMING STRONG TO SEVERE...WITH STRONG WINDS THE PRIMARY
CONCERNS.
RODRIGUEZ
//PREV DISCUSSION...
330 AM CDT
PRIMARY FORECAST CONCERNS THIS GO AROUND INCLUDE THE IMPACTS OF THE
VIGOROUS TROUGH OVER THE NORTHERN PLAINS THAT GUIDANCE CONTINUE TO
DEVELOP INTO AN ABNORMALLY VIGOROUS UPPER LOW THAT WILL MEANDER
AROUND THE REGION FOR THE REST OF THE WORK WEEK.
ELEVATED ISOLATED WAA CONVECTION OVER THE CHICAGO AREA NOW SHOULD
HAVE LIFTED NORTHEAST INTO MICHIGAN BY SUNRISE...WITH SOME
OPPORTUNITY FOR SOME SUNSHINE EARLY THIS MORNING...MAINLY EASTERN
CWA. WHAT LIMITED SUNSHINE THERE IS THIS MORNING SHOULD QUICKLY GIVE
WAY TO OVERCAST CONDITIONS BY EARLY AFTERNOON WITH RAIN CHANCES
GRADUALLY RAMPING UP. SURFACE OBS AND GOES SOUNDER PWAT IMAGERY BOTH
SHOW A RELATIVE DEARTH IN MOISTURE IMMEDIATELY UPSTREAM OVER
MISSOURI WHICH SHOULD KEEP US MOSTLY DRY THIS MORNING...BUT LURKING
JUST TO THE WEST IS SECONDARY SURGE OF DEEPER MOISTURE IMMEDIATELY
IN ADVANCE OF THE STRENGTHENING COLD FRONT. STRONG SOUTHERLY FLOW
TODAY WILL RESULT IN RAPID NORTHEASTWARD TRANSPORT OF THIS DEEPER
MOISTURE AND MODELS ARE BREAKING OUT SCATTERED PRECIPITATION BY
EARLY AFTERNOON IN RESPONSE TO THE STRONG PUSH OF HIGHER LOW LEVEL
THETA-E AIR MASS.
MORE ORGANIZED FRONTAL AND POST-FRONTAL PRECIPITATION LOOKS SLATED
TO ARRIVE IN OUR WESTERN CWA LATE THIS AFTERNOON INTO EARLY THIS
EVENING. A SUBSTANTIAL INCREASE IN THE COVERAGE AND INTENSITY OF THE
PRECIPITATION IS EXPECTED IN THE 21-03Z TIME FRAME AS THE DEEP
SYNOPTIC SCALE FORCING SPREADS SOUTHEAST AND BEGINS TO ENCOUNTER THE
DEEPER MOISTURE ADVECTING NORTHEAST INTO THE REGION. FORCING LOOKS
TO BE VERY IMPRESSIVE AS VIGOROUS SHORTWAVE PIVOTING AROUND THE BASE
OF THE INTENSIFYING UPPER LOW LEADS TO ENTIRE UPPER TROUGH/LOW
TAKING ON NEGATIVE TILT WITH ILLINOIS COUPLING OF STRONG UPPER LEVEL
DIVERGENCE AND VERY STRONG LOW LEVEL FRONTOGENESIS LEADING TO VERY
STRONG UPWARD VERTICAL VELOCITIES AND BLOSSOMING AREA OF PRECIP.
MOST MODELS GENERALLY KEEP THE INSTABILITY SOUTH OF OUR CWA...THOUGH
A FEW SREF MEMBERS DO BRING UPWARDS OF 250 J/KG OF SBCAPE INTO OUR
SOUTHERN CWA THIS EVENING. WHAT WE LACK IN INSTABILITY WILL
CERTAINLY BE MADE UP FOR WITH FORCING AND HAVE MAINTAINED CHANCE OF
THUNDER THIS AFTERNOON AND EVENING. WHILE LIGHTNING MAY NOT BE
OVERLY PREVALENT...WE COULD SEE A BAND OF STRONG FORCING LOW TOPPED
CONVECTION THAT COULD STILL TRANSPORT SOME STRONGER WINDS TO THE
SURFACE THIS EVENING...ESPECIALLY SOUTHERN CWA WHERE THERE COULD BE
A BIT OF SB INSTABILITY. THE STRONG FORCING AND SEASONABLY HIGH
PWATS SHOULD RESULT IN A FAIRLY RESPECTABLE RAINFALL ACROSS THE CWA
WITH WIDESPREAD 1 TO 2 THIRD OF A INCH TOTALS LIKELY...AND LOCALIZED
AMOUNTS OF AN INCH POSSIBLE.
TAKING A QUICK STEP BACK...TEMPS TODAY WILL BE TRICKY AS 08Z TEMPS
ARE STILL IN THE MID-UPPER 60S IN CHICAGO AND UPPER 50S/LOW 60S
OUTSIDE THE CITY. WHILE SUNSHINE SHOULD BE LIMITED TODAY...SUCH A
WARM START TO THE DAY DOES ARGUE FOR GOING A BIT ABOVE GUIDANCE FOR
HIGHS TODAY WITH PARTICULARLY EASTERN CWA STANDING A REASONABLE SHOT
AT CLIMBING ABOVE 70F AGAIN. AFTER AN UNSEASONABLY BALMY (ALMOST
SUMMER-LIKE NIGHT) TUES NIGHT...STRONG COLD AIR ADVECTION IN THE
WAKE OF THE FRONT TONIGHT WILL PROVIDE THE AREA WITH A COLD HARD
SLAP OF AUTUMNAL REALITY WITH READINGS BACK INTO THE 40S BY THURS
MORNING ALONG WITH MODERATELY BRISK WEST WINDS ADDING MORE OF A
CHILL TO THE AIR.
COULD LITERALLY CUT AND PASTE LAST NIGHT`S AFD INTO THIS AFD
REGARDING THURSDAY AND FRIDAY`S FORECAST. MASSIVE AND UNSEASONABLY
STRONG/COLD ATMOSPHERIC GYRE WILL SET-UP SHOP OVER THE WESTERN GREAT
LAKES RESULTING IN PERIODIC SHOWERY CONDITIONS THURSDAY INTO
FRIDAY...WITH STEEP LAPSE RATES AND COLD TEMPS ALOFT RESULT IN THE
POTENTIAL FOR SOME GRAUPEL AND MAYBE EVEN A BIT RUMBLE OR TWO OF
THUNDER. COVERAGE AND INTENSITY OF THE SHOWERS WILL BE GREATEST
DURING THE AFTERNOON/EVENING HOURS AND TIED TO INDIVIDUAL VORT LOBES
PIVOTING AROUND THE UPPER LOW. WHILE THERE WILL BE A DIURNAL MAXIMA
OF SHOWER ACTIVITY...SOME SHOWERS WILL CONTINUE THROUGH THE
NIGHT...ESPECIALLY NEAR MORE VIGOROUS VORTS. CONSIDERABLE CLOUD
COVER AND VERY COLD NATURE OF THE LOW WILL RESULT IN MUCH BELOW
AVERAGE TEMPS THURS AND FRIDAY WITH HIGHS STRUGGLING TO REACH 50F
BOTH BOTH DAYS.
MEDIUM RANGE MODELS REMAIN LOCKSTEP WITH EACH OTHER IN THIS UPPER
LOW MOVING EAST UNCHARACTERISTICALLY QUICK FOR SUCH A STRONG/BIG CUT
OFF. THIS HASTY EXIT IS THE RESULT OF YET ANOTHER UNUSUALLY STRONG
UPPER TROUGH/CUT OFF LOW PROGGED TO TAKE SHAPE OVER THE PAC NW
RESULTING IN DOWNSTREAM AMPLIFICATION OF THE RIDGE OVER OUR AREA. IN
FACT...MEDIUM RANGE MODELS ARE IN GREAT AGREEMENT IN BUILDING A
RESPECTABLE UPPER RIDGE INTO THE REGION WITH H8 TEMPS SURGING TO 1-2
SIGMA ABOVE AVERAGE BY EARLY NEXT WEEK. ALL INDICATIONS ARE AT THIS
POINT THAT WE COULD SEE READINGS BACK ABOVE 70 DEGREES BY EARLY NEXT
WEEK.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* TIMING OF COLD FRONTAL PASSAGE AND ASSOCIATED WIND SHIFT
TONIGHT.
* PERIODS OF SHRA/TSRA REST OF AFTERNOON AND THIS EVENING.
* LOCAL MVFR CEILING AND/OR VISIBILITY WITH SHRA/TSRA BECOMING
PREVAILING MVFR CEILINGS BY EARLY EVENING.
* THREAT OF SHRA/TSRA AND ASSOCIATED MVFR CONDITIONS INCREASING
DURING LATER THU MORNING INTO AFTERNOON.
TRS
//DISCUSSION...UPDATED 18Z...
INCREASING LOW LEVEL MOISTURE HAS QUICKLY ADVECTED NORTH-NORTHEAST
FROM THE MID MS VALLEY ACROSS NORTHERN IL AND FAR NW IN WITH MID-
UPPER 50S DEW POINTS JUST UPSTREAM OVER NE MO AND CENTRAL IL.
AS AN UPPER LOW...WITHIN THE UPPER TROUGH FROM MANITOBA SSE TO
NORTHERN OK...CONTINUES TO DEVELOP AND PROGRESS SOUTHEASTWARD OVER
THE UPPER MS VALLEY THE REST OF THE AFTERNOON AND THIS EVENING
SHRA AND TSRA EXPECTED TO BECOME MORE NUMEROUS AS INCREASINGLY
STRONG ISENTROPIC LIFT SPREADS E AND NE ACROSS THE MID MS VALLEY.
MODELS IN FAIRLY GOOD AGREEMENT IN ROTATING THE MID LEVEL TROUGH
TO NW AND E CENTRAL IL BY 06Z AND PUSHING THE COLD FRONT...
CURRENTLY CURVING FROM E CENTRAL MN AND W CENTRAL WI TO E CENTRAL
AND SE IA AND THEN TO NW AND W CENTRAL MO...E ACROSS THE MID MS
VALLEY AND TO IL BY MIDNIGHT. SOME LIGHTER SHOWERS MAY PERSIST
BEHIND THE COLD FRONT TIL THE MID LEVEL TROUGH AXIS PASSES BY
THEN SUBSIDENCE AND DRYING PREVAIL OVERNIGHT.
DURING THE DAY THU A NEARLY VERTICALLY STACKED LOW IS PROGGED TO
SETTLE SLOWLY SE FROM SOUTHEASTERN MN TO SW WI AND NE IA BY 00Z
FRI. COLD TEMPERATURES IN THE MID AND UPPER LEVELS ASSOCIATED WITH
THE STACKED LOW COLD POOL...ALONG WITH DEEP CYCLONIC FLOW...WILL
ENCOURAGE CU TO DEVELOP AND TO GROW TO A DEEP ENOUGH DEPTH TO
SUPPORT SHOWERS AND SOME TS WITH ELEVATED CAPE ACROSS THE AREA.
TRS
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
*HIGH CONFIDENCE IN INCREASING COVERAGE OF SHRA AND TSRA THROUGH
REST OF AFTERNOON INTO THIS EVENING.
*MODERATE CONFIDENCE IN TIMING OF PERIODS OF SHRA AND TSRA REST OF
AFTERNOON AND THIS EVENING.
*MODERATE CONFIDENCE IN TIME OF COLD FRONT PASSAGE/WINDSHIFT TO
WITHIN +/- 1 HR.
*MODERATE CONFIDENCE IN TIMING OF LOCAL MVFR CEILINGS AND
VISIBILITIES BECOMING PREVAILING BY THIS EVENING.
TRS
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
* THURSDAY NIGHT...RAIN WITH MVFR CIGS/VIS POSSIBLE.
* FRIDAY...RAIN LIKELY WITH CHANCE TSRA IN THE AFTERNOON. MVFR
CIGS/VIS POSSIBLE.
* SATURDAY AND SUNDAY...VFR. WX NIL.
* MONDAY AND TUESDAY...CHANCE OF SHRA.
KREIN
&&
.MARINE...
331 PM CDT
AN AREA OF DEEPENING LOW PRESSURE AVERAGING IS LOCATED OVER
NORTHERN MINNESOTA THIS AFTERNOON. SOUTHWEST OF THIS LOW...OVER
THE DAKOTAS...WINDS HAVE BEEN GUSTING ABOVE 50 KT. THE LOW WILL
SLIDE INTO WISCONSIN TONIGHT. A COLD FRONT TRAILING SOUTH FROM THE
LOW WILL SWEEP FROM SOUTHWEST TO NORTHEAST ACROSS LAKE MICHIGAN
TONIGHT AND EARLY TOMORROW. AHEAD OF THE FRONT TONIGHT...SOUTH TO
SOUTHEAST WINDS COULD POSSIBLY BE MUCH STRONGER THAN
FORECAST...PERHAPS OVER 40 KT...AND A GALE WARNING MAY YET BE
NEEDED FOR THE OVERNIGHT HOURS. TALLER VESSELS ARE LIKELY TO SEE
AT LEAST OCCASIONAL GALE FORCE GUSTS TONIGHT. THE UNCERTAINTY
COMES FROM THE CLOSE PROXIMITY OF THE LOW TO THE LAKE...WHICH CAN
RESULT IN LOWER WINDS...AND THE WARMTH OF THE AIR BEING LIFTED
OVER THE COOLER WATERS. IN CONTRAST...THE STRONG GUSTS OVER THE
DAKOTAS ARE IN A REGION OF COLD AIR MOVING OVER WARMER GROUND.
VERY SLOWLY THE LOW WILL THEN DRIFT EAST ACROSS LAKE MICHIGAN BY
FRIDAY AND INTO THE EASTERN GREAT LAKES BY SATURDAY AS IT WEAKENS
SLIGHTLY. MEANWHILE...A WEAK RIDGE OF HIGH PRESSURE WILL MOVE
EAST OVER THE MISSISSIPPI VALLEY FRIDAY NIGHT AND SATURDAY. THE
RIDGE WILL CONTINUE EAST TO THE EASTERN GREAT LAKES AND OHIO
VALLEY SATURDAY NIGHT.
LENNING
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM THURSDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
311 PM CDT WED OCT 17 2012
.DISCUSSION...
1230 PM CDT
MAIN FORECAST ISSUES/CONCERNS THIS AFTERNOON ARE WITH
SHOWER/THUNDERSTORM POTENTIAL AND SMALL BUT NOT ZERO CHANCE FOR
SEVERE WEATHER ACROSS THE SOUTHERN CWA...CENTRAL/EAST CENTRAL
ILLINOIS AND NORTHWEST INDIANA.
MADE SOME MINOR EDITS TO THE GRIDS...PRIMARILY WITH RESPECT TO THE
POP/WX GRIDS FOR THIS AFTERNOON SLOWING DOWN THE ONSET OF PRECIP.
WAA WHICH HAS BEEN PROMINENT ALL MORNING HAS BEEN STIFLED WITH THE
APPROACH OF THE LARGE SCALE TROUGH TO THE WEST. ALTHOUGH THIS WAA
HAS WEAKENED...SEVERAL WAVES OF ENERGY CONTINUE TO EJECT OUT
AHEAD OF THIS SYSTEM PROVIDING ENOUGH LIFT TO AID IN EXPANSIVE
CLOUD SHIELD TO THE SOUTHWEST OF THE CWA...TO CONTINUE SPREADING
NORTH AS WELL AS SOME ISOLATED SHOWER AND THUNDERSTORM
DEVELOPMENT. LATEST RADAR IMAGERY DEPICTING AN ISOLATED AREA OF
SHOWERS QUICKLY MOVING NORTHEAST ACROSS COOK COUNTY. AS A NARROW
RIBBON OF INSTABILITY IS POKING NORTH ACROSS NORTHERN
ILLINOIS...PER LATEST RAP ANALYSIS...A FEW LIGHTNING STRIKES HAVE
BEEN REPORTED. ALTHOUGH...AM NOT EXPECTING MUCH TO RESULT FROM
THESE SHOWERS/THUNDERSTORMS OUTSIDE OF BRIEF GUSTY WINDS AND BRIEF
DOWNPOURS. SO...HAVE PULLED BACK POPS ACROSS THE CWA THROUGH EARLY
AFTERNOON WITH THE EXPECTED DELAY IN PRECIP. ALTHOUGH WITH THE
APPROACH OF A FAIRLY STOUT VORT LOBE OUT AHEAD OF THIS DIGGING
TROUGH...FORCING WILL REALLY RAMP UP. THIS WILL HELP AN EXPANDING
AREA OF PRECIP TO SPREAD NORTHEAST ACROSS THE ENTIRE CWA LATE THIS
AFTERNOON THROUGH THE EVENING. SEVERAL FORCING MECHANISMS WILL
COME TOGETHER DURING THIS TIME FRAME AND PROVIDE STRONG FORCING TO
OCCUR OVERHEAD. WITH THIS STRONG FORCING COINCIDING WITH AN
INCREASE IN MOISTURE...LINGERING WEAK INSTABILITY...AND AN
INCREASE IN BULK SHEAR...HAVE BECOME A LITTLE MORE CONCERNED WITH
THUNDERSTORM POTENTIAL. ALTHOUGH THUNDERSTORMS WILL BE POSSIBLE
ACROSS THE ENTIRE CWA THIS AFTERNOON...PREVIOUS THINKING CONTINUES
WITH THE BETTER CHANCES FOR THUNDERSTORMS APPEARING TO BE SOUTH OF
INTERSTATE 80 LATE THIS AFTERNOON AND EVENING WITH A FEW POSSIBLY
BECOMING STRONG TO SEVERE...WITH STRONG WINDS THE PRIMARY
CONCERNS.
RODRIGUEZ
//PREV DISCUSSION...
330 AM CDT
PRIMARY FORECAST CONCERNS THIS GO AROUND INCLUDE THE IMPACTS OF THE
VIGOROUS TROUGH OVER THE NORTHERN PLAINS THAT GUIDANCE CONTINUE TO
DEVELOP INTO AN ABNORMALLY VIGOROUS UPPER LOW THAT WILL MEANDER
AROUND THE REGION FOR THE REST OF THE WORK WEEK.
ELEVATED ISOLATED WAA CONVECTION OVER THE CHICAGO AREA NOW SHOULD
HAVE LIFTED NORTHEAST INTO MICHIGAN BY SUNRISE...WITH SOME
OPPORTUNITY FOR SOME SUNSHINE EARLY THIS MORNING...MAINLY EASTERN
CWA. WHAT LIMITED SUNSHINE THERE IS THIS MORNING SHOULD QUICKLY GIVE
WAY TO OVERCAST CONDITIONS BY EARLY AFTERNOON WITH RAIN CHANCES
GRADUALLY RAMPING UP. SURFACE OBS AND GOES SOUNDER PWAT IMAGERY BOTH
SHOW A RELATIVE DEARTH IN MOISTURE IMMEDIATELY UPSTREAM OVER
MISSOURI WHICH SHOULD KEEP US MOSTLY DRY THIS MORNING...BUT LURKING
JUST TO THE WEST IS SECONDARY SURGE OF DEEPER MOISTURE IMMEDIATELY
IN ADVANCE OF THE STRENGTHENING COLD FRONT. STRONG SOUTHERLY FLOW
TODAY WILL RESULT IN RAPID NORTHEASTWARD TRANSPORT OF THIS DEEPER
MOISTURE AND MODELS ARE BREAKING OUT SCATTERED PRECIPITATION BY
EARLY AFTERNOON IN RESPONSE TO THE STRONG PUSH OF HIGHER LOW LEVEL
THETA-E AIR MASS.
MORE ORGANIZED FRONTAL AND POST-FRONTAL PRECIPITATION LOOKS SLATED
TO ARRIVE IN OUR WESTERN CWA LATE THIS AFTERNOON INTO EARLY THIS
EVENING. A SUBSTANTIAL INCREASE IN THE COVERAGE AND INTENSITY OF THE
PRECIPITATION IS EXPECTED IN THE 21-03Z TIME FRAME AS THE DEEP
SYNOPTIC SCALE FORCING SPREADS SOUTHEAST AND BEGINS TO ENCOUNTER THE
DEEPER MOISTURE ADVECTING NORTHEAST INTO THE REGION. FORCING LOOKS
TO BE VERY IMPRESSIVE AS VIGOROUS SHORTWAVE PIVOTING AROUND THE BASE
OF THE INTENSIFYING UPPER LOW LEADS TO ENTIRE UPPER TROUGH/LOW
TAKING ON NEGATIVE TILT WITH ILLINOIS COUPLING OF STRONG UPPER LEVEL
DIVERGENCE AND VERY STRONG LOW LEVEL FRONTOGENESIS LEADING TO VERY
STRONG UPWARD VERTICAL VELOCITIES AND BLOSSOMING AREA OF PRECIP.
MOST MODELS GENERALLY KEEP THE INSTABILITY SOUTH OF OUR CWA...THOUGH
A FEW SREF MEMBERS DO BRING UPWARDS OF 250 J/KG OF SBCAPE INTO OUR
SOUTHERN CWA THIS EVENING. WHAT WE LACK IN INSTABILITY WILL
CERTAINLY BE MADE UP FOR WITH FORCING AND HAVE MAINTAINED CHANCE OF
THUNDER THIS AFTERNOON AND EVENING. WHILE LIGHTNING MAY NOT BE
OVERLY PREVALENT...WE COULD SEE A BAND OF STRONG FORCING LOW TOPPED
CONVECTION THAT COULD STILL TRANSPORT SOME STRONGER WINDS TO THE
SURFACE THIS EVENING...ESPECIALLY SOUTHERN CWA WHERE THERE COULD BE
A BIT OF SB INSTABILITY. THE STRONG FORCING AND SEASONABLY HIGH
PWATS SHOULD RESULT IN A FAIRLY RESPECTABLE RAINFALL ACROSS THE CWA
WITH WIDESPREAD 1 TO 2 THIRD OF A INCH TOTALS LIKELY...AND LOCALIZED
AMOUNTS OF AN INCH POSSIBLE.
TAKING A QUICK STEP BACK...TEMPS TODAY WILL BE TRICKY AS 08Z TEMPS
ARE STILL IN THE MID-UPPER 60S IN CHICAGO AND UPPER 50S/LOW 60S
OUTSIDE THE CITY. WHILE SUNSHINE SHOULD BE LIMITED TODAY...SUCH A
WARM START TO THE DAY DOES ARGUE FOR GOING A BIT ABOVE GUIDANCE FOR
HIGHS TODAY WITH PARTICULARLY EASTERN CWA STANDING A REASONABLE SHOT
AT CLIMBING ABOVE 70F AGAIN. AFTER AN UNSEASONABLY BALMY (ALMOST
SUMMER-LIKE NIGHT) TUES NIGHT...STRONG COLD AIR ADVECTION IN THE
WAKE OF THE FRONT TONIGHT WILL PROVIDE THE AREA WITH A COLD HARD
SLAP OF AUTUMNAL REALITY WITH READINGS BACK INTO THE 40S BY THURS
MORNING ALONG WITH MODERATELY BRISK WEST WINDS ADDING MORE OF A
CHILL TO THE AIR.
COULD LITERALLY CUT AND PASTE LAST NIGHT`S AFD INTO THIS AFD
REGARDING THURSDAY AND FRIDAY`S FORECAST. MASSIVE AND UNSEASONABLY
STRONG/COLD ATMOSPHERIC GYRE WILL SET-UP SHOP OVER THE WESTERN GREAT
LAKES RESULTING IN PERIODIC SHOWERY CONDITIONS THURSDAY INTO
FRIDAY...WITH STEEP LAPSE RATES AND COLD TEMPS ALOFT RESULT IN THE
POTENTIAL FOR SOME GRAUPEL AND MAYBE EVEN A BIT RUMBLE OR TWO OF
THUNDER. COVERAGE AND INTENSITY OF THE SHOWERS WILL BE GREATEST
DURING THE AFTERNOON/EVENING HOURS AND TIED TO INDIVIDUAL VORT LOBES
PIVOTING AROUND THE UPPER LOW. WHILE THERE WILL BE A DIURNAL MAXIMA
OF SHOWER ACTIVITY...SOME SHOWERS WILL CONTINUE THROUGH THE
NIGHT...ESPECIALLY NEAR MORE VIGOROUS VORTS. CONSIDERABLE CLOUD
COVER AND VERY COLD NATURE OF THE LOW WILL RESULT IN MUCH BELOW
AVERAGE TEMPS THURS AND FRIDAY WITH HIGHS STRUGGLING TO REACH 50F
BOTH BOTH DAYS.
MEDIUM RANGE MODELS REMAIN LOCKSTEP WITH EACH OTHER IN THIS UPPER
LOW MOVING EAST UNCHARACTERISTICALLY QUICK FOR SUCH A STRONG/BIG CUT
OFF. THIS HASTY EXIT IS THE RESULT OF YET ANOTHER UNUSUALLY STRONG
UPPER TROUGH/CUT OFF LOW PROGGED TO TAKE SHAPE OVER THE PAC NW
RESULTING IN DOWNSTREAM AMPLIFICATION OF THE RIDGE OVER OUR AREA. IN
FACT...MEDIUM RANGE MODELS ARE IN GREAT AGREEMENT IN BUILDING A
RESPECTABLE UPPER RIDGE INTO THE REGION WITH H8 TEMPS SURGING TO 1-2
SIGMA ABOVE AVERAGE BY EARLY NEXT WEEK. ALL INDICATIONS ARE AT THIS
POINT THAT WE COULD SEE READINGS BACK ABOVE 70 DEGREES BY EARLY NEXT
WEEK.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* TIMING OF COLD FRONTAL PASSAGE AND ASSOCIATED WIND SHIFT
TONIGHT.
* PERIODS OF SHRA/TSRA REST OF AFTERNOON AND THIS EVENING.
* LOCAL MVFR CEILING AND/OR VISIBILITY WITH SHRA/TSRA BECOMING
PREVAILING MVFR CEILINGS BY EARLY EVENING.
* THREAT OF SHRA/TSRA AND ASSOCIATED MVFR CONDITIONS INCREASING
DURING LATER THU MORNING INTO AFTERNOON.
TRS
//DISCUSSION...UPDATED 18Z...
INCREASING LOW LEVEL MOISTURE HAS QUICKLY ADVECTED NORTH-NORTHEAST
FROM THE MID MS VALLEY ACROSS NORTHERN IL AND FAR NW IN WITH MID-
UPPER 50S DEW POINTS JUST UPSTREAM OVER NE MO AND CENTRAL IL.
AS AN UPPER LOW...WITHIN THE UPPER TROUGH FROM MANITOBA SSE TO
NORTHERN OK...CONTINUES TO DEVELOP AND PROGRESS SOUTHEASTWARD OVER
THE UPPER MS VALLEY THE REST OF THE AFTERNOON AND THIS EVENING
SHRA AND TSRA EXPECTED TO BECOME MORE NUMEROUS AS INCREASINGLY
STRONG ISENTROPIC LIFT SPREADS E AND NE ACROSS THE MID MS VALLEY.
MODELS IN FAIRLY GOOD AGREEMENT IN ROTATING THE MID LEVEL TROUGH
TO NW AND E CENTRAL IL BY 06Z AND PUSHING THE COLD FRONT...
CURRENTLY CURVING FROM E CENTRAL MN AND W CENTRAL WI TO E CENTRAL
AND SE IA AND THEN TO NW AND W CENTRAL MO...E ACROSS THE MID MS
VALLEY AND TO IL BY MIDNIGHT. SOME LIGHTER SHOWERS MAY PERSIST
BEHIND THE COLD FRONT TIL THE MID LEVEL TROUGH AXIS PASSES BY
THEN SUBSIDENCE AND DRYING PREVAIL OVERNIGHT.
DURING THE DAY THU A NEARLY VERTICALLY STACKED LOW IS PROGGED TO
SETTLE SLOWLY SE FROM SOUTHEASTERN MN TO SW WI AND NE IA BY 00Z
FRI. COLD TEMPERATURES IN THE MID AND UPPER LEVELS ASSOCIATED WITH
THE STACKED LOW COLD POOL...ALONG WITH DEEP CYCLONIC FLOW...WILL
ENCOURAGE CU TO DEVELOP AND TO GROW TO A DEEP ENOUGH DEPTH TO
SUPPORT SHOWERS AND SOME TS WITH ELEVATED CAPE ACROSS THE AREA.
TRS
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
*HIGH CONFIDENCE IN INCREASING COVERAGE OF SHRA AND TSRA THROUGH
REST OF AFTERNOON INTO THIS EVENING.
*MODERATE CONFIDENCE IN TIMING OF PERIODS OF SHRA AND TSRA REST OF
AFTERNOON AND THIS EVENING.
*MODERATE CONFIDENCE IN TIME OF COLD FRONT PASSAGE/WINDSHIFT TO
WITHIN +/- 1 HR.
*MODERATE CONFIDENCE IN TIMING OF LOCAL MVFR CEILINGS AND
VISIBILITIES BECOMING PREVAILING BY THIS EVENING.
TRS
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
* THURSDAY NIGHT...RAIN WITH MVFR CIGS/VIS POSSIBLE.
* FRIDAY...RAIN LIKELY WITH CHANCE TSRA IN THE AFTERNOON. MVFR
CIGS/VIS POSSIBLE.
* SATURDAY AND SUNDAY...VFR. WX NIL.
* MONDAY AND TUESDAY...CHANCE OF SHRA.
KREIN
&&
.MARINE...
320 AM CDT
BRISK SOUTH WINDS WILL PERSIST THROUGH WED AS LOW PRESSURE OVER
SOUTH DAKOTA AND ANOTHER LOW JUST WEST OF LAKE WINNIPEG WILL
MERGE INTO A SINGLE LOW PRESSURE SYSTEM OVER NORTHERN MINNESOTA
BY THIS EVENING. WINDS SHOULD BE IN THE 30KT RANGE OVER THE OPEN
WATERS...BUT A FEW GALE FORCE GUSTS TO 35KT ARE NOT OUT OF THE
QUESTION. A STRONG COLD FRONT ASSOCIATED WITH THIS LOW WILL SWEEP
EAST ACROSS LAKE MICHIGAN WEDNESDAY NIGHT...SHIFTING WINDS TO MORE
SOUTHWESTERLY. WINDS WILL DIMINISH AS THE LOW SLOWLY DRIFTS EAST
ACROSS LAKE MICHIGAN FRIDAY AND INTO THE EASTERN GREAT LAKES BY
SATURDAY. WINDS WILL FURTHER WEAKEN AS A WEAK RIDGE OF HIGH
PRESSURE MOVES ACROSS THE MISSISSIPPI VALLEY FRIDAY NIGHT AND
SATURDAY. THE RIDGE WILL PUSH EAST OF LAKE MICHIGAN SATURDAY
NIGHT.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM THURSDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
219 PM CDT WED OCT 17 2012
.DISCUSSION...
1230 PM CDT
MAIN FORECAST ISSUES/CONCERNS THIS AFTERNOON ARE WITH
SHOWER/THUNDERSTORM POTENTIAL AND SMALL BUT NOT ZERO CHANCE FOR
SEVERE WEATHER ACROSS THE SOUTHERN CWA...CENTRAL/EAST CENTRAL
ILLINOIS AND NORTHWEST INDIANA.
MADE SOME MINOR EDITS TO THE GRIDS...PRIMARILY WITH RESPECT TO THE
POP/WX GRIDS FOR THIS AFTERNOON SLOWING DOWN THE ONSET OF PRECIP.
WAA WHICH HAS BEEN PROMINENT ALL MORNING HAS BEEN STIFLED WITH THE
APPROACH OF THE LARGE SCALE TROUGH TO THE WEST. ALTHOUGH THIS WAA
HAS WEAKENED...SEVERAL WAVES OF ENERGY CONTINUE TO EJECT OUT
AHEAD OF THIS SYSTEM PROVIDING ENOUGH LIFT TO AID IN EXPANSIVE
CLOUD SHIELD TO THE SOUTHWEST OF THE CWA...TO CONTINUE SPREADING
NORTH AS WELL AS SOME ISOLATED SHOWER AND THUNDERSTORM
DEVELOPMENT. LATEST RADAR IMAGERY DEPICTING AN ISOLATED AREA OF
SHOWERS QUICKLY MOVING NORTHEAST ACROSS COOK COUNTY. AS A NARROW
RIBBON OF INSTABILITY IS POKING NORTH ACROSS NORTHERN
ILLINOIS...PER LATEST RAP ANALYSIS...A FEW LIGHTNING STRIKES HAVE
BEEN REPORTED. ALTHOUGH...AM NOT EXPECTING MUCH TO RESULT FROM
THESE SHOWERS/THUNDERSTORMS OUTSIDE OF BRIEF GUSTY WINDS AND BRIEF
DOWNPOURS. SO...HAVE PULLED BACK POPS ACROSS THE CWA THROUGH EARLY
AFTERNOON WITH THE EXPECTED DELAY IN PRECIP. ALTHOUGH WITH THE
APPROACH OF A FAIRLY STOUT VORT LOBE OUT AHEAD OF THIS DIGGING
TROUGH...FORCING WILL REALLY RAMP UP. THIS WILL HELP AN EXPANDING
AREA OF PRECIP TO SPREAD NORTHEAST ACROSS THE ENTIRE CWA LATE THIS
AFTERNOON THROUGH THE EVENING. SEVERAL FORCING MECHANISMS WILL
COME TOGETHER DURING THIS TIME FRAME AND PROVIDE STRONG FORCING TO
OCCUR OVERHEAD. WITH THIS STRONG FORCING COINCIDING WITH AN
INCREASE IN MOISTURE...LINGERING WEAK INSTABILITY...AND AN
INCREASE IN BULK SHEAR...HAVE BECOME A LITTLE MORE CONCERNED WITH
THUNDERSTORM POTENTIAL. ALTHOUGH THUNDERSTORMS WILL BE POSSIBLE
ACROSS THE ENTIRE CWA THIS AFTERNOON...PREVIOUS THINKING CONTINUES
WITH THE BETTER CHANCES FOR THUNDERSTORMS APPEARING TO BE SOUTH OF
INTERSTATE 80 LATE THIS AFTERNOON AND EVENING WITH A FEW POSSIBLY
BECOMING STRONG TO SEVERE...WITH STRONG WINDS THE PRIMARY
CONCERNS.
RODRIGUEZ
//PREV DISCUSSION...
330 AM CDT
PRIMARY FORECAST CONCERNS THIS GO AROUND INCLUDE THE IMPACTS OF THE
VIGOROUS TROUGH OVER THE NORTHERN PLAINS THAT GUIDANCE CONTINUE TO
DEVELOP INTO AN ABNORMALLY VIGOROUS UPPER LOW THAT WILL MEANDER
AROUND THE REGION FOR THE REST OF THE WORK WEEK.
ELEVATED ISOLATED WAA CONVECTION OVER THE CHICAGO AREA NOW SHOULD
HAVE LIFTED NORTHEAST INTO MICHIGAN BY SUNRISE...WITH SOME
OPPORTUNITY FOR SOME SUNSHINE EARLY THIS MORNING...MAINLY EASTERN
CWA. WHAT LIMITED SUNSHINE THERE IS THIS MORNING SHOULD QUICKLY GIVE
WAY TO OVERCAST CONDITIONS BY EARLY AFTERNOON WITH RAIN CHANCES
GRADUALLY RAMPING UP. SURFACE OBS AND GOES SOUNDER PWAT IMAGERY BOTH
SHOW A RELATIVE DEARTH IN MOISTURE IMMEDIATELY UPSTREAM OVER
MISSOURI WHICH SHOULD KEEP US MOSTLY DRY THIS MORNING...BUT LURKING
JUST TO THE WEST IS SECONDARY SURGE OF DEEPER MOISTURE IMMEDIATELY
IN ADVANCE OF THE STRENGTHENING COLD FRONT. STRONG SOUTHERLY FLOW
TODAY WILL RESULT IN RAPID NORTHEASTWARD TRANSPORT OF THIS DEEPER
MOISTURE AND MODELS ARE BREAKING OUT SCATTERED PRECIPITATION BY
EARLY AFTERNOON IN RESPONSE TO THE STRONG PUSH OF HIGHER LOW LEVEL
THETA-E AIR MASS.
MORE ORGANIZED FRONTAL AND POST-FRONTAL PRECIPITATION LOOKS SLATED
TO ARRIVE IN OUR WESTERN CWA LATE THIS AFTERNOON INTO EARLY THIS
EVENING. A SUBSTANTIAL INCREASE IN THE COVERAGE AND INTENSITY OF THE
PRECIPITATION IS EXPECTED IN THE 21-03Z TIME FRAME AS THE DEEP
SYNOPTIC SCALE FORCING SPREADS SOUTHEAST AND BEGINS TO ENCOUNTER THE
DEEPER MOISTURE ADVECTING NORTHEAST INTO THE REGION. FORCING LOOKS
TO BE VERY IMPRESSIVE AS VIGOROUS SHORTWAVE PIVOTING AROUND THE BASE
OF THE INTENSIFYING UPPER LOW LEADS TO ENTIRE UPPER TROUGH/LOW
TAKING ON NEGATIVE TILT WITH ILLINOIS COUPLING OF STRONG UPPER LEVEL
DIVERGENCE AND VERY STRONG LOW LEVEL FRONTOGENESIS LEADING TO VERY
STRONG UPWARD VERTICAL VELOCITIES AND BLOSSOMING AREA OF PRECIP.
MOST MODELS GENERALLY KEEP THE INSTABILITY SOUTH OF OUR CWA...THOUGH
A FEW SREF MEMBERS DO BRING UPWARDS OF 250 J/KG OF SBCAPE INTO OUR
SOUTHERN CWA THIS EVENING. WHAT WE LACK IN INSTABILITY WILL
CERTAINLY BE MADE UP FOR WITH FORCING AND HAVE MAINTAINED CHANCE OF
THUNDER THIS AFTERNOON AND EVENING. WHILE LIGHTNING MAY NOT BE
OVERLY PREVALENT...WE COULD SEE A BAND OF STRONG FORCING LOW TOPPED
CONVECTION THAT COULD STILL TRANSPORT SOME STRONGER WINDS TO THE
SURFACE THIS EVENING...ESPECIALLY SOUTHERN CWA WHERE THERE COULD BE
A BIT OF SB INSTABILITY. THE STRONG FORCING AND SEASONABLY HIGH
PWATS SHOULD RESULT IN A FAIRLY RESPECTABLE RAINFALL ACROSS THE CWA
WITH WIDESPREAD 1 TO 2 THIRD OF A INCH TOTALS LIKELY...AND LOCALIZED
AMOUNTS OF AN INCH POSSIBLE.
TAKING A QUICK STEP BACK...TEMPS TODAY WILL BE TRICKY AS 08Z TEMPS
ARE STILL IN THE MID-UPPER 60S IN CHICAGO AND UPPER 50S/LOW 60S
OUTSIDE THE CITY. WHILE SUNSHINE SHOULD BE LIMITED TODAY...SUCH A
WARM START TO THE DAY DOES ARGUE FOR GOING A BIT ABOVE GUIDANCE FOR
HIGHS TODAY WITH PARTICULARLY EASTERN CWA STANDING A REASONABLE SHOT
AT CLIMBING ABOVE 70F AGAIN. AFTER AN UNSEASONABLY BALMY (ALMOST
SUMMER-LIKE NIGHT) TUES NIGHT...STRONG COLD AIR ADVECTION IN THE
WAKE OF THE FRONT TONIGHT WILL PROVIDE THE AREA WITH A COLD HARD
SLAP OF AUTUMNAL REALITY WITH READINGS BACK INTO THE 40S BY THURS
MORNING ALONG WITH MODERATELY BRISK WEST WINDS ADDING MORE OF A
CHILL TO THE AIR.
COULD LITERALLY CUT AND PASTE LAST NIGHT`S AFD INTO THIS AFD
REGARDING THURSDAY AND FRIDAY`S FORECAST. MASSIVE AND UNSEASONABLY
STRONG/COLD ATMOSPHERIC GYRE WILL SET-UP SHOP OVER THE WESTERN GREAT
LAKES RESULTING IN PERIODIC SHOWERY CONDITIONS THURSDAY INTO
FRIDAY...WITH STEEP LAPSE RATES AND COLD TEMPS ALOFT RESULT IN THE
POTENTIAL FOR SOME GRAUPEL AND MAYBE EVEN A BIT RUMBLE OR TWO OF
THUNDER. COVERAGE AND INTENSITY OF THE SHOWERS WILL BE GREATEST
DURING THE AFTERNOON/EVENING HOURS AND TIED TO INDIVIDUAL VORT LOBES
PIVOTING AROUND THE UPPER LOW. WHILE THERE WILL BE A DIURNAL MAXIMA
OF SHOWER ACTIVITY...SOME SHOWERS WILL CONTINUE THROUGH THE
NIGHT...ESPECIALLY NEAR MORE VIGOROUS VORTS. CONSIDERABLE CLOUD
COVER AND VERY COLD NATURE OF THE LOW WILL RESULT IN MUCH BELOW
AVERAGE TEMPS THURS AND FRIDAY WITH HIGHS STRUGGLING TO REACH 50F
BOTH BOTH DAYS.
MEDIUM RANGE MODELS REMAIN LOCKSTEP WITH EACH OTHER IN THIS UPPER
LOW MOVING EAST UNCHARACTERISTICALLY QUICK FOR SUCH A STRONG/BIG CUT
OFF. THIS HASTY EXIT IS THE RESULT OF YET ANOTHER UNUSUALLY STRONG
UPPER TROUGH/CUT OFF LOW PROGGED TO TAKE SHAPE OVER THE PAC NW
RESULTING IN DOWNSTREAM AMPLIFICATION OF THE RIDGE OVER OUR AREA. IN
FACT...MEDIUM RANGE MODELS ARE IN GREAT AGREEMENT IN BUILDING A
RESPECTABLE UPPER RIDGE INTO THE REGION WITH H8 TEMPS SURGING TO 1-2
SIGMA ABOVE AVERAGE BY EARLY NEXT WEEK. ALL INDICATIONS ARE AT THIS
POINT THAT WE COULD SEE READINGS BACK ABOVE 70 DEGREES BY EARLY NEXT
WEEK.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* TIMING OF COLD FRONTAL PASSAGE AND ASSOCIATED WIND SHIFT
TONIGHT.
* SHRA/TSRA BECOMING MORE NUMEROUS DURING MID-LATE AFTERNOON
AND PERSISTING INTO EVENING.
* LOCAL MVFR CEILING AND/OR VISIBILITY WITH SHRA/TSRA BECOMING
PREVAILING MVFR CEILINGS FOR A PERIOD FOLLOWING FROPA.
* THREAT OF SHRA/TSRA AND ASSOCIATED MVFR CONDITIONS INCREASING
DURING LATER MORNING INT AFTERNOON.
TRS
//DISCUSSION...UPDATED 18Z...
INCREASING LOW LEVEL MOISTURE HAS QUICKLY ADVECTED NORTH-NORTHEAST
FROM THE MID MS VALLEY ACROSS NORTHERN IL AND FAR NW IN WITH MID-
UPPER 50S DEW POINTS JUST UPSTREAM OVER NE MO AND CENTRAL IL.
AS AN UPPER LOW...WITHIN THE UPPER TROUGH FROM MANITOBA SSE TO
NORTHERN OK...CONTINUES TO DEVELOP AND PROGRESS SOUTHEASTWARD OVER
THE UPPER MS VALLEY THE REST OF THE AFTERNOON AND THIS EVENING
SHRA AND TSRA EXPECTED TO BECOME MORE NUMEROUS AS INCREASINGLY
STRONG ISENTROPIC LIFT SPREADS E AND NE ACROSS THE MID MS VALLEY.
MODELS IN FAIRLY GOOD AGREEMENT IN ROTATING THE MID LEVEL TROUGH
TO NW AND E CENTRAL IL BY 06Z AND PUSHING THE COLD FRONT...
CURRENTLY CURVING FROM E CENTRAL MN AND W CENTRAL WI TO E CENTRAL
AND SE IA AND THEN TO NW AND W CENTRAL MO...E ACROSS THE MID MS
VALLEY AND TO IL BY MIDNIGHT. SOME LIGHTER SHOWERS MAY PERSIST
BEHIND THE COLD FRONT TIL THE MID LEVEL TROUGH AXIS PASSES BY
THEN SUBSIDENCE AND DRYING PREVAIL OVERNIGHT.
DURING THE DAY THU A NEARLY VERTICALLY STACKED LOW IS PROGGED TO
SETTLE SLOWLY SE FROM SOUTHEASTERN MN TO SW WI AND NE IA BY 00Z
FRI. COLD TEMPERATURES IN THE MID AND UPPER LEVELS ASSOCIATED WITH
THE STACKED LOW COLD POOL...ALONG WITH DEEP CYCLONIC FLOW...WILL
ENCOURAGE CU TO DEVELOP AND TO GROW TO A DEEP ENOUGH DEPTH TO
SUPPORT SHOWERS AND SOME TS WITH ELEVATED CAPE ACROSS THE AREA.
TRS
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
*HIGH CONFIDENCE IN INCREASING COVERAGE OF SHRA AND TS THROUGH
REST OF AFTERNOON INTO THIS EVENING.
*MODERATE CONFIDENCE IN TIME OF COLD FRONT PASSAGE/WINDSHIFT TO
WITHIN +/- 1 HR.
*MODERATE CONFIDENCE IN TIMING OF LOCAL MVFR CEILINGS AND
VISIBILITIES BECOMING PREVAILING BY THIS EVENING.
TRS
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
* THURSDAY NIGHT...RAIN WITH MVFR CIGS/VIS POSSIBLE.
* FRIDAY...RAIN LIKELY WITH CHANCE TSRA IN THE AFTERNOON. MVFR
CIGS/VIS POSSIBLE.
* SATURDAY AND SUNDAY...VFR. WX NIL.
* MONDAY AND TUESDAY...CHANCE OF SHRA.
KREIN
&&
.MARINE...
320 AM CDT
BRISK SOUTH WINDS WILL PERSIST THROUGH WED AS LOW PRESSURE OVER
SOUTH DAKOTA AND ANOTHER LOW JUST WEST OF LAKE WINNIPEG WILL
MERGE INTO A SINGLE LOW PRESSURE SYSTEM OVER NORTHERN MINNESOTA
BY THIS EVENING. WINDS SHOULD BE IN THE 30KT RANGE OVER THE OPEN
WATERS...BUT A FEW GALE FORCE GUSTS TO 35KT ARE NOT OUT OF THE
QUESTION. A STRONG COLD FRONT ASSOCIATED WITH THIS LOW WILL SWEEP
EAST ACROSS LAKE MICHIGAN WEDNESDAY NIGHT...SHIFTING WINDS TO MORE
SOUTHWESTERLY. WINDS WILL DIMINISH AS THE LOW SLOWLY DRIFTS EAST
ACROSS LAKE MICHIGAN FRIDAY AND INTO THE EASTERN GREAT LAKES BY
SATURDAY. WINDS WILL FURTHER WEAKEN AS A WEAK RIDGE OF HIGH
PRESSURE MOVES ACROSS THE MISSISSIPPI VALLEY FRIDAY NIGHT AND
SATURDAY. THE RIDGE WILL PUSH EAST OF LAKE MICHIGAN SATURDAY
NIGHT.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM THURSDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
616 PM CDT THU OCT 18 2012
.AVIATION...
MVFR CONDITIONS WITH -RA WILL DETERIORATE TO IFR CONDITIONS AFT
03Z/19 AS THE UPPER LOW ROTATES SOUTHEAST INTO NORTHERN ILLINOIS.
THE -RA WILL END FOR SEVERAL HOURS BEFORE -DZ DEVELOPS AFT 03Z/19. THE
POTENTIAL DOES EXIST FOR PERIODS OF LIFR PRIOR TO SUNRISE FRIDAY.
AFT SUNRISE FRIDAY THERE WILL BE A SLOW IMPROVEMENT TO MVFR
CONDITIONS. LIKE TODAY...A PERIOD OF RAIN SHOWERS IS LIKELY OVER
THE REGION DURING THE LATE MORNING THROUGH AFTERNOON HOURS. MVFR
CONDITIONS SHOULD CONTINUE DURING THIS PERIOD.
ERVIN
&&
.PREV DISCUSSION... /ISSUED 432 PM CDT THU OCT 18 2012/
UPDATE...
UPDATED FOR 100 PERCENT COVERAGE OF RAINFALL IN THE PERSISTENT
BAND OF RAIN OVER THE CWA THE REMAINDER OF THE AFTERNOON. ALSO
INCREASED POPS SOMEWHAT OVER THE SOUTH HALF THIS EVENING DUE TO
WIDESPREAD COVERAGE. RAINFALL AMOUNTS FROM TODAY AND EARLY EVENING
SHOULD RANGE FROM 0.1 TO 0.2 IN MOST LOCATIONS.
ERVIN
PREV DISCUSSION... /ISSUED 352 PM CDT THU OCT 18 2012/
SYNOPSIS...
12Z UA ANALYSIS HAS AN 850MB LOW ALONG THE MN/WI BORDER NORTHEAST
OF KMSP. THE 850MB COLD FRONT RAN FROM THE LOW INTO LOWER MICHIGAN
AND THEN SOUTH TO SOUTHEAST ARKANSAS AND THEN INTO CENTRAL TEXAS.
SEVERAL TROFS RAN BEHIND THE COLD FRONT FROM WI/IL BACK THROUGH
IOWA AND NEBRASKA. SATELLITE/RADAR TRENDS THROUGH MID AFTERNOON
SHOW EXTENSIVE WRAP AROUND CLOUDS ACROSS THE AREA WITH LIGHT RAIN
AND DRIZZLE ACROSS THE AREA.
18Z SFC ANALYSIS PLACES THE SFC LOW NEAR KMSP WITH AN OCCLUDED
FRONT NORTHEAST TO ANOTHER SFC LOW OVER WESTERN LAKE SUPERIOR.
NUMEROUS WEAK TROFS RAN FROM WI/IL BACK THROUGH IOWA AND INTO
NEBRASKA. DEW POINTS WERE MAINLY IN THE 30S AND 40S ACROSS THE
MIDWEST.
SHORT TERM...TONIGHT AND FRIDAY...
ISENTROPIC UPGLIDE WILL CONTINUE ACROSS THE AREA LATE THIS
AFTERNOON RESULTING IN A LIGHT RAIN. HOWEVER...DOWNGLIDE WAS
OCCURRING ACROSS NORTHERN AND EXTREME NORTHEAST IOWA RESULTING IN
DRY CONDITIONS. TRENDS FROM THE RAP INDICATE THIS DOWNGLIDE WILL
MOVE INTO THE NORTHWEST TO NORTHERN CWFA EARLY THIS EVENING
BRIEFLY ENDING THE RAIN. THE MORE SUBSTANTIAL RAIN WILL PUSH TO
THE SOUTHERN THIRD TO 40 PERCENT OF THE CWFA.
BY LATE EVENING AND CONTINUING OVERNIGHT WEAK UPGLIDE WILL AGAIN
MOVE INTO THE NORTHERN CWFA WHILE THE MORE SUBSTANTIAL RAIN
CONTINUES TO SINK SOUTH. THUS LIGHT RAIN/DRIZZLE WILL AGAIN
DEVELOP ACROSS THE NORTHERN CWFA. AFTER MIDNIGHT WINDS ACROSS THE
NORTHERN PARTS OF THE CWFA DROP OFF SUGGESTING SOME PATCHY FOG MAY
DEVELOP PRIOR TO SUNRISE.
ON FRIDAY SPOTTY LIGHT RAIN/DRIZZLE WILL CONTINUE EARLY IN THE
MORNING WITH SOME PATCHY FOG POSSIBLE ACROSS THE NORTH. ISENTROPIC
UPGLIDE AGAIN BECOMES RE-ESTABLISHED BY LATE MORNING AND THROUGH
THE AFTERNOON. THUS...LIGHT RAIN IN CENTRAL IOWA WILL AGAIN ADVECT
INTO THE WESTERN CWFA AND CONTINUE MOVING EAST THROUGH THE
AFTERNOON HOURS. RIGHT NOW MAX TEMPERATURES FOR FRIDAY ARE IN THE
UPPER 40S TO LOWER 50S. HOWEVER...THESE MAY STILL BE TOO WARM AND
ACTUAL TEMPERATURES COULD BE SIMILAR TO THURSDAY. 08
LONG TERM...FRIDAY NIGHT THROUGH NEXT THURSDAY...
UPPER LOW WILL GRADUALLY RELINQUISH CONTROL OF OUR WEATHER FRIDAY
NIGHT INTO SATURDAY AS IT CONTINUES TO PUSHLY SLOWLY EAST ACROSS
THE GREAT LAKES REGION. AREAS OF LIGHT RAIN AND DRIZZLE LOOK TO
SHUT DOWN FRIDAY EVENING WITH SUBSIDENCE BUILDING FOR OVERNIGHT.
DESPITE THE SUBSIDENCE HAVE REMAINED MORE ON PESSIMISTIC SIDE ON
SKY COVER AND CLEARING TRENDS FRIDAY NIGHT INTO SATURDAY...GIVEN
ABUNDANT LOW LEVEL MOISTURE (AIDED BY PAST FEW DAYS OF RAIN)
BENEATH INVERSION... LOWER SUN ANGLE... AND EXTENSIVE CLOUD SHIELD
AROUND UPPER LOW DEPICTED WELL BY THE NAM MODEL WHICH IS MOST
AGGRESSIVE WITH MAINTAINING CLOUDS. AS RESULT... CONTINUE TO BE
NEAR WARM SIDE OF GUIDANCE ON LOWS FRIDAY NIGHT AND NEAR BLEND OR
COOL SIDE OF GUIDANCE FOR HIGHS ON SATURDAY.
PATTERN ALOFT SET TO TRANSITION TO SOUTHWEST FLOW OVER THE REGION
BY LATE IN THE WEEKEND... WITH THE MEDIUM RANGE MODELS GENERALLY
AGREEING ON MAINTAINING SOUTHWEST FLOW ALOFT THROUGH MUCH OF NEXT
WEEK. THIS REGIME FAVORS ABOVE NORMAL TEMPS ALONG WITH BOUTS OF
UNSETTLED WEATHER. THE CHALLENGE LIES IN THE DETAILS OF THE
FORECAST AS THE MODELS DIVERGE ON ENERGY EJECTING FROM WESTERN
TROUGH... ESPECIALLY BY TUESDAY AND CONTINUING INTO THURSDAY... WHICH
HAS IMPACT ON MOVEMENT OF FRONTAL ZONE AND SUBSEQUENT TEMPERATURE
FORECAST. GIVEN THE UNCERTAINTY... STAYED LARGELY WITH MODEL CONSENSUS
ON TEMPS/POPS FOR MONDAY THROUGH THURSDAY. DPROG/DT OF BOTH ECMWF
AND GFS SHOW CONTINUED SLOWING AND FURTHER NORTHWEST TREND WITH FRONTAL
ZONE IN GENERAL BY TUESDAY INTO THURSDAY. IF TRENDS PERSIST WOULD
EXPECT DECREASE IN RAIN CHANCES AND FURTHER WARMING ON TEMPS TO MUCH
ABOVE NORMAL FOR SOME OR MOST OF THIS PERIOD TUESDAY INTO THURSDAY.
TRANSITION TO MUCH COLDER REGIME IS STILL DEPICTED BY BOTH ECMWF AND
GFS BEYOND THE SCOPE OF CURRENT EXTENDED. MAIN CHALLENGE APPEARS TO
BE JUST EXACTLY WHEN THIS TRANSITION OCCURS. 05
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
ERVIN
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
417 PM CDT WED OCT 17 2012
.UPDATE...
UPDATED POPS AND WEATHER TO REFLECT THE CURRENT RADAR POSITION OF
WIDESPREAD SHOWERS FOR THIS AFTERNOON AND EARLY EVENING.
ERVIN
&&
.PREV DISCUSSION... /ISSUED 331 PM CDT WED OCT 17 2012/
SYNOPSIS...
12Z UA ANALYSIS HAS 850MB LOWS ON THE NORTH SHORE OF LAKE WINNIPEG
AND IN NORTHWEST MINNESOTA. AN 850MB COLD FRONT RAN FROM THE
MINNESOTA LOW INTO SOUTHEAST NEW MEXICO WITH A TROF FROM SOUTHERN
MINNESOTA INTO SOUTH TEXAS. SATELLITE/RADAR TRENDS SHOWS EXTENSIVE
LOW AND MID LEVEL CLOUDS WITH STRONG CONVECTION ACROSS MISSOURI
AND MORE SCATTERED CONVECTION ACROSS IOWA/ILLINOIS.
18Z SFC ANALYSIS HAS A LOW EAST OF KFAR WITH THE COLD FRONT SOUTH
INTO SOUTHEAST KANSAS. TWO MESO LOWS WERE IN SOUTHWEST MISSOURI
AND NORTHEAST OKLAHOMA. A PRE-FRONTAL TROF RAN FROM JUST EAST OF
KMSP TO ABOUT KIRK. DEW POINTS AHEAD OF THE COLD FRONT WERE IN THE
50S AND 60S WITH 20S AND 30S BEHIND THE COLD FRONT IN THE PLAINS.
SHORT TERM...TONIGHT AND THURSDAY
THE CURRENT PICTURE AT MID AFTERNOON HAS MID LEVEL FORCING OR A
WEAK VORT MAX PUSHING A SLUG OF MAINLY SHRA ACROSS THE CWFA. A
MUCH STRONGER VORT MAX IS ROTATING NORTHEAST ACROSS MISSOURI. IF
THE TRENDS OF THE RAP ARE CORRECT...THERE SHOULD BE A BAND OF
ENHANCED CONVECTION THAT DEVELOPS LATE THIS AFTERNOON IN THE
SOUTHEAST QUADRANT OF THE CWFA AND ROTATES NORTHEAST.
THIS BAND OF CONVECTION WILL BE ACROSS ROUGHLY THE EASTERN 40
PERCENT OF THE CWFA DURING THE EARLY EVENING HOURS BEFORE EXITING
THE CWFA. SOME LINGERING SHRA SHOULD THEN BE SEEN IN THE THE MID
AND LATE EVENING HOURS BEFORE ENDING.
AFTER MIDNIGHT THERE SHOULD BE SOME CLEARING OF THE CLOUDS WITH
DRY CONDITIONS AS CONDENSATION PRESSURE DEFICITS RISE
CONSIDERABLY. CONDENSATION PRESSURE DEFICITS IN THE 850-700MB
LAYER COLLAPSE AGAIN ACROSS THE CWFA PRIOR TO SUNRISE BUT THE
1000-850MB LAYER CONDENSATION PRESSURE DEFICITS ONLY LOWER
SLIGHTLY. THUS MOST OF THE AREA SHOULD REMAIN DRY AFTER MIDNIGHT
BUT SOME SPRINKLES MIGHT ENTER THE FAR NORTHWEST PART OF THE CWFA
JUST PRIOR TO DAWN.
THURSDAY...WRAP AROUND CLOUDS/PRECIP MOVE SOUTHEAST THROUGH THE
CWFA DURING THE MORNING HOURS. STEEP LAPSE RATES WILL AID IN
DEVELOPING NEW DIURNAL CLOUDS IN AREAS THAT WERE PARTIALLY CLEAR
AT SUNRISE. SCATTERED SHRA WILL BECOME MORE NUMEROUS DURING THE
DAY AS A VORT MAX ROTATES THROUGH AND INCREASES THE LIFT. THE
FREEZING LEVEL IS 3.0-3.5 KFT AGL PLUS/MINUS 700 FT DEPENDING ON
LOCAL ELEVATION ABOVE SEA LEVEL. HOWEVER...THE LOWEST 2 KFT ABOVE
THE GROUND REMAINS ABOVE FREEZING. THUS IN THE STRONGER SHOWERS
THE POTENTIAL DOES EXIST FOR SOME SMALL GRAUPEL TO DEVELOP THAT
REACHES THE GROUND.
TEMPERATURES WILL REMAIN IN THE 40S FOR MUCH OF THE DAY BUT THE
SOUTHEAST THIRD TO 40 PERCENT OF THE CWFA MAY MANAGE TO GET INTO
THE LOWER 50S. REGARDLESS...IT WILL BE A COLD RAW DAY WHEN THE
WIND IS FACTORED IN. 08
LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY
UPPER LOW PROGGED TO EXIT INTO THE GREAT LAKES REGION BY FRI NGT.
UNTIL THEN WILL SEE CONSIDERABLE CLOUDINESS ALONG WITH BOUTS OF
LIGHT RAIN OR SHOWERS... AS SPOKES OF ENERGY ROTATE DOWN THE
BACKSIDE OF THE LOW. CLOUDS WILL ACT AS BLANKET AND LIMIT DIURNAL
SWINGS INTO FRI. CLOUD FORECAST CHALLENGING FRI NGT INTO SAT WITH
OVERALL INCOMING SUBSIDENCE IN WAKE OF DEPARTING LOW SUPPORTIVE OF
CLEARING... BUT NAM BUFR SOUNDINGS DEPICT A LOT OF LOW LEVEL
MOISTURE TRAPPED BENEATH SUBSIDENCE INVERSION. TIME OF YEAR WITH
LOWER SUN ANGLE BECOMING MORE FAVORABLE FOR THESE SCENARIOS AND
NUDGED TOWARD A MORE PESSIMISTIC SKY COVER FRI NGT THUS STAYING AT
OR ABOVE WARM SIDE OF GUIDANCE ON LOWS.
SAT-SUN... DRY WITH WARMING TREND TO ABOVE NORMAL TEMPS BY SUN AS
NEXT SIGNIFICANT TROUGH PUSHES INTO THE PACIFIC NORTHWEST... WHICH
RESULTS IN DOWNSTREAM AMPLIFICATION OF UPPER RIDGE OVER THE REGION.
MON-WED... ABOVE NORMAL TEMPS GENERALLY SUGGESTED WITH DEEP TROUGHING
OVER THE WESTERN CONUS AND SW FLOW ALOFT. SW FLOW COUPLED WITH FRONTAL
ZONE WAVERING NEARBY WILL RESULT IN OCCASIONAL RAIN CHCS AS WELL
DURING THE PERIOD. THE FIRST RAIN CHCS APPEAR TO ARRIVE AS EARLY AS
MONDAY MORNING WITH MORE ROBUST LOW LEVEL WARM ADVECTION REGIME.
OTHERWISE... IT IS DIFFICULT TO PIN DOWN RAIN CHCS THEREAFTER WITH
MODELS OFFERING DIFFERENCES ON LOCATION OF THE FRONT AND TIMING OF
UPPER LEVEL DISTURBANCES EJECTING FROM WESTERN TROUGH.
TRANSITION TO SIGNIFICANTLY COLDER REGIME IS DEPICTED BY ECMWF AND GFS
BY THE END OF NEXT WEEK INTO NEXT WEEKEND. 05
AVIATION... /ISSUED 1247 PM CDT WED OCT 17 2012/
A COLD FRONT WILL SWEEP THROUGH EASTERN IOWA AND ILLINOIS IN THE
18Z/17 TO 00Z/18 TIME FRAME. VFR WX IS GENERALLY EXPECTED WITH
SPRINKLES OR SHRA. ALONG/EAST OF THE MISSISSIPPI RIVER ISOLD TSRA
WILL BE POSSIBLE THAT ARE EXPECTED TO BECOME MORE NUMEROUS AFT
21Z. VFR CONDITIONS ARE EXPECTED BUT THERE MAY BE BRIEF INCURSIONS
OF MVFR CONDITIONS WITH ANY TSRA OR STRONGER SHRA. AFT 00Z/18 VFR
CONDITIONS ARE EXPECTED. CIGS WILL LOWER AGAIN AFT 12Z/18 BUT
SHOULD REMAIN VFR. 08
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
331 PM CDT WED OCT 17 2012
.SYNOPSIS...
12Z UA ANALYSIS HAS 850MB LOWS ON THE NORTH SHORE OF LAKE WINNIPEG
AND IN NORTHWEST MINNESOTA. AN 850MB COLD FRONT RAN FROM THE
MINNESOTA LOW INTO SOUTHEAST NEW MEXICO WITH A TROF FROM SOUTHERN
MINNESOTA INTO SOUTH TEXAS. SATELLITE/RADAR TRENDS SHOWS EXTENSIVE
LOW AND MID LEVEL CLOUDS WITH STRONG CONVECTION ACROSS MISSOURI
AND MORE SCATTERED CONVECTION ACROSS IOWA/ILLINOIS.
18Z SFC ANALYSIS HAS A LOW EAST OF KFAR WITH THE COLD FRONT SOUTH
INTO SOUTHEAST KANSAS. TWO MESO LOWS WERE IN SOUTHWEST MISSOURI
AND NORTHEAST OKLAHOMA. A PRE-FRONTAL TROF RAN FROM JUST EAST OF
KMSP TO ABOUT KIRK. DEW POINTS AHEAD OF THE COLD FRONT WERE IN THE
50S AND 60S WITH 20S AND 30S BEHIND THE COLD FRONT IN THE PLAINS.
&&
.SHORT TERM...TONIGHT AND THURSDAY
THE CURRENT PICTURE AT MID AFTERNOON HAS MID LEVEL FORCING OR A
WEAK VORT MAX PUSHING A SLUG OF MAINLY SHRA ACROSS THE CWFA. A
MUCH STRONGER VORT MAX IS ROTATING NORTHEAST ACROSS MISSOURI. IF
THE TRENDS OF THE RAP ARE CORRECT...THERE SHOULD BE A BAND OF
ENHANCED CONVECTION THAT DEVELOPS LATE THIS AFTERNOON IN THE
SOUTHEAST QUADRANT OF THE CWFA AND ROTATES NORTHEAST.
THIS BAND OF CONVECTION WILL BE ACROSS ROUGHLY THE EASTERN 40
PERCENT OF THE CWFA DURING THE EARLY EVENING HOURS BEFORE EXITING
THE CWFA. SOME LINGERING SHRA SHOULD THEN BE SEEN IN THE THE MID
AND LATE EVENING HOURS BEFORE ENDING.
AFTER MIDNIGHT THERE SHOULD BE SOME CLEARING OF THE CLOUDS WITH
DRY CONDITIONS AS CONDENSATION PRESSURE DEFICITS RISE
CONSIDERABLY. CONDENSATION PRESSURE DEFICITS IN THE 850-700MB
LAYER COLLAPSE AGAIN ACROSS THE CWFA PRIOR TO SUNRISE BUT THE
1000-850MB LAYER CONDENSATION PRESSURE DEFICITS ONLY LOWER
SLIGHTLY. THUS MOST OF THE AREA SHOULD REMAIN DRY AFTER MIDNIGHT
BUT SOME SPRINKLES MIGHT ENTER THE FAR NORTHWEST PART OF THE CWFA
JUST PRIOR TO DAWN.
THURSDAY...WRAP AROUND CLOUDS/PRECIP MOVE SOUTHEAST THROUGH THE
CWFA DURING THE MORNING HOURS. STEEP LAPSE RATES WILL AID IN
DEVELOPING NEW DIURNAL CLOUDS IN AREAS THAT WERE PARTIALLY CLEAR
AT SUNRISE. SCATTERED SHRA WILL BECOME MORE NUMEROUS DURING THE
DAY AS A VORT MAX ROTATES THROUGH AND INCREASES THE LIFT. THE
FREEZING LEVEL IS 3.0-3.5 KFT AGL PLUS/MINUS 700 FT DEPENDING ON
LOCAL ELEVATION ABOVE SEA LEVEL. HOWEVER...THE LOWEST 2 KFT ABOVE
THE GROUND REMAINS ABOVE FREEZING. THUS IN THE STRONGER SHOWERS
THE POTENTIAL DOES EXIST FOR SOME SMALL GRAUPEL TO DEVELOP THAT
REACHES THE GROUND.
TEMPERATURES WILL REMAIN IN THE 40S FOR MUCH OF THE DAY BUT THE
SOUTHEAST THIRD TO 40 PERCENT OF THE CWFA MAY MANAGE TO GET INTO
THE LOWER 50S. REGARDLESS...IT WILL BE A COLD RAW DAY WHEN THE
WIND IS FACTORED IN. 08
.LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY
UPPER LOW PROGGED TO EXIT INTO THE GREAT LAKES REGION BY FRI NGT.
UNTIL THEN WILL SEE CONSIDERABLE CLOUDINESS ALONG WITH BOUTS OF
LIGHT RAIN OR SHOWERS... AS SPOKES OF ENERGY ROTATE DOWN THE
BACKSIDE OF THE LOW. CLOUDS WILL ACT AS BLANKET AND LIMIT DIURNAL
SWINGS INTO FRI. CLOUD FORECAST CHALLENGING FRI NGT INTO SAT WITH
OVERALL INCOMING SUBSIDENCE IN WAKE OF DEPARTING LOW SUPPORTIVE OF
CLEARING... BUT NAM BUFR SOUNDINGS DEPICT A LOT OF LOW LEVEL
MOISTURE TRAPPED BENEATH SUBSIDENCE INVERSION. TIME OF YEAR WITH
LOWER SUN ANGLE BECOMING MORE FAVORABLE FOR THESE SCENARIOS AND
NUDGED TOWARD A MORE PESSIMISTIC SKY COVER FRI NGT THUS STAYING AT
OR ABOVE WARM SIDE OF GUIDANCE ON LOWS.
SAT-SUN... DRY WITH WARMING TREND TO ABOVE NORMAL TEMPS BY SUN AS
NEXT SIGNIFICANT TROUGH PUSHES INTO THE PACIFIC NORTHWEST... WHICH
RESULTS IN DOWNSTREAM AMPLIFICATION OF UPPER RIDGE OVER THE REGION.
MON-WED... ABOVE NORMAL TEMPS GENERALLY SUGGESTED WITH DEEP TROUGHING
OVER THE WESTERN CONUS AND SW FLOW ALOFT. SW FLOW COUPLED WITH FRONTAL
ZONE WAVERING NEARBY WILL RESULT IN OCCASIONAL RAIN CHCS AS WELL
DURING THE PERIOD. THE FIRST RAIN CHCS APPEAR TO ARRIVE AS EARLY AS
MONDAY MORNING WITH MORE ROBUST LOW LEVEL WARM ADVECTION REGIME.
OTHERWISE... IT IS DIFFICULT TO PIN DOWN RAIN CHCS THEREAFTER WITH
MODELS OFFERING DIFFERENCES ON LOCATION OF THE FRONT AND TIMING OF
UPPER LEVEL DISTURBANCES EJECTING FROM WESTERN TROUGH.
TRANSITION TO SIGNIFICANTLY COLDER REGIME IS DEPICTED BY ECMWF AND GFS
BY THE END OF NEXT WEEK INTO NEXT WEEKEND. 05
&&
.AVIATION... /ISSUED 1247 PM CDT WED OCT 17 2012/
A COLD FRONT WILL SWEEP THROUGH EASTERN IOWA AND ILLINOIS IN THE
18Z/17 TO 00Z/18 TIME FRAME. VFR WX IS GENERALLY EXPECTED WITH
SPRINKLES OR SHRA. ALONG/EAST OF THE MISSISSIPPI RIVER ISOLD TSRA
WILL BE POSSIBLE THAT ARE EXPECTED TO BECOME MORE NUMEROUS AFT
21Z. VFR CONDITIONS ARE EXPECTED BUT THERE MAY BE BRIEF INCURSIONS
OF MVFR CONDITIONS WITH ANY TSRA OR STRONGER SHRA. AFT 00Z/18 VFR
CONDITIONS ARE EXPECTED. CIGS WILL LOWER AGAIN AFT 12Z/18 BUT
SHOULD REMAIN VFR. 08
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
08/05
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1247 PM CDT WED OCT 17 2012
.UPDATE...
ANOTHER UPDATE HAS BEEN DONE TO THE FCST. THE POSSIBILITY OF A
NONLINEAR EVENT IS NOW A BIT HIGHER THAN IT WAS A FEW HOURS AGO.
BASED ON SUGGESTED TRENDS FROM THE RAP AND RADAR...THE
DEVELOPMENT OF ISOLATED TSRA ARE POSSIBLE PRIOR TO MID AFTERNOON
FROM APPROXIMATELY THE MISS RIVER ON EAST. THE MOISTURE BEING
ADVECTED NORTHWARD IS STARTING TO WIN AGAINST THE DRY AIR WITH
MORE VIRGA SHOWING UP ON RADAR.
TRENDS IN THE RAP MODEL ARE SUGGESTING A THETA E GRADIENT IS
DEVELOPING JUST WEST OF THE MISSISSIPPI. THIS GRADIENT ALONG WITH
WHAT DIFFERENTIAL HEATING OCCURRED MAY BE JUST ENOUGH TO INITIATE
A FEW ISOLATE TSRA. TSRA THAT HAVE DEVELOPED FROM EASTERN MISSOURI
INTO CENTRAL ILLINOIS SHOULD WEAKEN A LITTLE AS THEY ENCOUNTER
SLIGHTLY DRIER AIR.
THERE SHOULD STILL BE A RESPECTABLE BAND OF CONVECTION THAT FIRES
MID TO LATE AFTERNOON ALONG/EAST OF THE MISSISSIPPI RIVER. THE
TIMING AND PLACEMENT OF SAID BAND AS OF YET IS NOT FULLY KNOWN BUT
SHOULD BECOME OBVIOUS OVER THE NEXT FEW HOURS. ..08..
&&
.AVIATION...
A COLD FRONT WILL SWEEP THROUGH EASTERN IOWA AND ILLINOIS IN THE
18Z/17 TO 00Z/18 TIME FRAME. VFR WX IS GENERALLY EXPECTED WITH
SPRINKLES OR SHRA. ALONG/EAST OF THE MISSISSIPPI RIVER ISOLD TSRA
WILL BE POSSIBLE THAT ARE EXPECTED TO BECOME MORE NUMEROUS AFT
21Z. VFR CONDITIONS ARE EXPECTED BUT THERE MAY BE BRIEF INCURSIONS
OF MVFR CONDITIONS WITH ANY TSRA OR STRONGER SHRA. AFT 00Z/18 VFR
CONDITIONS ARE EXPECTED. CIGS WILL LOWER AGAIN AFT 12Z/18 BUT
SHOULD REMAIN VFR. ..08..
&&
.PREV DISCUSSION... /ISSUED 1053 AM CDT WED OCT 17 2012/
UPDATE...
A FAIRLY SIGNIFICANT REVISION TO THE FCST HAS BEEN DONE.
HOWEVER...THE MODELS ARE HINTING THAT A NONLINEAR EVENT MAY BE IN
THE OFFERING. IF CORRECT...THERE COULD BE ADDITIONAL
CHANGES...POSSIBLY SIGNIFICANT...TO THE FCST.
CURRENT DATA SHOWS THE WAA PRECIP IS SLOWLY EVAPORATING DUE TO THE
INITIALLY DRY ATMOSPHERE ACROSS THE AREA. WHAT IS BEING SUGGESTED
BY THE RAP AND THE 12Z WRF IS THAT THE INITIAL PLUME OF 6-7C 850MB
MOISTURE OVER THE AREA...PER 12Z RAOBS...WILL SHIFT EAST THE
REMAINDER OF THE MORNING. THUS THERE SHOULD BE MORE DRY AIR ALOFT
TO GENERATE MAINLY VIRGA/SPRINKLES WITH SCATTERED SHRA. THIS
SCENARIO IS PARTLY SUPPORTED BY A VORT MAX ROTATING THROUGH THE
AREA PER THE RAP/WRF THIS MORNING WITH LIFT INCREASING AND THEN
DECREASING.
THIS AFTERNOON THE MAIN FORCING WITH THE MAINLY POST FRONTAL
PRECIPITATION WILL MOVE INTO THE WESTERN CWFA SO WILL CONTINUE
WITH LIKELY POPS THERE. THE RAP/WRF CONTINUE TO PUSH MOISTURE
NORTHWARD SO THE REMAINDER OF THE CWFA SHOULD START SEEING MORE
SCATTERED SHRA DEVELOPMENT FOR THE FIRST PART OF THE AFTERNOON.
LATE THIS AFTERNOON THE LIFT AND HEAVY RAIN TOOLS WHEN APPLIED TO
THE RAP/WRF ARE SUGGESTING A FAIRLY SUBSTANTIAL BAND OF CONVECTION
COULD FIRE ROUGHLY ALONG OR JUST EAST OF THE MISSISSIPPI AND MOVE
EAST. SINCE MOISTURE WOULD BE MAXIMIZING JUST PAST PEAK HEATING
WITH THE FRONT IN ROUGHLY THE SAME AREA...THIS SCENARIO HAS SOME
PLAUSIBILITY TO IT. IF CORRECT...THE BETTER PRECIPITATION TOTALS
WOULD BE OVER THE EASTERN THIRD OF THE CWFA. ..08..
PREV DISCUSSION... /ISSUED 340 AM CDT WED OCT 17 2012/
SYNOPSIS...
THE BEGINNINGS OF ANOTHER MUCH NEEDED RAIN EVENT IS DEVELOPING OUT
OVER THE PLAINS THIS MORNING. A STRONG SURFACE LOW OVER EASTERN
SOUTH DAKOTA HAS A STRONG COLD FRONT DRAPED SOUTHWEST FROM IT ACROSS
NEBRASKA AND NORTHWEST KANSAS AND BACK INTO COLORADO. THERE IS ALSO
A WARM FRONT...WHICH PASSED THROUGH THE FORECAST AREA YESTERDAY
DRAPED ACROSS SOUTHERN MINNESOTA AND WISCONSIN. SOUTH WINDS HAVE
STAYED UP VERY NICELY OVERNIGHT AND TEMPERATURES AS OF 3 AM ARE
STILL IN THE MID 50S TO LOW 60S...HIGHLY UNUSUAL FOR THIS TIME OF
YEAR. SHOWERS HAVE ALREADY DEVELOPED OVER WESTERN IOWA...SOUTHWEST
MINNESOTA...EASTERN SOUTH DAKOTA...NEBRASKA AND KANSAS. AT UPPER
LEVELS WE HAVE A NICE PLUME OF HIGHER DEWPOINT AIR AT 850MB
EXTENDING FROM TEXAS UP INTO CENTRAL IOWA AND EVEN SOUTHERN
MINNESOTA...ASSOCIATED WITH A NICE LOW LEVEL FLOW OF 25-30KTS. THAT
THIS INCOMING SYSTEM IS VERY POWERFUL IS INDICATED BY THE DRAMATIC
HEIGHT FALLS AT 500MB OVER THE NORTHERN ROCKIES...AND THE STRONG JET
OF 140KTS+ IMPINGING ON THE WEST OREGON COAST. LE
SHORT TERM...TODAY AND TONIGHT...
THERE IS MUCH TO LOOK AT WITH THIS VERY DYNAMIC SYSTEM THAT WILL
MOVE OVER THE FORECAST AREA IN THE NEXT 24 HOURS. CANNOT WRITE ALL
THAT ONE WOULD LIKE WITH THIS MUCH TO LOOK AT...BUT HERE GOES.
THIS MORNING THIS SYSTEM WILL CONTINUE TO MOVE OUR DIRECTION...AS
THE UPPER LEVEL FEATURES BEGIN TO INTERACT MORE STRONGLY WITH THE
DEEPER MOISTURE NOW AVAILABLE OVER THE FORECAST AREA. THIS MORNING
IN THE WARM SECTOR AIRMASS WE SHOULD GET SOME CONVECTIVE
SHOWERS...SIMILAR TO WHAT WE ARE NOW SEEING OVER CENTRAL IOWA.
THESE SHOWERS SHOULD AFFECT MAINLY THE WESTERN PORTIONS OF THE
FORECAST AREA DUE TO THE DIMINISHING MOISTURE TO THE EAST...AND
THE BETTER ISENTROPIC LIFT TO THE WEST. THE BETTER DYNAMICS ARE
STILL TO COME...AND ARE EXPECTED TO MOVE ACROSS THE FORECAST AREA
THIS AFTERNOON AND EVENING. THE SURFACE LOW NOW OVER EASTERN SOUTH
DAKOTA WILL SWING NORTHEAST ACROSS MINNESOTA TODAY. A SECONDARY
LOW...NOT TERRIBLY STRONG...IS EXPECTED TO DEVELOP OVER THE
FORECAST AREA AS THE SURFACE COLD FRONT MOVES ACROSS THE AREA THIS
AFTERNOON AND EVENING. THIS WILL LIKELY ACT TO INCREASE THE
CONVERGENCE ALONG THE BOUNDARY AND INCREASE OUR PRECIPITATION
POTENTIAL. WE ALSO HAVE A BAND OF STRONG FRONTOGENESIS ALONG AND
BEHIND THE FRONT TO GENERATE PRECIPITATION AS WELL. FOR NOW HAVE A
STEEP GRADIENT OF POPS OVER THE AREA FROM JUST SLIGHT CHANCE POPS
NORTHEAST TO LIKELY OVER THE WESTERN PORTIONS THIS
MORNING...RAMPING UP TO CHANCES WEST AND CATEGORICAL EAST FOR THIS
AFTERNOON. WHILE MUCH OF THE PRECIPITATION WITH THIS SYSTEM WILL
BE STRATIFORM...ESPECIALLY LATER IN THE DAY...THERE WILL AT LEAST
BE SOME EMBEDDED THUNDER THIS AFTERNOON WITH THE STRONGEST LIFT
AND STEEPEST MID LEVEL LAPSE RATES. HIGH TEMPERATURES TODAY TO
ALSO HAVE A STEEP GRADIENT FROM AROUND 60 NORTHWEST TO UPPER 60S
SOUTHEAST.
TONIGHT THE RAIN OVER THE EASTERN PORTIONS OF THE AREA WILL SWEEP
QUICKLY OFF TO THE EAST...LEAVING THE AREA DRY BY THE TIME WE GET TO
MIDNIGHT...OR CLOSE TO IT. THERE MAY BE SOME LINGERING RAIN IN THE
NORTHEAST AFTERWARDS...DEPENDING ON WHICH MODEL YOU USE AND THE
TRACK OF THE SURFACE LOW. TEMPERATURES IN THE LOW 40S WILL SWEEP
INTO THE AREA BEHIND THIS SYSTEM...LIKELY WITH AT LEAST A BRIEF
PERIOD OF AT LEAST THINNER CLOUDS TO AID IN COOLING THE
TEMPERATURES. LE
LONG TERM...THURSDAY THROUGH TUESDAY...
LARGE UPPER LEVEL CLOSED LOW TO PROVIDE CLOUDY...COOL...AND DAMP
WEATHER THU...WHICH IS NOW LOOKING MORE LIKELY TO CONTINUE THROUGH
FRIDAY AS WELL. A PROGRESSIVE UPPER LEVEL PATTERN QUICKLY SWEEPS
THIS SYSTEM EAST OVER THE WEEKEND WITH RETURN FLOW BY SUNDAY LEADING
TO MODERATING TEMPERATURES. THE WARMING TREND CONTINUES INTO
MONDAY...ALONG WITH INCREASING CHANCES FOR RAIN AS MOISTURE
INCREASES IN A SW FLOW AHEAD OF A SLOW MOVING FRONT.
00Z MODELS ARE SOMEWHAT SIMILAR WITH DETAILS OF THE UPPER LOW WITH
THE NOTABLE EXCEPTION BEING THE WRF/NAM...WHICH BECOMES A SLOWER
OUTLIER WITH THE EJECTING SURFACE AND UPPER LOW HANGING FURTHER WEST
ON FRIDAY. WILL KEEP THE FORECAST CLOSE TO THE NON-WRF MODEL
CONSENSUS. STRONG UPPER VORT CENTER AND SURFACE LOW ROTATING AROUND
THE NW AND WESTERN SIDE OF THE UPPER LOW OVER WI WILL DROP SOUTH
INTO THE FORECAST AREA THURSDAY AFTERNOON. WRAP AROUND MOISTURE AND
SUFFICIENT LIFT SHOULD LEAD TO WIDESPREAD LIGHT RAIN OR SHOWERS...
SPREADING FROM NORTHWEST TO SOUTHEAST BY AFTERNOON. WITH INCREASING
CONFIDENCE...POPS HAVE BEEN INCREASED TO LIKELY BY AFTERNOON ACROSS
A LARGER AREA OF THE NORTH. WILL CERTAINLY BE A RAW DAY WITH BRISK
W-NW WINDS AND TEMPERATURES NOT LIKELY CLIMBING OUT OF THE 40S IN
THE NORTH WHERE RAIN ARRIVES EARLIER...WHILE THE FAR SOUTH MAY REACH
THE LOWER 50S. THURSDAY NIGHT POPS HAVE BEEN RAISED TO LIKELY ACROSS
THE BOARD AS THE SURFACE LOW MIGRATES SOUTHEAST ACROSS EASTERN IA
INTO NORTH CENTRAL IL BY MORNING. WHILE MOISTURE WILL BE LIMITED TO
WHAT ROTATES AROUND THE GREAT LAKES UPPER LOW...THE EXTENDED PERIOD
OF LOW LEVEL CONVERGENCE AND MID LEVEL FORCING SHOULD SQUEEZE OUT
RAIN AMOUNTS FROM SEVERAL HUNDREDTHS OF A INCH TO PERHAPS OVER A
QUARTER INCH THU AND THU NIGHT.
FRIDAY...ANOTHER LOBE OF ENERGY ROTATING AROUND THE LOW SHOWN NEAR
CHICAGO WILL KEEP AT LEAST SCATTERED LIGHT RAIN SHOWERS A
POSSIBILITY THROUGH MUCH OF THE DAY. OUTSIDE THE SHOWERS...THE
PROSPECT OF SUNSHINE LOOKS VERY LIMITED IN THE CYCLONIC FLOW AND
LAYER OF MOISTURE SHOWN BELOW 850...WHICH SHOULD LIMIT HIGHS TO THE
LOWER 50S AT BEST.
SATURDAY THROUGH TUESDAY...A PASSING RIDGE AT THE SURFACE AND UPPER
LEVELS SATURDAY INTO SATURDAY NIGHT WILL BE FOLLOWED BY STRONG
RETURN FLOW AND WARM ADVECTION SUNDAY INTO MONDAY. HAVE KEPT HIGHS
TRENDING FROM THE UPPER 50S TO LOWER 60S SATURDAY...RISING TO THE
UPPER 60S TO MID 70S MONDAY WHILE LOWS CLIMB FROM THE 30S FRIDAY
NIGHT TO THE 50S FOLLOWING RISING DEWPOINTS MONDAY MORNING. BASED ON
850 MB TEMPERATURES...HIGHS MONDAY COULD POTENTIALLY BE NEARLY AS
WARM AS YESTERDAY. OVERALL...THE 00Z MODELS HAVE COME INTO BETTER
AGREEMENT WITH THE UPPER LEVEL PATTERN AND SURFACE FRONTAL FEATURES
MONDAY INTO TUESDAY...DEVELOPING WARM ADVECTION AND MOISTURE RETURN
THAT COULD LEAD TO RAIN CHANCES FROM LATE SUNDAY NIGHT THROUGH
TUESDAY. BASED ON THE WARM ADVECTION...RETURN OF GULF MOISTURE...AND
STEEP MID LEVEL LAPSE RATES...THUNDERSTORMS WILL BE POSSIBLE
ESPECIALLY MONDAY INTO MONDAY NIGHT AND HAVE ADDED MENTION.
SHEETS
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1218 PM CDT WED OCT 17 2012
...UPDATED AVIATION DISCUSSION...
.SHORT TERM /TODAY/...
SEVERAL FORECAST CONCERNS TODAY WITH STRONG COLD FRONT EXPECTED TO
SWEEP ACROSS IOWA THIS MORNING. FROPA WILL BE BETWEEN 11-15Z THIS
MORNING FROM WEST TO EAST ACROSS THE FORECAST AREA. LEANED TOWARD A
BLEND OF THE SHORT TERM HIGH-RESOLUTION MODELS HRRR/4.0KM WRF AND
SREF/NAM12 AS THEY SEEMED TO HAVE BEST HANDLE ON TIMING OF FRONT AND
POPS.
SHARP PRESSURE GRADIENT COMBINED WITH A DECENT TROPOPAUSE UNDULATION
LATE THIS MORNING INTO THE AFTERNOON WILL PROVIDE A WINDY DAY. WINDS
ATOP THE MIX LAYER RANGE FROM 30-35KTS WEST OF THE INTERSTATE 35 AND
WITH THE CLOUDS CLEARING OUT THIS AFTERNOON IN WESTERN IOWA...SHOULD
ENHANCE THE WIND GUSTS. TWEAKED WINDS UP SLIGHTLY IN THIS AREA
THROUGH 18Z. STILL BORDER LINE WIND ADVISORY ATTM. KEPT MENTION OF
THE NON-DIURNAL TEMPS WITH THE STRONG CAA DEVELOPING LATE THIS
MORNING. 850MB TEMPS DROP TO +2C TO +4C BY THIS AFTERNOON. A NICE
STRATUS DECK LOOKS TO MOVE IN BY AROUND 00Z THURSDAY AS RH AT 850MB
INCREASES GREATER THAN 80 PERCENT. INCREASED SKY COVER ACROSS THE FAR
NORTHWEST.
BEST POPS WILL BE ACROSS THE SOUTHEAST LATE THIS MORNING WHERE
STRONGEST FORCING AND BEST THETA-E ADVECTION IS LOCATED. IN
ADDITION...SOME ELEVATED INSTABILITY IS PRESENT AND LIKELY WILL THE
HIGHER QPF AMOUNTS. THE LATEST HRRR COINCIDES WITH THIS THINKING AND
TWEAKED UP QPF THROUGH 18Z.
.LONG TERM /TONIGHT THROUGH TUESDAY/...
DEEPENING UPPER LOW WILL BE DIVING INTO MINNESOTA AND IOWA OVERNIGHT
WITH AN IMPRESSIVE 90-100KT JET ROUNDING THE BASE OF THE TROUGH AND
BEING INGESTED INTO THE SYSTEM THROUGH THURSDAY. THERE IS A
SIGNIFICANT AMOUNT OF ENERGY EMBEDDED IN THE FLOW WHICH WILL WRAP
AROUND THE SYSTEM THE NEXT FEW DAYS. ONE OF THE MORE VIGOROUS
IMPULSES IS MOVING THROUGH SRN IA AND MISSOURI TODAY AND WILL WRAP
AROUND THE SYSTEM AND MOVE ACROSS MINNESOTA AND IOWA ON THURSDAY AND
WILL SHIFT THE AXIS OF THE UPPER LOW BACK WEST A BIT. THIS SYSTEM
WILL ALSO HAVE GOOD THETA-E ADVECTION EMBEDDED WHICH WILL HELP PUSH
PWATS BACK TO NEAR 0.75 INCHES AND COMBINED WITH THE KINEMATIC
ENERGY...SHOULD RESULT IN WIDESPREAD SHOWERS BY THURSDAY AFTERNOON
AND EVENING. IN ADDITION...AN INCREASING PRESSURE GRADIENT OVER
WESTERN IOWA AND WINDS APPROACHING 50 KTS IN THE LOWEST 4 KFT OF THE
ATMOSPHERE DOES RAISE CONCERNS ABOUT POTENTIAL WIND ADVISORY
CRITERIA. IT WILL BE CLOSE...WEST OF INTERSTATE 35 THOUGH THERE ARE
A FEW NEGATIVES THAT WILL KEEP THE WINDS FROM REACHING MAX
POTENTIAL. A STRATUS DECK SHOULD ENGULF MUCH OF IOWA ON THURSDAY AND
THIS WILL LIMIT HIGH TEMPERATURES AND POTENTIAL FOR MIXING.
TEMPERATURES WILL LIKELY LINGER IN THE 40S FOR MUCH OF THE DAY. THE
GOOD REGION OF SUBSIDENCE WILL BE WEST OF THE MISSOURI RIVER AND
THAT WILL BE THE REGION FOR GOOD MOMENTUM TRANSFER AND BETTER MIXING
OF WINDS ALOFT.
PRECIPITATION CHANCES WILL CONTINUE THURSDAY NIGHT BEFORE THE BULK
OF THE ENERGY ROUNDS THE BASE OF THE UPPER LOW AND IT BEGINS TO
SHIFT OFF TO THE EAST ON FRIDAY. A FEW SHOWERS MAY LINGER FRIDAY
BEFORE MID LEVEL RIDGING MOVES IN FOR THE WEEKEND WITH WARMER
TEMPERATURES. STRENGTHENING HIGH PRESSURE OVER THE SOUTHEAST CONUS
AND REGION OF LOW PRESSURE TO THE WEST WILL ENHANCE THE WARM
ADVECTION INTO SUNDAY. AS MENTIONED LAST NIGHT...THIS SET UP IS
CONDUCIVE TO A STRONG SURGE OF LOW LEVEL GULF MOISTURE. SOME MINOR
TIMING DETAILS ON WHEN THIS MOISTURE ARRIVES IN IOWA...EITHER LATE
SUNDAY OR SUNDAY NIGHT. THIS MOISTURE WILL LIFT NORTH AND POOL AHEAD
OF A SFC BOUNDARY THAT WILL BE INCHING SOUTHEAST THROUGH IOWA SUNDAY
THROUGH MONDAY. THIS TYPE OF MOISTURE OFTEN RESULTS IN A STRATUS
FIELD AND MAY BE ACCOMPANIED WITH FOG OR DRIZZLE. ENHANCED VERTICAL
TURBULENCE WITH THE SFC BOUNDARY NEAR BY ENHANCES THAT POSSIBILITY.
ANY STRATUS CERTAINLY WOULD IMPACT TEMPERATURES. A SHORT WAVE
LIFTING THROUGH THE SOUTHWEST FLOW WILL INTRODUCE SOME CONVECTIVE
POTENTIAL MONDAY AND MONDAY NIGHT. THE MILD SOUTHWEST FLOW WILL
MAINTAIN THROUGH THE END OF THE EXTENDED WITH HIGHS IN THE 60S AND
70S.
&&
.AVIATION...17/18Z
PRECIPITATION BEHIND COLD FRONT WILL CONTINUE TO PUSH
EASTWARD...AFFECTING KDSM/KOTM/KMCW/KALO THROUGH 00Z. THERE WILL BE
LOCALIZED MVFR CEILINGS...BUT DO NOT ANTICIPATE THEM TO AFFECT
SITES...AND IF SO ONLY BRIEFLY. BEHIND FRONT...WINDS WILL BE STRONG
AND GUSTY FROM THE WEST TO NORTHWEST. WINDS WILL REMAIN STRONG
THROUGH THE NIGHT....AND WILL INCREASE AFTER 12Z...WITH GUSTS AGAIN
RETURNING. IN ADDITION...ANOTHER ROUND OF PRECIPITATION WILL BEGIN
TO AFFECT THE WESTERN SITES...KFOD/KDSM LATE IN THE PERIOD WITH MVFR
CEILINGS AND -RA POSSIBLE NEAR 15Z. HOWEVER...DO NOT HAVE ENOUGH
CONFIDENCE TO INCLUDE MENTION ATTM.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...PODRAZIK
LONG TERM...DONAVON
AVIATION...AWB
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1053 AM CDT WED OCT 17 2012
.UPDATE...
A FAIRLY SIGNIFICANT REVISION TO THE FCST HAS BEEN DONE.
HOWEVER...THE MODELS ARE HINTING THAT A NONLINEAR EVENT MAY BE IN
THE OFFERING. IF CORRECT...THERE COULD BE ADDITIONAL
CHANGES...POSSIBLY SIGNIFICANT...TO THE FCST.
CURRENT DATA SHOWS THE WAA PRECIP IS SLOWLY EVAPORATING DUE TO THE
INITIALLY DRY ATMOSPHERE ACROSS THE AREA. WHAT IS BEING SUGGESTED
BY THE RAP AND THE 12Z WRF IS THAT THE INITIAL PLUME OF 6-7C 850MB
MOISTURE OVER THE AREA...PER 12Z RAOBS...WILL SHIFT EAST THE
REMAINDER OF THE MORNING. THUS THERE SHOULD BE MORE DRY AIR ALOFT
TO GENERATE MAINLY VIRGA/SPRINKLES WITH SCATTERED SHRA. THIS
SCENARIO IS PARTLY SUPPORTED BY A VORT MAX ROTATING THROUGH THE
AREA PER THE RAP/WRF THIS MORNING WITH LIFT INCREASING AND THEN
DECREASING.
THIS AFTERNOON THE MAIN FORCING WITH THE MAINLY POST FRONTAL
PRECIPITATION WILL MOVE INTO THE WESTERN CWFA SO WILL CONTINUE
WITH LIKELY POPS THERE. THE RAP/WRF CONTINUE TO PUSH MOISTURE
NORTHWARD SO THE REMAINDER OF THE CWFA SHOULD START SEEING MORE
SCATTERED SHRA DEVELOPMENT FOR THE FIRST PART OF THE AFTERNOON.
LATE THIS AFTERNOON THE LIFT AND HEAVY RAIN TOOLS WHEN APPLIED TO
THE RAP/WRF ARE SUGGESTING A FAIRLY SUBSTANTIAL BAND OF CONVECTION
COULD FIRE ROUGHLY ALONG OR JUST EAST OF THE MISSISSIPPI AND MOVE
EAST. SINCE MOISTURE WOULD BE MAXIMIZING JUST PAST PEAK HEATING
WITH THE FRONT IN ROUGHLY THE SAME AREA...THIS SCENARIO HAS SOME
PLAUSIBILITY TO IT. IF CORRECT...THE BETTER PRECIPITATION TOTALS
WOULD BE OVER THE EASTERN THIRD OF THE CWFA. ..08..
&&
.PREV DISCUSSION... /ISSUED 653 AM CDT WED OCT 17 2012/
AVIATION...
STRONG COLD FRONT TO MOVE ACROSS THE TERMINALS TODAY. AHEAD OF THE
FRONT SCATTERED SHOWERS WILL MOVE INTO THE AREA FROM THE WEST.
ISOLATED THUNDER IS POSSIBLE...BUT HAVE LEFT OUT OF TERMINALS DUE
TO TIMING UNCERTAINTY. SOUTH WINDS 10-15KTS WITH GUSTS TO 20KTS TO
DIMINISH AS THE FRONT APPROACHES. THE FRONT IS EXPECTED TO MOVE
ACROSS THE TERMINALS BETWEEN 18Z AND 23Z...INITIALLY SWITCHING
WINDS TO SOUTHWEST AROUND 10-15KTS. A PERIOD OF LIGHT TO MODERATE
SHOWERS IS EXPECTED WITH THE FRONT...WITH A GOOD CHANCE FOR MVFR
VISIBILITIES AT MLI AND BRL FROM 19Z TO 00Z WHICH COULD ALSO
INCLUDE A RUMBLE OF THUNDER. MAINLY VFR CIGS THROUGH THE
PERIOD...THOUGH SOME LOCATIONS MAY RECEIVE A SHORT PERIOD OF MVFR
CIGS WITH STRONGEST BAND OF PRECIPITATION. WILL NEED TO ADD THESE
IN ONCE THERE IS MORE CERTAINTY IN TIMING. AFTER 04Z/18...SKIES
SHOULD BECOME VFR AS THE RAIN MOVES OUT OF THE AREA...AND WINDS
SHOULD MAINTAIN A GUSTY WEST TO NORTHWEST AT 10-15 GUST TO 20 KTS.
LE
PREV DISCUSSION... /ISSUED 340 AM CDT WED OCT 17 2012/
SYNOPSIS...
THE BEGINNINGS OF ANOTHER MUCH NEEDED RAIN EVENT IS DEVELOPING OUT
OVER THE PLAINS THIS MORNING. A STRONG SURFACE LOW OVER EASTERN
SOUTH DAKOTA HAS A STRONG COLD FRONT DRAPED SOUTHWEST FROM IT ACROSS
NEBRASKA AND NORTHWEST KANSAS AND BACK INTO COLORADO. THERE IS ALSO
A WARM FRONT...WHICH PASSED THROUGH THE FORECAST AREA YESTERDAY
DRAPED ACROSS SOUTHERN MINNESOTA AND WISCONSIN. SOUTH WINDS HAVE
STAYED UP VERY NICELY OVERNIGHT AND TEMPERATURES AS OF 3 AM ARE
STILL IN THE MID 50S TO LOW 60S...HIGHLY UNUSUAL FOR THIS TIME OF
YEAR. SHOWERS HAVE ALREADY DEVELOPED OVER WESTERN IOWA...SOUTHWEST
MINNESOTA...EASTERN SOUTH DAKOTA...NEBRASKA AND KANSAS. AT UPPER
LEVELS WE HAVE A NICE PLUME OF HIGHER DEWPOINT AIR AT 850MB
EXTENDING FROM TEXAS UP INTO CENTRAL IOWA AND EVEN SOUTHERN
MINNESOTA...ASSOCIATED WITH A NICE LOW LEVEL FLOW OF 25-30KTS. THAT
THIS INCOMING SYSTEM IS VERY POWERFUL IS INDICATED BY THE DRAMATIC
HEIGHT FALLS AT 500MB OVER THE NORTHERN ROCKIES...AND THE STRONG JET
OF 140KTS+ IMPINGING ON THE WEST OREGON COAST. LE
SHORT TERM...TODAY AND TONIGHT...
THERE IS MUCH TO LOOK AT WITH THIS VERY DYNAMIC SYSTEM THAT WILL
MOVE OVER THE FORECAST AREA IN THE NEXT 24 HOURS. CANNOT WRITE ALL
THAT ONE WOULD LIKE WITH THIS MUCH TO LOOK AT...BUT HERE GOES.
THIS MORNING THIS SYSTEM WILL CONTINUE TO MOVE OUR DIRECTION...AS
THE UPPER LEVEL FEATURES BEGIN TO INTERACT MORE STRONGLY WITH THE
DEEPER MOISTURE NOW AVAILABLE OVER THE FORECAST AREA. THIS MORNING
IN THE WARM SECTOR AIRMASS WE SHOULD GET SOME CONVECTIVE
SHOWERS...SIMILAR TO WHAT WE ARE NOW SEEING OVER CENTRAL IOWA.
THESE SHOWERS SHOULD AFFECT MAINLY THE WESTERN PORTIONS OF THE
FORECAST AREA DUE TO THE DIMINISHING MOISTURE TO THE EAST...AND
THE BETTER ISENTROPIC LIFT TO THE WEST. THE BETTER DYNAMICS ARE
STILL TO COME...AND ARE EXPECTED TO MOVE ACROSS THE FORECAST AREA
THIS AFTERNOON AND EVENING. THE SURFACE LOW NOW OVER EASTERN SOUTH
DAKOTA WILL SWING NORTHEAST ACROSS MINNESOTA TODAY. A SECONDARY
LOW...NOT TERRIBLY STRONG...IS EXPECTED TO DEVELOP OVER THE
FORECAST AREA AS THE SURFACE COLD FRONT MOVES ACROSS THE AREA THIS
AFTERNOON AND EVENING. THIS WILL LIKELY ACT TO INCREASE THE
CONVERGENCE ALONG THE BOUNDARY AND INCREASE OUR PRECIPITATION
POTENTIAL. WE ALSO HAVE A BAND OF STRONG FRONTOGENESIS ALONG AND
BEHIND THE FRONT TO GENERATE PRECIPITATION AS WELL. FOR NOW HAVE A
STEEP GRADIENT OF POPS OVER THE AREA FROM JUST SLIGHT CHANCE POPS
NORTHEAST TO LIKELY OVER THE WESTERN PORTIONS THIS
MORNING...RAMPING UP TO CHANCES WEST AND CATEGORICAL EAST FOR THIS
AFTERNOON. WHILE MUCH OF THE PRECIPITATION WITH THIS SYSTEM WILL
BE STRATIFORM...ESPECIALLY LATER IN THE DAY...THERE WILL AT LEAST
BE SOME EMBEDDED THUNDER THIS AFTERNOON WITH THE STRONGEST LIFT
AND STEEPEST MID LEVEL LAPSE RATES. HIGH TEMPERATURES TODAY TO
ALSO HAVE A STEEP GRADIENT FROM AROUND 60 NORTHWEST TO UPPER 60S
SOUTHEAST.
TONIGHT THE RAIN OVER THE EASTERN PORTIONS OF THE AREA WILL SWEEP
QUICKLY OFF TO THE EAST...LEAVING THE AREA DRY BY THE TIME WE GET TO
MIDNIGHT...OR CLOSE TO IT. THERE MAY BE SOME LINGERING RAIN IN THE
NORTHEAST AFTERWARDS...DEPENDING ON WHICH MODEL YOU USE AND THE
TRACK OF THE SURFACE LOW. TEMPERATURES IN THE LOW 40S WILL SWEEP
INTO THE AREA BEHIND THIS SYSTEM...LIKELY WITH AT LEAST A BRIEF
PERIOD OF AT LEAST THINNER CLOUDS TO AID IN COOLING THE
TEMPERATURES. LE
LONG TERM...THURSDAY THROUGH TUESDAY...
LARGE UPPER LEVEL CLOSED LOW TO PROVIDE CLOUDY...COOL...AND DAMP
WEATHER THU...WHICH IS NOW LOOKING MORE LIKELY TO CONTINUE THROUGH
FRIDAY AS WELL. A PROGRESSIVE UPPER LEVEL PATTERN QUICKLY SWEEPS
THIS SYSTEM EAST OVER THE WEEKEND WITH RETURN FLOW BY SUNDAY LEADING
TO MODERATING TEMPERATURES. THE WARMING TREND CONTINUES INTO
MONDAY...ALONG WITH INCREASING CHANCES FOR RAIN AS MOISTURE
INCREASES IN A SW FLOW AHEAD OF A SLOW MOVING FRONT.
00Z MODELS ARE SOMEWHAT SIMILAR WITH DETAILS OF THE UPPER LOW WITH
THE NOTABLE EXCEPTION BEING THE WRF/NAM...WHICH BECOMES A SLOWER
OUTLIER WITH THE EJECTING SURFACE AND UPPER LOW HANGING FURTHER WEST
ON FRIDAY. WILL KEEP THE FORECAST CLOSE TO THE NON-WRF MODEL
CONSENSUS. STRONG UPPER VORT CENTER AND SURFACE LOW ROTATING AROUND
THE NW AND WESTERN SIDE OF THE UPPER LOW OVER WI WILL DROP SOUTH
INTO THE FORECAST AREA THURSDAY AFTERNOON. WRAP AROUND MOISTURE AND
SUFFICIENT LIFT SHOULD LEAD TO WIDESPREAD LIGHT RAIN OR SHOWERS...
SPREADING FROM NORTHWEST TO SOUTHEAST BY AFTERNOON. WITH INCREASING
CONFIDENCE...POPS HAVE BEEN INCREASED TO LIKELY BY AFTERNOON ACROSS
A LARGER AREA OF THE NORTH. WILL CERTAINLY BE A RAW DAY WITH BRISK
W-NW WINDS AND TEMPERATURES NOT LIKELY CLIMBING OUT OF THE 40S IN
THE NORTH WHERE RAIN ARRIVES EARLIER...WHILE THE FAR SOUTH MAY REACH
THE LOWER 50S. THURSDAY NIGHT POPS HAVE BEEN RAISED TO LIKELY ACROSS
THE BOARD AS THE SURFACE LOW MIGRATES SOUTHEAST ACROSS EASTERN IA
INTO NORTH CENTRAL IL BY MORNING. WHILE MOISTURE WILL BE LIMITED TO
WHAT ROTATES AROUND THE GREAT LAKES UPPER LOW...THE EXTENDED PERIOD
OF LOW LEVEL CONVERGENCE AND MID LEVEL FORCING SHOULD SQUEEZE OUT
RAIN AMOUNTS FROM SEVERAL HUNDREDTHS OF A INCH TO PERHAPS OVER A
QUARTER INCH THU AND THU NIGHT.
FRIDAY...ANOTHER LOBE OF ENERGY ROTATING AROUND THE LOW SHOWN NEAR
CHICAGO WILL KEEP AT LEAST SCATTERED LIGHT RAIN SHOWERS A
POSSIBILITY THROUGH MUCH OF THE DAY. OUTSIDE THE SHOWERS...THE
PROSPECT OF SUNSHINE LOOKS VERY LIMITED IN THE CYCLONIC FLOW AND
LAYER OF MOISTURE SHOWN BELOW 850...WHICH SHOULD LIMIT HIGHS TO THE
LOWER 50S AT BEST.
SATURDAY THROUGH TUESDAY...A PASSING RIDGE AT THE SURFACE AND UPPER
LEVELS SATURDAY INTO SATURDAY NIGHT WILL BE FOLLOWED BY STRONG
RETURN FLOW AND WARM ADVECTION SUNDAY INTO MONDAY. HAVE KEPT HIGHS
TRENDING FROM THE UPPER 50S TO LOWER 60S SATURDAY...RISING TO THE
UPPER 60S TO MID 70S MONDAY WHILE LOWS CLIMB FROM THE 30S FRIDAY
NIGHT TO THE 50S FOLLOWING RISING DEWPOINTS MONDAY MORNING. BASED ON
850 MB TEMPERATURES...HIGHS MONDAY COULD POTENTIALLY BE NEARLY AS
WARM AS YESTERDAY. OVERALL...THE 00Z MODELS HAVE COME INTO BETTER
AGREEMENT WITH THE UPPER LEVEL PATTERN AND SURFACE FRONTAL FEATURES
MONDAY INTO TUESDAY...DEVELOPING WARM ADVECTION AND MOISTURE RETURN
THAT COULD LEAD TO RAIN CHANCES FROM LATE SUNDAY NIGHT THROUGH
TUESDAY. BASED ON THE WARM ADVECTION...RETURN OF GULF MOISTURE...AND
STEEP MID LEVEL LAPSE RATES...THUNDERSTORMS WILL BE POSSIBLE
ESPECIALLY MONDAY INTO MONDAY NIGHT AND HAVE ADDED MENTION.
SHEETS
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
633 AM CDT WED OCT 17 2012
...UPDATED AVIATION DISCUSSION...
.SHORT TERM /TODAY/...
SEVERAL FORECAST CONCERNS TODAY WITH STRONG COLD FRONT EXPECTED TO
SWEEP ACROSS IOWA THIS MORNING. FROPA WILL BE BETWEEN 11-15Z THIS
MORNING FROM WEST TO EAST ACROSS THE FORECAST AREA. LEANED TOWARD A
BLEND OF THE SHORT TERM HIGH-RESOLUTION MODELS HRRR/4.0KM WRF AND
SREF/NAM12 AS THEY SEEMED TO HAVE BEST HANDLE ON TIMING OF FRONT AND
POPS.
SHARP PRESSURE GRADIENT COMBINED WITH A DECENT TROPOPAUSE UNDULATION
LATE THIS MORNING INTO THE AFTERNOON WILL PROVIDE A WINDY DAY. WINDS
ATOP THE MIX LAYER RANGE FROM 30-35KTS WEST OF THE INTERSTATE 35 AND
WITH THE CLOUDS CLEARING OUT THIS AFTERNOON IN WESTERN IOWA...SHOULD
ENHANCE THE WIND GUSTS. TWEAKED WINDS UP SLIGHTLY IN THIS AREA
THROUGH 18Z. STILL BORDER LINE WIND ADVISORY ATTM. KEPT MENTION OF
THE NON-DIURNAL TEMPS WITH THE STRONG CAA DEVELOPING LATE THIS
MORNING. 850MB TEMPS DROP TO +2C TO +4C BY THIS AFTERNOON. A NICE
STRATUS DECK LOOKS TO MOVE IN BY AROUND 00Z THURSDAY AS RH AT 850MB
INCREASES GREATER THAN 80 PERCENT. INCREASED SKY COVER ACROSS THE FAR
NORTHWEST.
BEST POPS WILL BE ACROSS THE SOUTHEAST LATE THIS MORNING WHERE
STRONGEST FORCING AND BEST THETA-E ADVECTION IS LOCATED. IN
ADDITION...SOME ELEVATED INSTABILITY IS PRESENT AND LIKELY WILL THE
HIGHER QPF AMOUNTS. THE LATEST HRRR COINCIDES WITH THIS THINKING AND
TWEAKED UP QPF THROUGH 18Z.
.LONG TERM /TONIGHT THROUGH TUESDAY/...
DEEPENING UPPER LOW WILL BE DIVING INTO MINNESOTA AND IOWA OVERNIGHT
WITH AN IMPRESSIVE 90-100KT JET ROUNDING THE BASE OF THE TROUGH AND
BEING INGESTED INTO THE SYSTEM THROUGH THURSDAY. THERE IS A
SIGNIFICANT AMOUNT OF ENERGY EMBEDDED IN THE FLOW WHICH WILL WRAP
AROUND THE SYSTEM THE NEXT FEW DAYS. ONE OF THE MORE VIGOROUS
IMPULSES IS MOVING THROUGH SRN IA AND MISSOURI TODAY AND WILL WRAP
AROUND THE SYSTEM AND MOVE ACROSS MINNESOTA AND IOWA ON THURSDAY AND
WILL SHIFT THE AXIS OF THE UPPER LOW BACK WEST A BIT. THIS SYSTEM
WILL ALSO HAVE GOOD THETA-E ADVECTION EMBEDDED WHICH WILL HELP PUSH
PWATS BACK TO NEAR 0.75 INCHES AND COMBINED WITH THE KINEMATIC
ENERGY...SHOULD RESULT IN WIDESPREAD SHOWERS BY THURSDAY AFTERNOON
AND EVENING. IN ADDITION...AN INCREASING PRESSURE GRADIENT OVER
WESTERN IOWA AND WINDS APPROACHING 50 KTS IN THE LOWEST 4 KFT OF THE
ATMOSPHERE DOES RAISE CONCERNS ABOUT POTENTIAL WIND ADVISORY
CRITERIA. IT WILL BE CLOSE...WEST OF INTERSTATE 35 THOUGH THERE ARE
A FEW NEGATIVES THAT WILL KEEP THE WINDS FROM REACHING MAX
POTENTIAL. A STRATUS DECK SHOULD ENGULF MUCH OF IOWA ON THURSDAY AND
THIS WILL LIMIT HIGH TEMPERATURES AND POTENTIAL FOR MIXING.
TEMPERATURES WILL LIKELY LINGER IN THE 40S FOR MUCH OF THE DAY. THE
GOOD REGION OF SUBSIDENCE WILL BE WEST OF THE MISSOURI RIVER AND
THAT WILL BE THE REGION FOR GOOD MOMENTUM TRANSFER AND BETTER MIXING
OF WINDS ALOFT.
PRECIPITATION CHANCES WILL CONTINUE THURSDAY NIGHT BEFORE THE BULK
OF THE ENERGY ROUNDS THE BASE OF THE UPPER LOW AND IT BEGINS TO
SHIFT OFF TO THE EAST ON FRIDAY. A FEW SHOWERS MAY LINGER FRIDAY
BEFORE MID LEVEL RIDGING MOVES IN FOR THE WEEKEND WITH WARMER
TEMPERATURES. STRENGTHENING HIGH PRESSURE OVER THE SOUTHEAST CONUS
AND REGION OF LOW PRESSURE TO THE WEST WILL ENHANCE THE WARM
ADVECTION INTO SUNDAY. AS MENTIONED LAST NIGHT...THIS SET UP IS
CONDUCIVE TO A STRONG SURGE OF LOW LEVEL GULF MOISTURE. SOME MINOR
TIMING DETAILS ON WHEN THIS MOISTURE ARRIVES IN IOWA...EITHER LATE
SUNDAY OR SUNDAY NIGHT. THIS MOISTURE WILL LIFT NORTH AND POOL AHEAD
OF A SFC BOUNDARY THAT WILL BE INCHING SOUTHEAST THROUGH IOWA SUNDAY
THROUGH MONDAY. THIS TYPE OF MOISTURE OFTEN RESULTS IN A STRATUS
FIELD AND MAY BE ACCOMPANIED WITH FOG OR DRIZZLE. ENHANCED VERTICAL
TURBULENCE WITH THE SFC BOUNDARY NEAR BY ENHANCES THAT POSSIBILITY.
ANY STRATUS CERTAINLY WOULD IMPACT TEMPERATURES. A SHORT WAVE
LIFTING THROUGH THE SOUTHWEST FLOW WILL INTRODUCE SOME CONVECTIVE
POTENTIAL MONDAY AND MONDAY NIGHT. THE MILD SOUTHWEST FLOW WILL
MAINTAIN THROUGH THE END OF THE EXTENDED WITH HIGHS IN THE 60S AND
70S.
&&
.AVIATION...17/12Z
COLD FRONT WILL PUSH THROUGH THIS MORNING AND WINDS LOOK TO SHIFT
AND INCREASE OUT OF THE WEST B/T 13-15Z. THERE IS SOME LIGHT SHOWER
ACTIVITY BUT EXPECTING CONDITIONS TO REMAIN VFR FOR VIS AND CIGS.
WINDS WILL CONTINUE TO INCREASE THROUGH THE AFTERNOON WITH GUSTS
NEAR 30KTS. PRESSURE GRADIENT REMAINS TIGHT OVERNIGHT TONIGHT WITH
ANOTHER STRATUS DECK MOVING INTO NORTHERN IOWA THIS EVENING. KEPT
VFR CONDITIONS FOR NOW AS MVFR/IFR CIGS LOOK TO AFFECT NORTHERN IOWA
PAST 06Z THURSDAY AND TIMING AND LOCATION STILL UNCERTAIN.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...PODRAZIK
LONG TERM...DONAVON
AVIATION...PODRAZIK
AREA FORECAST DISCUSSION
NWS DES MOINES IA
353 AM CDT WED OCT 17 2012
.SHORT TERM /TODAY/...
SEVERAL FORECAST CONCERNS TODAY WITH STRONG
COLD FRONT EXPECTED TO SWEEP ACROSS IOWA THIS MORNING. FROPA WILL BE
BETWEEN 11-15Z THIS MORNING FROM WEST TO EAST ACROSS THE FORECAST
AREA. LEANED TOWARD A BLEND OF THE SHORT TERM HIGH-RESOLUTION MODELS
HRRR/4.0KM WRF AND SREF/NAM12 AS THEY SEEMED TO HAVE BEST HANDLE ON
TIMING OF FRONT AND POPS.
SHARP PRESSURE GRADIENT COMBINED WITH A DECENT TROPOPAUSE UNDULATION
LATE THIS MORNING INTO THE AFTERNOON WILL PROVIDE A WINDY DAY. WINDS
ATOP THE MIX LAYER RANGE FROM 30-35KTS WEST OF THE INTERSTATE 35 AND
WITH THE CLOUDS CLEARING OUT THIS AFTERNOON IN WESTERN IOWA...SHOULD
ENHANCE THE WIND GUSTS. TWEAKED WINDS UP SLIGHTLY IN THIS AREA
THROUGH 18Z. STILL BORDER LINE WIND ADVISORY ATTM. KEPT MENTION OF
THE NON-DIURNAL TEMPS WITH THE STRONG CAA DEVELOPING LATE THIS
MORNING. 850MB TEMPS DROP TO +2C TO +4C BY THIS AFTERNOON. A NICE
STRATUS DECK LOOKS TO MOVE IN BY AROUND 00Z THURSDAY AS RH AT 850MB
INCREASES GREATER THAN 80 PERCENT. INCREASED SKY COVER ACROSS THE FAR
NORTHWEST.
BEST POPS WILL BE ACROSS THE SOUTHEAST LATE THIS MORNING WHERE
STRONGEST FORCING AND BEST THETA-E ADVECTION IS LOCATED. IN
ADDITION...SOME ELEVATED INSTABILITY IS PRESENT AND LIKELY WILL THE
HIGHER QPF AMOUNTS. THE LATEST HRRR COINCIDES WITH THIS THINKING AND
TWEAKED UP QPF THROUGH 18Z.
.LONG TERM /TONIGHT THROUGH TUESDAY/...
DEEPENING UPPER LOW WILL BE DIVING INTO MINNESOTA AND IOWA OVERNIGHT
WITH AN IMPRESSIVE 90-100KT JET ROUNDING THE BASE OF THE TROUGH AND
BEING INGESTED INTO THE SYSTEM THROUGH THURSDAY. THERE IS A
SIGNIFICANT AMOUNT OF ENERGY EMBEDDED IN THE FLOW WHICH WILL WRAP
AROUND THE SYSTEM THE NEXT FEW DAYS. ONE OF THE MORE VIGOROUS
IMPULSES IS MOVING THROUGH SRN IA AND MISSOURI TODAY AND WILL WRAP
AROUND THE SYSTEM AND MOVE ACROSS MINNESOTA AND IOWA ON THURSDAY AND
WILL SHIFT THE AXIS OF THE UPPER LOW BACK WEST A BIT. THIS SYSTEM
WILL ALSO HAVE GOOD THETA-E ADVECTION EMBEDDED WHICH WILL HELP PUSH
PWATS BACK TO NEAR 0.75 INCHES AND COMBINED WITH THE KINEMATIC
ENERGY...SHOULD RESULT IN WIDESPREAD SHOWERS BY THURSDAY AFTERNOON
AND EVENING. IN ADDITION...AN INCREASING PRESSURE GRADIENT OVER
WESTERN IOWA AND WINDS APPROACHING 50 KTS IN THE LOWEST 4 KFT OF THE
ATMOSPHERE DOES RAISE CONCERNS ABOUT POTENTIAL WIND ADVISORY
CRITERIA. IT WILL BE CLOSE...WEST OF INTERSTATE 35 THOUGH THERE ARE
A FEW NEGATIVES THAT WILL KEEP THE WINDS FROM REACHING MAX
POTENTIAL. A STRATUS DECK SHOULD ENGULF MUCH OF IOWA ON THURSDAY AND
THIS WILL LIMIT HIGH TEMPERATURES AND POTENTIAL FOR MIXING.
TEMPERATURES WILL LIKELY LINGER IN THE 40S FOR MUCH OF THE DAY. THE
GOOD REGION OF SUBSIDENCE WILL BE WEST OF THE MISSOURI RIVER AND
THAT WILL BE THE REGION FOR GOOD MOMENTUM TRANSFER AND BETTER MIXING
OF WINDS ALOFT.
PRECIPITATION CHANCES WILL CONTINUE THURSDAY NIGHT BEFORE THE BULK
OF THE ENERGY ROUNDS THE BASE OF THE UPPER LOW AND IT BEGINS TO
SHIFT OFF TO THE EAST ON FRIDAY. A FEW SHOWERS MAY LINGER FRIDAY
BEFORE MID LEVEL RIDGING MOVES IN FOR THE WEEKEND WITH WARMER
TEMPERATURES. STRENGTHENING HIGH PRESSURE OVER THE SOUTHEAST CONUS
AND REGION OF LOW PRESSURE TO THE WEST WILL ENHANCE THE WARM
ADVECTION INTO SUNDAY. AS MENTIONED LAST NIGHT...THIS SET UP IS
CONDUCIVE TO A STRONG SURGE OF LOW LEVEL GULF MOISTURE. SOME MINOR
TIMING DETAILS ON WHEN THIS MOISTURE ARRIVES IN IOWA...EITHER LATE
SUNDAY OR SUNDAY NIGHT. THIS MOISTURE WILL LIFT NORTH AND POOL AHEAD
OF A SFC BOUNDARY THAT WILL BE INCHING SOUTHEAST THROUGH IOWA SUNDAY
THROUGH MONDAY. THIS TYPE OF MOISTURE OFTEN RESULTS IN A STRATUS
FIELD AND MAY BE ACCOMPANIED WITH FOG OR DRIZZLE. ENHANCED VERTICAL
TURBULENCE WITH THE SFC BOUNDARY NEAR BY ENHANCES THAT POSSIBILITY.
ANY STRATUS CERTAINLY WOULD IMPACT TEMPERATURES. A SHORT WAVE
LIFTING THROUGH THE SOUTHWEST FLOW WILL INTRODUCE SOME CONVECTIVE
POTENTIAL MONDAY AND MONDAY NIGHT. THE MILD SOUTHWEST FLOW WILL
MAINTAIN THROUGH THE END OF THE EXTENDED WITH HIGHS IN THE 60S AND
70S.
&&
.AVIATION...17/06Z
VFR CONDITIONS WILL PREVAIL ACROSS ALL TAF SITES THROUGH AT LEAST
17/11Z. AN UPPER LEVEL SYSTEM AND AN ASSOCIATED COLD FRONT WILL
SWEEP THROUGH ALL TAF SITES TODAY...PROVIDING A WIND SHIFT TO STRONG
GUSTY WEST/NORTHWESTERLIES AND SOME POST FRONTAL PRECIPITATION. THE
PRECIPITATION WILL BE GENERALLY LIGHT...ESPECIALLY ACROSS
NORTHWESTERN SITES...BUT SOME BRIEF MVFR CIGS MAY ACCOMPANY THIS
PRECIPITATION BAND AS IT SLIDES ACROSS ALL TAF SITES. HAVE DECIDED
NOT TO INCLUDE ATTM DUE TO THE EXPECTED BREVITY...BUT THIS POTENTIAL
WILL BE FINE TUNED IN THE COMING FORECASTS. GUSTS WILL DIE DOWN
TOWARDS THE END OF THE PERIOD...BUT WINDS WILL REMAIN RATHER BRISK
AT 15-20 KTS THROUGH THE END OF THE TAF PERIOD.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...PODRAZIK
LONG TERM...DONAVON
AVIATION...DEITSCH
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1010 PM CDT THU OCT 18 2012
...UPDATE TO SYNOPSIS...
.SYNOPSIS...
ISSUED AT 1010 PM CDT THU OCT 18 2012
THE 19.00Z 250 HPA RAOB MAP SHOWED A STRONG CYCLONICALLY CURVED JET
EXTENDING FROM KUNR TO KLZK TO KPIT. MAXIMUM SPEED OF AROUND 120 KT
WAS OBSERVED AT THE BASE OF THE LONGWAVE TROF AND THEN ACROSS THE MID
ATLANTIC STATES. AT 500 HPA, A 532 DM CYCLONE WAS NOTED ACROSS SOUTHERN
WISCONSIN. THIS MID LEVEL FEATURE HAD A COLD POOL OF -26 DEG C ASSOCIATED
WITH IT. FAIRLY IMPRESSIVE RIBBONS OF VORTICITY WERE ALSO NOTED IN ASSOCIATION
WITH THE PRESSURE PERTURBATION VIA SATELLITE WV IMAGERY. AT 700 HPA,
A COLD POOL OF AROUND -10 DEG C WAS OBSERVED ACROSS IOWA/ILLINOIS/WISCONSIN.
CLOSER TO KANSAS, TEMPERATURES WARMED A FEW DEGREES BUT WERE STILL FAIRLY
COOL AT -4 DEG C. AT 850 HPA, THE MOST SIGNIFICANT ITEM OF INTEREST
RELEVANT TO KANSAS WAS THE STRONG WIND PROFILE WITH 35-45 KT OBSERVED
IN THE WAKE OF THE SYNOPTIC WAVE. AT THE SURFACE, A SLOWLY FILLING SURFACE
LOW OF 993 HPA WAS NOTED ACROSS THE UPPER MIDWEST. A RIDGE OF HIGH PRESSURE
EXTENDED ACROSS THE HIGH PLAINS/ROCKIES.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 219 PM CDT THU OCT 18 2012
THE STRONG NORTHWEST WINDS SHOULD CONTINUE THROUGH THE REMAINDER
OF THIS AFTERNOON ALTHOUGH THEY MAY ABATE SOMEWHAT DURING THE NEXT
FEW HOURS. WILL LET THE HIGH WIND WARNING AND WIND ADVISORY
HEADLINES RUN UNTIL EXPIRATION TIME AT 7 PM CDT AS THERE WILL
PROBABLY BE AT LEAST SOME THREAT FOR MEETING CRITERIA UNTIL WE GET
CLOSE TO SUNSET. THE MODELS ARE SHOWING WINDS IN THE 850-750 MB
LAYER STAYING UP IN THE 45-50 KNOT RANGE OVERNIGHT OVER SOUTHWEST
KANSAS. THIS SHOULD KEEP WINDS IN THE 10 TO 15 MPH RANGE OVERNIGHT
WHICH SHOULD ALSO KEEP TEMPERATURES FROM BOTTOMING OUT TOO MUCH
GIVEN THE DRY AIR THAT HAS ADVECTED IN TO THE REGION. GIVEN THE
EXPECTED WINDS AND LOW DEWPOINTS, DO NOT THINK THAT FROST WILL BE
A PROBLEM. THE SOUTHWEST CORNER WOULD HAVE THE BEST POTENTIAL
GIVEN SLIGHTLY HIGHER DEWPOINTS. WILL MENTION SOME PATCHY FROST IN
THAT AREA LATER TONIGHT.
FRIDAY WILL BE A QUIETER DAY ACROSS WESTERN KANSAS. THE UPPER LOW
WILL SLOWLY MOVE INTO THE SOUTHERN GREAT LAKES REGION WHILE
WESTERLY FLOW ALOFT SPREADS EAST TOWARDS THE NORTHERN AND CENTRAL
HIGH PLAINS. AT THE SURFACE, THE STRONGEST PRESSURE GRADIENT WILL
BE SHIFTING INTO EASTERN KANSAS. THERE WILL BE A PERIOD OF BREEZY
NORTH WINDS OVER SOUTHWEST INTO CENTRAL KANSAS DURING THE MORNING
HOURS BUT THE WINDS WILL BE DIMINISHING AND BECOMING LIGHT AND
VARIABLE AS THE SURFACE RIDGE MOVES EAST. FARTHER WEST, WINDS WILL
BECOME SOUTHERLY IN RESPONSE TO LOWERING PRESSURES IN THE EASTERN
SLOPES OF THE ROCKIES.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 342 PM CDT THU OCT 18 2012
TWO MAIN THINGS IN THE FORECAST THAT WILL NEED TO BE WATCHED FOR
DURING THE SATURDAY THROUGH WEDNESDAY TIME FRAME. THE FIRST IS AN
EJECTING SUBTROPICAL LOW CURRENTLY STATIONED OFF THE BAJA CALIFORNIA
COAST. THIS WILL MOVE NORTHEAST INLAND...TRACKING ACROSS NEW MEXICO
DURING THE DAY SUNDAY THEN ACROSS THE SOUTHERN/CENTRAL PLAINS
MONDAY. THERE WILL BE FAIRLY SUBSTANTIAL MOISTURE ADVECTION
NORTHWARD TOWARD THE CENTRAL PLAINS AHEAD OF THIS FEATURE...BUT
GIVEN THE PROGRESSIVE NATURE OF THIS WAVE MOVING ACROSS...AND ITS
TRACK TO THE SOUTH OF SOUTHWEST KANSAS...PRETTY MUCH ALL OF THE
PRECIPITATION WILL BE REALIZED WELL TO THE EAST OF SOUTHWEST
KANSAS. THAT BEING SAID WILL CARRY 20 POPS ACROSS SOUTH CENTRAL KS
COUNTIES BOTH MONDAY AND MONDAY NIGHT AHEAD OF THE WEAK SURFACE
FRONT/LOW. THIS FRONT WILL STALL OUT AND WEAKEN IN FAVOR OF
DEEPENING LEESIDE LOW MONDAY NIGHT.
BROAD SOUTHWEST FLOW IN THE MID/UPPER TROPOSPHERE WILL OCCUR TUESDAY
ACROSS THE SOUTHWESTERN CONUS EXTENDING INTO THE WESTERN PLAINS.
THIS IS A FAIRLY WARM SETUP FOR THE PLAINS. THERE ARE QUESTIONS
STILL ON HOW FAR THE INITIAL FRONT WILL PUSH SOUTH AND THUS HOW FAR
NORTH THE REALLY WARM AIR WILL EXTEND INTO KANSAS ON TUESDAY. IF
THE FRONT PUSHES WELL NORTH...THE VERY WARM LOWER TROPOSPHERE WILL
YIELD SURFACE TEMPERATURES WELL INTO THE 80S. THE SAME GOES FOR
WEDNESDAY AS SOUTHWEST MOMENTUM IS SUGGESTED TO PERSIST ACROSS THE
ROCKIES.
A JET STREAK WILL EVENTUALLY CROSS THE NORTHERN PLAINS WHICH WILL
ALLOW COLDER CANADIAN AIR TO SPILL SOUTH DOWN THE WESTERN PLAINS
MID-WEEK. TEMPERATURE FORECAST FROM WEDNESDAY INTO THE END OF NEXT
WEEK WILL BE COMPLICATED BY DEGREE OF COLD AIR ADVECTION AND HOW
LONG SURFACE COLD AIR INTRUSION WILL LAST IN FAVOR OF RENEWED WARM
ADVECTION SHOULD LONGWAVE TROUGHING REMAIN PARKED ALONG THE WEST
COAST. OVERALL...THIS PATTERN IS DRY FOR WESTERN KANSAS AND OTHER
THAN THE BRIEF SHOT AT SOME PRECIPITATION ACROSS SOUTH-CENTRAL
KANSAS MONDAY/MONDAY NIGHT...THE FORECAST DURING THE MEDIUM RANGE
WILL REMAIN A DRY ONE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 606 PM CDT THU OCT 18 2012
GUSTY NORTHWEST WINDS HAVE BEGUN TO SUBSIDE AS OF 23Z AND ARE
EXPECTED TO CONTINUE TO DECREASE THROUGH SUNSET AS THE MIXING
DEPTH DECREASES. LATEST RAP APPEARS TO HAVE A DECENT HANDLE ON
THESE DECREASING WINDS SO WILL FOLLOW THE RAPS TREND OF WIND
SPEEDS FALLING BACK INTO THE 10 TO 15KT RANGE BY 8 PM. BOUNDARY
LAYER WINDS OVERNIGHT OF NEAR 25KTS OBSERVED IN NORTH CENTRAL
KANSAS SO WILL KEEP WIND SPEEDS SLIGHTLY STRONGER HERE DURING THE
OVERNIGHT PERIOD. BASED ON BUFR SOUNDINGS VFR CONDITIONS ARE
EXPECTED. MVFR VSBYS AT HYS WILL IMPROVE TO VFR BY 01Z AS THE
GUSTY NORTHWEST WINDS SUBSIDE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 33 72 41 81 / 0 0 0 0
GCK 32 72 39 81 / 0 0 0 0
EHA 35 75 44 82 / 0 0 0 0
LBL 33 73 40 81 / 0 0 0 0
HYS 33 68 37 80 / 0 0 0 0
P28 36 72 43 82 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...GERARD
LONG TERM...UMSCHEID
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
650 PM CDT THU OCT 18 2012
...UPDATED TO REMOVE HEADLINES OF STRONG WINDS AND RED FLAG
WARNING...
.SYNOPSIS...
ISSUED AT 219 PM CDT THU OCT 18 2012
THE 12Z UPPER AIR ANALYSIS SHOWED A NEARLY VERTICALLY STACKED
UPPER LOW OVER NORTHWEST WISCONSIN. A 110+ KNOT JET AT 250 MB
EXTENDING FROM CENTRAL MONTANA THROUGH THE CENTRAL HIGH PLAINS.
WIND FLOW THROUGH THE ATMOSPHERE WAS UNIDIRECTIONAL FROM THE
NORTHWEST OVER THE CENTRAL HIGH PLAINS. STRONG WINDS HAVE BEEN
OCCURRING AT THE SURFACE OVER CENTRAL AND MUCH OF SOUTHWEST KANSAS.
HIGH WIND WARNINGS HAVE BEEN EXPANDED SOUTHWESTWARD TO A LINE FROM
DIGHTON THROUGH DODGE CITY AND COLDWATER. WINDS TAPER OFF TO LESS
THAN 10 KNOTS OVER THE SOUTHWEST CORNER OF THE STATE AT ELKHART
NEAR THE SURFACE RIDGE.
&&
.UPDATE...
ISSUED AT 644 PM CDT THU OCT 18 2012
OVER THE PAST HOUR THE WIND SPEEDS ACROSS NORTH CENTRAL AND SOUTH
CENTRAL KANSAS HAVE DECREASED INTO THE 15 TO 30 MPH RANGE. THESE
WINDS ARE EXPECTED TO CONTINUE TO SUBSIDE AS THE MIXING DEPTH
DECREASES AND THE TIGHT PRESSURE GRADIENT LOCATED AT THE SURFACE
WEAKENS. AS A RESULT WILL ALLOW THE HIGH WIND WARNING AND WIND
ADVISORY TO EXPIRE AT 7 PM. LATEST OBSERVATIONS ACROSS WESTERN
KANSAS ALSO INDICATING RELATIVE HUMIDITIES WERE BEGINNING TO CLIMB
ABOVE 15 PERCENT SO WILL ALSO ALLOW THE RED FLAG WARNING EXPIRE AS
WELL.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 219 PM CDT THU OCT 18 2012
THE STRONG NORTHWEST WINDS SHOULD CONTINUE THROUGH THE REMAINDER
OF THIS AFTERNOON ALTHOUGH THEY MAY ABATE SOMEWHAT DURING THE NEXT
FEW HOURS. WILL LET THE HIGH WIND WARNING AND WIND ADVISORY
HEADLINES RUN UNTIL EXPIRATION TIME AT 7 PM CDT AS THERE WILL
PROBABLY BE AT LEAST SOME THREAT FOR MEETING CRITERIA UNTIL WE GET
CLOSE TO SUNSET. THE MODELS ARE SHOWING WINDS IN THE 850-750 MB
LAYER STAYING UP IN THE 45-50 KNOT RANGE OVERNIGHT OVER SOUTHWEST
KANSAS. THIS SHOULD KEEP WINDS IN THE 10 TO 15 MPH RANGE OVERNIGHT
WHICH SHOULD ALSO KEEP TEMPERATURES FROM BOTTOMING OUT TOO MUCH
GIVEN THE DRY AIR THAT HAS ADVECTED IN TO THE REGION. GIVEN THE
EXPECTED WINDS AND LOW DEWPOINTS, DO NOT THINK THAT FROST WILL BE
A PROBLEM. THE SOUTHWEST CORNER WOULD HAVE THE BEST POTENTIAL
GIVEN SLIGHTLY HIGHER DEWPOINTS. WILL MENTION SOME PATCHY FROST IN
THAT AREA LATER TONIGHT.
FRIDAY WILL BE A QUIETER DAY ACROSS WESTERN KANSAS. THE UPPER LOW
WILL SLOWLY MOVE INTO THE SOUTHERN GREAT LAKES REGION WHILE
WESTERLY FLOW ALOFT SPREADS EAST TOWARDS THE NORTHERN AND CENTRAL
HIGH PLAINS. AT THE SURFACE, THE STRONGEST PRESSURE GRADIENT WILL
BE SHIFTING INTO EASTERN KANSAS. THERE WILL BE A PERIOD OF BREEZY
NORTH WINDS OVER SOUTHWEST INTO CENTRAL KANSAS DURING THE MORNING
HOURS BUT THE WINDS WILL BE DIMINISHING AND BECOMING LIGHT AND
VARIABLE AS THE SURFACE RIDGE MOVES EAST. FARTHER WEST, WINDS WILL
BECOME SOUTHERLY IN RESPONSE TO LOWERING PRESSURES IN THE EASTERN
SLOPES OF THE ROCKIES.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 342 PM CDT THU OCT 18 2012
TWO MAIN THINGS IN THE FORECAST THAT WILL NEED TO BE WATCHED FOR
DURING THE SATURDAY THROUGH WEDNESDAY TIME FRAME. THE FIRST IS AN
EJECTING SUBTROPICAL LOW CURRENTLY STATIONED OFF THE BAJA CALIFORNIA
COAST. THIS WILL MOVE NORTHEAST INLAND...TRACKING ACROSS NEW MEXICO
DURING THE DAY SUNDAY THEN ACROSS THE SOUTHERN/CENTRAL PLAINS
MONDAY. THERE WILL BE FAIRLY SUBSTANTIAL MOISTURE ADVECTION
NORTHWARD TOWARD THE CENTRAL PLAINS AHEAD OF THIS FEATURE...BUT
GIVEN THE PROGRESSIVE NATURE OF THIS WAVE MOVING ACROSS...AND ITS
TRACK TO THE SOUTH OF SOUTHWEST KANSAS...PRETTY MUCH ALL OF THE
PRECIPITATION WILL BE REALIZED WELL TO THE EAST OF SOUTHWEST
KANSAS. THAT BEING SAID WILL CARRY 20 POPS ACROSS SOUTH CENTRAL KS
COUNTIES BOTH MONDAY AND MONDAY NIGHT AHEAD OF THE WEAK SURFACE
FRONT/LOW. THIS FRONT WILL STALL OUT AND WEAKEN IN FAVOR OF
DEEPENING LEESIDE LOW MONDAY NIGHT.
BROAD SOUTHWEST FLOW IN THE MID/UPPER TROPOSPHERE WILL OCCUR TUESDAY
ACROSS THE SOUTHWESTERN CONUS EXTENDING INTO THE WESTERN PLAINS.
THIS IS A FAIRLY WARM SETUP FOR THE PLAINS. THERE ARE QUESTIONS
STILL ON HOW FAR THE INITIAL FRONT WILL PUSH SOUTH AND THUS HOW FAR
NORTH THE REALLY WARM AIR WILL EXTEND INTO KANSAS ON TUESDAY. IF
THE FRONT PUSHES WELL NORTH...THE VERY WARM LOWER TROPOSPHERE WILL
YIELD SURFACE TEMPERATURES WELL INTO THE 80S. THE SAME GOES FOR
WEDNESDAY AS SOUTHWEST MOMENTUM IS SUGGESTED TO PERSIST ACROSS THE
ROCKIES.
A JET STREAK WILL EVENTUALLY CROSS THE NORTHERN PLAINS WHICH WILL
ALLOW COLDER CANADIAN AIR TO SPILL SOUTH DOWN THE WESTERN PLAINS
MID-WEEK. TEMPERATURE FORECAST FROM WEDNESDAY INTO THE END OF NEXT
WEEK WILL BE COMPLICATED BY DEGREE OF COLD AIR ADVECTION AND HOW
LONG SURFACE COLD AIR INTRUSION WILL LAST IN FAVOR OF RENEWED WARM
ADVECTION SHOULD LONGWAVE TROUGHING REMAIN PARKED ALONG THE WEST
COAST. OVERALL...THIS PATTERN IS DRY FOR WESTERN KANSAS AND OTHER
THAN THE BRIEF SHOT AT SOME PRECIPITATION ACROSS SOUTH-CENTRAL
KANSAS MONDAY/MONDAY NIGHT...THE FORECAST DURING THE MEDIUM RANGE
WILL REMAIN A DRY ONE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 606 PM CDT THU OCT 18 2012
GUSTY NORTHWEST WINDS HAVE BEGUN TO SUBSIDE AS OF 23Z AND ARE
EXPECTED TO CONTINUE TO DECREASE THROUGH SUNSET AS THE MIXING
DEPTH DECREASES. LATEST RAP APPEARS TO HAVE A DECENT HANDLE ON
THESE DECREASING WINDS SO WILL FOLLOW THE RAPS TREND OF WIND
SPEEDS FALLING BACK INTO THE 10 TO 15KT RANGE BY 8 PM. BOUNDARY
LAYER WINDS OVERNIGHT OF NEAR 25KTS OBSERVED IN NORTH CENTRAL
KANSAS SO WILL KEEP WIND SPEEDS SLIGHTLY STRONGER HERE DURING THE
OVERNIGHT PERIOD. BASED ON BUFR SOUNDINGS VFR CONDITIONS ARE
EXPECTED. MVFR VSBYS AT HYS WILL IMPROVE TO VFR BY 01Z AS THE
GUSTY NORTHWEST WINDS SUBSIDE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 34 72 41 81 / 0 0 0 0
GCK 33 72 39 81 / 0 0 0 0
EHA 35 75 44 82 / 0 0 0 0
LBL 35 73 40 81 / 0 0 0 0
HYS 35 68 37 80 / 0 0 0 0
P28 36 72 43 82 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING UNTIL 7 PM CDT THIS EVENING FOR KSZ030-031-
044>046-064>066-078>081-089-090.
RED FLAG WARNING UNTIL 7 PM CDT /6 PM MDT/ THIS EVENING FOR
KSZ030-031-043>046-061>066-074>081-084>090.
WIND ADVISORY UNTIL 7 PM CDT /6 PM MDT/ THIS EVENING FOR KSZ043-
061>063-075>077-086>088.
&&
$$
UPDATE...BURGERT
SYNOPSIS...GERARD
SHORT TERM...GERARD
LONG TERM...UMSCHEID
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
609 PM CDT THU OCT 18 2012
...UPDATED AVIATION DISCUSSION...
.SYNOPSIS...
ISSUED AT 219 PM CDT THU OCT 18 2012
THE 12Z UPPER AIR ANALYSIS SHOWED A NEARLY VERTICALLY STACKED
UPPER LOW OVER NORTHWEST WISCONSIN. A 110+ KNOT JET AT 250 MB
EXTENDING FROM CENTRAL MONTANA THROUGH THE CENTRAL HIGH PLAINS.
WIND FLOW THROUGH THE ATMOSPHERE WAS UNIDIRECTIONAL FROM THE
NORTHWEST OVER THE CENTRAL HIGH PLAINS. STRONG WINDS HAVE BEEN
OCCURRING AT THE SURFACE OVER CENTRAL AND MUCH OF SOUTHWEST KANSAS.
HIGH WIND WARNINGS HAVE BEEN EXPANDED SOUTHWESTWARD TO A LINE FROM
DIGHTON THROUGH DODGE CITY AND COLDWATER. WINDS TAPER OFF TO LESS
THAN 10 KNOTS OVER THE SOUTHWEST CORNER OF THE STATE AT ELKHART
NEAR THE SURFACE RIDGE.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 219 PM CDT THU OCT 18 2012
THE STRONG NORTHWEST WINDS SHOULD CONTINUE THROUGH THE REMAINDER
OF THIS AFTERNOON ALTHOUGH THEY MAY ABATE SOMEWHAT DURING THE NEXT
FEW HOURS. WILL LET THE HIGH WIND WARNING AND WIND ADVISORY
HEADLINES RUN UNTIL EXPIRATION TIME AT 7 PM CDT AS THERE WILL
PROBABLY BE AT LEAST SOME THREAT FOR MEETING CRITERIA UNTIL WE GET
CLOSE TO SUNSET. THE MODELS ARE SHOWING WINDS IN THE 850-750 MB
LAYER STAYING UP IN THE 45-50 KNOT RANGE OVERNIGHT OVER SOUTHWEST
KANSAS. THIS SHOULD KEEP WINDS IN THE 10 TO 15 MPH RANGE OVERNIGHT
WHICH SHOULD ALSO KEEP TEMPERATURES FROM BOTTOMING OUT TOO MUCH
GIVEN THE DRY AIR THAT HAS ADVECTED IN TO THE REGION. GIVEN THE
EXPECTED WINDS AND LOW DEWPOINTS, DO NOT THINK THAT FROST WILL BE
A PROBLEM. THE SOUTHWEST CORNER WOULD HAVE THE BEST POTENTIAL
GIVEN SLIGHTLY HIGHER DEWPOINTS. WILL MENTION SOME PATCHY FROST IN
THAT AREA LATER TONIGHT.
FRIDAY WILL BE A QUIETER DAY ACROSS WESTERN KANSAS. THE UPPER LOW
WILL SLOWLY MOVE INTO THE SOUTHERN GREAT LAKES REGION WHILE
WESTERLY FLOW ALOFT SPREADS EAST TOWARDS THE NORTHERN AND CENTRAL
HIGH PLAINS. AT THE SURFACE, THE STRONGEST PRESSURE GRADIENT WILL
BE SHIFTING INTO EASTERN KANSAS. THERE WILL BE A PERIOD OF BREEZY
NORTH WINDS OVER SOUTHWEST INTO CENTRAL KANSAS DURING THE MORNING
HOURS BUT THE WINDS WILL BE DIMINISHING AND BECOMING LIGHT AND
VARIABLE AS THE SURFACE RIDGE MOVES EAST. FARTHER WEST, WINDS WILL
BECOME SOUTHERLY IN RESPONSE TO LOWERING PRESSURES IN THE EASTERN
SLOPES OF THE ROCKIES.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 342 PM CDT THU OCT 18 2012
TWO MAIN THINGS IN THE FORECAST THAT WILL NEED TO BE WATCHED FOR
DURING THE SATURDAY THROUGH WEDNESDAY TIME FRAME. THE FIRST IS AN
EJECTING SUBTROPICAL LOW CURRENTLY STATIONED OFF THE BAJA CALIFORNIA
COAST. THIS WILL MOVE NORTHEAST INLAND...TRACKING ACROSS NEW MEXICO
DURING THE DAY SUNDAY THEN ACROSS THE SOUTHERN/CENTRAL PLAINS
MONDAY. THERE WILL BE FAIRLY SUBSTANTIAL MOISTURE ADVECTION
NORTHWARD TOWARD THE CENTRAL PLAINS AHEAD OF THIS FEATURE...BUT
GIVEN THE PROGRESSIVE NATURE OF THIS WAVE MOVING ACROSS...AND ITS
TRACK TO THE SOUTH OF SOUTHWEST KANSAS...PRETTY MUCH ALL OF THE
PRECIPITATION WILL BE REALIZED WELL TO THE EAST OF SOUTHWEST
KANSAS. THAT BEING SAID WILL CARRY 20 POPS ACROSS SOUTH CENTRAL KS
COUNTIES BOTH MONDAY AND MONDAY NIGHT AHEAD OF THE WEAK SURFACE
FRONT/LOW. THIS FRONT WILL STALL OUT AND WEAKEN IN FAVOR OF
DEEPENING LEESIDE LOW MONDAY NIGHT.
BROAD SOUTHWEST FLOW IN THE MID/UPPER TROPOSPHERE WILL OCCUR TUESDAY
ACROSS THE SOUTHWESTERN CONUS EXTENDING INTO THE WESTERN PLAINS.
THIS IS A FAIRLY WARM SETUP FOR THE PLAINS. THERE ARE QUESTIONS
STILL ON HOW FAR THE INITIAL FRONT WILL PUSH SOUTH AND THUS HOW FAR
NORTH THE REALLY WARM AIR WILL EXTEND INTO KANSAS ON TUESDAY. IF
THE FRONT PUSHES WELL NORTH...THE VERY WARM LOWER TROPOSPHERE WILL
YIELD SURFACE TEMPERATURES WELL INTO THE 80S. THE SAME GOES FOR
WEDNESDAY AS SOUTHWEST MOMENTUM IS SUGGESTED TO PERSIST ACROSS THE
ROCKIES.
A JET STREAK WILL EVENTUALLY CROSS THE NORTHERN PLAINS WHICH WILL
ALLOW COLDER CANADIAN AIR TO SPILL SOUTH DOWN THE WESTERN PLAINS
MID-WEEK. TEMPERATURE FORECAST FROM WEDNESDAY INTO THE END OF NEXT
WEEK WILL BE COMPLICATED BY DEGREE OF COLD AIR ADVECTION AND HOW
LONG SURFACE COLD AIR INTRUSION WILL LAST IN FAVOR OF RENEWED WARM
ADVECTION SHOULD LONGWAVE TROUGHING REMAIN PARKED ALONG THE WEST
COAST. OVERALL...THIS PATTERN IS DRY FOR WESTERN KANSAS AND OTHER
THAN THE BRIEF SHOT AT SOME PRECIPITATION ACROSS SOUTH-CENTRAL
KANSAS MONDAY/MONDAY NIGHT...THE FORECAST DURING THE MEDIUM RANGE
WILL REMAIN A DRY ONE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 606 PM CDT THU OCT 18 2012
GUSTY NORTHWEST WINDS HAVE BEGUN TO SUBSIDE AS OF 23Z AND ARE
EXPECTED TO CONTINUE TO DECREASE THROUGH SUNSET AS THE MIXING
DEPTH DECREASES. LATEST RAP APPEARS TO HAVE A DECENT HANDLE ON
THESE DECREASING WINDS SO WILL FOLLOW THE RAPS TREND OF WIND
SPEEDS FALLING BACK INTO THE 10 TO 15KT RANGE BY 8 PM. BOUNDARY
LAYER WINDS OVERNIGHT OF NEAR 25KTS OBSERVED IN NORTH CENTRAL
KANSAS SO WILL KEEP WIND SPEEDS SLIGHTLY STRONGER HERE DURING THE
OVERNIGHT PERIOD. BASED ON BUFR SOUNDINGS VFR CONDITIONS ARE
EXPECTED. MVFR VSBYS AT HYS WILL IMPROVE TO VFR BY 01Z AS THE
GUSTY NORTHWEST WINDS SUBSIDE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 34 72 41 81 / 0 0 0 0
GCK 33 72 39 81 / 0 0 0 0
EHA 35 75 44 82 / 0 0 0 0
LBL 35 73 40 81 / 0 0 0 0
HYS 35 68 37 80 / 0 0 0 0
P28 36 72 43 82 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING UNTIL 7 PM CDT THIS EVENING FOR KSZ030-031-
044>046-064>066-078>081-089-090.
RED FLAG WARNING UNTIL 7 PM CDT /6 PM MDT/ THIS EVENING FOR
KSZ030-031-043>046-061>066-074>081-084>090.
WIND ADVISORY UNTIL 7 PM CDT /6 PM MDT/ THIS EVENING FOR KSZ043-
061>063-075>077-086>088.
&&
$$
SYNOPSIS...GERARD
SHORT TERM...GERARD
LONG TERM...UMSCHEID
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1233 AM EDT WED OCT 17 2012
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN ACROSS THE REGION ON WEDNESDAY RIGHT
THROUGH WEDNESDAY NIGHT. THE HIGH WILL MOVE EAST OF THE STATE ON
THURSDAY.
&&
.NEAR TERM /THROUGH TODAY/...
1230AM UPDATE...
NO MAJOR CHANGES. RAISED OVERNIGHT LOWS SLIGHTLY AS WINDS PERSIST.
REDUCED DEW POINTS FOR WEDNESDAY AS AIR LOOKS DRIER THAN
PREVIOUSLY THOUGHT.
UPDATE: LAST BIT OF SHOWERS EXITING THE NORTHERN TIER AND CLOUDS
BEGINNING TO BREAK UP. THE CANADIAN GEM AND RUC DOING OK W/SLOWLY
CLEARING THINGS OUT OVERNIGHT. TEMPERATURES HOLDING UP A BIT
LONGER THAN PRECIOUS ANTICIPATED AND THEREFORE, SLOWED UP THE
COOLING PROCESS BY 2 HRS. REST OF THE FCST LOOKS FINE.
PREVIOUS DISCUSSION...
LOW PRES WILL QUICKLY LIFT NORTHEAST AND MOVE AWAY TONIGHT AS HIGH
PRESSURE BUILDS OVER THE STATE. CLEARING THROUGHOUT THE REGION
TONIGHT W/TEMPS DROPPING TO NEAR OR JUST BELOW FREEZING IN MOST
AREAS. HIGH PRESSURE WILL REMAIN OVER THE REGION WEDNESDAY
BRINGING SUNSHINE WITH AFTERNOON TEMPS RANGING FROM THE UPPER 50S
DOWNEAST TO THE LOW 50S OVER THE NORTH. WINDS WILL BE VERY LIGHT
AS THE HIGH CRESTS OVER THE REGION.
&&
.SHORT TERM /TONIGHT THROUGH FRIDAY/...
NORTHERN NEW ENGLAND WILL BEGIN THIS FORECAST PERIOD UNDERNEATH AN
UPPER RIDGE. THIS WILL ALLOW FOR ABOVE NORMAL TEMPERATURES AND
DRY WEATHER. HIGH CLOUDS WILL SPILL OVER THE RIDGE AXIS FOR MOSTLY
CLOUDY SKIES. WILL HAVE TO WATCH OUT FOR LOW CLOUDS AND FOG ALONG
THE COASTAL ZONES LATE THURSDAY NIGHT AND EARLY FRIDAY MORNING DUE
TO A STRONG ONSHORE FLOW.
WINDS WILL INCREASE ON FRIDAY AS AN OCCLUDED FRONT APPROACHES FROM
THE WEST. EXPECT RAIN OR RAIN SHOWERS TO DEVELOP DURING THE DAY
ACROSS NORTHERN AND DOWNEAST MAINE.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AN OCCLUDED FRONT WILL CROSS THE REGION FRIDAY NIGHT THROUGH
SATURDAY NIGHT...THOUGH UNCERTAINTY STILL EXISTS REGARDING HOW
QUICKLY THE FRONT MOVES EAST OF THE REGION LATER SATURDAY THROUGH
SATURDAY NIGHT. AN AREA OF RAIN WILL CROSS THE REGION IN ADVANCE
OF THE OCCLUSION FRIDAY NIGHT INTO SATURDAY...THEN TAPER TO
SHOWERS IN THE WAKE OF THE FRONT LATER SATURDAY INTO SATURDAY
NIGHT DEPENDENT ON THE TIMING OF THE FRONT. SHOWERS WRAPPING
AROUND THE EXITING SYSTEM COULD BRING A CHANCE OF SHOWERS TO THE
NORTH/MOUNTAINS SUNDAY...WITH PARTLY CLOUDY SKIES DOWNEAST. HIGH
PRESSURE SHOULD THEN BUILD ACROSS THE REGION MONDAY. A COLD FRONT
COULD THEN BRING A CHANCE OF SHOWERS TUESDAY. TEMPERATURES SHOULD
BE AT SLIGHTLY ABOVE NORMAL LEVELS SATURDAY THROUGH MONDAY...WITH
NEAR NORMAL LEVEL TEMPERATURES TUESDAY.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
NEAR TERM: CONDITIONS WILL IMPROVE TO VFR TONIGHT THEN REMAIN VFR
IN MOSTLY CLEAR SKIES ON WEDNESDAY.
SHORT TERM: MVFR CIGS AND VSBYS ARE POSSIBLE AT KBHB AND KBGR LATE
THURSDAY NIGHT AND EARLY FRIDAY MORNING DUE TO LOW CLOUDS AND FOG.
MVFR CIGS AND VSBYS ARE POSSIBLE FRIDAY AFTERNOON AT ALL TAF SITES
DUE TO LOW CLOUDS AND SHOWERS AS AN OCCLUDED FRONT MOVES INTO THE
REGION. MVFR/IFR CONDITIONS ARE EXPECTED ACROSS THE REGION FRIDAY
NIGHT INTO EARLY SATURDAY NIGHT...WITH MVFR CONDITIONS LATER
SATURDAY NIGHT. OCCASIONAL MVFR CONDITIONS COULD LINGER ACROSS
THE NORTH/MOUNTAINS SUNDAY...WITH VFR CONDITIONS DOWNEAST.
&&
.MARINE...
NEAR TERM: AN SCA WILL CONTINUE OVERNIGHT. WINDS WILL DIMINISH
BY MORNING AS THE HIGH CRESTS OVER THE WATERS.
SHORT TERM: SCA CONDITIONS ARE LIKELY THURSDAY WITH WAVE HEIGHTS IN
THE 4 TO 7 FOOT RANGE AND FRIDAY WITH WAVE HEIGHTS IN THE 6 TO 9
FOOT RANGE AND WIND GUSTS IN EXCESS OF 25 KNOTS.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT THIS MORNING FOR
ANZ050>052.
&&
$$
NEAR TERM...HEWITT/MCW
SHORT TERM...
LONG TERM...
AVIATION...HEWITT/MCW
MARINE...HEWITT/MCW/
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
433 PM EDT WED OCT 17 2012
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 432 PM EDT WED OCT 17 2012
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A TROF IN THE PROCESS OF
AMPLIFYING OVER THE PLAINS. THERE ARE A NUMBER OF EMBEDDED SHORTWAVES
IN THE DEEPENING TROF...BUT THE 130-140KT JET PER LATEST RUC
CURRENTLY DROPPING DOWN THE BACKSIDE OF THE TROF WILL BE THE FACTOR
LEADING TO THE TROF CONTINUING TO DEEPEN. IN FACT...TROF WILL BECOME
DEEP FOR THIS TIME OF YEAR. AT PEAK INTENSITY THU OVER THE
MID/UPPER MISSISSIPPI VALLEY...500MB HEIGHTS WILL BE 3.5 STANDARD
DEVIATIONS BLO THE LONG TERM AVG FOR MID OCT. AT THE SFC...LOW PRES
OF 29.1 INCHES IS OVER NW MN WITH COLD FRONT EXTENDING INTO FAR WRN
WI/FAR ERN IA AND MO. SO FAR...PCPN COVERAGE HAS BEEN GREATEST NEAR
THE SFC LOW OVER NW MN/ERN ND. HOWEVER...SHRA ARE INCREASING IN
COVERAGE SOUTHWARD ALONG/AHEAD OF COLD FRONT AS UPPER DIFFLUENCE
IMPROVES DUE TO AFOREMENTIONED UPPER JET DROPPING DOWN BACKSIDE OF
THE TROF.
AS TROF CONTINUES TO DEEPEN TONIGHT...A NEW LOW PRES CENTER IS
EXPECTED TO DEVELOP ON COLD FRONT IN ERN WI AND THEN LIFT NW TO THE
VCNTY OF WRN LAKE SUPERIOR THU MORNING. DEEPENING SYSTEM WILL LEAD
TO LOW-LEVEL JET RAMPING UP TO AROUND 50KT WHICH WILL TRANSPORT
ABUNDANT MOISTURE N INTO THE AREA (PRECIPITABLE WATER INCREASES TO
200PCT OF NORMAL OR BETTER). STRONG DIRECTIONAL DIFFLUENCE AT UPPER
LEVELS OVERTOP TIGHTENING LOW LEVEL FRONTAL BOUNDARY WILL SUPPORT AN
EXPANDING AREA OF SHRA SPREADING INTO THE FCST AREA TONIGHT. LIKELY
TO CATEGORICAL POPS LOOK ON TRACK. MODELS HAVE AND CONTINUE TO POINT
TOWARD SW/W UPPER MI RECEIVING THE HEAVIEST RAINFALL WITH THAT AREA
NEAR THE TRACK OF NW MOVING SFC WAVE. SO...AS IN PREVIOUS FCSTS...
HIGHEST POPS WERE PAINTED IN THAT AREA. NOT OUT OF THE QUESTION THAT
THERE MAY BE A FEW RUMBLES OF THUNDER GIVEN SHOWALTER INDEX FALLING
TOWARD ZERO. MIN TEMPS WILL BE WELL ABOVE NORMAL GIVEN CLOUDS/DEEP
MOISTURE. MINS SHOULD RANGE FROM THE MID 40S FAR W WHERE CAA WILL
GET UNDERWAY OVERNIGHT TO THE MID 50S EAST.
MAIN PUSH OF PCPN FROM TONIGHT WILL ROTATE NW OF THE AREA BY
MORNING. SO THERE MAY BE SOMEWHAT OF A BREAK IN PCPN FOR A WHILE THU
MORNING. HOWEVER...A SHORTWAVE ROTATING AROUND MIDLEVEL LOW WILL BE
SWINGING N TOWARD ERN UPPER MI...AND SHOULD BRING ANOTHER ROUND OF
GREATER SHRA COVERAGE INTO ESPECIALLY THE CNTRL AND ERN FCST AREA
FOR THE AFTN. TEMP RISE THU WILL BE LIMITED BY CLOUDS/CAA.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 432 PM EDT WED OCT 17 2012
AN UPPER LOW WILL BE SPINNING OVER FAR SW WI AT 00Z FRI...WITH A SFC
LOW TO THE N OF IT BUT S OF WRN LAKE SUPERIOR. A SHORTWAVE TROUGH
WILL BE JUST SE OF THE CWA AT 00Z FRI...MOVING E TO W TO NEAR THE
CENTER OF THE CWA BY 06Z FRI...THEN TO FAR WRN UPPER MI/FAR WRN LAKE
SUPERIOR BY 12Z FRI. MODELS ARE IN GOOD AGREEMENT WITH THE
SHORTWAVE...WITH ONLY MINOR TIMING DIFFERENCES BETWEEN THEM /THE GFS
WAS USED WITH THE HIGHEST WEIGHT SINCE THE TIMING WAS BETWEEN THE
FASTER NAM AND SLOWER ECMWF/. THE BEST CHANCES FOR WIDESPREAD PRECIP
WILL BE FROM 00Z-06Z FRI. AFTER 06Z FRI...THE SFC LOW MOVING THROUGH
WITH THE SHORTWAVE WILL QUICKLY MOVE TO SW WI. ALSO...BETWEEN
00Z-12Z FRI...THE MID/UPPER LOWS WILL BE STACKED JUST W OF LAKE
MICHIGAN...WITH LOW LEVEL CYCLONIC FLOW UP THE LONG AXIS OF LAKE
MICHIGAN. 850MB TEMPS WILL BE BETWEEN 0C AND -1C...SO LAKE ENHANCED
RAIN WILL BE POSSIBLE INTO SCENTRAL AND ERN UPPER MI LATE THU NIGHT
INTO FRI MORNING.
SFC FEATURES BEGIN TO BREAK DOWN QUICKLY ON FRI AS THE SYSTEM MOVES
TO SE LOWER MI BY LATE IN THE DAY. THE ECMWF IS ABOUT 12 HOURS
SLOWER IN MOVING THE SYSTEM INTO QUEBEC ON SAT. EVEN SO...MODELS
AGREE WITH SHOWING A SFC RIDGE MOVING INTO THE CWA AROUND 18Z
SAT...WITH AN UPPER RIDGE PUSHING IN FROM THE NW. THE RIDGE WILL
LEAD TO PRETTY QUIET WEATHER OVER THE WEEKEND...WITH ANY SIGNIFICANT
CHANCES FOR RAIN BEING OVER THE FAR E AS THE LOW MOVES E OF THE CWA
SAT...BUT THOSE CHANCES ARE SMALL. SINCE WARM AIR WILL NOT START TO
RETURN TO THE AREA UNTIL THE SFC RIDGE MOVES THROUGH...SAT WILL SEE
SIMILAR TEMPS TO FRI WITH HIGHS IN THE MID 40S TO MID 50S. SUN WILL
BE WARMER AS 850MB TEMPS INCREASE TO 8-10C...LEADING TO HIGHS IN THE
50S AND 60S.
AFTER SUN...SUBSTANTIAL MODEL DISAGREEMENT ON THE LOCATION OF A SFC
RIDGE THAT MAY MOVE IN THE REGION. THE PROBLEM COMES FROM A SFC
TROUGH/STATIONARY FRONT THAT WILL BE S OF THE RIDGE. THE GFS KEEPS
THE RIDGE OVER THE CWA THROUGH NEXT WED...KEEPING US DRY...BUT THE
ECMWF HAS THE TROUGH/FRONT OVER THE CWA THROUGH MUCH OF THE
PERIOD...WHICH WOULD RESULT IN A MOST WET FORECAST. WITH HIGH MODEL
DISAGREEMENT AND LOW RUN TO RUN CONTINUITY...USED A CONSENSUS OF
MODELS IN THIS PORTION OF THE FORECAST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 140 PM EDT WED OCT 17 2012
LOW PRESSURE SYSTEM OVER NW MN WILL SETTLE INTO THE WESTERN GREAT
LAKES REGION TONIGHT AND THU. AHEAD OF SYSTEM...EXPECT VFR
CONDITIONS THRU THE AFTN AT KIWD/KCMX/KSAW. AS SHRA DEVELOP/SPREAD
INTO THE AREA TONIGHT...EXPECT CONDITIONS TO FALL TO IFR/LIFR AS
ABUNDANT MOISTURE SWINGS N. CONDITIONS SHOULD BE LOWEST AT KSAW
UNDER FAVORABLE UPSLOPING WIND. MAIN PCPN AREA SHOULD LIFT OUT BY
SUNRISE WITH CONDITIONS RISING TO HIGH IFR/LOW MVFR DURING THE
MORNING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 432 PM EDT WED OCT 17 2012
A TRICKY FCST SHAPING UP TONIGHT INTO THU. DEEP SFC LOW NOW IN NW MN
WILL BE REPLACED BY A NEW LOW PRES WAVE THAT WILL DEVELOP IN ERN WI
TONIGHT AND THEN ROTATE NW TO VCNTY OF WRN LAKE SUPERIOR THU. IN
RESPONSE TO THE NEW LOW...A BRIEF PERIOD OF E TO SE GALES MAY
DEVELOP LATE TONIGHT INTO THU MORNING OVER CNTRL AND ERN LAKE
SUPERIOR. GIVEN UNCERTAINTY IN HOW QUICK OR DEEP THE NEW LOW WILL
BECOME BY THU MORNING...HELD OFF ON THE ISSUANCE OF A GALE WARNING
FOR NOW. AS A TROUGH MOVES THROUGH THURSDAY NIGHT...SOUTHEAST WINDS OVER
EASTERN LAKE SUPERIOR AND NORTHEAST WINDS OVER WESTERN LAKE SUPERIOR
WILL GUST TO AROUND 25KTS. WINDS WILL THEN DIMINISH TO BELOW 20KTS
FRIDAY THROUGH MONDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...TITUS
AVIATION...ROLFSON
MARINE...ROLFSON/TITUS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
145 AM EDT WED OCT 17 2012
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 431 PM EDT TUE OCT 16 2012
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW ZONAL FLOW ALF
OVER THE UPR LKS. SHRTWV EMBEDDED WITHIN THIS FLOW IS MOVING THRU
ONTARIO/MN. COMBINATION OF ISENTROPIC ASCENT BEST DEPICTED ON THE
295-300K SFCS/H7 MSTR CNVGC AND UPR DVGC IN RRQ OF 80KT H3 JET MAX
MOVING THRU SE CANADA IS CAUSING AN AREA OF SHRA OVER THE UPR LKS
THIS AFTN. THE PCPN IS MOST WIDESPREAD OVER THE N AND CNTRL CWA...
WITH DRIER AIR BLO H75 DEPICTED ON THE 12Z GRB RAOB AND MORE
IMPRESSIVE ISENTROPIC ASCENT TO THE N RESTRICTING PCPN COVERAGE OVER
THE SCNTRL. TO THE W...DNVA/MID LVL DRYING/LARGER SCALE QVECTOR DVGC
IN THE WAKE OF THE SHRTWV ARE BRINGING A DRYING TREND IN MN...WITH
THE BACK EDGE OF THE RA AREA PUSHING THRU WRN LK SUP EARLY THIS
AFTN. SKIES ARE MOCLR OVER THE NRN PLAINS INTO MN UNDER THE RDG
TRAILING THE SHRTWV. ANOTHER POTENT SHRTWV EMBEDDED IN THE ZONAL
FLOW ALF IS PUSHING INTO THE NRN ROCKIES. THERE WERE SOME 00Z-12Z H3
HGT FALLS IN EXCESS OF 200M ASSOCIATED WITH THIS DISTURBANCE.
MAIN FCST CONCERNS IN THE SHORT TERM REVOLVE ARND PCPN/CLD TRENDS
THRU THE REST OF THIS AFTN THEN TO POTENTIAL FOR FOG TNGT AS DRIER
AIR ALF OVERSPREADS THE AREA. FOCUS FOR WED TURNS TO PCPN CHCS
ASSOCIATED WITH SHRTWV NOW MOVG THRU THE NRN ROCKIES.
LATE TDAY...BEST H7 MSTR TRANSPORT/UPR DVGC INDICATES THE HEAVIER/
MORE WDSPRD SHRA WL SHIFT INTO THE ERN ZNS WHILE DRYING ALF/LARGER
SCALE QVECTOR DVGC ENDS THE PCPN OVER THE W.
TNGT...EXPECT LINGERING SHRA OVER THE E TO END BY MIDNGT WITH THE
PASSAGE OF THE SHRTWV/ARRIVAL OF DRYING ALF AND DNVA/LARGE SCALE
QVECTOR DVGC. GIVEN THE UPR DRYING/CLD TRENDS...EXPECT CLRG TO
OVERSPREAD THE AREA. WITH LINGERING LLVL MSTR...SUSPECT FOG WL DVLP.
WITH A FAIRLY STEADY SSE WIND...THE BEST CHC FOR MORE WDSPRD/DENSER
FOG AND LO CLDS WL BE OVER THE CNTRL ZNS WHERE THAT FLOW UPSLOPES.
TENDED TOWARD THE LO END OF GUIDANCE FOR MIN TEMPS GIVEN EXPECTED
DRYING ALF...BUT STEADY WIND WL RESTRICT THE FALL FM GOING TOO FAR.
WED...THE AT LEAST THE MRNG SHOULD BE DRY WITH LINGERING DRY AIR/UPR
RDG STILL IN PLACE. BUT STRONG SHRTWV NOW MOVING THRU THE NRN
ROCKIES IS FCST TO CLOSE OFF AND DRIFT INTO FAR NW MN BY 00Z THU. AS
SFC LO MOVES INTO NE MN...ATTENDANT COLD FNT IS PROGGED TO APRCH IWD
LATE IN THE DAY. LOOKS LIKE MOST IMPRESSIVE DPVA/DEEP LYR QVECTOR
CNVGC ASSOCIATED WITH THE SHRTWV WL STAY TO THE NW OF THE AREA WHILE
ANOTHER AREA OF DEEP LYR FORCING/UPR DVGC PASSES WELL TO THE S
CLOSER TO UPR JET AXIS/DEEPER MSTR CNVGC. SO OPTED TO GO NO HIER
THAN CHC POPS OVER THE W HALF OF THE CWA IN THE AFTN...WITH DRY WX
EXPECTED OVER THE E HALF CLOSER TO DEPARTING RDG/DRY AIR. ALTHOUGH
FOG MAY LINGER OVER THE CENTRAL WELL THRU THE MRNG WITH PERSISTENT
UPSLOPE SSE FLOW...RETURN OF MORE SUNSHINE IN THE AFTN WITH H85
TEMPS AS HI AS 10-12C SUG TEMPS WL RISE TO WELL ABV NORMAL. COOLER
CONDITIONS ARE LIKELY OVER THE W WHERE THERE WL BE MORE CLD COVER IN
THE AFTN...BUT SOME MRNG SUNSHINE/DOWNSLOPE S WIND WITH LESS FOG
STILL INDICATE A WARM DAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 431 PM EDT TUE OCT 16 2012
TO BEGIN THE LONG TERM...A DEEP TROF (500MB DEPTH PEAKS THU MORNING
AT 3.5 STANDARD DEVIATIONS FROM THE LONG TERM AVG) WILL BE OVER THE
MID AND UPPER MISSISSIPPI VALLEY. TROF THEN UNRAVELS QUICKLY AND
GETS KICKED NE BY BROAD TROF SETTLING INTO WRN NAMERICA. MEDIUM
RANGE GUIDANCE IS IN POOR AGREEMENT ON THE STRUCTURE/EVOLUTION OF
THE WRN TROF AND STRENGTH/TIMING/TRACKS OF SHORTWAVES EJECTING FROM
TROF. THE GFS RUN-TO-RUN CONSISTENCY FROM LATE WEEKEND INTO EARLY
NEXT WEEK IS IMPROVING WITH LATEST RUNS MORE AGGRESSIVE PUSHING
ENERGY E...FLATTENING DOWNSTREAM RIDGE OVER THE GREAT LAKES/ERN
CONUS AND SHIFTING RIDGE BACK TO THE W. THE ECMWF HAD SHOWN SOMEWHAT
BETTER CONSISTENCY IN DEPICTING A SLOWLY PROGRESSIVE WRN TROF AND A
MORE PRONOUNCED ERN RIDGE THRU EARLY NEXT WEEK. HOWEVER...THE 12Z
ECMWF HAS MADE A BIG SHIFT TOWARD THE GFS IDEA. THRU 12Z MON...THE
GLOBAL GEM/UKMET OFFER OTHER VARYING IDEAS ON THE WRN TROF...BUT
TEND TO LOOK A LITTLE MORE LIKE PREVIOUS ECMWF RUNS. ALL THIS LEADS
TO A VERY LOW CONFIDENCE FCST FOR THE LATTER HALF OF THE LONG TERM
WITH RESPECT TO BOTH TEMPS AND PCPN. GIVEN THE MODEL ISSUES...
TODAY`S LONG TERM FCST WON`T FAVOR ANY SOLUTION IN PARTICULAR THOUGH
IT WOULD SEEM THE 12Z GFS/12Z ECMWF MAY BE WHERE MEDIUM RANGE
GUIDANCE WILL BE HEADING IN UPCOMING RUNS. OVERALL...NEAR NORMAL
TEMPS LATE THIS WEEK SHOULD TREND ABOVE NORMAL BY LATE WEEKEND AND
THEN BEGIN TO FALL BACK CLOSER TO NORMAL. AFTER LINGERING SHRA
CHANCES LATE IN THE WORK WEEK WITH DEPARTING TROF...DEVELOPING GREAT
LAKES/ERN RIDGE SHOULD INITIALLY LEAD TO DRIER WEATHER OVER THE
WEEKEND BEFORE PCPN CHANCES RETURN MON/TUE.
BEGINNING WED NIGHT...TROF WILL BE APPROACHING MAX DEPTH AS 500MB
LOW CLOSES OFF IN THE VCNTY OF NE IA. SFC WAVE WILL DEVELOP/DEEPEN
AND ROTATE THRU ERN WI TOWARD NW WI/WRN UPPER MI OVERNIGHT.
AHEAD OF FRONT/SFC WAVE...WARM CONVEYOR PCPN WILL SWING ACROSS UPPER
MI. NICE DIRECTIONALLY DIFFLUENT UPPER LEVEL FLOW OVERTOP SHARPENING
850MB FRONT WILL AID THE PCPN. LIKELY/CATEGORICAL POPS SPREADING
ACROSS THE AREA APPEARS REASONABLE. CLOUDS/PCPN WILL HOLD MIN TEMPS
IN THE 40S...AND POSSIBLY AROUND 50 E.
WARM CONVEYOR PCPN SHOULD ROTATE OUT OF THE AREA THU...BUT DEEP
CYCLONIC FLOW AND INDICATIONS OF SHORTWAVE PIVOTING AROUND MID LEVEL
LOW TOWARD UPPER MI WILL WORK TO KEEP PCPN CHANCES OVER THE AREA
THRU THE DAY. ABUNDANT CLOUD COVER AND WEAK CAA WILL LIMIT DIURNAL
TEMP RISE. EXPECT HIGHS IN THE UPPER 40S TO MID 50S.
THU NIGHT/FRI...ENTIRE SYSTEM WEAKENS RATHER QUICKLY AND FOCUSED
PCPN SHOULD DIMINISH AS LOW/MID LEVEL WIND FIELDS WEAKEN
DRAMATICALLY. IN FACT...MUCH OF THE GUIDANCE SUGGESTS A TREND TOWARD
MOSTLY DRY LATER THU NIGHT INTO FRI. HOWEVER...WHILE ORGANIZED PCPN
AREAS WILL DIMINISH THU NIGHT...PROXIMITY OF THE CENTER OF WEAKENING
MID LEVEL LOW SUGGESTS MAINTAINING CHC/SLIGHT CHC POPS THU
NIGHT/FRI. MAY END UP BEING MORE OF A DRIZZLE SITUATION WITH PATCHY
-RA. DIURNAL TEMP SWING THU NIGHT/FRI SHOULD CONTINUE TO BE LIMITED
BY CLOUDS AND ALSO BY LITTLE TEMP ADV.
AS WEAKENING SYSTEM BEGINS TO ACCELERATE TO THE NE SAT...WILL OPT
FOR A DRY DAY. BEST SHOT FOR A DRY DAY WILL BE SUN AS AMPLIFYING
RIDGE AXIS DOWNSTREAM OF DEVELOPING WRN TROF SHIFTS ACROSS THE UPPER
LAKES. SUN WILL BE THE WARMEST DAY...WITH MID 50S E AND PERHAPS
AROUND 60F OVER THE W
AS MENTIONED ABOVE...THERE IS VERY LOW CONFIDENCE IN FCST FOR EARLY
NEXT WEEK. EXPECT A CHC OF PCPN AT SOME POINT SUN NIGHT INTO TUE AS
COLD FRONT SLIPS THRU THE AREA. THE 12Z ECMWF/GFS SUGGEST LIMITED
PCPN CHC THAT WILL BE CONFINED MAINLY TO MON OVER THE SCNTRL AND E.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 144 AM EDT WED OCT 17 2012
CONDITIONS WILL CONTINUE TO BE VFR THROUGH MOST OF THE NIGHT AT KCMX
AND KSAW...THEN EXPECT SOME FOG/LO CLD TO DVLP WITH NOCTURNAL
COOLING OF THE FAIRLY MOIST LLVLS UNDER THE DRYING ALF. THE BEST CHC
FOR IFR AND EVEN LIFR CONDITIONS WL BE AT SAW...WITH FAVORABLE
UPSLOPE SSE WIND. KIWD WILL HAVE ENOUGH HIGH CLOUDS TO PREVENT FOG
AND WILL STAY VFR THROUGH THE PERIOD UNTIL RAIN ARRIVES AND CAUSES
MVFR CIGS IN THE EVENING. ONSET OF DAYTIME HEATING/MIXING ON WED WL
BREAK UP ANY FOG/LO CLD THAT DEVELOPS AT KSAW AND KCMX WITH VFR
CONDITIONS CONTINUING THROUGH THE REST OF THE TAF PERIOD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 431 PM EDT TUE OCT 16 2012
EXPECT S WINDS UP TO 25-30 KTS OVER THE E HALF TO DIMINISH A BIT
TONIGHT WITH THE ARRIVAL OF A WEAKER PRES GRADIENT. SE WINDS UP TO
25 KTS WILL CONTINUE ON WED IN ADVANCE OF AN APPROACHING DEEP LO
PRES CENTER. THE STRONGEST WINDS WILL BE OVER THE E HALF AGAIN WHERE
THE TERRAIN TENDS TO ENHANCE THESE WINDS.
DEEPENING SFC LOW ROTATING NW THRU NRN WI WED NIGHT WILL RESULT IN
AN INCREASE IN E TO SE WINDS ACROSS LAKE SUPERIOR. NOT OUT OF THE
QUESTION THAT SOME GALE FORCE GUSTS COULD DEVELOP LATE IN THE NIGHT
FROM AROUND WHITEFISH PT TO AROUND ISLE ROYALE. WINDS WILL THEN
DIMINISH DURING THE DAY THU AS LOW PRES WEAKENS. BY THU AFTN...WINDS
SHOULD BE UNDER 15KT OVER WRN LAKE SUPERIOR AND DOWN TO 15 TO 25KT
OVER CNTRL AND ERN LAKE SUPERIOR. BEYOND THU...NO SIGNIFICANT
WEATHER SYSTEMS ARE EXPECTED TO AFFECT THE UPPER LAKES THRU THE
WEEKEND. IN FACT...WEAK PRES GRADIENT MAY LEAD TO A PERIOD OF LIGHT
WINDS UNDER 15KT OVER MUCH OF LAKE SUPERIOR FRI THRU SUN.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...ROLFSON
AVIATION...07
MARINE...KC/ROLFSON
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
625 AM CDT WED OCT 17 2012
.UPDATED FOR 12Z AVIATION DISCUSSION BELOW...
.DISCUSSION...
PRETTY VIGOROUS SYSTEM TO AFFECT WX ACROSS AREA FOR NEXT COUPLE OF
DAYS WITH SOME NEEDED PCPN AND A LOT OF WIND. STRENGTH OF
DEEPENING UPPER TROF DROPPING OUT OF SASK EVIDENCE BY 500 MB
HEIGHT FALLS OF AS MUCH AS 150 M IN GGW THIS EVENING. THE UPPER
TROF PROGGED BY MODELS TO CONTINUE TO WIND UP AS IT DROPS SE
ACROSS AREA WITH 140 KT UPPER JET PLOWING ACROSS THE PACIFIC NW
INTO THE CENTRL PLAINS.
AHEAD OF THIS FEATURE WV IMAGERY SHOWING A NICE VORT LIFTING ENE
ACROSS SODAK...CURRENTLY AROUND KHON. RADAR MOSAIC SHOWING A NICE
AREA OF SHWRS ACROSS MUCH OF NE/EC SODAK AHEAD OF THIS FEATURE.
NARROW FATHER FAST MOVING BAND OF SHOWERS SOUTH OF THIS AREA IS
MOVING RAPIDLY ACROSS SC MN. HRRR AND LOCAL WRF KEEP MAIN AREA OF
SHOWERS THIS MORNING ACROSS WC INTO CENTRAL MN ASSOCIATED WITH
SODAK VORT...AND THIS SEEMS REASONABLE GIVEN RADAR TRENDS. ANOTHER
AREA OF SHOWERS DEVELOPS ACROSS IA/SE MN INTO WI AHEAD OF CDFNT
LATER THIS MRNG INTO THE AFTN. LOWERED POPS A BIT ACROSS S AREAS
AS WELL AS QPF...KEEPING LIKELY POPS MORE INTO CNTL MN.
RETAINED WIND ADVY SW OF THE MN FOR LT MRNG INTO EARLY EVENING.
STRONGEST CAA AND SURFACE PRESSURE RISES REMAIN S OF THAT
AREA...MORE ACROSS SODAK/NEB INTO IA BUT SOME OF THE HIER TERRAIN
SHUD SEE SOME SUSTAINED WINDS ARND 30 MPH. SHARPEST FALL IN
DEWPOINTS AND RH ALSO SOUTH OF OUR AREA SO WILL NOT BE ISSUING ANY
FIRE WX HEADLINES...BUT WILL ADDRESS THE STRONG WINDS IN A HEADLINE.
AS UPPER LOW BEGINS TO WIND UP ON THURSDAY INTO THURS NITE ACROSS S
MN/N IA STRONG ISENTROPIC LIFT SETS IN A STRONG WAA PATTERN NORTH
OF THE LOW WHICH SHUD BRING IN LIKELY POPS ESP ACROSS WESTERN
HALF OF CWA. DIFFERENCES IN MODEL PLACEMENT OF SFC LOW...BUT THEY
ALL TIGHTEN PRESSURE GRADIENT MAINLY ACROSS W MN DURING THE DAY
THURSDAY WHICH MAY REQUIRE ANOTHER WIND ADVY.
SOME LINGERING PCPN INTO FRIDAY...THEN WARMING AND DRYING TREND
FOR THE WEEKEND AS DEEP LOW PRESSURE GETS KICKED OUT AND SW FLOW
RETURNS. SHUD SEE HIGHS NEAR 60 SW AREAS ON SATURDAY AND INTO THE
60S ACROSS THE AREA FOR SUNDAY.
&&
.AVIATION.../12Z TAF ISSUANCE/
MODELS SUGGEST BEST FORCING ASSOCIATED WITH UPPER LOW WILL MOVE
ACROSS THE NORTHWEST PORTION OF THE FORECAST AREA TODAY. THIS WILL
AFFECT KAXN/KSTC MUCH OF THE DAY WITH -RA THIS MORNING AND SHOULD
EXIT TO THE NORTH THIS AFTERNOON AS SURFACE LOW LIFTS INTO NORTHEAST
MN. MVFR CONDITIONS EXPECTED WITH THIS AREA OF PRECIPITATION. WILL
KEEP THE REMAINDER OF THE REGION VFR FOR NOW AS COLD FRONT MOVES
THROUGH. SURFACE WINDS WILL BECOME MORE SOUTHWEST TO WEST WITH
FROPA AND WILL BE GUSTY OVER WESTERN AREAS....SPREADING EAST WITH
FROPA. STRONGEST GRADIENT REMAINS OVER WESTERN AREAS THROUGH
TONIGHT/THURSDAY. AS SYSTEM OCCLUDES LATER TODAY...FORCING IS
DIRECTED BACK ACROSS WESTERN AREAS OVERNIGHT AND INTO THE EAST ON
THURSDAY. THIS WILL DROP CEILINGS TO IFR AT KAXN AFTER 07Z THU AND
COULD MOVE INTO KSTC BEFORE 12Z THU. WILL HAVE TO MONITOR
DEVELOPMENT OF UPPER LOW. OTHER AREAS WILL SEE CEILING LOWER TO MVFR
AT LEAST-IN THE EAST AFTER 06Z THU.
KMSP...WILL MAINTAIN VFR CONDITIONS THROUGH THIS EVENING. SOME HAZY
CONDITIONS DROPPING VSBY TO 6SM THIS AM...THEN SOME LIGHT -SHRA
POSSIBLE AS COLD FRONT MOVES IN THROUGH 18Z. THIS WILL SHIFT WINDS
TO MORE WEST/SOUTHWEST BY MIDDAY AND MORE WESTERLY THIS AFTERNOON.
SHOULD SEE SOME GUSTS NEAR 25 KNOTS AS FRONT MOVES THROUGH. MODELS
SUGGEST UPPER LOW ROTATING MORE PRECIPITATION TO THE SOUTHWEST LATER
TONIGHT AND OVER THE EAST THURSDAY. WILL LOWER CEILING TO MVFR
AGAIN AFTER 06Z THU AND MENTION VCSH FOR NOW.
/OUTLOOK FOR KMSP/
THU...MVFR CIGS WITH MVFR VSBY DURING SHRA. IFR CIGS POSSIBLE.
W/NW WINDS 15 TO 25 KT WITH GUSTS ABOVE 30 KTS.
FRI...MVFR CIGS...SCT -SHRA. NW WINDS 10 KTS.
SAT...VFR. S WINDS 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WIND ADVISORY FROM 10 AM THIS MORNING TO 7 PM CDT THIS EVENING
FOR BROWN-LAC QUI PARLE-MARTIN-REDWOOD-WATONWAN-YELLOW
MEDICINE.
WI...NONE.
&&
$$
BAP/DE
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
352 AM CDT WED OCT 17 2012
.DISCUSSION...
PRETTY VIGOROUS SYSTEM TO AFFECT WX ACROSS AREA FOR NEXT COUPLE OF
DAYS WITH SOME NEEDED PCPN AND A LOT OF WIND. STRENGTH OF
DEEPENING UPPER TROF DROPPING OUT OF SASK EVIDENCE BY 500 MB
HEIGHT FALLS OF AS MUCH AS 150 M IN GGW THIS EVENING. THE UPPER
TROF PROGGED BY MODELS TO CONTINUE TO WIND UP AS IT DROPS SE
ACROSS AREA WITH 140 KT UPPER JET PLOWING ACROSS THE PACIFIC NW
INTO THE CENTRL PLAINS.
AHEAD OF THIS FEATURE WV IMAGERY SHOWING A NICE VORT LIFTING ENE
ACROSS SODAK...CURRENTLY AROUND KHON. RADAR MOSAIC SHOWING A NICE
AREA OF SHWRS ACROSS MUCH OF NE/EC SODAK AHEAD OF THIS FEATURE.
NARROW FATHER FAST MOVING BAND OF SHOWERS SOUTH OF THIS AREA IS
MOVING RAPIDLY ACROSS SC MN. HRRR AND LOCAL WRF KEEP MAIN AREA OF
SHOWERS THIS MORNING ACROSS WC INTO CENTRAL MN ASSOCIATED WITH
SODAK VORT...AND THIS SEEMS REASONABLE GIVEN RADAR TRENDS. ANOTHER
AREA OF SHOWERS DEVELOPS ACROSS IA/SE MN INTO WI AHEAD OF CDFNT
LATER THIS MRNG INTO THE AFTN. LOWERED POPS A BIT ACROSS S AREAS
AS WELL AS QPF...KEEPING LIKELY POPS MORE INTO CNTL MN.
RETAINED WIND ADVY SW OF THE MN FOR LT MRNG INTO EARLY EVENING.
STRONGEST CAA AND SURFACE PRESSURE RISES REMAIN S OF THAT
AREA...MORE ACROSS SODAK/NEB INTO IA BUT SOME OF THE HIER TERRAIN
SHUD SEE SOME SUSTAINED WINDS ARND 30 MPH. SHARPEST FALL IN
DEWPOINTS AND RH ALSO SOUTH OF OUR AREA SO WILL NOT BE ISSUING ANY
FIRE WX HEADLINES...BUT WILL ADDRESS THE STRONG WINDS IN A HEADLINE.
AS UPPER LOW BEGINS TO WIND UP ON THURSDAY INTO THURS NITE ACROSS S
MN/N IA STRONG ISENTROPIC LIFT SETS IN A STRONG WAA PATTERN NORTH
OF THE LOW WHICH SHUD BRING IN LIKELY POPS ESP ACROSS WESTERN
HALF OF CWA. DIFFERENCES IN MODEL PLACEMENT OF SFC LOW...BUT THEY
ALL TIGHTEN PRESSURE GRADIENT MAINLY ACROSS W MN DURING THE DAY
THURSDAY WHICH MAY REQUIRE ANOTHER WIND ADVY.
SOME LINGERING PCPN INTO FRIDAY...THEN WARMING AND DRYING TREND
FOR THE WEEKEND AS DEEP LOW PRESSURE GETS KICKED OUT AND SW FLOW
RETURNS. SHUD SEE HIGHS NEAR 60 SW AREAS ON SATURDAY AND INTO THE
60S ACROSS THE AREA FOR SUNDAY.
&&
.AVIATION.../06Z TAF ISSUANCE/
NO ISSUES TO START THE TAF BUT WILL LOOK FOR CONDITIONS TO
DETERIORATE BY 12Z IN WESTERN MINNESOTA THEN GRADUALLY TRANSITION
TO EASTERN MINNESOTA AND WESTERN WISCONSIN AS A POTENT COLD FRONT
APPROACHES FROM THE WEST. FEW BANDS OF RAIN...SOME OF WHICH MAY
CONTAIN MVFR CEILINGS...WILL CROSS THROUGH THE AREA DURING THE
FIRST HALF OF THE TAF PERIOD. CONDITIONS LOOK TO IMPROVE BY AROUND
18Z AS MODELS DEPICT A DRY SLOT WITHIN THE ROTATING LOW PRESSURE
SYSTEM. THIS DRY SLOT SHOULD ALLOW FOR A BRIEF DRYING-OUT PERIOD
ALONG WITH IMPROVED FLIGHT CONDITIONS. THE TIMING OF IT IS HIGHLY
PROBLEMATIC SO HAVE TRIED TO ADVERTISE IT WITH NO MENTION OF
VCSH/-RA IN THE MID-TO-LATE AFTN HOURS. ONCE THE SYSTEM MOVES FAR
ENOUGH INTO THE GREAT LAKES...A PRECIP SHIELD ON THE BACKSIDE OF
THE SYSTEM WILL PUSH THROUGH THE AREA MAINLY AFTER 18/00Z. HAVE
ADVERTISED MVFR CIGS AFTER 18/00Z IN ANTICIPATION OF A MORE
STRATIFORM TYPE OF PRECIP...BUT MODELS ARE A BIT MORE OPTIMISTIC
AND KEEP THINGS VFR. THE OTHER MAIN CONCERN WILL BE SHIFTING THEN
GUSTY WINDS WITH THE COLD FROPA. WINDS WILL QUICKLY GO SE-SW-W
LATE MORNING INTO THE EARLY AFTN AS THE FRONT PUSHES THROUGH. ONCE
IT PASSES...SUSTAINED SPEEDS WILL INCREASE GENERALLY TO THE 15-20
KT RANGE WITH GUSTS 25-30KT...THOUGH WESTERN MN WILL LIKELY SEE
20-25KT WITH GUSTS UPWARDS OF 35 KT OR POSSIBLY EVEN HIGHER.
KMSP...NO ISSUES TO START WITH RELATIVELY LIGHT SE WINDS. CLOSE TO
SUNRISE...WINDS WILL SHIFT AROUND TO SW AND INCREASE TO NEAR 10 KT
AS A COLD FRONT APPROACHES. LIGHT RAIN SHOWERS WILL MOVE ACROSS
THE FIELD AROUND DAYBREAK AND PERSIST THROUGH LATE MRNG. MAY BE A
FEW PERIODS OF MVFR CIGS...BUT GENERALLY CONDITIONS WILL REMAIN
VFR DURG THE RAIN. RAIN WILL STEADILY SHIFT OFF TO THE EAST...
THOUGH THERE MAY BE A FEW LINGERING SHOWERS DURING THE MIDDAY
PERIOD. THE DRY SLOT OF THIS SYSTEM LOOKS TO MOVE OVER THE AREA
DURING THE AFTERNOON HOURS...BUT WIND SPEEDS WILL ALSO KICK UP AT
THIS POINT TO ARND 15 KT WITH GUSTS TO ARND 25 KT...POSSIBLY EVEN
HIGHER AT TIMES. SPEEDS WILL SETTLE DOWN BY SUNSET BUT ANOTHER
ROUND OF RAIN SHOWERS CAN BE EXPECTED LATE TONIGHT INTO EARLY
THURSDAY MRNG. AM EXPECTING A MORE PESSIMISTIC RUN OF CEILINGS
LATE WED NIGHT/EARLY THU MORNING THAN MODELS.
/OUTLOOK FOR KMSP/
THU...MVFR CIGS WITH MVFR VSBY DURING SHRA. IFR CIGS POSSIBLE.
W/NW WINDS 15 TO 25 KT WITH GUSTS ABOVE 30 KTS.
FRI...MVFR CIGS...SCT -SHRA. NW WINDS 10 KTS.
SAT...VFR. S WINDS 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WIND ADVISORY FROM 10 AM THIS MORNING TO 7 PM CDT THIS EVENING
FOR BROWN-LAC QUI PARLE-MARTIN-REDWOOD-WATONWAN-YELLOW
MEDICINE.
WI...NONE.
&&
$$
BAP/DWE
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
950 PM CDT THU OCT 18 2012
.UPDATE...
ISSUED AT 947 PM CDT THU OCT 18 2012
UPDATING TO BUMP UP POPS FOR THE REST OF THE NIGHT FOR THE ENTIRE
AREA...ESPECIALLY ALONG AND NORTH OF THE I-70/I-64 CORRIDOR IN
MISSOURI AND ILLINOIS RESPECTIVELY. AREA OF LIGHT RAIN IS MOVING
EAST-SOUTHEAST THROUGH EASTERN MISSOURI AND SOUTHWEST ILLINOIS AT
THIS TIME...AND HRRR TAKES THE RAIN CURRENTLY OVER SOUTHWEST IOWA
AND DROPS IT SOUTHEAST INTO OUR AREA AFTER MIDNIGHT INTO FRIDAY
MORNING. THE HRRR IS HANDLING THE CURRENT PRECIP VERY WELL...SO
HAVE NO REASON TO DOUBT IT AT THIS TIME.
CARNEY
&&
.SHORT TERM...
ISSUED AT 341 PM CDT THU OCT 18 2012
(TONIGHT)
GUSTY WINDS SHOULD DIMINISH AFTER SUNSET HOWEVER SUSTAINED WINDS
SHOULD REMAIN ABOVE 10 KTS OVERNIGHT DUE TO A FAIRLY TIGHT PRESSURE
GRADIENT BETWEEN A LOW PRESSURE SYSTEM NEAR THE GRTLKS AND A SFC
HIGH OVER TX. SEVERAL VORT LOBES ROTATING AROUND THE GRTLKS LOW
PRESSURE CENTER WILL SUPPORT BANDS OF ISO-SCT SHRA ACROSS MOST OF
THE CWA TONIGHT WITH THE HIGHEST COVERAGE EXPECTED ACROSS THE NRN
CWA.
KANOFSKY
&&
.LONG TERM...
ISSUED AT 328 PM CDT THU OCT 18 2012
(FRIDAY THROUGH THURSDAY)
UPPER LEVEL LOW TO CONTINUE TO SPIN OVER THE GREAT LAKES REGION ON
FRIDAY WITH IT SLOWLY SHIFTING TO THE EAST. SO WRAP AROUND CLOUDS
AND LIGHT SHOWERS TO PERSIST ESPECIALLY FRIDAY MORNING...MAINLY
ALONG AND NORTHEAST OF A MEXICO MO TO SPARTA IL LINE. THEN THE
SHOWERS TO TAPER OFF DURING THE AFTERNOON AND EARLY EVENING HOURS ON
FRIDAY. COLDER AIR TO CONTINUE FILTERING IN WITH HIGHS ONLY IN THE
50S. LOWS FRIDAY NIGHT WILL BE IN THE LOW 40S.
THEN BY MIDDAY ON SATURDAY...CLOUDS TO CLEAR OUT WITH WEAK SURFACE
RIDGE BUILDING IN. TEMPS TO BEGIN TO WARM BACK UP...INTO THE LOW TO
MID 60S. BY SUNDAY...SOUTHERLY FLOW TO RETURN WITH TEMPS IN THE LOW
TO MID 70S...MAYBE EVEN UPPER 70S OVER CENTRAL MO.
THEN NEXT WEATHER SYSTEM APPROACHES THE REGION SUNDAY NIGHT.
EXTENDED MODELS HAVE DIFFERING OPINIONS ON HOW TO HANDLE THE FRONTAL
BOUNDARY...BUT ALL SEEM TO HINT AT STALLING IT OUT JUST NORTHWEST OF
FORECAST AREA. FOR NOW HAVE CHANCE POPS FOR SHOWERS AND
THUNDERSTORMS FOR PORTIONS OF THE FORECAST AREA MONDAY THROUGH
TUESDAY. ANOTHER ROUND OF SHOWERS POSSIBLE WEDNESDAY NIGHT AND
THURSDAY...BUT TIMING AND COVERAGE HARD TO PIN DOWN. OTHERWISE...
TEMPS TO REMAIN ABOVE NORMAL THROUGH THE PERIOD.
BYRD
&&
.AVIATION...
ISSUED AT 727 PM CDT THU OCT 18 2012
LOWER CIGS OVER IA AND FAR NRN MO ARE EXPECTED TO BUILD SWD
TONIGHT AND EVENTUALLY ENVELOPE ALL OF THE TAF SITES WITH AT LEAST
MVFR CIGS. MAY SEE CIGS DIP INTO IFR RANGE FOR KUIN BUT FOR NOW
HAVE LOWERED FCST TO 1KFT LATE TONIGHT AND FRIDAY MORNING UNTIL WE
SEE MORE ACTUAL IFR CIGS DEVELOP UPSTREAM...AS THERE WAS VERY
LITTLE AT TAF ISSUANCE TIME. BANDS OF LIGHT RAIN WILL DO THE
SAME...PENETRATING SWD... WITH MUCH OF IT IN THE EARLY GOING BEING
JUST SPRINKLES AND NOT EXPECTED TO RESULT IN WET RUNWAYS. BUT
POCKETS OF HEAVIER RAIN DO EXIST FURTHER N...AND SHOULD IMPACT THE
KUIN TERMINAL THIS EVENING AND PERHAPS AT TIMES LATE TONIGHT AND
INTO FRIDAY. DO NOT THINK THAT THESE POCKETS OF HEAVIER RAIN WILL
MAKE IT AS FAR S AS THE I-70 CORRIDOR BUT COULD...CURRENTLY HAVE
JUST VCSH IN FOR THE I-70 TERMNALS OR TEMPO SPRINKLES FOR NOW.
RAIN THREAT SHOULD GRADUALLY RECEDE ON FRIDAY...BUT NOT BEFORE
GETTING SOME RE-INVIGORATION FROM DIURNAL INFLUENCES TO PROLONG IT
A BIT MORE BEFORE FINALLY EXITING LATE IN THE DAY. GUSTY W-SW SFC
WNDS WILL VEER SLIGHTLY AND LOSE ITS GUSTINESS LATER TONIGHT
BEFORE RE-APPEARING ON FRIDAY.
SPECIFICS FOR KSTL...VFR CIGS LOWERING TO MVFR AROUND 06Z AND
REMAINING THRU LATE FRIDAY AFTERNOON...BEST MEASURING RAIN THREAT
TO BE FROM TOWARDS MIDNIGHT THRU LATE TONIGHT...QUESTIONABLE HOW
MUCH RE-DEVELOPMENT OF SHRA WILL OCCUR FRIDAY MIDDAY-AFTN AND HOW
CLOSE IT WILL BE TO TERMINAL...CIGS SHOULD RISE ON FRIDAY BUT
CURRENTLY BELIEVE THEY WILL BE AOB 3KFT STILL...UNTIL LOSS OF
SUNSHINE WILL RESULT IN SOME BREAKUP AND RETURN TO VFR. SOME MODEL
SOLUTIONS RETURN THE LO CIGS FRIDAY NIGHT BUT FOR NOW REMAINING
OPTIMISTIC.
TES
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1101 PM EDT THU OCT 18 2012
.SYNOPSIS...
A STRONG WEATHER SYSTEM WILL IMPACT THE REGION TONIGHT, WITH RAIN,
HEAVY AT TIMES, GRADUALLY OVERSPREADING THE AREA TONIGHT. RAIN
WILL END FROM WEST TO EAST FRIDAY MORNING TO MIDDAY. UNSETTLED
SHOWERY WEATHER WILL THEN CONTINUE THROUGH THE UPCOMING WEEKEND.
&&
.NEAR TERM /THROUGH FRIDAY/...
10 PM UPDATE...
CHANGES TO THE TIMING TO SPEED UP THE ONSET OF RAIN IN THE SOUTH.
ALSO ADDED THUNDER BECAUSE THUNDER JUST UPSTREAM IN MIDDLETOWN.
TEMPERATURES AT THEIR LOWS NOW SO ADJUSTED UP THE HOURLY TEMPS.
PREVIOUS DISCUSSION...
LATEST VIS SATELLITE IMAGERY CONTINUES TO SHOW CLOUDS STREAMING
NORTHEAST FROM THE LWR OHIO VALLEY THIS AFTERNOON AS COLD/OCCLUDED
FRONTAL BOUNDARY ADVANCES EAST. ALOFT...WATER VAPOR IMAGERY
SHOWING A DEEPLY WOUND- UP UPPER LOW ACROSS THE UPPER MISS RVR VLY
WITH RUC POTENTIAL VORTICITY COMPOSITES INDICATING THE THE UPPER
PV ANOMALY EXTENDS DOWN TO NEAR 500 MB ACROSS THE OHIO/MISS RVR
CONFLUENCE REGION. THIS LEAD WAVE WILL CONTINUE MOVING NORTHEAST
OVERNIGHT WHICH WILL ULTIMATELY HELP PROPEL THE AFOREMENTIONED
COLD/OCCLUDED FRONT EAST INTO OUR FCST AREA. LATEST RADAR TRENDS
NOW SHOWING INITIAL FRONTAL WAVE RAIN BAND SLOWLY LIFTING
NORTHEAST THROUGH EASTERN OHIO THIS AFTERNOON WHICH WITH TIME
SHOULD BEGIN ENTERING OUR WESTERN ZONES AFTER 00Z THIS EVENING.
CLOSER TO THE SFC...A STRONG PRESSURE GRADIENT BETWEEN THIS DEEPLY
WOUND-UP SYSTEM AND DEPARTING HIGH PRESSURE OFF THE EAST COAST HAS
ALLOWED FOR STRONG SOUTHEASTERLY WINDS THIS AFTERNOON WITH LATEST
OBSERVATIONS SHOWING GUSTS AS HIGH AS 35 KTS ACROSS THE REGION.
AS HAS THE BEEN THE CONCERN IN RECENT DAYS...12Z MODEL GUIDANCE
CONTINUES TO ADVERTISE FAVORABLE CONDITIONS FOR A DECENT RAINFALL
EVENT ACROSS MUCH OF CENTRAL NY AND NE PA BEGINNING TONIGHT AS
INITIAL PV ANOMALY AND SFC FRONT TRANSLATE NORTHEAST OVER THE AREA.
AHEAD OF THESE FEATURES...STRONG MOISTURE ADVECTION CHARACTERIZED
H925 V-WIND COMPONENTS ON THE ORDER OF 2-3 STANDARD DEVIATIONS ABOVE
NORMAL WILL HELP INCREASE PWAT VALUES TO WELL OVER 1 INCH ACROSS THE
EASTERN ZONES BY 12Z FRI. AS THIS OCCURS...MODELS NOW SHOWING A
SECONDARY FRONTAL WAVE AND CORRESPONDING WARM FRONT MOVING NORTH
ALONG THE OCCLUDED FRONT OVERNIGHT WHICH WILL EFFECTIVELY HELP
STALL THE MAIN OCCLUDED FRONT WITH TIME ACROSS OUR FCST AREA EARLY
FRI. BY 15Z...MODELS INDICATE THAT THE TRIPLE POINT WILL RESIDE
OVER OR REGION WITH EASTERN ZONES EFFECTIVELY BECOMING PLACED IN
MODIFYING WARM SECTOR AIR. MODELS CONTINUE TO SUGGEST THE
DEVELOPMENT OF WEAK INSTABILITY AFTER 12Z FRI AS DEW POINTS CLIMB
INTO THE MIDDLE TO UPPER 50S...AND POSSIBLY LOWER 60S ACROSS OUR
FAR SOUTHEAST. MEANWHILE ALOFT...MODELS STILL ADVERTISING THE
ENTRANCE OF A MID-LEVEL JET BY LATE MORNING WHICH WILL INCREASE
THE VERTICAL WIND SHEAR PROFILE ACROSS THE REGION. CONSIDERING
THAT SUCH STRONG WIND FIELD WILL BE IN PLACE (0-6 KM BULK SHEAR
WELL OVER 50 KTS)...DEVELOPING CONVECTION COULD EASILY BE SHEARED
APART AS IT FIRES. THAT SAID...WITH STRONGER INSTABILITY SUGGESTED
WITH TODAY/S RUNS...HAVE ELECTED TO REINTRODUCE A THUNDER MENTION
FOR FRI FROM THE LWR WYOMING VLY NORTH THROUGH THE POCONOS AND
CATSKILLS.
WITH RESPECT TO FCST QPF AMOUNTS...HPC GUIDANCE CONTINUES TO
ADVERTISE CLOSE TO 2" ACROSS THE EASTERN POCONOS AND CATSKILLS
WHERE MOIST SOUTHEAST WINDS WILL INTERACT WITH UPSLOPE TERRAIN
INFLUENCES. FOR NOW HAVE FOLLOWED BOTH HPC AND RFC QPF GUIDANCE
WHICH KEEPS THE HIGHEST AMOUNTS ACROSS THE EASTERN HALF OF THE
CWA. BY LATE MORNING...MODELS INDICATE THAT A WELL DEVELOPED DRY
SLOT WILL BEGIN WORKING INTO OUR WESTERN ZONES WHICH SHOULD RESULT
IN RAIN COMING TO AN END FROM WEST TO EAST DURING THE LATE
MORNING/EARLY AFTERNOON HRS.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
UNSETTLED WX EXPECTED TO CONTINUE RIGHT THROUGH THE WEEKEND AS
UPPER LOW CONTINUES TO PINWHEEL ACROSS THE REGION BOTH FRIDAY
NIGHT AND SATURDAY. FOR ALL INTENSIVE PURPOSES...MAIN RAIN BAND
SHOULD BE EXITING TO THE EAST BY FRIDAY EVENING AS NORTHWARD
MOVING FRONTAL WAVE FRIDAY AFTERNOON FINALLY EXITS TO THE
NORTHEAST. WITH AFOREMENTIONED DRY SLOT LINGERING...HAVE MAINTAINED
SLGT CHC TO CHC MENTION FOR POPS FRI NGT. FOR SATURDAY...UPPER
WAVE TO INCH EVER SO CLOSER TO THE REGION WITH THE NEXT ROUND OF
SHORTWAVE ENERGY EXPECTED TO LEAD TO ADDITIONAL SHWRS LATE SAT
MORNING/AFTERNOON. RIGHT NOW BEST POTENTIAL FOR REDEVELOPING SHWRS
APPEAR ACROSS THE NORTHERN ZONES WHERE COLD TEMPS ALOFT WILL
COMBINE WITH BEST FORCING FOR ASCENT FROM THE MAIN SFC LOW FCST
TO LIFT FROM THE CENTRAL LAKES INTO SOUTHERN ONTARIO.
UPPER LOW TO FINALLY BEGIN LIFTING NORTHEAST OF THE REGION SAT
NIGHT/EARLY SUN AS HEIGHTS BUILD ACROSS THE NORTHERN MISS RVR
VLY/SOUTHERN CANADIAN PRAIRIE PROVINCES. BEHIND THE FEATURE...H85
TEMPS ONLY DROP TO NEAR 0C WHICH MAY RESULT IN SCATTERED LAKE
EFFECT RAIN SHWRS JUST TO OUR NORTH IN SUSTAINED SOUTHWEST LOW-
LEVEL FLOW.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
DURING THE EXTENDED PERIOD MEDIUM RANGE MODELS ARE IN AGREEMENT
THAT THE UPPER LEVEL TROF OVER THE NORTHEAST WILL BE REPLACED BY
RISING HEIGHTS AND DEVELOPMENT OF AN UPPER LEVEL RIDGE. AT THE
SURFACE THINGS ARE A BIT MORE TRICKY WITH LOW PRES MOVING THROUGH
THE UPPER GREAT LAKES WITH POSSIBLE FROPA TUESDAY NIGHT. GENERALLY
FOLLOWED HPC GUIDANCE.
SUNDAY EVENING WILL INCLUDE SLIGHT CHC POPS FAR NRN CWA ON BACK
SIDE OF UPPER LEVEL TROF THEN DRY. DRY WEATHER IS EXPECTED
MONDAY THROUGH MUCH OF MONDAY NIGHT THEN CHC/SLIGHT CHC POPS
TUESDAY THROUGH WEDNESDAY DUE TO PASSING COLD FRONT AND NORTHWEST
FLOW BEHIND BOUNDARY. DRY WEATHER WILL RETURN WED NIGHT/THURSDAY
AS SFC HIGH BUILDS DOWN FROM CANADA. TEMPS WILL BE 5-10 DEGREES
ABOVE NORMAL.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
00Z FRI UPDATE... LINGERING VFR EARLY THIS EVE...WILL GIVE WAY TO
DETERIORATING CONDS AFTER 04-06Z...AS LWR CIGS/STEADIER RAIN MOVES
IN. FOR THE MOST PART...MVFR SHOULD BE THE PREVAILING CAT...BUT
PDS OF IFR SEEM LIKELY IN BOUTS OF RA/+RA TWDS DAYBREAK...SPCLY AT
KITH/KBGM ON THE HILLTOPS.
BY MID TO LATE AFTN FRI...IMPROVING CONDS SHOULD BEGIN...AS A DRY
SLOT ROTATES IN BEHIND THE COLD/OCCLUDED FRNTL PASSAGE.
S TO SE WINDS THIS EVE (STILL A BIT GUSTY)...WILL DIMINISH LATE
TNT/EARLY FRI...AS THE RAIN MOVES IN. SW WINDS 5-10 KT ARE
EXPECTED AFTER ABT 18-20Z.
OUTLOOK...
FRI NIGHT THROUGH SAT...MVFR RESTRICTIONS EXPECTED IN OCNL -SHRA.
SUN AND MON...MAINLY VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...CMG/TAC
NEAR TERM...CMG/TAC
SHORT TERM...CMG
LONG TERM...RRM
AVIATION...MLJ/RRM
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
753 PM EDT THU OCT 18 2012
.SYNOPSIS...
A STRONG WEATHER SYSTEM WILL BEGIN IMPACTING THE REGION LATER
TONIGHT WITH RAIN GRADUALLY OVERSPREADING THE AREA AS THE
OVERNIGHT HOURS PROGRESS. AT TIMES...RAIN MAY BECOME HEAVY AT
TIMES LATER TONIGHT AND FRIDAY MORNING AS HIGH AMOUNTS OF MOISTURE
INTERACT WITH A NORTHWARD MOVING WARM FRONT AND SURFACE LOW. RAIN
WILL LINGER ACROSS THE REGION ON FRIDAY WITH THUNDERSTORMS
BECOMING POSSIBLE FROM THE LOWER WYOMING VALLEY NORTH THROUGH THE
POCONOS AND CATSKILLS. UNSETTLED WEATHER WILL THEN CONTINUE
THROUGH THE UPCOMING WEEKEND AS THE UPPER LOW SLOWLY MOVES OVER
THE REGION.
&&
.NEAR TERM /THROUGH FRIDAY/...
LATEST VIS SATELLITE IMAGERY
CONTINUES TO SHOW CLOUDS STREAMING NORTHEAST FROM THE LWR OHIO
VALLEY THIS AFTERNOON AS COLD/OCCLUDED FRONTAL BOUNDARY ADVANCES
EAST. ALOFT...WATER VAPOR IMAGERY SHOWING A DEEPLY WOUND- UP UPPER
LOW ACROSS THE UPPER MISS RVR VLY WITH RUC POTENTIAL VORTICITY
COMPOSITES INDICATING THE THE UPPER PV ANOMALY EXTENDS DOWN TO
NEAR 500 MB ACROSS THE OHIO/MISS RVR CONFLUENCE REGION. THIS LEAD
WAVE WILL CONTINUE MOVING NORTHEAST OVERNIGHT WHICH WILL
ULTIMATELY HELP PROPEL THE AFOREMENTIONED COLD/OCCLUDED FRONT EAST
INTO OUR FCST AREA. LATEST RADAR TRENDS NOW SHOWING INITIAL
FRONTAL WAVE RAIN BAND SLOWLY LIFTING NORTHEAST THROUGH EASTERN
OHIO THIS AFTERNOON WHICH WITH TIME SHOULD BEGIN ENTERING OUR
WESTERN ZONES AFTER 00Z THIS EVENING. CLOSER TO THE SFC...A STRONG
PRESSURE GRADIENT BETWEEN THIS DEEPLY WOUND-UP SYSTEM AND
DEPARTING HIGH PRESSURE OFF THE EAST COAST HAS ALLOWED FOR STRONG
SOUTHEASTERLY WINDS THIS AFTERNOON WITH LATEST OBSERVATIONS
SHOWING GUSTS AS HIGH AS 35 KTS ACROSS THE REGION.
AS HAS THE BEEN THE CONCERN IN RECENT DAYS...12Z MODEL GUIDANCE
CONTINUES TO ADVERTISE FAVORABLE CONDITIONS FOR A DECENT RAINFALL
EVENT ACROSS MUCH OF CENTRAL NY AND NE PA BEGINNING TONIGHT AS
INITIAL PV ANOMALY AND SFC FRONT TRANSLATE NORTHEAST OVER THE AREA.
AHEAD OF THESE FEATURES...STRONG MOISTURE ADVECTION CHARACTERIZED
H925 V-WIND COMPONENTS ON THE ORDER OF 2-3 STANDARD DEVIATIONS ABOVE
NORMAL WILL HELP INCREASE PWAT VALUES TO WELL OVER 1 INCH ACROSS THE
EASTERN ZONES BY 12Z FRI. AS THIS OCCURS...MODELS NOW SHOWING A
SECONDARY FRONTAL WAVE AND CORRESPONDING WARM FRONT MOVING NORTH
ALONG THE OCCLUDED FRONT OVERNIGHT WHICH WILL EFFECTIVELY HELP
STALL THE MAIN OCCLUDED FRONT WITH TIME ACROSS OUR FCST AREA EARLY
FRI. BY 15Z...MODELS INDICATE THAT THE TRIPLE POINT WILL RESIDE
OVER OR REGION WITH EASTERN ZONES EFFECTIVELY BECOMING PLACED IN
MODIFYING WARM SECTOR AIR. MODELS CONTINUE TO SUGGEST THE
DEVELOPMENT OF WEAK INSTABILITY AFTER 12Z FRI AS DEW POINTS CLIMB
INTO THE MIDDLE TO UPPER 50S...AND POSSIBLY LOWER 60S ACROSS OUR
FAR SOUTHEAST. MEANWHILE ALOFT...MODELS STILL ADVERTISING THE
ENTRANCE OF A MID-LEVEL JET BY LATE MORNING WHICH WILL INCREASE
THE VERTICAL WIND SHEAR PROFILE ACROSS THE REGION. CONSIDERING
THAT SUCH STRONG WIND FIELD WILL BE IN PLACE (0-6 KM BULK SHEAR
WELL OVER 50 KTS)...DEVELOPING CONVECTION COULD EASILY BE SHEARED
APART AS IT FIRES. THAT SAID...WITH STRONGER INSTABILITY SUGGESTED
WITH TODAY/S RUNS...HAVE ELECTED TO REINTRODUCE A THUNDER MENTION
FOR FRI FROM THE LWR WYOMING VLY NORTH THROUGH THE POCONOS AND
CATSKILLS.
WITH RESPECT TO FCST QPF AMOUNTS...HPC GUIDANCE CONTINUES TO
ADVERTISE CLOSE TO 2" ACROSS THE EASTERN POCONOS AND CATSKILLS
WHERE MOIST SOUTHEAST WINDS WILL INTERACT WITH UPSLOPE TERRAIN
INFLUENCES. FOR NOW HAVE FOLLOWED BOTH HPC AND RFC QPF GUIDANCE
WHICH KEEPS THE HIGHEST AMOUNTS ACROSS THE EASTERN HALF OF THE
CWA. BY LATE MORNING...MODELS INDICATE THAT A WELL DEVELOPED DRY
SLOT WILL BEGIN WORKING INTO OUR WESTERN ZONES WHICH SHOULD RESULT
IN RAIN COMING TO AN END FROM WEST TO EAST DURING THE LATE
MORNING/EARLY AFTERNOON HRS.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
UNSETTLED WX EXPECTED TO CONTINUE RIGHT THROUGH THE WEEKEND AS
UPPER LOW CONTINUES TO PINWHEEL ACROSS THE REGION BOTH FRIDAY
NIGHT AND SATURDAY. FOR ALL INTENSIVE PURPOSES...MAIN RAIN BAND
SHOULD BE EXITING TO THE EAST BY FRIDAY EVENING AS NORTHWARD
MOVING FRONTAL WAVE FRIDAY AFTERNOON FINALLY EXITS TO THE
NORTHEAST. WITH AFOREMENTIONED DRY SLOT LINGERING...HAVE MAINTAINED
SLGT CHC TO CHC MENTION FOR POPS FRI NGT. FOR SATURDAY...UPPER
WAVE TO INCH EVER SO CLOSER TO THE REGION WITH THE NEXT ROUND OF
SHORTWAVE ENERGY EXPECTED TO LEAD TO ADDITIONAL SHWRS LATE SAT
MORNING/AFTERNOON. RIGHT NOW BEST POTENTIAL FOR REDEVELOPING SHWRS
APPEAR ACROSS THE NORTHERN ZONES WHERE COLD TEMPS ALOFT WILL
COMBINE WITH BEST FORCING FOR ASCENT FROM THE MAIN SFC LOW FCST
TO LIFT FROM THE CENTRAL LAKES INTO SOUTHERN ONTARIO.
UPPER LOW TO FINALLY BEGIN LIFTING NORTHEAST OF THE REGION SAT
NIGHT/EARLY SUN AS HEIGHTS BUILD ACROSS THE NORTHERN MISS RVR
VLY/SOUTHERN CANADIAN PRAIRIE PROVINCES. BEHIND THE FEATURE...H85
TEMPS ONLY DROP TO NEAR 0C WHICH MAY RESULT IN SCATTERED LAKE
EFFECT RAIN SHWRS JUST TO OUR NORTH IN SUSTAINED SOUTHWEST LOW-
LEVEL FLOW.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
DURING THE EXTENDED PERIOD MEDIUM RANGE MODELS ARE IN AGREEMENT
THAT THE UPPER LEVEL TROF OVER THE NORTHEAST WILL BE REPLACED BY
RISING HEIGHTS AND DEVELOPMENT OF AN UPPER LEVEL RIDGE. AT THE
SURFACE THINGS ARE A BIT MORE TRICKY WITH LOW PRES MOVING THROUGH
THE UPPER GREAT LAKES WITH POSSIBLE FROPA TUESDAY NIGHT. GENERALLY
FOLLOWED HPC GUIDANCE.
SUNDAY EVENING WILL INCLUDE SLIGHT CHC POPS FAR NRN CWA ON BACK
SIDE OF UPPER LEVEL TROF THEN DRY. DRY WEATHER IS EXPECTED
MONDAY THROUGH MUCH OF MONDAY NIGHT THEN CHC/SLIGHT CHC POPS
TUESDAY THROUGH WEDNESDAY DUE TO PASSING COLD FRONT AND NORTHWEST
FLOW BEHIND BOUNDARY. DRY WEATHER WILL RETURN WED NIGHT/THURSDAY
AS SFC HIGH BUILDS DOWN FROM CANADA. TEMPS WILL BE 5-10 DEGREES
ABOVE NORMAL.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
00Z FRI UPDATE... LINGERING VFR EARLY THIS EVE...WILL GIVE WAY TO
DETERIORATING CONDS AFTER 04-06Z...AS LWR CIGS/STEADIER RAIN MOVES
IN. FOR THE MOST PART...MVFR SHOULD BE THE PREVAILING CAT...BUT
PDS OF IFR SEEM LIKELY IN BOUTS OF RA/+RA TWDS DAYBREAK...SPCLY AT
KITH/KBGM ON THE HILLTOPS.
BY MID TO LATE AFTN FRI...IMPROVING CONDS SHOULD BEGIN...AS A DRY
SLOT ROTATES IN BEHIND THE COLD/OCCLUDED FRNTL PASSAGE.
S TO SE WINDS THIS EVE (STILL A BIT GUSTY)...WILL DIMINISH LATE
TNT/EARLY FRI...AS THE RAIN MOVES IN. SW WINDS 5-10 KT ARE
EXPECTED AFTER ABT 18-20Z.
OUTLOOK...
FRI NIGHT THROUGH SAT...MVFR RESTRICTIONS EXPECTED IN OCNL -SHRA.
SUN AND MON...MAINLY VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...CMG
NEAR TERM...CMG
SHORT TERM...CMG
LONG TERM...RRM
AVIATION...MLJ/RRM
AREA FORECAST DISCUSSION
NWS BUFFALO NY
115 AM EDT WED OCT 17 2012
.SYNOPSIS...
MAINLY CLEAR SKIES THIS EVENING WILL GIVE-WAY TO INCREASING MID
LEVEL CLOUDS WHICH ARE ASSOCIATED WITH A WARM FRONT. EXPECT
MAINLY DRY CONDITIONS WEDNESDAY AND WARMER WITH AFTERNOON HIGH
TEMPERATURES CLIMBING INTO THE 60S...AND A FEW LOWER 70S. OUR AREA
WILL REMAIN ON THE MILD SIDE INTO THURSDAY...BEFORE A GUSTY COLD
FRONT AND SHOWERS CROSSES THE AREA THURSDAY AFTERNOON AND EVENING.
&&
.NEAR TERM /THROUGH TODAY/...
IR SATELLITE IMAGERY SHOWS MUCH OF THE LAKE EFFECT CLOUDS HAVE
DISSIPATED BY LATE EVENING...EXCEPT FOR A SMALL AREA LINGERING
EAST OF LAKE ONTARIO. THESE CLOUDS SHOULD ALSO DISSIPATE AS THE
NIGHT GOES ON. THIS CLEARING HAS ALLOWED TEMPERATURES TO DROP
RATHER QUICKLY DURING THE EVENING HOURS...SO HAVE NUDGED THE LOW
TEMPERATURE FORECAST A TAD LOWER. LOWS WILL LARGELY BE REACHED
TOWARD MIDNIGHT...BUT THEN TEMPERATURES SHOULD LEVEL OFF AS MID-
HIGH CLOUDS APPROACHING FROM THE SOUTHWEST SPREAD ACROSS THE
REGION. THESE CLOUDS ARE ASSOCIATED WITH A WARM FRONT...AND CAN
ALREADY BE SEEN ACROSS LAKE ERIE LATE THIS EVENING.
LOWS SHOULD RANGE FROM THE LOWER TO MID 30S IN THE TYPICALLY
COLDER INTERIOR VALLEYS...TO AROUND 40 CLOSER TO THE LAKE SHORES.
A HIGH PRESSURE RIDGE WILL EXTEND FROM THE APPALACHIANS AND INTO
WESTERN NEW YORK OVERNIGHT. MEANWHILE...A WARM FRONT WILL BRUSH WESTERN
PORTIONS OF NEW YORK TOWARDS DAWN...BUT WITH DEEP MOISTURE ALSO
LINGERING TO OUR WEST...EXPECT THE BULK OF THE REGION TO REMAIN
DRY LATE OVERNIGHT AND TOMORROW WITH THE WARM FRONT. THE HRRR IS
COMING IN RIGHT IN LINE WITH OTHER MODEL GUIDANCE...SUGGESTING
SOME LIGHT SHOWERS OR SPRINKLES CLIPPING FAR NW PORTIONS OF THE
STATE EARLY WEDNESDAY MORNING.
WITH THE WARM FRONT LIFTING INTO CANADA WEDNESDAY...OUR REGION WILL
FALL INTO THE WARM SECTOR. TEMPERATURES ALOFT AT 850 HPA WILL CLIMB
TOWARDS +10 TO +12C ACROSS OUR REGION. HOWEVER WE MIGHT NOT MIX UP TO
THIS LEVEL...AND WILL USE 925 HPA TEMPERATURES INSTEAD TO FORECAST
HIGHS FOR WEDNESDAY. AT 925 HPA...WE WARM TO +17C TO THE WEST AND
+13C ACROSS THE SOUTHERN GENESEE VALLEY AND EASTERN NORTH COUNTRY.
MIXING THESE TEMPERATURE VALUES DOWN TO THE SURFACE...AND WITH A
MIX OF CLOUDS AND SUNSHINE WE SHOULD HAVE HIGHS IN THE 60S...WITH
A FEW DOWNSLOPING AREAS OF THE GENESEE VALLEY WESTWARD REACHING
INTO THE LOWER 70S.
WINDS WILL BECOME SOUTHERLY TOMORROW WITH HIGH PRESSURE TO OUR
EAST...AND LOW HANGING WELL TO OUR WEST OVER THE NORTHERN PLAINS.
THE PRESSURE GRADIENT DOES INCREASE LATE IN THE DAY TO THE
WEST...AND SOME AFTERNOON LIGHT BREEZES WILL BE LIKELY ACROSS WNY.
&&
.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
DRY WEATHER SHOULD BE MAINTAINED WEDNESDAY NIGHT AHEAD OF THE
APPROACHING SLOW MOVING COLD FRONT. WARM AIR ADVECTION REGIME ON A
40 KNOT SOUTHERLY LOW LEVEL JET WILL ALLOW TEMPERATURES TO REMAIN
MILD...AND MAY EVEN RISE SLIGHTLY OVERNIGHT AS CLOUD COVER SPREADS
ACROSS THE AREA.
SOUTHERLY LOW LEVEL JET WILL CONTINUE TO STRENGTHEN AHEAD OF THE
FRONT THURSDAY...REACHING AT LEAST 50 KNOTS. WINDY CONDITIONS WILL
LIKELY DEVELOP...ESPECIALLY IF ANY SUNSHINE CAN DEVELOP AND AID
MIXING PROCESS. MODEL SOUNDINGS SUGGEST THE POTENTIAL FOR WIND GUSTS
TO 45 MPH AND POSSIBLY HIGHER FOR FAVORED DOWNSLOPE AREAS...THE
HIGHER TERRAIN OF THE SOUTHERN TIER AND FINGER LAKES. THE FRONT
LOOKS TO PUSH INTO WESTERN NEW YORK BY LATE IN THE DAY...ACCOMPANIED
BY A BAND OF SHOWERS AS A WELL DEFINED THETA E RIDGE LOOKS TO
DEVELOP ALONG AND JUST AHEAD OF THE FRONT. UPPER LEVEL SUPPORT LOOKS
DECENT UNDERNEATH LEFT EXIT REGION OF A 110 KNOT PLUS UPPER LEVEL
JET STREAK. TEMPERATURES LOOK MILD AHEAD OF THE FRONT WITH HIGHS IN
THE MID 60S TO LOWER 70S....ALTHOUGH COULD BE WARMER WITH ADDITIONAL
SUNSHINE AND SLOWER MOVEMENT OF THE COLD FRONT.
THE COLD FRONT AND BAND OF SHOWERS WILL SLOWLY WORK INTO EASTERN
SECTIONS THURSDAY NIGHT. A SHARP MID LEVEL DRY SLOT SURGING INTO THE
REGION IN WAKE OF THE FRONT SHOULD END THE PRECIPITATION FROM WEST
TO EAST. THERE LOOKS TO BE A BREAK IN THE PRECIPITATION FOR A GOOD
PART OF FRIDAY IN THE WAKE OF THE FRONT AND AHEAD OF THE SLOWLY
EVOLVING UPPER LEVEL LOW ACROSS THE NATIONS HEARTLAND. WESTERN
SECTIONS WILL HAVE THE BETTER CHANCES FOR SEEING PRECIPITATION
ASSOCIATED WITH THE UPPER LOW LATE IN THE DAY FRIDAY.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
MODEL DISCREPANCIES CONTINUE TO EXIST DURING THE PERIOD...ALTHOUGH
THE GENERAL MODEL IDEA TO SUGGEST A SLOW MOVING UPPER LOW WILL BE
PASSING ACROSS THE AREA OVER THE WEEKEND. THE SPEED/TIMING OF THE
UPPER LEVEL CIRCULATION IS CONTINUED TO BE HANDLE DIFFERENTLY BY THE
MEDIUM RANGE MODELS. THE 12Z GFS/CMC SUGGESTING A MORE PROGRESSIVE
SOLUTION WHICH LIFTS THE LOW OUT WITH A RETURN TO A MORE ZONAL FLOW
REGIME RATHER QUICKLY...WHILE THE ECMWF MAINTAINS A SLOWER AND MORE
SOUTHERN SOLUTION. AT THIS POINT...WOULD PREFER TO LEAN TOWARD THE
SLOWER ECMWF BASED A GENERAL BLOCKING PATTERN SEEN SOUTH OF
NEWFOUNDLAND DURING THIS TIME FRAME. THE SLOWER TIMING OF THE UPPER
LOW AND ASSOCIATED COLD POOL ALOFT WOULD FAVOR BETTER CHANCES FOR
SHOWERS...ESPECIALLY EARLY IN THE WEEKEND. WITH THE COLD POOL
OVERHEARD FOR THE WEEKEND...HIGH TEMPERATURES WILL LIKELY STRUGGLE
TO WARM OUT OF THE MIDDLE TO UPPER 50S BOTH WEEKEND DAYS...WITH
OVERNIGHT LOWS GENERALLY HOVERING IN THE LOWER TO MIDDLE 40S. BY
EARLY NEXT WEEK...ECMWF SUGGESTS THE UPPER LOW WILL FINALLY EXIT AS
THE NEXT UPPER TROUGH STARTS DIGGING ACROSS THE WESTERN CONUS AND
THE RIDGING SOUTH OF NEWFOUNDLAND BREAKS DOWN. THIS AGREES WELL WITH
THE GFS/CMC MODEL SOLUTIONS AND THEREFORE HAVE MAINTAINED DRY
WEATHER FOR THE REMAINDER OF THE PERIOD...WITH A GRADUAL WARMING
TREND.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
A WARM FRONT DRAPED ACROSS THE CENTRAL GREAT LAKES WILL LIFT
NORTHEAST ACROSS THE AREA TODAY...WITH FAIRLY WIDESPREAD MID AND
HIGH LEVEL CLOUDS PRECEDING AND ACCOMPANYING ITS PASSAGE. A FEW
SPRINKLES OR VERY LIGHT SHOWERS WILL ALSO BE POSSIBLE ACROSS FAR
WESTERN NEW YORK THIS MORNING...HOWEVER THESE SHOULD HAVE NO
IMPACT ON AVIATION OPERATIONS WITH ALL LOCATIONS REMAINING VFR.
TONIGHT...VFR CONDITIONS WILL CONTINUE WITH SKIES CLEARING OUT
SOMEWHAT BEHIND THE DEPARTING FRONT. OVERNIGHT...A DEVELOPING
SOUTHERLY LOW LEVEL JET WILL LIKELY BRING SOME LOW LEVEL WIND
SHEAR CONCERNS...HOWEVER THESE WILL FALL AFTER THE END OF THE
CURRENT TAF PERIOD.
OUTLOOK...
THURSDAY AND THURSDAY NIGHT...DETERIORATING TO MVFR WITH A PERIOD
OF RAIN SHOWERS THURSDAY AFTERNOON AND NIGHT.
FRIDAY...MAINLY VFR WITH A CHANCE OF RAIN SHOWERS.
SATURDAY AND SUNDAY...VFR/MVFR WITH SCATTERED SHOWERS.
&&
.MARINE...
HIGH PRESSURE OVER THE OHIO VALLEY WILL CONTINUE TO RIDGE NORTHWARD
ACROSS THE EASTERN GREAT LAKES THIS EVENING.
A WARM FRONT WILL LIFT ACROSS THE LAKES WEDNESDAY BUT WINDS AND
WAVES SHOULD REMAIN BELOW SCA LEVELS. WEDNESDAY NIGHT UNDER A
CONTINUED SOUTHERLY FLOW WAVES WILL START TO BUILD TOWARDS 4 FEET ON
THE NORTHEASTERN PORTION OF LAKE ONTARIO.
ON THURSDAY WINDS WILL INCREASE WITH SCA LIKELY FOR BOTH LAKES AND
POSSIBLY SOME OF OUR TWO RIVERS.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...THOMAS
NEAR TERM...APFFEL/THOMAS
SHORT TERM...TMA
LONG TERM...TMA
AVIATION...JJR
MARINE...APFFEL/THOMAS
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1132 PM EDT THU OCT 18 2012
.SYNOPSIS...
AN APPROACHING COLD FRONT WILL BRING A CHANCE OF SHOWERS AND
ISOLATED THUNDERSTORMS THROUGH MIDDAY FRIDAY...AND ACCOMPANIED BY
WARM TEMPERATURES. DRIER AND SLIGHTLY COOLER AIR WILL OVERSPREAD THE
REGION THIS WEEKEND. HIGH PRESSURE WILL BRING FAIR WEATHER AND A
WARMING TREND EARLY NEXT WEEK...ALONG WITH ABOVE NORMAL
TEMPERATURES THROUGH MID WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
AS OF 1055 PM THURSDAY...BOWLING BALL LOW PRESSURE BARRELING ACROSS
THE MIDWEST IS DRIVING A POTENT SFC COLD FRONT TO THE
WINDWARD SIDE OF THE APPALACHIANS AT THE MOMENT. THIS COLD FRONT
WILL CROSS THE APPALACHIANS AND REACH THE CENTRAL CAROLINAS
BY EARLY FRIDAY...AND OFF THE ILM CWA COAST BY MIDDAY FRIDAY AND
ENDING THE 40 PERCENT THREAT FOR CONVECTION.
WV/11-3.9 MICRON IR IMAGERY SHOW TWO AREAS OF ENHANCED MOISTURE
MOVING ACROSS THE SOUTHEAST LATE THIS EVENING. THE FIRST...WHICH
IS THE MID-UPPER LEVEL CLOUD DECK ACROSS THE CENTRAL AND EASTERN
PORTIONS OF THE FA...WHICH IS A DEBRIS CLOUD FIELD FROM
A REMNANT UPSTREAM SQUALL LINE THAT WEAKENED CONSIDERABLY THIS
AFTERNOON AND EARLY EVENING. WILL CONTINUE THE MAINLY DRY
LATE EVENING AND OVERNIGHT FORECAST. A SECOND AREA OF ENHANCED
MOISTURE JUST AHEAD OF THE FRONT WILL PARTIALLY MERGE WITH THE
1ST AREA OF MOISTURE OVERNIGHT. A WEAK MID-LEVEL S/W TROF ROTATING
AROUND THE MASSIVE CUTOFF UPPER LOW CENTERED OVER THE GREAT LAKES...
WILL BE IN THE NEIGHBORHOOD DURING THE PRE-DAWN HRS. THE DYNAMICS
FROM THIS...MOISTURE AVAILABILITY...AND THE SFC FEATURES...WILL
END PRODUCE A DEVELOPING/MOVING BAND/LINE OF SHOWERS WITH ISOLATED
TSTMS CROSSING THE ILM CWA. THE LATEST HRRR HAS BECOME MORE
OBSESSIVE WITH THIS OUTCOME OVERNIGHT...WITH A MORE ROBUST NE-SW LINE
ACROSS THE WESTERN CWA BY 07-08Z...AND REACHING THE COAST BY 10-13Z
FRI. STILL LOOKING AT SUB-SEVERE WIND GUSTS POSSIBLE.
TEMPS OVERNIGHT WILL BE TEMPERED BY CONTINUED SOUTHERLY FLOW AND
CLOUD COVER...FALLING ONLY SLOWLY AHEAD OF THE FRONT...THEN MORE
RAPIDLY IN THE EXTREME WEST AS THE FRONT MOVES FROM WEST TO EAST.
MINS TONIGHT LOOK TO BE JUST BELOW 60 IN THE EXTREME NW...TO THE MID
60S AT THE COAST.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
AS OF 3 PM THURSDAY...COLUMN MOISTURE WILL REMAIN SUFFICIENT FOR
SHOWERS THROUGH AT LEAST LATE MORNING AS A MODERATELY WEAK COLD
FRONT TRAVERSES THE FORECAST AREA. SHOWERS HOWEVER MAY LINGER
THROUGH FRIDAY AFTERNOON ALONG THE COASTAL/EASTERN ZONES WITH
HEATING AND RESIDUAL MOISTURE TO 12000 FEET. BY FRIDAY EVENING
IT APPEARS ANY CONVECTION WILL SHUT DOWN DUE TO FURTHER DRYING
AND DIURNAL COOLING.
DESPITE THE DRYING REGIME...NORTH WINDS WILL NOT BE REALIZED UNTIL
LAGGING HIGH PRESSURE BUILDS FROM THE GULF COAST STATES AND AN
UPPER TROUGH AXIS MOVES OFFSHORE. THUS DRYING WILL BE OUTPACING
THE WEAK COOL AIR ADVECTION. THE AIR MASS CHANGE WILL BE MORE
EVIDENT LATE SATURDAY AS THE HIGH PRESSURE CENTER LIFTS INTO THE
CENTRAL APPALACHIANS...AND IMPARTS NORTH WINDS.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 3 PM THURSDAY...SURFACE HIGH PRESSURE WILL COMBINE WITH
BUILDING 500MB RIDGE TO CREATE SUNNY AND WARMING TEMPS THROUGH THE
EXTENDED. WEAK S/W WILL BE EXITING AT THE START OF THE PERIOD
CREATING SUBSIDENCE THROUGH THE COLUMN. ALTHOUGH WE WILL SEE
WALL-TO-WALL SUNSHINE SUNDAY...WEAK CAA ON LEE SIDE OF ADVANCING
HIGH PRESSURE WILL KEEP TEMPS RIGHT AROUND CLIMO.
THEREAFTER...SURFACE HIGH SLOWLY DRIFTS EAST TOWARDS THE WATERS
WHILE MID LEVEL RIDGING BULGES UP FROM THE GULF OF MEXICO. ALTHOUGH
BOUTS OF HIGH LEVEL CI WILL PERIODICALLY AFFECT SKY COVER...MON-THU
WILL FEATURE NEARLY COMPLETE SUNSHINE WITH MAX TEMPS RISING EACH
DAY...FROM MID 70S MONDAY TO AROUND 80 WED/THU. NEARLY IDEAL
RADIATIONAL COOLING AT NIGHT SUGGESTS MINS WILL FALL TO AROUND OR
SLIGHTLY BELOW CLIMO EACH NIGHT.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
AS OF 00Z...A COLD FRONT WILL MOVE THROUGH THE KFLO/KLBT TERMINALS
OVERNIGHT...REACHING THE COASTAL TERMINALS AROUND SUNRISE. MODERATE
CONFIDENCE VFR WILL CONTINUE THROUGH MIDNIGHT LOCAL TIME...ALTHOUGH
THE COASTAL TERMINALS COULD EXPERIENCE SHORT PERIODS OF MVFR
CEILINGS WITH SCATTERED IFR LEVEL STRATUS LATER THIS EVENING.
CONFIDENCE OF VFR LOWERS AFTER MIDNIGHT AS RAIN DEVELOPS AHEAD OF
THE FRONT AND MOVES INTO THE KFLO/KLBT TERMS. VFR EXPECTED WITH THE
RAIN WITH TEMPO PERIODS OF MVFR. ANY IFR SHOULD BE OF TOO SHORT OF A
DURATION TO MENTION IN TAFS. AFTER THE RAIN ENDS AT KFLO/KLBT THERE
IS MODERATE CONFIDENCE OF POST FRONTAL IFR/LIFR CONDITIONS
DEVELOPING IN FOG AND LOW STRATUS. THIS SHOULD LAST 2-3 HOURS OR
UNTIL STRONGER WINDS AND DRIER AIR BEHIND THE FRONT MOVES IN LIFTING
CONDITIONS TO VFR. AT THE COASTAL TERMINALS AFTER 05Z UNTIL THE RAIN
ARRIVES THERE IS LOW-MODERATE CONFIDENCE OF IFR CEILINGS DEVELOPING.
AS THE RAIN AFFECTS THE COASTAL TERMINALS IN THE PRE-DAWN HOURS
EXPECT THE SAME GENERAL VFR/TEMPO MVFR CONDITIONS...ALTHOUGH THE
RAIN MAY BE LIGHTER AND OF SHORTER DURATION. MODERATE CONFIDENCE OF
A PERIOD OF POST FRONTAL MVFR CEILINGS OCCURRING BEFORE STRONGER
WINDS AND DRIER AIR BEHIND THE FRONT MOVES IN LIFTING CONDITIONS TO
VFR. WEST-SOUTHWEST TO WEST NORTHWEST WINDS EXPECTED FRIDAY UNDER
VFR CONDITIONS WITH WINDS BECOMING SOUTHWEST BY AFTERNOON.
EXTENDED OUTLOOK...LOW CONFIDENCE OF PRE-DAWN FOG/SUB-VFR VSBYS
MONDAY AND TUESDAY MORNINGS. OTHERWISE VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1045 PM THURSDAY...SOUTH-SOUTHWEST WINDS WILL GRADUALLY VEER
TO THE SW ALTOGETHER AND INCREASE TO AROUND 15 KTS AHEAD OF AN
ADVANCING COLD FRONT OVERNIGHT. AS THE WINDS PICK UP SEAS WILL
BUILD SLIGHTLY...FROM THE CURRENT 3 FT...TO 3-4 FT...THANKS TO AN
INCREASED CONTRIBUTION FROM THE 4-5 SECOND WIND CHOP. A SLIGHTLY
DECREASING 3 FT 10-11 SEC EASTERLY GROUND SWELL WILL EXIST WITHIN
THE SPECTRUM.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 PM THURSDAY...A WEAK COLD FRONT WILL CROSS THE WATERS LATE
MORNING TO EARLY AFTERNOON BARELY SHIFTING WINDS...MAINLY FROM SW
TO WSW IN THE AFTERNOON. WSW-W WINDS LOOK TO PREVAIL SATURDAY 15
KNOTS OR LESS AND NO ADVISORIES OR CAUTION STATEMENTS ARE EXPECTED
BOTH FRIDAY AND SATURDAY. HIGH PRESSURE BUILDING FROM THE GULF
COAST STATES INTO THE CENTRAL APPALACHIANS WILL BRING WINDS TO
THE NW AND NNW LATE SATURDAY NIGHT...BUT WELL BELOW ADVISORY WIND
SPEEDS. SEAS MAINLY 2 TO 4 FEET THROUGH THE PERIOD IN A MIX OF SE
WAVES 2-3 FEET AT 10 SECONDS AND 1-2 FOOT SW WIND-WAVES AND CHOP.
LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 3 PM THURSDAY...HIGH PRESSURE WILL RIDGE ACROSS THE WATERS
THROUGH THE EXTENDED...CREATING MOSTLY LIGHT N/NE WINDS EACH DAY.
THE EXCEPTION WILL BE ON SUNDAY...WHEN A WEAK NORTHERLY SURGE WILL
CONTINUE AHEAD OF THE ADVANCING HIGH...CREATING NORTHERLY WINDS OF
10-15 KTS BEFORE EASING BY SUNDAY NIGHT TO LESS THAN 10 KTS. SEAS
WILL BE 2-3 FT SUNDAY...FALLING TO 1-2 FT MON/TUE AS WINDS EASE AND
ONLY A WEAK SE SWELL PERSISTS WITHIN THE WAVE SPECTRUM.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MJC
NEAR TERM...DCH/JDW
SHORT TERM...MJC
LONG TERM...JDW
AVIATION...MRR
AREA FORECAST DISCUSSION
NWS RALEIGH NC
805 PM EDT THU OCT 18 2012
.SYNOPSIS...
A COLD FRONT WILL CROSS THE REGION LATE TONIGHT INTO EARLY FRIDAY.
HIGH PRESSURE WILL BUILD INTO THE CAROLINAS AND SOUTHERN VIRGINIA IN
THE WAKE OF THE FRONT AND LINGER OVER THE AREA THROUGH SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
AS OF 305 PM THURSDAY...
CLOUDS WILL INCREASE IN COVERAGE FROM WEST TO EAST THIS EVENING
AHEAD OF A COLD FRONT APPROACHING FROM THE WEST. AS OF THE 12Z UPPER
AIR ANALYSIS...UPPER LEVEL LOW PRESSURE WAS LOCATED OVER SRN MN/NRN
IA WITH THE TROUGH EXTENDING SOUTH INTO THE LOWER MS RIVER VALLEY.
BEST HEIGHT FALLS ARE STILL WELL TO THE NW...WITH A 140KT JET AT 250
MB OVER AR EXPECTED TO MOVE EASTWARD OVER THE APPALACHIANS LATER
TODAY. 16Z SURFACE ANALYSIS PLACES THE LOW OVER WI AND THE FRONT
EXTENDING EAST AND THEN SOUTH THROUGH THE OH AND TN VALLEYS. AS THIS
FRONT MIGRATES EASTWARD TODAY...WILL SEE INCREASING LOW-LEVEL
MOISTURE AND CLOUDS. AS FOR THE CONVECTION...THE 12Z NCEP WRF NMM
DEVELOPS A LINE OF SHOWERS OVER THE WESTERN PORTIONS OF THE AREA
BETWEEN 21Z AND 00Z...MAKING IT TO APPROX THE TRIANGLE AREA BEFORE
LIFTING NE AND DISSIPATING. THE 00Z NSSL WRF ARW SHOWS A SIMILAR
SCENARIO. GIVEN THE CURRENT SPC ANALYSES SHOWING INCREASING
LOW-LEVEL LAPSE RATES AHEAD OF THE DEVELOPING LINE OF SHOWERS AND
EFFECTIVE BULK SHEAR VALUES 45-50 KTS OVER THE MTS...CURRENTLY ABOUT
20 KTS OVER CENTRAL NC. ALSO...MUCAPE VALUES ARE AROUND 500 J/KG...
MAINLY ACROSS THE SOUTH. RUC ANALYSIS SHOWS BULK SHEAR VALUES
OVER CENTRAL NC INCREASING TO 50-60 KTS...WITH CAPE OF 500-1000
J/KG...MAINLY ACROSS THE WEST. THIS SUPPORTS THE POTENTIAL FOR
THUNDERSTORMS TO DEVELOP ACROSS THE WESTERN HALF OF THE AREA
TONIGHT...WITH AN ISOLATED STRONG TO SEVERE STORM POSSIBLE. MAIN
THREAT WOULD BE DAMAGING WINDS. SHOWERS AND ISOLATED STORMS ARE ALSO
POSSIBLE ALONG THE COASTAL PLAIN AHEAD OF THE MAIN LINE OF SHOWERS
AND STORMS THIS EVENING. HOW QUICKLY THE SHOWERS AND CLOUDS MOVE OUT
OF THE AREA WILL IMPACT THE LOW TEMPS FOR TONIGHT...BUT GENERALLY
LOOKING AT NEAR 50 DEGREES NW TO LOW 60S SE.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
AS OF 240 PM THURSDAY...
FRIDAY...
LARGE UPPER LOW OVER THE UPPER MIDWEST WILL MIGRATE EAST OVER THE
GREAT LAKES ON FRIDAY. THE COLD FRONT TO SLOWLY CROSS CENTRAL NC
TONIGHT IS FORECAST TO MOVE FROM ROUGHLY US HWY 1 AT 12Z TO WELL
EAST OF I-95 BY 18Z. EARLY IN THE DAY...FORCING FOR ACCENT WILL
MAINLY BE LIMITED TO UPPER DIVERGENCE IN THE RIGHT ENTRANCE OF THE
DEPARTING 120KT UPPER JET...WITH ONLY 30M HEIGHT FALLS AND
INCREASINGLY STABLE AND DRY AIR ALOFT. ANY REDEVELOPMENT OF SHOWERS
DURING THE FIRST HALF OF THE DAY WILL BE TIED TO WEAK FRONTAL
CONVERGENCE OVER THE COASTAL PLAIN...BUT EVEN THAT IS FORECAST TO
WEAKEN AS THE FLOW BECOMES MORE UNIDIRECTIONAL AND SOUTHWESTERLY.
WITH CLEARING SKIES AND A MODEST HEIGHT GRADIENT BEHIND THE
FRONT...FORECAST SOUNDINGS SHOW BOUNDARY LAYER MIXING...GREATEST IN
THE WEST...LEADING TO SOUTHWESTERLY WIND GUSTS OF UP TO 20-25KT
DURING THE AFTERNOON. A LOW LEVEL TRAJECTORY OUT OF THE SOUTHWEST
BEHIND THE FRONT WILL NOT LEAD TO A LARGE COOL DOWN BASED ON THE
UPSTREAM AIRMASS...WITH MOST GUIDANCE SHOWING HIGHS OF 70-78
NORTHWEST TO SOUTHEAST.
FRIDAY NIGHT...
OTHER THAN THE POTENTIAL FOR MID CLOUDS PASSING THROUGH THE BASE OF
THE UPPER LEVEL LOW...WHICH WILL BEGIN TO OPEN UP BY SATURDAY
MORNING...SKIES SHOULD BE MOSTLY CLEAR. AGAIN THERE IS NO REAL
STRONG COLD ADVECTION SATURDAY NIGHT AND LOWS SHOULD SETTLE JUST
BELOW NORMAL INTO THE MID TO UPPER 40S FOR MOST AREAS.
SATURDAY THROUGH SUNDAY......
THE MEAN TROUGH AXIS IS FORECAST TO CROSS THE APPALACHIANS AS
THE UPPER LOW OPENS AND LIFTS NORTHEASTWARD ON SATURDAY. THE
COMBINATION OF UPSTREAM MOISTURE AND THE COLDEST AIR ALOFT PASSING
OVERHEAD SHOULD LEAD TO ENHANCED STRATOCU IN THE LEE OF THE
MOUNTAINS DURING THE AFTERNOON. 1000-850MB THICKNESSES HOVER IN THE
1360S DURING THE DAY WITH A WEAK DOWNSLOPE FLOW POTENTIALLY
OFFSETTING WEAK COLD ADVECTION. THUS...WILL KEEP HIGHS WITHIN A
COUPLE DEGREES OF THOSE BASED ON THICKNESSES...66-73 NORTHWEST TO
SOUTHEAST. LOWS SATURDAY NIGHT IN THE LOW TO MID 40S UNDER MOSTLY
CLEAR SKIES...ALTHOUGH FORECAST SOUNDINGS SUGGEST CONDITIONS COULD
BE FAVORABLE FOR SOME OROGRAPHIC CIRRUS. HIGH PRESSURE WILL BEGIN TO
BUILD INTO THE AREA FROM THE SOUTHWEST SUNDAY WITH MOSTLY SUNNY
SKIES AND HIGHS AROUND 70S.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 250 PM THURSDAY...
OVERALL...THIS PERIOD WILL BE DOMINATED BY HIGH PRESSURE BOTH AT THE
SURFACE AND ALOFT. SURFACE HIGH PRESSURE WILL SETTLE RIGHT OVER THE
REGION...WHILE A MID LEVEL RIDGE WILL BUILD IN FROM THE GULF COAST
AREA. THIS WILL RESULT IN A PROLONGED PERIOD OF DRY CONDITIONS. AS
HEIGHTS GRADUALLY INCREASE THROUGHOUT THE PERIOD...TEMPS WILL SLOWLY
MODERATE...WITH HIGHS TRENDING TO ABOVE NORMAL. HOWEVER...WITH
FAIRLY DRY AIR IN PLACE AND MOSTLY CLEAR SKIES...OUR DIURNAL RANGE
SHOULD BE LARGE...WITH OVERNIGHT LOWS ABLE TO DROP OFF INTO THE 40S.
A BACK DOOR FRONT MAY APPROACH THE REGION LATE IN THE PERIOD...BUT
AS OF NOW MODELS SHOW LITTLE IMPACT TO THE AREA.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
AS OF 802 PM THURSDAY...
SHOWERS WEST OF KINT AND KGSO WILL MOVE INTO THE AREA OVER THE NEXT
HOUR AND WILL AFFECT THE AREA THROUGH APPROXIMATELY 03Z... WITH KRDU
AND KFAY EXPERIENCING SHOWERS BETWEEN 03 AND 06Z. SOUTHERLY FLOW AND
INCREASED MOISTURE IN ADVANCE OF THE FRONT WILL BRING LOWERED
CEILINGS TO ALL TERMINALS BETWEEN 06 AND 12Z... BEFORE DRIER AIR
BEGINS TO MOVE IN TO THE AREA FROM THE WEST LATE FRIDAY MORNING
BEHIND THE FRONT. GUSTY WINDS OF 15 TO 20 KTS ARE POSSIBLE FRIDAY
AFTERNOON. HIGH PRESSURE WILL BUILD IN TO THE AREA THROUGH
MIDWEEK... BRINGING GENERALLY VFR CONDITIONS.
&&
.FIRE WEATHER...
A COLD FRONT WILL CROSS CENTRAL NC LATE TONIGHT AND EARLY FRIDAY.
BEHIND THE FRONT...DEWPOINTS ARE FORECAST TO MIX OUT INTO THE LOW
TO MID 30S...WHILE TEMPS WILL BE RELATIVELY WARM FOR A POST-FRONTAL
AIRMASS. THIS WILL CAUSE RH VALUES TO DROP BELOW 30 PERCENT OVER
MUCH OF THE WESTERN PIEDMONT. CONCURRENTLY...SOUTHWESTERLY WIND
GUSTS WILL LIKELY REACH THE 20-25MPH RANGE FRIDAY AFTERNOON.
DESPITE THESE CONDITIONS...THE NCFS REPORTS RELATIVELY HIGH FUEL
MOISTURE AT THIS TIME...AND THUS NO STATEMENTS REGARDING FIRE
WEATHER WILL BE ISSUED FOR FRIDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BLS
NEAR TERM...KC
SHORT TERM...BLS
LONG TERM...KRR
AVIATION...SEC
FIRE WEATHER...BLS
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
902 PM CDT THU OCT 18 2012
.DISCUSSION...
MAIN ADJUSTMENTS FOR THIS EVENING ARE TO EXTEND THE STRONG WINDS A
BIT LONGER. LOW HAS CONTINUED TO WOBBLE OVER NORTHEASTERN AND
CENTRAL MN...WITH THE STRONG PRESSURE GRADIENT REMAINING OVER THE
CWA. THERE HAS BEEN NOT MUCH DECOUPLING AFTER SUNSET...AND WINDS
IN THE RED RIVER VALLEY AND DEVILS LAKE BASIN HAVE REMAINED OVER
30 KTS SUSTAINED AT MANY LOCATIONS WITH GUSTS STILL ABOVE 40 KTS.
HRRR HAS BEEN TOO LOW ON WINDS...BUT NAM SHOWS 925MB WINDS STAYING
ABOVE 40 KTS FOR MUCH OF THE NIGHT AND RAP ALSO HAS WINDS STAYING
HIGH UNTIL AFTER 06Z. THE LAV GUIDANCE ALSO HAS SUSTAINED WINDS
ABOVE 25 KTS UNTIL AFTER 08 OR 09Z. FOR THIS REASON...WILL EXTEND
THE WIND ADVISORY PAST THE 03Z EXPIRATION TIME TO 09Z.
AS FAR AS PRECIP...MAIN DEFORMATION BAND PRECIP HAS SHIFTED A BIT
FURTHER WEST THAN EXPECTED...BUT MODELS HAVE THE MID LEVEL
DEFORMATION WEAKENING A BIT AND THEN SHIFTING EAST LATER TONIGHT.
MADE SOME MINOR ADJUSTMENTS TO POPS FOR ONGOING RADAR TRENDS...BUT
DID NOT CHANGE TOO MUCH. ADJUSTED LOWS DOWN A BIT IN THE NORTHWEST
WHERE TEMPS HAVE ALREADY FALLEN INTO THE UPPER 30S.
&&
.AVIATION...
MVFR TO IFR CEILINGS AND VIS WILL CONTINUE THROUGH MUCH OF THE
NIGHT AS MOISTURE CONTINUES TO WRAP AROUND THE BACKSIDE OF A LOW
PRESSURE SYSTEM. SOME LIFR CEILINGS ARE POSSIBLE...PARTICULARLY AT
THE EASTERN TAF SITES. THE LOW WILL ALSO BRING STRONG NORTH TO
NORTHWEST WINDS AT 20 TO 30 KTS WITH GUST UP TO 40 KTS FOR A BIT
LONGER THIS EVENING FOR EVERYONE BUT KBJI. WINDS SHOULD START TO
DECREASE AROUND 09Z OR SO. THERE WILL BE A POSSIBILITY OF LOW LEVEL
WIND SHEAR IN THE CENTRAL TAF SITES AS SFC WINDS DECREASE BUT
REMAIN AROUND 40 KTS AT 1500 FT UP. WINDS WILL DECREASE SOME BY
TOMORROW...ALTHOUGH SOME GUSTS UP TO 25 KTS WILL STILL BE
POSSIBLE. SOME IMPROVEMENT TO VFR WILL BE POSSIBLE AFTER 00Z
TOMORROW EVENING.
&&
.PREV DISCUSSION... /ISSUED 352 PM CDT THU OCT 18 2012/
DISCUSSION...
SEEING SOME GUSTS WORKING DOWN THRU THE FERGUS FALLS AND ELBOW
LAKE AREAS NOW WHICH ARE EITHER AT OR NEAR WIND AVISORY CRITERIA.
THEREFORE WILL EXPAND THE CURRENT WIND ADVISORY TO ADD WESTERN
OTTER TAIL AND GRANT COUNTIES.
PREV DISCUSSION... /ISSUED 243 PM CDT THU OCT 18 2012/
SHORT TERM...
THE MAIN FORECAST CHALLENGES WILL BE RAIN AND WIND. THE WIND
SHOULD SLOWLY DECREASE THIS EVENING WHILE THE RAIN LOOKS TO
CONTINUE INTO FRIDAY. WILL UTILIZE A MODEL BLEND FOR THIS PORTION
OF THE FORECAST.
TONIGHT...ALTHOUGH IT TOOK QUITE A WHILE FOR THE RAIN TO MOVE BACK
IN TODAY IT IS HERE NOW. THE MAIN BAND OF RAIN IS BASICALLY OVER
THE RED RIVER VALLEY AND NORTHWEST MN...PIVOTING AROUND THE LOW
WHICH IS LOCATED OVER EASTERN MN. MODELS CONTINUE TO INDICATE THIS
BAND HANGING IN ROUGHLY THE SAME AREA THRU TONIGHT. RAINFALL
AMOUNTS WILL BE STEADY AGAIN BUT REALLY NOT AMOUNTING TO HUGE
TOTALS. WIND SPEEDS HAVE FINALLY INCREASED TO WIND ADVISORY
CRITERIA LEVELS IN MOST OF THE ADVISORY AREA. THE WAHPETON
BRECKENRIDGE AREA HAS NOT QUITE RISEN INTO ADVISORY CRITERIA
SPEEDS YET BUT SHOULD SHORTLY. THEN IT IS JUST A MATTER OF HOW
LONG THEY WILL LAST TONIGHT. TRADITIONALLY THE BEST DOWNWARD
MOMENTUM TRANSFER OCCURS DURING DAYLIGHT HOURS SO WOULD EXPECT
THE STRONGEST WINDS TO RELAX SOME AFTER SUNSET. ALSO NOT SEEING
ANY PUSH OF COLD AIR YET...ACTUALLY THE SYSTEM STILL WRAPS SOME
WARM AIR BACK IN TONIGHT. SO WILL LET THE CURRENT WIND ADVISORY
END TIME OF 10 PM STAND AS IS AND EVENING SHIFT CAN ADJUST IF THE
SPEEDS DO NOT SLACKEN OFF AS EXPECTED.
FRI-SUN...WILL PROBABLY BE SOME LINGERING PCPN ON FRIDAY
ESPECIALLY ALONG AND EAST OF THE RED RIVER VALLEY. AGAIN AMOUNTS
WILL NOT BE VERY MUCH. COULD BE A FEW BREAKS OF SUN TRYING TO WORK
INTO THE WESTERN FA AS WELL. WIND SPEEDS WILL CONTINUE TO SLOWLY
DECREASE THRU THE DAY. SAT IS LOOKING LIKE A VERY NICE DAY WITH
HIGH TEMPS PUSHING THE 60 DEGREE MARK. SFC WIND DIRECTION NOT
LOOKING TOO FAVORABLE FOR A STRONG WARMING PUSH AS THEY STILL
LOOK MORE STRAIGHT SOUTHERLY. SUNDAY SHOULD STILL BE A NICE DAY
WITH TEMPS CLOSE TO THOSE FROM SATURDAY. ONLY CHANCE OF SPRINKLES
OR VERY LIGHT RAIN LOOK TO BE SAT NIGHT AND EARLY SUNDAY OVER
PORTIONS OF THE DEVILS LAKE REGION OR FAR NORTHERN RED RIVER
VALLEY AS THE UPPER JET NOSES IN.
LONG TERM (SUN NIGHT-THU)...
LARGE SCALE FIELDS ARE SIMILAR AT THE BEGINNING OF THE PERIOD WITH SW
FLOW ALOFT...PIECES OF ENERGY EJECTING FROM THE WEST COAST TROF.
CHANCES FOR RAIN ARE POSSIBLE AT THE BEGINNING OF THE
WEEK...ALTHOUGH ON THE LOW END. A VIGOROUS S/WV WILL LIFT NEWD IN
THE UPPER MIDWEST WED NIGHT INTO THU WITH A SURFACE LOW MOVING CROSS
THE DAKOTAS. THIS SYSTEM LOOKS TO BE A STRONG SYSTEM WITH HIGHER
POPS FROM MIDWEEK AND BEYOND. THERMAL PROFILES SUGGEST A MIXTURE OF
RA/SN WED NIGHT INTO THU FOR THE DEVILS LAKES BASIN. TEMPS WILL BE
AT OR ABOVE NORMAL AT THE BEGINNING OF THE PD THEN TRENDING TO BELOW
NORMAL BY WED.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WIND ADVISORY UNTIL 4 AM CDT FRIDAY FOR NDZ006>008-014>016-024-
026>030-038-039-049-052>054.
MN...WIND ADVISORY UNTIL 4 AM CDT FRIDAY FOR MNZ001>004-007-029-030-
040.
&&
$$
JR
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1221 PM CDT WED OCT 17 2012
.DISCUSSION...
UPDATE TO REMOVE BURLEIGH AND EMMONS COUNTIES FROM THE RED FLAG
WARNING AS THE LATEST HRRR AND RAP RUNS DEPICT PRECIPITATION
LASTING THROUGH MUCH OF THE AFTERNOON. ALSO GETTING FROM REPORTS
OF SLEET IN THE MINOT AREA. THE 12 UTC GUIDANCE CONSENSUS IS
APPARENTLY NOT PICKING UP ON AN ELEVATED MELTING LAYER...AND WILL
ADD A MENTION OF SLEET TO THE TERMINAL MORAINE WHERE A RELATIVE
MINIMUM IN 850 MB TEMPERATURE EXIST.
&&
.AVIATION...
CIGS HAD IMPROVED TO VFR AT KISN/KDIK...AND EXPECT VFR CIGS TO
PERSIST AT KISN BUT RETURN TO MVFR LATER TONIGHT. CIGS TO BECOME
SCATTERED AT KDIK THIS AFTERNOON. FARTHER EAST AT
KMOT/KBIS/KJMS...EXPECT PERIODS OF MVFR CIGS AND SHOWERS LINGERING
INTO THE AFTERNOON. CIGS AT KBIS MAY BECOME VFR FOR A TIME IN THE
AFTERNOON...THEN GO BACK TO MVFR AFT 00Z. WINDS WILL CONTINUE TO
INCREASE THROUGH THE AFTERNOON...LIKELY REACHING GUSTS AROUND 45-55
KTS. WINDS WILL DIMINISH SLIGHTLY LATER TONIGHT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING UNTIL 7 PM CDT /6 PM MDT/ THURSDAY FOR
NDZ001>005-009>013-017>023-025-031>037-040>048-050-051.
RED FLAG WARNING UNTIL 10 PM CDT /9 PM MDT/ THIS EVENING FOR
NDZ009-017>020-031>034-040>045.
&&
$$
SHORT TERM...AYD
AVIATION...JV
AREA FORECAST DISCUSSION
NWS BISMARCK ND
448 AM CDT WED OCT 17 2012
.SHORT TERM...NOW THROUGH THURSDAY AFTERNOON...
THE MAIN FORECAST PROBLEM THIS MORNING DEALS WITH THE COMMA HEAD
PRECIPITATION SLIDING SOUTHEAST ACROSS THE WESTERN PORTION OF
NORTH DAKOTA IN 4 AM CDT RADAR AND SATELLITE IMAGERY.
A DRASTIC INCREASE IN WIND SPEEDS IS COINCIDENT WITH THE FRONT
EDGE OF COMMA HEAD RAIN BASED ON CURRENT OBSERVATIONS...SO WIND
GRIDS WERE GENERALLY TIMED USING THAT BOUNDARY. THE GREATEST
UNCERTAINTY WITH WINDS AT THIS POINT IS ACROSS THE NORTH WHERE
WINDS MAY NOT QUITE REACH HIGH WIND CRITERIA ON THURSDAY.
VERY SHORT TERM PRECIPITATION IS BASED ON 06 UTC HRRR SIMULATED
REFLECTIVITY AND CURRENT TRENDS...BUT 00 UTC CONSENSUS BLEND WAS
USED FOR PRECIPITATION CHANCES AFTER 12 UTC THIS MORNING.
.LONG TERM...THURSDAY NIGHT THROUGH TUESDAY...
THE MAIN FORECAST ISSUES IN THE LONG TERM WILL BE THE TIMING OF
SEVERAL SHORT WAVE TROUGHS IN THE DEVELOPING SOUTHWEST FLOW...AND
ASSOCIATED PRECIP CHANCES. ON THURSDAY NIGHT...LIGHT PRECIPITATION
WILL BE LINGERING FROM THE JAMES RIVER VALLEY THROUGH THE TURTLE
MOUNTAINS. WARMER AIR ALOFT WILL WRAP BACK INTO THE AREA BEHIND
THE EXITING SURFACE LOW. HOWEVER...SURFACE TEMPS ARE EXPECTED TO
REMAIN ABOVE FREEZING AND PRECLUDE ANY FREEZING RAIN. WINDS WILL
STILL BE QUITE GUSTY DURING THE EVENING HOURS SOUTHEAST...AND
ADVISORY HEADLINES MAY BE NEEDED BEYOND THE CURRENT HIGH WIND
WARNING. UPPER RIDGING WILL RESULT IN A TEMPORARY WARM-UP FRIDAY
INTO SATURDAY...FOLLOWED BY COOLER TEMPS SUNDAY INTO EARLY NEXT
WEEK. BASED ON A GFS/ECMWF CONSENSUS...SATURDAY NIGHT IS FAVORED
FOR RAIN OR A RAIN/SNOW MIX. ALSO MAINTAINED LOW POPS SUNDAY NIGHT
THROUGH TUESDAY.
&
.AVIATION...
EXPECT PERIODS OF MVFR CIGS AND SHOWERS THIS MORNING...LIKELY
LINGERING INTO THE AFTERNOON AT KMOT AND POSSIBLY KJMS. LOWER
CLOUDS MAY ALSO IMPACT KISN/KBIS LATER TONIGHT. WINDS ARE ALREADY
BECOMING QUITE STRONG ACROSS WESTERN NORTH DAKOTA...AND WILL
CONTINUE TO INCREASE THROUGH THE MORNING AND AFTERNOON...LIKELY
REACHING GUSTS AROUND 45-50 KTS. WINDS WILL DIMINISH SLIGHTLY
LATER TONIGHT.
&&
.FIRE WEATHER...
A REVIEW OF TWO SOUTH DAKOTA CASES WITH CONDITIONS SIMILAR TO
THOSE FORECAST TODAY AND TOMORROW SUGGESTS THAT RELATIVE
HUMIDITIES BELOW 40 PERCENT WITH WINDS GUSTING TO AROUND 60 MPH
WILL RESULT IN CRITICAL FIRE GROWTH IF ONE SHOULD IGNITE.
COORDINATION WITH STATE AND FEDERAL FIRE OFFICIALS SUGGESTS THAT
RELATIVE HUMIDITIES WOULD HAVE TO BE EVEN HIGHER TO KEEP FIRES
FROM UNCONTROLLABLE SPREADING...SO 50 PERCENT WAS GENERALLY USED AS
THE DECIDING FACTOR FOR WHO SHOULD BE IN A RED FLAG WARNING TODAY.
USING THE SAME METHODOLOGY...THURSDAY WOULD ALSO REQUIRE A RED
FLAG WARNING FROM NORTHWEST THROUGH SOUTH CENTRAL NORTH DAKOTA.
THERE IS UNCERTAINTY WITH REGARD TO HOW MUCH RAINFALL WILL OCCUR
TODAY...AND ITS OVERALL IMPACT ON DRY FUELS...BUT ANOTHER RED
FLAG WARNING MAY BE NECESSARY THURSDAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING UNTIL 7 PM CDT /6 PM MDT/ THURSDAY FOR
NDZ001>005-009>013-017>023-025-031>037-040>048-050-051.
RED FLAG WARNING FROM 9 AM CDT /8 AM MDT/ THIS MORNING TO 10 PM
CDT /9 PM MDT/ THIS EVENING FOR NDZ001-009-017>021-031>036-
040>048-050-051.
&&
$$
SHORT TERM/FIRE WEATHER...SCHECK
LONG TERM/AVIATION...KINNEY
AREA FORECAST DISCUSSION
NWS BISMARCK ND
112 AM CDT WED OCT 17 2012
.DISCUSSION...
THE MAIN FORECAST PROBLEM THIS MORNING DEALS WITH THE COMMA HEAD
PRECIPITATION SLIDING SOUTHEAST ACROSS THE WESTERN PORTION OF
NORTH DAKOTA THIS MORNING. COLLABORATION WITH SURROUNDING OFFICES
HAS ALLOWED FOR CONSIDERABLE DEVIATION FROM THE PREVIOUS FORECAST.
ALL CHANGES ARE BASED ON 12 AM CDT SATELLITE AND RADAR DATA...AS
WELL AS 02 UTC HRRR SIMULATED REFLECTIVITY.
A 51 KNOT WIND GUST NEAR GLASGOW IN THE PAST COUPLE HOURS
SUGGESTS THAT THE WIND FORECAST FOR WESTERN NORTH DAKOTA IS ON
TRACK.
&&
.AVIATION...
BIGGEST CONCERN IN THE EXTENDED WILL BE TIMING OF STRONG WINDS
BEHIND COLD FRONT IN NORTHEAST MONTANA. CEILING REMAIN VFR EVEN
WELL BEHIND THE SYSTEM IN WESTERN SASKATCHEWAN. HOWEVER SOME MVFR
CEILINGS ARE POSSIBLE AS LOW DEEPENS OVERNIGHT.
&&
.FIRE WEATHER...
RED FLAG WARNING WEDNESDAY WHERE THE WINDS WERE
FORECAST 40 MPH OR MORE AND RELATIVE HUMIDITY 40 PERCENT OR LESS.
HIGH WINDS WILL OVERRIDE THE RELATIVE HUMIDITY WITH THE ABUNDANT
DRY VEGETATION. RAINFALL THIS AFTERNOON AND TONIGHT IS NOT
EXPECTED TO SIGNIFICANTLY WET THE AREA WITHIN THE RED FLAG
WARNING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING UNTIL 7 PM CDT /6 PM MDT/ THURSDAY FOR
NDZ001>003-009>011-017>021-031>034-040>045.
RED FLAG WARNING FROM 9 AM CDT /8 AM MDT/ THIS MORNING TO 10 PM
CDT /9 PM MDT/ THIS EVENING FOR NDZ001-009-017>021-031>036-
040>048-050-051.
HIGH WIND WARNING UNTIL 7 PM CDT THURSDAY FOR NDZ004-005-012-013-
022-023-025-035>037-046>048-050-051.
&&
$$
DISCUSSION...SCHECK
AVIATION...HW
FIRE WEATHER...JV
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
216 PM EDT WED OCT 17 2012
.SYNOPSIS...
HIGH PRESSURE SLIPS EAST WEDNESDAY. COLD FRONT BRINGS GOOD CHANCE
FOR SHOWERS THURSDAY INTO FRIDAY. THE PARENT DEEP LOW PRESSURE
SYSTEM APPROACHES FROM THE NORTHWEST FRIDAY NIGHT INTO SATURDAY.
&&
.NEAR TERM /THROUGH THURSDAY/...
SLOW BUT STEADY PRESSURE FALLS TO OCCUR WITH THE APPROACH OF THE
COLD FRONT FROM THE WEST...CURRENTLY SITUATED JUST TO THE WEST OF
THE UPPER REACHES OF THE MISSISSIPPI. FRONTAL SYSTEM WILL BE IN
THE PROCESS OF OCCLUDING OVER THE WESTERN GREAT LAKES. THIS
STACKED LOW PRESSURE SYSTEM WILL BEGIN TO FILL AT THE SURFACE AND
ALOFT WHILE THE FRONT BARRELS THROUGH THE OHIO VALLEY AND
ULTIMATELY THROUGH THE MOUNTAINS.
RELIED HEAVILY...BUT NOT COMPLETELY...ON STRAIGHT NAM VALUES FOR
WIND VELOCITIES DURING THE NEAR TERM...USUALLY BETTER
REPRESENTATIVE OF A STRONGER WIND SCENARIO. COULD SEE SPORADIC
30KT GUSTS. LOW LEVEL JET AHEAD OF THE FRONT WILL PEAK OUT NEAR
60KTS.
THIS WILL BE A LOW INSTABILITY/HIGHLY DYNAMIC SYSTEM...WHICH WILL
LEAD TO SOME THUNDER POTENTIAL IN THE AFTERNOON HOURS. STRONG FLOW
THROUGH THE LAYERS WILL BRING SOME ORGANIZATION TO SHOWERS/STORMS
THAT COULD FORM...SO ISOLATED WIND PROBLEMS ARE POSSIBLE. ONE
THING TO WATCH WILL BE THE POSITIONING OF THE COLD FRONT AS IT
PUSHES INTO THE MOUNTAINS. NORTHERN PORTIONS OF THE CWA MAY END UP
BEING CUT OFF FROM THE BETTER AVAILABLE MOISTURE IN SOUTHERLY
FLOW...WHICH MAY RELEGATE ANY THUNDER TO THE SOUTHERN ZONES.
REGARDLESS...DESPITE THE SPC OUTLOOK...WILL GO MODEST ON THE
THUNDER POTENTIAL IN THE GRIDS FOR NOW...AND WILL CAP IT AT LOW
CHANCE. WILL LET THE MID SHIFT REEVALUATE THIS.
SHORT LIVED DRY SLOT WITH MAINLY CLEAR SKIES SHOULD FOLLOW THE
FRONT. MORE LOW LEVEL MOISTURE RETURNS TO THE FRINGES OF THE
WESTERN ZONES JUST PRIOR TO 00Z FRIDAY.
FRONTAL PASSAGE/RAIN WILL KNOCK TEMPERATURES OFF A FEW DEGREES
TOMORROW FROM THE WARMER VALUES CURRENTLY OCCURRING.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY NIGHT/...
THE NAM/CMC/GFS/ECMWF ARE IN AGREEMENT WITH THE TIMING OF
CONVECTION ASSOCIATED WITH APPROACHING COLD FRONT OVER SOUTHEAST
OH BY 12Z THURSDAY. HOWEVER...THERE ARE INTENSITY DIFFERENCES IN
QPF FIELDS...AS WELL AS IN THE UPPER LEVEL SUPPORT. THE GFS HAS
STRONGER MID LEVEL FORCING ACROSS THE OH RIVER...WHILE THE NAM
WEAKENS ITS FORCING. NEVERTHELESS...BELIEVE IN PREVIOUS FORECAST
BRINGING HIGH CATEGORICAL POPS INTO SOUTHEAST OH BY 12Z...DECREASING
TO LIKELY AS THE FRONT SWEEPS EAST INTO THE AFTERNOON HOURS. H850
WINDS AHEAD OF THE FRONT ARE BETWEEN 55-60 KNOTS IN THE WARM
SECTOR. DEWPOINTS WILL INCREASE INTO THE LOWER 50S UNDER DEEP
SOUTH SOUTHWEST FLOW...DESPITE OF AFTERNOON MIXING.
HOWEVER...PWATS LOOKS RATHER LOW BARELY OVER ONE INCH.
VERY WEAK LAYERED CAPE...BUT DEEP LAYERED SHEAR EXCEEDING 55
KNOTS...STORM RELATIVE HELICITY EXCEEDING 300 M2/S2...AND BOUNDARY
LAYER CONVERGENCE ALONG THE FRONT CALLS FOR A DYNAMIC ENVIRONMENT
CAPABLE TO PRODUCE STORMS. KEPT STORM MENTION WITH LIKELY POPS
DECREASING IN COVERAGE AS THE FRONT MOVE EAST THURSDAY AFTERNOON.
SEVERE STORMS ARE NOT ANTICIPATED AT THIS TIME...STRONG GUSTY FLOW
ARE WORTH TO BE MENTIONED IN THE HWO.
STRONG GUSTY WINDS CAN MIX DOWN TO SFC ALONG FRONTAL
CONVECTION...AND CAN BE POSSIBLE ALSO OVER THE HIGHER ELEVATIONS.
KEPT SFC FRONT EXITING EASTERN MOUNTAINS BY 21Z..IF NOT A LITTLE
SOONER. EXPECT DRY SLOT TO PRODUCE SOME BREAKS IN THE CLOUDS
MAINLY SOUTH AND CENTRAL SECTIONS OF OUR CWA.
THIS COLD FRONT...EXTENDS NORTHWEST AS A OCCLUDED FRONT INTO THE
PARENT DEEP LOW PRESSURE SYSTEM OVER THE GREAT LAKES. SOME
DIFFERENCES NOTED IN THE H5 LOW CENTER...WITH THE NAM SHOWING IT
OVER THE OH VALLEY...THE GFS OVER THE GREAT LAKES...AS WELL AS THE
ECMWF AND CMC. THEREFORE...PER CONSENSUS...EXPECT LOW PRESSURE
TO APPROACH OUR AREA FROM THE NORTHWEST...BUT LIFT NORTHEAST
FRIDAY NIGHT. RAP AROUND MOISTURE BEHIND THE DEPARTURE LOW WILL
BRING CHANCES OF STRATIFORM RAIN ACROSS THE NORTHERN PORTIONS OF
THE AREA FRIDAY...INTO EARLY SATURDAY MORNING...PER GFS/ECMWF/CMC
CONSENSUS.
KEPT WIND GUSTS 20-30 KNOTS DO TO CAA AND EFFICIENT MOMENTUM
TRANSFER AS SEEN IN INVERTED V FEATURE IN BUFKIT SOUNDING FRIDAY.
WENT A DEGREE OR TWO LOWER THAN MAV/MET GUIDANCE PER UNCERTAINTY
OF CLOUD COVER...GENERALLY UPPER 60S LOWLANDS...RANGING INTO THE
MID 50S HIGHEST ELEVATIONS...FOR THURSDAY. EXPECT A COOLER TREND
THURSDAY NIGHT AND FRIDAY UNDER CAA...AND CLOUD COVER.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
STILL SOME ISSUES WITH MODEL AGREEMENT IN THE LONG TERM PERIOD IN
TERMS OF TIMING AND PATH OF EXITING LOW PRESSURE. GFS IS STILL
FASTER AND FARTHER TO THE NORTH WITH THE UPPER LOW THAN THE ECMWF.
BUT REGARDLESS...A GRADUAL DRYING TREND IS EXPECTED TO BEGIN ON
SATURDAY AS THE UPPER LOW GRADUALLY PUSHES EAST...AND A RIDGE OF
HIGH PRESSURE GRADUALLY STARTS TO BUILD IN FOR THE BEGINNING OF NEXT
WEEK. DID START TO BUMP TEMPERATURES UP A BIT FROM PREVIOUS
FORECAST...AND DRY OUT FORECAST FOR LATE THIS WEEK/EARLY NEXT WEEK.
SOME ISSUES CONCERNING THE TIMING OF NEXT SYSTEM...PROGGED TO ENTER
CWA BY MID WEEK...BUT FOR NOW...MAINTAINED A DRY FORECAST INTO
PERIOD DUE TO UNCERTAINTY.
&&
.AVIATION /17Z WEDNESDAY THROUGH SUNDAY/...
INCREASING CLOUD COVER INTO TONIGHT WILL REMAIN VFR UNTIL
SHOWERS/FRONTAL BOUNDARY ARRIVE. MVFR CEILINGS/VISIBILITIES
PREVAIL WITH THE SHOWERS THURSDAY...ALTHOUGH SOME BOUNCING DURING
THIS TIME IS POSSIBLE. MAY SEE CB TOWARDS 18Z...ESPECIALLY SOUTH
AT BKW.
WIND GUSTS COULD BE MORE PROBLEMATIC...WITH GUSTS 20 TO 30 KNOTS
AHEAD OF THE FRONT POSSIBLE...GENERALLY OUT OF THE SOUTH. NAM
SUGGESTS LLWS POSSIBLE AT CRW AND BKW TONIGHT THROUGH EARLY
THURSDAY. WINDS EASE OFF SOMEWHAT AFTER FRONTAL PASSAGE...AND WILL
KEEP THE GUSTS 20KTS OR BELOW WITH LITTLE DIRECTION CHANGE FOR THE
WESTERN TERMINALS.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z THURSDAY...
FORECAST CONFIDENCE: MEDIUM TO HIGH.
ALTERNATE SCENARIOS: MAY NEED SLIGHTLY LONGER MVFR CEILINGS WITH
FRONTAL PASSAGE THURSDAY. MAY NEED CB AT CRW AND CKB THURSDAY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 18Z THURSDAY...
NO WIDESPREAD IFR EXPECTED AT THIS TIME.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...50/26
NEAR TERM...26
SHORT TERM...ARJ
LONG TERM...SL
AVIATION...26
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1040 AM EDT WED OCT 17 2012
.SYNOPSIS...
HIGH PRESSURE SLIPS EAST WEDNESDAY. COLD FRONT BRINGS GOOD CHANCE
FOR SHOWERS THURSDAY INTO FRIDAY. THE PARENT DEEP LOW PRESSURE
SYSTEM APPROACHES FROM THE NORTHWEST FRIDAY NIGHT INTO SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...
WEAK TROUGH AXIS CENTERED OVER OHIO/INDIANA BORDER INTO EASTERN
KENTUCKY/TENNESSEE BRINGING SCATTERED CLOUDS TO THE WESTERN ZONES.
FEATURE WILL LIFT OUT LATER THIS AFTERNOON. PRESSURE GRADIENT TO
TIGHTEN UP WITH COLD FRONT APPROACH AND SUBSEQUENT STEADY PRESSURE
FALLS FOR THE NEXT 24 HOURS.
PREVIOUS DISCUSSION...
ZONAL FLOW WILL BECOME INCREASINGLY SOUTHWESTERLY TODAY IN ADVANCE
OF A CLOSED UPPER LOW DIGGING SOUTHEASTWARD ACROSS THE UPPER
MIDWEST. AN EMBEDDED S/W TROUGH IN THE MEAN FLOW WILL BRUSH BY THE
AREA TO THE NORTH/NORTHWEST THIS MORNING. NO PRECIP IS EXPECTED WITH
THIS FEATURE BUT WILL RESULT IN INCREASED CLOUD COVER...PARTICULARLY
DURING THE MORNING HOURS AND ACROSS THE SE OHIO ZONES. INHERITED MAX
TEMPS GENERALLY IN THE MID/UPPER 70S LOWLANDS LOOK GOOD WITH ONLY A
COUPLE MINOR TWEAKS.
WED EVENING AND OVERNIGHT THE UPPER LOW WILL BE CONTINUING TO
PROGRESS SE-WARD...ESSENTIALLY LOCATED ROUGHLY OVER SOUTHERN MN BY
12Z THU. RUN TO RUN NAM/GFS COMPS SHOW GENERAL CONSISTENCY WITH ITS
TRACK...BUT BOTH SHOW SLIGHT DECREASE IN STRENGTH. ATTENDANT SFC LOW
WILL BE ROUGHLY OVER WISCONSIN WITH THE COLD FRONT EXTENDING
SOUTHEASTWARD. STRONG FORCING FOR ASCENT MOVES OVER THE FORECAST
AREA AFTER 06Z ALONG WITH GOOD DYNAMICS...INCLUDING MIDLEVEL
DIFFLUENT FLOW...GOOD POTENTIAL VORT ADVECTION...AS WELL AS DECENT
LLVL WARM ADVECTION AND A STRONG 850MB JET LIFTING NE-WARD ACROSS
EASTERN KY PRIOR TO FRONT/S ARRIVAL. DESPITE ALL THIS...DRY LOW
LEVELS WILL BE IN PLACE...WITH GOOD LLVL MOISTURE ARRIVING POST-FRONT.
850MB AND 700MB FLOW WILL BE PARALLEL TO GENERALLY VEERED FROM THE
ORIENTATION OF THE SFC FRONT WHICH WOULD USUALLY BE A PRECURSOR FOR
A PRE-FRONTAL PRECIP REGIME. ALL THIS TO SAY THAT THE MAIN PRECIP
SHOULD BE ALONG AND POST-FRONTAL IN A RELATIVELY THIN BAND GENERATED
MAINLY BY FRONTO-G FORCING. BOTH THE LATEST NAM AND SREF DEPICT THE
SFC FRONT JUST ENTERING THE WESTERN KY ZONES AT 12Z...WITH THE GFS
JUST SLIGHTLY SLOWER. WITH THIS IN MIND...INHERITED POP GRIDS WHICH
BRING PRECIP INTO THE WESTERN KY ZONES AROUND 09Z WITH THE BULK OF
THE PRECIP ARRIVING NEAR AND AFTER 12Z THU STILL LOOK REASONABLE
WITH ONLY MINOR ADJUSTMENTS. FINALLY...WITH STRONG LLVL SOUTHWEST
FLOW AND WARM ADVECTION...CONTINUED PREV FCST OF GOING WELL ABOVE
GUIDANCE ON OVERNIGHT LOWS IN THE MID/UPPER 50S LOWLANDS.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
THE NAM/CMC/GFS/ECMWF ARE IN AGREEMENT WITH THE TIMING OF
CONVECTION ASSOCIATED WITH APPROACHING COLD FRONT OVER SOUTHEAST
OH BY 12Z THURSDAY. HOWEVER...THERE ARE INTENSITY DIFFERENCES IN
QPF FIELDS...AS WELL AS IN THE UPPER LEVEL SUPPORT. THE GFS HAS
STRONGER MID LEVEL FORCING ACROSS THE OH RIVER...WHILE THE NAM
WEAKENS ITS FORCING. NEVERTHELESS...BELIEVE IN PREVIOUS FORECAST
BRINGING HIGH CATEGORICAL POPS INTO SOUTHEAST OH BY 12Z...DECREASING
TO LIKELY AS THE FRONT SWEEPS EAST INTO THE AFTERNOON HOURS. H850
WINDS AHEAD OF THE FRONT ARE BETWEEN 55-60 KNOTS IN THE WARM
SECTOR. DEWPOINTS WILL INCREASE INTO THE LOWER 50S UNDER DEEP
SOUTH SOUTHWEST FLOW...DESPITE OF AFTERNOON MIXING.
HOWEVER...PWATS LOOKS RATHER LOW BARELY OVER ONE INCH.
VERY WEAK LAYERED CAPE...BUT DEEP LAYERED SHEAR EXCEEDING 55
KNOTS...STORM RELATIVE HELICITY EXCEEDING 300 M2/S2...AND BOUNDARY
LAYER CONVERGENCE ALONG THE FRONT CALLS FOR A DYNAMIC ENVIRONMENT
CAPABLE TO PRODUCE STORMS. KEPT STORM MENTION WITH LIKELY POPS
DECREASING IN COVERAGE AS THE FRONT MOVE EAST THURSDAY AFTERNOON.
SEVERE STORMS ARE NOT ANTICIPATED AT THIS TIME...STRONG GUSTY FLOW
ARE WORTH TO BE MENTIONED IN THE HWO.
STRONG GUSTY WINDS CAN MIX DOWN TO SFC ALONG FRONTAL
CONVECTION...AND CAN BE POSSIBLE ALSO OVER THE HIGHER ELEVATIONS.
KEPT SFC FRONT EXITING EASTERN MOUNTAINS BY 21Z..IF NOT A LITTLE
SOONER. EXPECT DRY SLOT TO PRODUCE SOME BREAKS IN THE CLOUDS
MAINLY SOUTH AND CENTRAL SECTIONS OF OUR CWA.
THIS COLD FRONT...EXTENDS NORTHWEST AS A OCCLUDED FRONT INTO THE
PARENT DEEP LOW PRESSURE SYSTEM OVER THE GREAT LAKES. SOME
DIFFERENCES NOTED IN THE H5 LOW CENTER...WITH THE NAM SHOWING IT
OVER THE OH VALLEY...THE GFS OVER THE GREAT LAKES...AS WELL AS THE
ECMWF AND CMC. THEREFORE...PER CONSENSUS...EXPECT LOW PRESSURE
TO APPROACH OUR AREA FROM THE NORTHWEST...BUT LIFT NORTHEAST
FRIDAY NIGHT. RAP AROUND MOISTURE BEHIND THE DEPARTURE LOW WILL
BRING CHANCES OF STRATIFORM RAIN ACROSS THE NORTHERN PORTIONS OF
THE AREA FRIDAY...INTO EARLY SATURDAY MORNING...PER GFS/ECMWF/CMC
CONSENSUS.
KEPT WIND GUSTS 20-30 KNOTS DO TO CAA AND EFFICIENT MOMENTUM
TRANSFER AS SEEN IN INVERTED V FEATURE IN BUFKIT SOUNDING FRIDAY.
WENT A DEGREE OR TWO LOWER THAN MAV/MET GUIDANCE PER UNCERTAINTY
OF CLOUD COVER...GENERALLY UPPER 60S LOWLANDS...RANGING INTO THE
MID 50S HIGHEST ELEVATIONS...FOR THURSDAY. EXPECT A COOLER TREND
THURSDAY NIGHT AND FRIDAY UNDER CAA...AND CLOUD COVER.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
STILL SOME ISSUES WITH MODEL AGREEMENT IN THE LONG TERM PERIOD IN
TERMS OF TIMING AND PATH OF EXITING LOW PRESSURE. GFS IS STILL
FASTER AND FARTHER TO THE NORTH WITH THE UPPER LOW THAN THE ECMWF.
BUT REGARDLESS...A GRADUAL DRYING TREND IS EXPECTED TO BEGIN ON
SATURDAY AS THE UPPER LOW GRADUALLY PUSHES EAST...AND A RIDGE OF
HIGH PRESSURE GRADUALLY STARTS TO BUILD IN FOR THE BEGINNING OF NEXT
WEEK. DID START TO BUMP TEMPERATURES UP A BIT FROM PREVIOUS
FORECAST...AND DRY OUT FORECAST FOR LATE THIS WEEK/EARLY NEXT WEEK.
SOME ISSUES CONCERNING THE TIMING OF NEXT SYSTEM...PROGGED TO ENTER
CWA BY MID WEEK...BUT FOR NOW...MAINTAINED A DRY FORECAST INTO
PERIOD DUE TO UNCERTAINTY.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
12Z WEDNESDAY THRU 12Z THURSDAY...
PASSING HIGH CIRRUS PASSING OVERHEAD...PARTICULARLY OVER SE OHIO
WHERE SOME MIDLEVEL CLOUDS ALSO BEING OBSERVED. ALL SITES CURRENTLY
VFR EXCEPT EKN WHERE EXPECTED VLIFR VIS/LOW STRATUS WITH FREEZING
FOG HAS MATERIALIZED. THIS SHOULD BURN OFF BY 14Z-15Z...WITH VFR
CONDITIONS EXPECTED FOR THE REMAINDER OF THE VALID PERIOD AT ALL
SITES. INCREASING AND LOWERING CLOUDS HOWEVER CAN BE EXPECTED
ACROSS THE WEST NEAR THE END OF THE PERIOD AS A COLD FRONT WITH
SHOWERS APPROACHES. MUCH IF NOT ALL OF THE ASSOCIATED PRECIP
SHOULD MOVE IN AFTER 12Z THU. ALSO OF NOTE...LOW LEVEL WIND SHEAR
MAY BE REALIZED BTWN 06Z-12Z THU MORNING...ESPECIALLY FOR SOUTHERN
AND WESTERN SITES...AS A STRONG 50-60KT LOW LEVEL JET PUSHES INTO
THE AREA FROM THE WEST.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z THURSDAY...
FORECAST CONFIDENCE: HIGH.
ALTERNATE SCENARIOS: DISSIPATION OF FOG/LOW STRATUS MAY VARY SLIGHTLY.
TIMING OF LOWERING CIGS AND SHOWERS LATE IN THE PERIOD MAY VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
EDT 1HRLY 10 11 12 13 14 15 16 17 18 19 20 21
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY L H H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 12Z THURSDAY...
LOCALIZED IFR CONDITIONS WILL BE POSSIBLE PRIMARILY THURSDAY MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/50
NEAR TERM...50/26
SHORT TERM...ARJ
LONG TERM...SL
AVIATION...50
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
642 AM EDT WED OCT 17 2012
.SYNOPSIS...
HIGH PRESSURE SLIPS EAST WEDNESDAY. COLD FRONT BRINGS GOOD CHANCE
FOR SHOWERS THURSDAY INTO FRIDAY. THE PARENT DEEP LOW PRESSURE
SYSTEM APPROACHES FROM THE NORTHWEST FRIDAY NIGHT INTO SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
ZONAL FLOW WILL BECOME INCREASINGLY SOUTHWESTERLY TODAY IN ADVANCE
OF A CLOSED UPPER LOW DIGGING SOUTHEASTWARD ACROSS THE UPPER
MIDWEST. AN EMBEDDED S/W TROUGH IN THE MEAN FLOW WILL BRUSH BY THE
AREA TO THE NORTH/NORTHWEST THIS MORNING. NO PRECIP IS EXPECTED WITH
THIS FEATURE BUT WILL RESULT IN INCREASED CLOUD COVER...PARTICULARLY
DURING THE MORNING HOURS AND ACROSS THE SE OHIO ZONES. INHERITED MAX
TEMPS GENERALLY IN THE MID/UPPER 70S LOWLANDS LOOK GOOD WITH ONLY A
COUPLE MINOR TWEAKS.
WED EVENING AND OVERNIGHT THE UPPER LOW WILL BE CONTINUING TO
PROGRESS SE-WARD...ESSENTIALLY LOCATED ROUGHLY OVER SOUTHERN MN BY
12Z THU. RUN TO RUN NAM/GFS COMPS SHOW GENERAL CONSISTENCY WITH ITS
TRACK...BUT BOTH SHOW SLIGHT DECREASE IN STRENGTH. ATTENDANT SFC LOW
WILL BE ROUGHLY OVER WISCONSIN WITH THE COLD FRONT EXTENDING
SOUTHEASTWARD. STRONG FORCING FOR ASCENT MOVES OVER THE FORECAST
AREA AFTER 06Z ALONG WITH GOOD DYNAMICS...INCLUDING MIDLEVEL
DIFFLUENT FLOW...GOOD POTENTIAL VORT ADVECTION...AS WELL AS DECENT
LLVL WARM ADVECTION AND A STRONG 850MB JET LIFTING NE-WARD ACROSS
EASTERN KY PRIOR TO FRONT/S ARRIVAL. DESPITE ALL THIS...DRY LOW
LEVELS WILL BE IN PLACE...WITH GOOD LLVL MOISTURE ARRIVING POST-FRONT.
850MB AND 700MB FLOW WILL BE PARALLEL TO GENERALLY VEERED FROM THE
ORIENTATION OF THE SFC FRONT WHICH WOULD USUALLY BE A PRECURSOR FOR
A PRE-FRONTAL PRECIP REGIME. ALL THIS TO SAY THAT THE MAIN PRECIP
SHOULD BE ALONG AND POST-FRONTAL IN A RELATIVELY THIN BAND GENERATED
MAINLY BY FRONTO-G FORCING. BOTH THE LATEST NAM AND SREF DEPICT THE
SFC FRONT JUST ENTERING THE WESTERN KY ZONES AT 12Z...WITH THE GFS
JUST SLIGHTLY SLOWER. WITH THIS IN MIND...INHERITED POP GRIDS WHICH
BRING PRECIP INTO THE WESTERN KY ZONES AROUND 09Z WITH THE BULK OF
THE PRECIP ARRIVING NEAR AND AFTER 12Z THU STILL LOOK REASONABLE
WITH ONLY MINOR ADJUSTMENTS. FINALLY...WITH STRONG LLVL SOUTHWEST
FLOW AND WARM ADVECTION...CONTINUED PREV FCST OF GOING WELL ABOVE
GUIDANCE ON OVERNIGHT LOWS IN THE MID/UPPER 50S LOWLANDS.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
THE NAM/CMC/GFS/ECMWF ARE IN AGREEMENT WITH THE TIMING OF
CONVECTION ASSOCIATED WITH APPROACHING COLD FRONT OVER SOUTHEAST
OH BY 12Z THURSDAY. HOWEVER...THERE ARE INTENSITY DIFFERENCES IN
QPF FIELDS...AS WELL AS IN THE UPPER LEVEL SUPPORT. THE GFS HAS
STRONGER MID LEVEL FORCING ACROSS THE OH RIVER...WHILE THE NAM
WEAKENS ITS FORCING. NEVERTHELESS...BELIEVE IN PREVIOUS FORECAST
BRINGING HIGH CATEGORICAL POPS INTO SOUTHEAST OH BY 12Z...DECREASING
TO LIKELY AS THE FRONT SWEEPS EAST INTO THE AFTERNOON HOURS. H850
WINDS AHEAD OF THE FRONT ARE BETWEEN 55-60 KNOTS IN THE WARM
SECTOR. DEWPOINTS WILL INCREASE INTO THE LOWER 50S UNDER DEEP
SOUTH SOUTHWEST FLOW...DESPITE OF AFTERNOON MIXING.
HOWEVER...PWATS LOOKS RATHER LOW BARELY OVER ONE INCH.
VERY WEAK LAYERED CAPE...BUT DEEP LAYERED SHEAR EXCEEDING 55
KNOTS...STORM RELATIVE HELICITY EXCEEDING 300 M2/S2...AND BOUNDARY
LAYER CONVERGENCE ALONG THE FRONT CALLS FOR A DYNAMIC ENVIRONMENT
CAPABLE TO PRODUCE STORMS. KEPT STORM MENTION WITH LIKELY POPS
DECREASING IN COVERAGE AS THE FRONT MOVE EAST THURSDAY AFTERNOON.
SEVERE STORMS ARE NOT ANTICIPATED AT THIS TIME...STRONG GUSTY FLOW
ARE WORTH TO BE MENTIONED IN THE HWO.
STRONG GUSTY WINDS CAN MIX DOWN TO SFC ALONG FRONTAL
CONVECTION...AND CAN BE POSSIBLE ALSO OVER THE HIGHER ELEVATIONS.
KEPT SFC FRONT EXITING EASTERN MOUNTAINS BY 21Z..IF NOT A LITTLE
SOONER. EXPECT DRY SLOT TO PRODUCE SOME BREAKS IN THE CLOUDS
MAINLY SOUTH AND CENTRAL SECTIONS OF OUR CWA.
THIS COLD FRONT...EXTENDS NORTHWEST AS A OCCLUDED FRONT INTO THE
PARENT DEEP LOW PRESSURE SYSTEM OVER THE GREAT LAKES. SOME
DIFFERENCES NOTED IN THE H5 LOW CENTER...WITH THE NAM SHOWING IT
OVER THE OH VALLEY...THE GFS OVER THE GREAT LAKES...AS WELL AS THE
ECMWF AND CMC. THEREFORE...PER CONSENSUS...EXPECT LOW PRESSURE
TO APPROACH OUR AREA FROM THE NORTHWEST...BUT LIFT NORTHEAST
FRIDAY NIGHT. RAP AROUND MOISTURE BEHIND THE DEPARTURE LOW WILL
BRING CHANCES OF STRATIFORM RAIN ACROSS THE NORTHERN PORTIONS OF
THE AREA FRIDAY...INTO EARLY SATURDAY MORNING...PER GFS/ECMWF/CMC
CONSENSUS.
KEPT WIND GUSTS 20-30 KNOTS DO TO CAA AND EFFICIENT MOMENTUM
TRANSFER AS SEEN IN INVERTED V FEATURE IN BUFKIT SOUNDING FRIDAY.
WENT A DEGREE OR TWO LOWER THAN MAV/MET GUIDANCE PER UNCERTAINTY
OF CLOUD COVER...GENERALLY UPPER 60S LOWLANDS...RANGING INTO THE
MID 50S HIGHEST ELEVATIONS...FOR THURSDAY. EXPECT A COOLER TREND
THURSDAY NIGHT AND FRIDAY UNDER CAA...AND CLOUD COVER.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
STILL SOME ISSUES WITH MODEL AGREEMENT IN THE LONG TERM PERIOD IN
TERMS OF TIMING AND PATH OF EXITING LOW PRESSURE. GFS IS STILL
FASTER AND FARTHER TO THE NORTH WITH THE UPPER LOW THAN THE ECMWF.
BUT REGARDLESS...A GRADUAL DRYING TREND IS EXPECTED TO BEGIN ON
SATURDAY AS THE UPPER LOW GRADUALLY PUSHES EAST...AND A RIDGE OF
HIGH PRESSURE GRADUALLY STARTS TO BUILD IN FOR THE BEGINNING OF NEXT
WEEK. DID START TO BUMP TEMPERATURES UP A BIT FROM PREVIOUS
FORECAST...AND DRY OUT FORECAST FOR LATE THIS WEEK/EARLY NEXT WEEK.
SOME ISSUES CONCERNING THE TIMING OF NEXT SYSTEM...PROGGED TO ENTER
CWA BY MID WEEK...BUT FOR NOW...MAINTAINED A DRY FORECAST INTO
PERIOD DUE TO UNCERTAINTY.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
12Z WEDNESDAY THRU 12Z THURSDAY...
PASSING HIGH CIRRUS PASSING OVERHEAD...PARTICULARLY OVER SE OHIO
WHERE SOME MIDLEVEL CLOUDS ALSO BEING OBSERVED. ALL SITES CURRENTLY
VFR EXCEPT EKN WHERE EXPECTED VLIFR VIS/LOW STRATUS WITH FREEZING
FOG HAS MATERIALIZED. THIS SHOULD BURN OFF BY 14Z-15Z...WITH VFR
CONDITIONS EXPECTED FOR THE REMAINDER OF THE VALID PERIOD AT ALL
SITES. INCREASING AND LOWERING CLOUDS HOWEVER CAN BE EXPECTED
ACROSS THE WEST NEAR THE END OF THE PERIOD AS A COLD FRONT WITH
SHOWERS APPROACHES. MUCH IF NOT ALL OF THE ASSOCIATED PRECIP
SHOULD MOVE IN AFTER 12Z THU. ALSO OF NOTE...LOW LEVEL WIND SHEAR
MAY BE REALIZED BTWN 06Z-12Z THU MORNING...ESPECIALLY FOR SOUTHERN
AND WESTERN SITES...AS A STRONG 50-60KT LOW LEVEL JET PUSHES INTO
THE AREA FROM THE WEST.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z THURSDAY...
FORECAST CONFIDENCE: HIGH.
ALTERNATE SCENARIOS: DISSIPATION OF FOG/LOW STRATUS MAY VARY SLIGHTLY.
TIMING OF LOWERING CIGS AND SHOWERS LATE IN THE PERIOD MAY VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 11 12 13 14 15 16 17 18 19 20 21 22
EDT 1HRLY 07 08 09 10 11 12 13 14 15 16 17 18
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY L L L H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 12Z THURSDAY...
LOCALIZED IFR CONDITIONS WILL BE POSSIBLE PRIMARILY THURSDAY MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/50
NEAR TERM...50
SHORT TERM...ARJ
LONG TERM...SL
AVIATION...50
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
426 AM EDT WED OCT 17 2012
.SYNOPSIS...
HIGH PRESSURE SLIPS EAST WEDNESDAY. COLD FRONT BRINGS GOOD CHANCE
FOR SHOWERS THURSDAY INTO FRIDAY. THE PARENT DEEP LOW PRESSURE
SYSTEM APPROACHES FROM THE NORTHWEST FRIDAY NIGHT INTO SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
ZONAL FLOW WILL BECOME INCREASINGLY SOUTHWESTERLY TODAY IN ADVANCE
OF A CLOSED UPPER LOW DIGGING SOUTHEASTWARD ACROSS THE UPPER
MIDWEST. AN EMBEDDED S/W TROUGH IN THE MEAN FLOW WILL BRUSH BY THE
AREA TO THE NORTH/NORTHWEST THIS MORNING. NO PRECIP IS EXPECTED WITH
THIS FEATURE BUT WILL RESULT IN INCREASED CLOUD COVER...PARTICULARLY
DURING THE MORNING HOURS AND ACROSS THE SE OHIO ZONES. INHERITED MAX
TEMPS GENERALLY IN THE MID/UPPER 70S LOWLANDS LOOK GOOD WITH ONLY A
COUPLE MINOR TWEAKS.
WED EVENING AND OVERNIGHT THE UPPER LOW WILL BE CONTINUING TO
PROGRESS SE-WARD...ESSENTIALLY LOCATED ROUGHLY OVER SOUTHERN MN BY
12Z THU. RUN TO RUN NAM/GFS COMPS SHOW GENERAL CONSISTENCY WITH ITS
TRACK...BUT BOTH SHOW SLIGHT DECREASE IN STRENGTH. ATTENDANT SFC LOW
WILL BE ROUGHLY OVER WISCONSIN WITH THE COLD FRONT EXTENDING
SOUTHEASTWARD. STRONG FORCING FOR ASCENT MOVES OVER THE FORECAST
AREA AFTER 06Z ALONG WITH GOOD DYNAMICS...INCLUDING MIDLEVEL
DIFFLUENT FLOW...GOOD POTENTIAL VORT ADVECTION...AS WELL AS DECENT
LLVL WARM ADVECTION AND A STRONG 850MB JET LIFTING NE-WARD ACROSS
EASTERN KY PRIOR TO FRONT/S ARRIVAL. DESPITE ALL THIS...DRY LOW
LEVELS WILL BE IN PLACE...WITH GOOD LLVL MOISTURE ARRIVING POST-FRONT.
850MB AND 700MB FLOW WILL BE PARALLEL TO GENERALLY VEERED FROM THE
ORIENTATION OF THE SFC FRONT WHICH WOULD USUALLY BE A PRECURSOR FOR
A PRE-FRONTAL PRECIP REGIME. ALL THIS TO SAY THAT THE MAIN PRECIP
SHOULD BE ALONG AND POST-FRONTAL IN A RELATIVELY THIN BAND GENERATED
MAINLY BY FRONTO-G FORCING. BOTH THE LATEST NAM AND SREF DEPICT THE
SFC FRONT JUST ENTERING THE WESTERN KY ZONES AT 12Z...WITH THE GFS
JUST SLIGHTLY SLOWER. WITH THIS IN MIND...INHERITED POP GRIDS WHICH
BRING PRECIP INTO THE WESTERN KY ZONES AROUND 09Z WITH THE BULK OF
THE PRECIP ARRIVING NEAR AND AFTER 12Z THU STILL LOOK REASONABLE
WITH ONLY MINOR ADJUSTMENTS. FINALLY...WITH STRONG LLVL SOUTHWEST
FLOW AND WARM ADVECTION...CONTINUED PREV FCST OF GOING WELL ABOVE
GUIDANCE ON OVERNIGHT LOWS IN THE MID/UPPER 50S LOWLANDS.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
THE NAM/CMC/GFS/ECMWF ARE IN AGREEMENT WITH THE TIMING OF
CONVECTION ASSOCIATED WITH APPROACHING COLD FRONT OVER SOUTHEAST
OH BY 12Z THURSDAY. HOWEVER...THERE ARE INTENSITY DIFFERENCES IN
QPF FIELDS...AS WELL AS IN THE UPPER LEVEL SUPPORT. THE GFS HAS
STRONGER MID LEVEL FORCING ACROSS THE OH RIVER...WHILE THE NAM
WEAKENS ITS FORCING. NEVERTHELESS...BELIEVE IN PREVIOUS FORECAST
BRINGING HIGH CATEGORICAL POPS INTO SOUTHEAST OH BY 12Z...DECREASING
TO LIKELY AS THE FRONT SWEEPS EAST INTO THE AFTERNOON HOURS. H850
WINDS AHEAD OF THE FRONT ARE BETWEEN 55-60 KNOTS IN THE WARM
SECTOR. DEWPOINTS WILL INCREASE INTO THE LOWER 50S UNDER DEEP
SOUTH SOUTHWEST FLOW...DESPITE OF AFTERNOON MIXING.
HOWEVER...PWATS LOOKS RATHER LOW BARELY OVER ONE INCH.
VERY WEAK LAYERED CAPE...BUT DEEP LAYERED SHEAR EXCEEDING 55
KNOTS...STORM RELATIVE HELICITY EXCEEDING 300 M2/S2...AND BOUNDARY
LAYER CONVERGENCE ALONG THE FRONT CALLS FOR A DYNAMIC ENVIRONMENT
CAPABLE TO PRODUCE STORMS. KEPT STORM MENTION WITH LIKELY POPS
DECREASING IN COVERAGE AS THE FRONT MOVE EAST THURSDAY AFTERNOON.
SEVERE STORMS ARE NOT ANTICIPATED AT THIS TIME...STRONG GUSTY FLOW
ARE WORTH TO BE MENTIONED IN THE HWO.
STRONG GUSTY WINDS CAN MIX DOWN TO SFC ALONG FRONTAL
CONVECTION...AND CAN BE POSSIBLE ALSO OVER THE HIGHER ELEVATIONS.
KEPT SFC FRONT EXITING EASTERN MOUNTAINS BY 21Z..IF NOT A LITTLE
SOONER. EXPECT DRY SLOT TO PRODUCE SOME BREAKS IN THE CLOUDS
MAINLY SOUTH AND CENTRAL SECTIONS OF OUR CWA.
THIS COLD FRONT...EXTENDS NORTHWEST AS A OCCLUDED FRONT INTO THE
PARENT DEEP LOW PRESSURE SYSTEM OVER THE GREAT LAKES. SOME
DIFFERENCES NOTED IN THE H5 LOW CENTER...WITH THE NAM SHOWING IT
OVER THE OH VALLEY...THE GFS OVER THE GREAT LAKES...AS WELL AS THE
ECMWF AND CMC. THEREFORE...PER CONSENSUS...EXPECT LOW PRESSURE
TO APPROACH OUR AREA FROM THE NORTHWEST...BUT LIFT NORTHEAST
FRIDAY NIGHT. RAP AROUND MOISTURE BEHIND THE DEPARTURE LOW WILL
BRING CHANCES OF STRATIFORM RAIN ACROSS THE NORTHERN PORTIONS OF
THE AREA FRIDAY...INTO EARLY SATURDAY MORNING...PER GFS/ECMWF/CMC
CONSENSUS.
KEPT WIND GUSTS 20-30 KNOTS DO TO CAA AND EFFICIENT MOMENTUM
TRANSFER AS SEEN IN INVERTED V FEATURE IN BUFKIT SOUNDING FRIDAY.
WENT A DEGREE OR TWO LOWER THAN MAV/MET GUIDANCE PER UNCERTAINTY
OF CLOUD COVER...GENERALLY UPPER 60S LOWLANDS...RANGING INTO THE
MID 50S HIGHEST ELEVATIONS...FOR THURSDAY. EXPECT A COOLER TREND
THURSDAY NIGHT AND FRIDAY UNDER CAA...AND CLOUD COVER.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
STILL SOME ISSUES WITH MODEL AGREEMENT IN THE LONG TERM PERIOD IN
TERMS OF TIMING AND PATH OF EXITING LOW PRESSURE. GFS IS STILL
FASTER AND FARTHER TO THE NORTH WITH THE UPPER LOW THAN THE ECMWF.
BUT REGARDLESS...A GRADUAL DRYING TREND IS EXPECTED TO BEGIN ON
SATURDAY AS THE UPPER LOW GRADUALLY PUSHES EAST...AND A RIDGE OF
HIGH PRESSURE GRADUALLY STARTS TO BUILD IN FOR THE BEGINNING OF NEXT
WEEK. DID START TO BUMP TEMPERATURES UP A BIT FROM PREVIOUS
FORECAST...AND DRY OUT FORECAST FOR LATE THIS WEEK/EARLY NEXT WEEK.
SOME ISSUES CONCERNING THE TIMING OF NEXT SYSTEM...PROGGED TO ENTER
CWA BY MID WEEK...BUT FOR NOW...MAINTAINED A DRY FORECAST INTO
PERIOD DUE TO UNCERTAINTY.
&&
.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
06Z WEDNESDAY THRU 06Z THURSDAY...
HIGH CIRRUS CURRENTLY OVERSPREADING THE AREA. STILL EXPECTING LIFR
FOG IN SHELTERED MOUNTAIN RIVER VALLEYS 08Z TO 12Z INCLUDING EKN.
OTHERWISE...VFR CONDITIONS WITH HIGH AND SOME MID-LEVEL CLOUDS
OVER THE AREA WITH SOUTHERLY SFC WINDS THROUGHOUT THE PERIOD.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z THURSDAY...
FORECAST CONFIDENCE: HIGH.
ALTERNATE SCENARIOS: FOG AT EKN MAY NOT BE AS DENSE AF FORECAST.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE WED 10/17/12
UTC 1HRLY 08 09 10 11 12 13 14 15 16 17 18 19
EDT 1HRLY 04 05 06 07 08 09 10 11 12 13 14 15
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY L L L L L L H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 06Z THURSDAY...
LOCALIZED IFR CONDITIONS WILL BE POSSIBLE PRIMARILY THURSDAY MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/50
NEAR TERM...50
SHORT TERM...ARJ
LONG TERM...SL
AVIATION...50
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1045 PM EDT THU OCT 18 2012
.SYNOPSIS...
A DEEP LOW PRESSURE SYSTEM WILL LINGER TO OUR NORTHWEST AS A COLD
FRONT MOVES OFF THE SOUTH CAROLINA COAST ON FRIDAY. DRY HIGH PRESSURE
WILL THEN BUILD IN BEHIND THE FRONT OVER THE WEEKEND AND REMAIN IN
PLACE WELL INTO NEXT WEEK.
&&
.NEAR TERM /THROUGH FRIDAY/...
EVENING UPDATE...THE RADAR STILL SHOWS A STORM BEING MAINTAINED
ACROSS RABUN COUNTY HEADING INTO NC JUST AHEAD OF THE COLD FRONT.
THIS STORM COULD BECOME FAIRLY STRONG...BUT DONT ANTICIPATE SEVERE
LEVELS. THE REMNANT STORM ACROSS THE NC PIEDMONT IS JUST NOW EXITING
THE CWFA. SOME LINGERING SMALL SCALE -SHRA MAY CONTINUE
OVERNIGHT...YET ANYTHING STRONG OR LONG LIVED IS NOT LIKELY. THE
MAIN CONCERN OVERNIGHT WILL BE THE THREAT OF FG AND JUST HOW DENSE
IT MAY BECOME. SOME AREAS ARE EXPERIENCING DENSE FG CURRENTLY AROUND
KAND AND KPJ...BUT THINK THE MAJORITY OF AREAS WILL SEE PATCHY
MODERATE FG. THIS SITUATION WILL NEED TO BE MONITORED OVERNIGHT
HOWEVER AS THE ERN ZONES HAVE RECEIVED A MODEST AMOUNT OF RAINFALL
IN THE PAST 6 HRS...WINDS HAVE BECOME CALM AND SKIES ARE BECOMING
CLEARER.
THIS AFTERNOON...STRATUS OVER THE MOUNTAINS AND HIGHER UPSTATE
TERRAIN SHOULD GRADUALLY MIX OUT FROM THE EDGES INWARD. SCATTERED
CUMULUS WILL LIKELY FILL IN THE AREAS SHORTLY AFTER CLEARING OCCURS.
SURFACE FRONT STILL ACROSS THE MID TN VALLEY NOW PRODUCING SOME
LIGHT PRECIP WITH A FEW SCATTERED CONVECTIVE CELLS OVER NE TN. THIS
IS VERY SIMILAR TO DEPICTION ON 15Z HRRR RUN. THE NE TN ACTIVITY
AFFECTS MAINLY THE NRN PORTION OF THE CWA IN THAT DEPICTION WHILE
THE LIGHTER MORE STRATIFORM ACTIVITY DOES NOT MAKE IT ACROSS THE
MOUNTAINS. THIS SUPPORTS EARLIER DECISION TO KEEP CHANCE POPS IN THE
NRN CWA NEAR THE SUPPORT FROM THE UPPER TROUGH. IN THE FAR EASTERN
CWA WHERE SKIES CLEARED EARLIER AND THERE HAS BEEN MORE TIME TO
DESTABILIZE...PROG SOUNDINGS SHOW 500 J OR SO OF CAPE WHICH
WARRANTED A CHC MENTION THERE. DEPENDING ON HOW SOON THE STRATUS
CLEAR OUT IN THE WEST AND DESTABILIZATION OCCURS...SUBSEQUENT
REVISIONS MAY NEED TO BE MADE TO INCREASE POPS IN THAT AREA.
FRONT SHOULD BE EAST OF THE CWA BY MID EVENING AND CLEAR SKIES
SHOULD PROGRESS EASTWARD. TEMPS SHOULD BE NEAR NORMAL AS WINDS WILL
KEEP THE AREA FROM EXPERIENCING PRIME RADIATIONAL COOLING AND ALSO
LIKELY KEEPING FOG AT BAY. SFC DEWPOINTS SHOULD GRADUALLY DROP
OVERNIGHT WHICH WILL INHIBIT FOG FORMATION AS WELL.
CLEAR SKIES AND COOL AIR ALOFT WILL CAUSE DEEP MIXING ON FRIDAY.
THIS WILL ALLOW STRONG WINDS TO MIX DOWN TO THE SURFACE...GENERALLY
IN THE 20 TO 25 KT RANGE...BUT SOMEWHAT HIGHER OVER THE MOUNTAINS.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY/...
AS OF 200 PM THURSDAY...A DEEP UPPER LOW OVER THE GREAT LAKES WILL
BEGIN TO SLOWLY SHIFT NORTHEAST AND REACH NORTHERN NEW ENGLAND ON
SUNDAY. MODEL GUIDANCE KEEPS THE DEEPER MOISTURE ASSOCIATED WITH THE
LARGE LOW TO THE NORTH OF THE AREA. HENCE...EXCEPT FOR SOME CLOUDS
ACROSS THE NC MOUNTAINS FRI NIGHT...GENERALLY CLEAR CONDITIONS ARE
ANTICIPATED SAT THROUGH SUN AS SURFACE HIGH PRESSURE GRADUALLY
BUILDS EAST OVER THE REGION.
MOS GUIDANCE IS RATHER CHILLY OVER THE MOUNTAINS FOR BOTH FRI NIGHT
AND SAT NIGHT WITH GENERALLY MID 30S FOR LOWS. THERE MAY BE ENOUGH
WIND/CLOUDS FRI NIGHT TO PRECLUDE WIDESPREAD FROST...BUT CONDITIONS
SAT NIGHT WILL FAVOR WIDESPREAD FROST AS HIGH PRESSURE SETTLES OVER
THE AREA. MAX TEMPS WILL BE NEAR CLIMO PER A MOS BLEND.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
AS OF 215 PM THURSDAY...LOOKS LIKE THE MEDIUM RANGE WILL BE QUIET
WITH TEMPS ABOVE CLIMO. ALL THE MEDIUM RANGE MODELS BUILD AN UPPER
RIDGE OVER THE EASTERN U.S. THE FIRST PART OF THE NEW WORK WEEK AND
IT THEN HOLDS SWAY INTO THE END OF THE WEEK. A BACKDOOR COLD FRONT
MAY APPROACH THU PER HPC/GFS GUIDANCE...BUT THE 00Z ECM KEEPS IT WELL NORTH
OF THE FORECAST AREA. THEREFORE...EXPECT SURFACE HIGH PRESSURE TO
PROVIDE MOSTLY CLEAR CONDITIONS THROUGH THE PERIOD WITH THE
AFOREMENTIONED SEASONALLY WARM CONDITIONS.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
AT KCLT...THE MAIN CONCERN OVER THE NEXT FEW HOURS WILL BE THE
EVOLUTION OF THE CONVECTIVE LINE JUST TO THE WEST OF THE TERMINAL.
DONT SEE A SIGFNT TSTM THREAT AS THIS AREA HAS REMAINED RATHER
STABLE THROUGHOUT THE DAY...BUT -SHRA SHOULD MOVE IN AROUND 00Z AND
SLOWLY MOVE EAST OF THE AIRFIELD BY 03Z. THIS HAS BEEN INCLUDED IN A
TEMPO ALONG WITH AN MVFR CIG AND VRB LOW END GUSTS. AFTER THE LINE
PUSHES EAST...DONT ANTICIPATE ANY FLIGHT RESTRICTIONS THROUGH THE
REMAINDER OF THE TAF PERIOD. HOWEVER...ONE THING THAT WILL BE
WATCHED WILL BE POSSIBLE FG DEVELOPMENT BY DAYBREAK. THIS WILL
DEPEND GREATLY ON THE AMOUNT OF SOIL SATURATION EXPERIENCED OVER THE
NEXT COUPLE OF HOURS. SW WIND GUST AROUND 20 KTS ARE PROBABLE IN THE
EARLY AFTERNOON.
ELSEWHERE...THE WEAK COLD FRONT REMAINS ACROSS THE MTNS AND IT IS
SLOWLY DISSIPATING ATTM. IR IMAGERY REMAINS UNIMPRESSIVE AND DONT
FORESEE ANY CIG ISSUES AT KAVL NOR KHKY DURING THE OVERNIGHT. WITH
LITTLE TO RAINFALL ACROSS THE TAF SITES...THE EARLY MORNING FG
THREAT REMAINS LOW...WITH KHKY HAVING A BETTER CHANCE. YET THERE IS
NOT ENOUGH CONFIDENCE TO INCLUDE IN THE TAF ATTM. EXPECT VFR AT ALL
OTHER TAF SITE OVERNIGHT...AND CONTINUED VFR CONDS THROUGH THE DAY
FRI. DEVELOPING WIND GUSTS AROUND 20K IS PROBABLE OUTSIDE THE
MTNS.
OUTLOOK...EXPECT VFR CONDITIONS TO CONTINUE THROUGH THE WEEKEND. THE
EXCEPTION WILL BE EARLY MORNING MOUNTAIN VALLEY FOG DURING THAT
TIMEFRAME. WINDS MAY GUST TO 20 KT OR MORE AT TIMES OVER THE REGION
FRIDAY AFTERNOON.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.FIRE WEATHER...
MAXIMUM TEMPERATURES IN THE 60S ACROSS THE MTNS AND 70S FOOTHILLS
AND PIEDMONT ON FRIDAY WILL COMBINE WITH DRIER DEW POINTS ACROSS THE
REGION TO PUSH AFTERNOON RH VALUES DOWN INTO THE 25 TO 30 PERCENT
RANGE FRI AFTN. IN ADDITION...BREEZY SW WINDS ARE EXPECTED THROUGH
THE DAY WITH OCCASIONAL GUSTS IN THE 25 TO 30 KT RANGE. DEPENDING
UPON HOW MUCH RAIN FALLS AHEAD OF THE FRONT PASSING THIS
AFTN/EVENING...FUELS COULD BE DRY ENOUGH TO CREATE HEIGHTENED FIRE
DANGER IN SOME AREAS FRI AFTN. RAIN CHANCES ARE BEST OVER THE NRN
MOUNTAINS AND ERN PIEDMONT. THIS WILL NEED TO BE MONITORED CLOSELY
THROUGH THU.
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...PAT
NEAR TERM...SBK/WIMBERLEY
SHORT TERM...LG
LONG TERM...LG
AVIATION...SBK
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1003 PM EDT THU OCT 18 2012
.SYNOPSIS...
A DEEP LOW PRESSURE SYSTEM WILL LINGER TO OUR NORTHWEST AS A COLD
FRONT MOVES OFF THE SOUTH CAROLINA COAST ON FRIDAY. DRY HIGH PRESSURE
WILL THEN BUILD IN BEHIND THE FRONT OVER THE WEEKEND AND REMAIN IN
PLACE WELL INTO NEXT WEEK.
&&
.NEAR TERM /THROUGH FRIDAY/...
0200 UTC UPDATE...CURRENT WEAK CONVECTION IS NOW LIMITED TO THE I-77
CORRIDOR JUST NORTH OF KCLT. RADAR TRENDS HAVE THIS STORM
WEAKENING...AND DONT EXPECT A MAJOR RESURGENCE OF UPDRAFTS AS THE
STORM MOVES INTO AN AREA OF RELATIVELY STABLE AIR. NOTICED THE DUAL
POL DID WELL IN IDENTIFYING ONLY RAIN WITHIN THE STORM AS IT PASSED
OVER THE AIRPORT...CC AROUND 1 AND ZDR AT 3. WITH THE DECENT
RAINFALL THE CONCERN FOR OVERNIGHT FG DEVELOPMENT HAS INCREASED AND
WILL PROBABLY INCLUDE PATCHY FG IN THE GRIDS WITH THE EVENING
UPDATE...MAINLY ACROSS THE I/85 CORRIDOR...NC FHILLS AND AREAS
EAST.
0000 UTC UPDATE...MADE SOME CHANGES TO POPS TO ACCOUNT FOR
DEVELOPING PREFRONTAL LINE. SMALL SCALE AND RELATIVELY WEAK QLCS
DEVELOPMENT IS NOT OUT OF THE QUESTION AS SHEAR LEVELS ARE RATHER
HIGH AND BULK SHEAR REMAINS OVER 60 KTS. HOWEVER...LOW LEVELS OF
INSTABILITY...ABOUT 250 J/KG SBCAPE...AND LOW MLVL LAPSE RATES
WILL BE LIMITING FACTORS OVER THE NEXT COUPLE OF HRS.
2100 UTC UPDATE...NO MAJOR CHANGES NEEDED TO THE FCST. SKY COVER
WILL BE TWEAKED TO ACCOUNT FOR STCU DISSIPATING AND REDEVELOPING
WHILE GENERALLY SHIFTING EAST. POPS WILL BE LEFT AS IS WITH LOW END
CHANCES ACROSS THE FARTHER NW ZONES. RADAR RETURNS AND THE LATEST
HRRR SUPPORT A LOW MENTION OVER THE NEXT FEW HRS...ESP ACROSS THE
ERN MOST NC COUNTIES.
THIS AFTERNOON...STRATUS OVER THE MOUNTAINS AND HIGHER UPSTATE
TERRAIN SHOULD GRADUALLY MIX OUT FROM THE EDGES INWARD. SCATTERED
CUMULUS WILL LIKELY FILL IN THE AREAS SHORTLY AFTER CLEARING OCCURS.
SURFACE FRONT STILL ACROSS THE MID TN VALLEY NOW PRODUCING SOME
LIGHT PRECIP WITH A FEW SCATTERED CONVECTIVE CELLS OVER NE TN. THIS
IS VERY SIMILAR TO DEPICTION ON 15Z HRRR RUN. THE NE TN ACTIVITY
AFFECTS MAINLY THE NRN PORTION OF THE CWA IN THAT DEPICTION WHILE
THE LIGHTER MORE STRATIFORM ACTIVITY DOES NOT MAKE IT ACROSS THE
MOUNTAINS. THIS SUPPORTS EARLIER DECISION TO KEEP CHANCE POPS IN THE
NRN CWA NEAR THE SUPPORT FROM THE UPPER TROUGH. IN THE FAR EASTERN
CWA WHERE SKIES CLEARED EARLIER AND THERE HAS BEEN MORE TIME TO
DESTABILIZE...PROG SOUNDINGS SHOW 500 J OR SO OF CAPE WHICH
WARRANTED A CHC MENTION THERE. DEPENDING ON HOW SOON THE STRATUS
CLEAR OUT IN THE WEST AND DESTABILIZATION OCCURS...SUBSEQUENT
REVISIONS MAY NEED TO BE MADE TO INCREASE POPS IN THAT AREA.
FRONT SHOULD BE EAST OF THE CWA BY MID EVENING AND CLEAR SKIES
SHOULD PROGRESS EASTWARD. TEMPS SHOULD BE NEAR NORMAL AS WINDS WILL
KEEP THE AREA FROM EXPERIENCING PRIME RADIATIONAL COOLING AND ALSO
LIKELY KEEPING FOG AT BAY. SFC DEWPOINTS SHOULD GRADUALLY DROP
OVERNIGHT WHICH WILL INHIBIT FOG FORMATION AS WELL.
CLEAR SKIES AND COOL AIR ALOFT WILL CAUSE DEEP MIXING ON FRIDAY.
THIS WILL ALLOW STRONG WINDS TO MIX DOWN TO THE SURFACE...GENERALLY
IN THE 20 TO 25 KT RANGE...BUT SOMEWHAT HIGHER OVER THE MOUNTAINS.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY/...
AS OF 200 PM THURSDAY...A DEEP UPPER LOW OVER THE GREAT LAKES WILL
BEGIN TO SLOWLY SHIFT NORTHEAST AND REACH NORTHERN NEW ENGLAND ON
SUNDAY. MODEL GUIDANCE KEEPS THE DEEPER MOISTURE ASSOCIATED WITH THE
LARGE LOW TO THE NORTH OF THE AREA. HENCE...EXCEPT FOR SOME CLOUDS
ACROSS THE NC MOUNTAINS FRI NIGHT...GENERALLY CLEAR CONDITIONS ARE
ANTICIPATED SAT THROUGH SUN AS SURFACE HIGH PRESSURE GRADUALLY
BUILDS EAST OVER THE REGION.
MOS GUIDANCE IS RATHER CHILLY OVER THE MOUNTAINS FOR BOTH FRI NIGHT
AND SAT NIGHT WITH GENERALLY MID 30S FOR LOWS. THERE MAY BE ENOUGH
WIND/CLOUDS FRI NIGHT TO PRECLUDE WIDESPREAD FROST...BUT CONDITIONS
SAT NIGHT WILL FAVOR WIDESPREAD FROST AS HIGH PRESSURE SETTLES OVER
THE AREA. MAX TEMPS WILL BE NEAR CLIMO PER A MOS BLEND.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
AS OF 215 PM THURSDAY...LOOKS LIKE THE MEDIUM RANGE WILL BE QUIET
WITH TEMPS ABOVE CLIMO. ALL THE MEDIUM RANGE MODELS BUILD AN UPPER
RIDGE OVER THE EASTERN U.S. THE FIRST PART OF THE NEW WORK WEEK AND
IT THEN HOLDS SWAY INTO THE END OF THE WEEK. A BACKDOOR COLD FRONT
MAY APPROACH THU PER HPC/GFS GUIDANCE...BUT THE 00Z ECM KEEPS IT WELL NORTH
OF THE FORECAST AREA. THEREFORE...EXPECT SURFACE HIGH PRESSURE TO
PROVIDE MOSTLY CLEAR CONDITIONS THROUGH THE PERIOD WITH THE
AFOREMENTIONED SEASONALLY WARM CONDITIONS.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
AT KCLT...THE MAIN CONCERN OVER THE NEXT FEW HOURS WILL BE THE
EVOLUTION OF THE CONVECTIVE LINE JUST TO THE WEST OF THE TERMINAL.
DONT SEE A SIGFNT TSTM THREAT AS THIS AREA HAS REMAINED RATHER
STABLE THROUGHOUT THE DAY...BUT -SHRA SHOULD MOVE IN AROUND 00Z AND
SLOWLY MOVE EAST OF THE AIRFIELD BY 03Z. THIS HAS BEEN INCLUDED IN A
TEMPO ALONG WITH AN MVFR CIG AND VRB LOW END GUSTS. AFTER THE LINE
PUSHES EAST...DONT ANTICIPATE ANY FLIGHT RESTRICTIONS THROUGH THE
REMAINDER OF THE TAF PERIOD. HOWEVER...ONE THING THAT WILL BE
WATCHED WILL BE POSSIBLE FG DEVELOPMENT BY DAYBREAK. THIS WILL
DEPEND GREATLY ON THE AMOUNT OF SOIL SATURATION EXPERIENCED OVER THE
NEXT COUPLE OF HOURS. SW WIND GUST AROUND 20 KTS ARE PROBABLE IN THE
EARLY AFTERNOON.
ELSEWHERE...THE WEAK COLD FRONT REMAINS ACROSS THE MTNS AND IT IS
SLOWLY DISSIPATING ATTM. IR IMAGERY REMAINS UNIMPRESSIVE AND DONT
FORESEE ANY CIG ISSUES AT KAVL NOR KHKY DURING THE OVERNIGHT. WITH
LITTLE TO RAINFALL ACROSS THE TAF SITES...THE EARLY MORNING FG
THREAT REMAINS LOW...WITH KHKY HAVING A BETTER CHANCE. YET THERE IS
NOT ENOUGH CONFIDENCE TO INCLUDE IN THE TAF ATTM. EXPECT VFR AT ALL
OTHER TAF SITE OVERNIGHT...AND CONTINUED VFR CONDS THROUGH THE DAY
FRI. DEVELOPING WIND GUSTS AROUND 20K IS PROBABLE OUTSIDE THE
MTNS.
OUTLOOK...EXPECT VFR CONDITIONS TO CONTINUE THROUGH THE WEEKEND. THE
EXCEPTION WILL BE EARLY MORNING MOUNTAIN VALLEY FOG DURING THAT
TIMEFRAME. WINDS MAY GUST TO 20 KT OR MORE AT TIMES OVER THE REGION
FRIDAY AFTERNOON.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.FIRE WEATHER...
MAXIMUM TEMPERATURES IN THE 60S ACROSS THE MTNS AND 70S FOOTHILLS
AND PIEDMONT ON FRIDAY WILL COMBINE WITH DRIER DEW POINTS ACROSS THE
REGION TO PUSH AFTERNOON RH VALUES DOWN INTO THE 25 TO 30 PERCENT
RANGE FRI AFTN. IN ADDITION...BREEZY SW WINDS ARE EXPECTED THROUGH
THE DAY WITH OCCASIONAL GUSTS IN THE 25 TO 30 KT RANGE. DEPENDING
UPON HOW MUCH RAIN FALLS AHEAD OF THE FRONT PASSING THIS
AFTN/EVENING...FUELS COULD BE DRY ENOUGH TO CREATE HEIGHTENED FIRE
DANGER IN SOME AREAS FRI AFTN. RAIN CHANCES ARE BEST OVER THE NRN
MOUNTAINS AND ERN PIEDMONT. THIS WILL NEED TO BE MONITORED CLOSELY
THROUGH THU.
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...PAT
NEAR TERM...SBK/WIMBERLEY
SHORT TERM...LG
LONG TERM...LG
AVIATION...SBK
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
601 PM CDT WED OCT 17 2012
.DISCUSSION... /ISSUED 234 PM CDT WED OCT 17 2012/
CURRENT CONDITIONS ARE FOR NOW QUITE TRANQUIL ACROSS THE MIDSOUTH
WITH DEWPOINTS SLOWLY RISING ON STRONG SOUTHERLY BREEZES.
TEMPERATURES WERE IN THE 70S WITH SUNNY TO MOSTLY SUNNY SKIES.
LATEST COLD FRONT LOCATION WAS ELONGATED FROM SOUTHWEST MISSOURI
TO JUST EAST OF DALLAS TEXAS WITH CONVECTION INITIATION JUST WEST
OF SPRINGFIELD. LATEST 18Z LZK SOUNDING SHOWING A STOUT CAP OF 5C
AT 810MB...JUST ABOVE THE STRATUS DECK. CHANCES ARE THAT IT WILL
BE LATER THIS AFTERNOON FOR CONVECTION INITIATION. WILL BE
INTERESTING TO ALSO SEE AND COMPARE THIS SOUNDING TO A 19Z
RESEARCH SOUNDING LAUNCH IN EASTERN ARKANSAS WHERE SKIES WERE
MOSTLY SUNNY.
FOR TONIGHT...SEVERE WEATHER IS STILL LIKELY AS BOTH A STRONG
SHORTWAVE OVER THE CENTRAL PLAINS AND ASSOCIATED COLD FRONT SWING
THROUGH THE MISSISSIPPI VALLEY. 12Z MODEL RUNS ARE IN VERY GOOD
AGREEMENT THAT THE BRUNT OF PRECIPITATION AND SEVERE WEATHER WILL
OCCUR BETWEEN 23-06Z...WITH A HALF TO PERHAPS ONE HALF INCHES OF
TOTAL RAINFALL. AFTER SCANNING SPC`S HHR MODEL... CONVECTION WILL
REMAIN ALONG THE COLD FRONT IN NORTHWEST ARKANSAS AND SOUTHERN
MISSOURI THROUGH THE AFTERNOON HOURS...WITH A PREFRONTAL TROUGH
DEVELOPING AND SPARKING OFF CONVECTION ALONG CROWLEY`S RIDGE BY 6PM.
WIDSPREAD STRATUS CLOUD COVER OVER WESTERN AND CENTRAL ARKANSAS MAY
BE THE REASON FOR THE GREATER FOCUS TO SHIFT TO THE PRE-FRONTAL
TROUGH. BOTH BOUNDARIES ARE EXPECTED TO COMPLETELY MERGE ALONG THE
TENNESSEE RIVER BY MIDNIGHT. STRAIGHT-LINE WINDS WITH STORMS REMAINS
THE GREATEST SEVERE THREAT AS STORM/LINE SPEEDS ARE EXPECTED TO
EXCEED 50 MPH. MOST LOCATIONS WILL SEE DEWPOINTS CLIMB INTO THE
UPPER 50S AND LOW 60S AHEAD OF THE FRONT...WITH MID AND UPPER 60S
MAKING THERE WAY INTO THE SOUTHWEST DELTA COUNTIES. STILL FEEL THAT
THIS LOCATION...THAT IS SOUTH OF I-40 AND WEST OF I-55...WILL HAVE
THE BEST CHANCE FOR A TORNADIC STORM BEFORE 02Z...AND TO A LESSER
DEGREE FURTHER NORTH AND EAST. BY 02Z STORMS WILL HAVE CROSSED INTO
WEST TENNESSEE AND INTO NORTH CENTRAL MISSISSIPPI...QUICKLY EVOLVING
INTO ONE LONG LINE OF INDIVIDUAL BOWING SEGMENTS. THIS BOUNDARY
MERGER/TRANSITION IS IN RESPONSE TO A 80KT 500MB JET CROSSING
ARKANSAS. THUS A BETTER CHANCE FOR WIND DAMAGE WILL EXIST DURING THE
MID TO LATE EVENING HOURS. MODELS INDICATE THAT CONVECTION WILL EXIT
THE MIDSOUTH BY 1AM WITH SURFACE WINDS VEERING MORE WEST
SOUTHWESTERLY. LOWS WILL FALL INTO THE UPPER 40S OVER THE NORTHWEST
COUNTIES WHERE CLEARER SKIES WILL EXIST BEFORE SUNRISE...50S WILL BE
SEEN ELSEWHERE.
THURSDAY THROUGH SATURDAY...A STRONG WEST TO NORTHWEST UPPER FLOW
WILL DOMINATE THE REGION AS A CLOSED UPPER LOW PIVOTS THROUGH THE
SOUTHERN GREAT LAKES. CLOSER TO THE SURFACE HIGH PRESSURE WILL
BUILD EASTWARD FROM THE PLAIN STATES. WEST SOUTHWESTERLY SURFACE
WINDS WILL BECOME GUSTY AGAIN TOMORROW...SO THE NEED FOR ANOTHER
WIND ADVISORY WILL NEED TO BE ACCESSED BY THE NIGHTCREW. WEAK CAA
WILL CONTINUE ON FRIDAY AND SATURDAY AS WINDS SHIFT MORE
NORTHWESTERLY. NONE-THE-LESS THE BEGINNING OF THE WEEKEND WILL BE
NICE.
SUNDAY AND MONDAY...A QUICK WARMING TREND IS ANTICIPATED AS THE
LOW LEVEL FLOW TURNS SOUTHERLY AND AN UPPER RIDGE BUILDS OVER THE
EASTERN HALF OF THE U.S. THE GFS AND EURO SHOW THE PRESENCE OF A
WEAK SHORTWAVE CLIPPING THE REGION SUNDAY NIGHT AND ON MONDAY AS
IT APPROACHES THE RIDGE AXIS. HAVE ADJUSTED A SLIGHT CHANCE FOR
RAIN UP 12 HOURS TO REFLECT THIS NEW TIMING BEGINNING SUNDAY
NIGHT. HIGHS WILL RANGE FROM FIVE TO TEN DEGREES ABOVE NORMAL.
EXTENDED PERIOD...MOSTLY DRY WEATHER AND ABOVE NORMAL
TEMPERATURES WILL PERSIST INTO THE MIDDLE OF NEXT WEEK WITH
SOUTHERLY WINDS KEEPING A FRONT STATIONARY ACROSS THE MID
MISSISSIPPI VALLEY.
JAB
&&
.AVIATION...
00Z TAF SET
NOT MUCH CHANGE FROM PREVIOUS TAF SET. SHRAS/TSRAS BEGINNING TO
DEVELOP OVER EASTERN ARKANSAS WHICH IS WHAT LATEST HRRR MODEL WAS
SHOWING. BEST TIMING FOR KMEM WILL BE BETWEEN 01-04Z...FOR KJBR
00-03Z...FOR KMKL 02-05Z...AND FOR KTUP 03-06Z. LOW CIGS AND VSBYS
WILL OCCUR WITH THE SHRAS/TSRAS. WINDS WILL SWITCH AROUND TO THE
NW BRIEFLY BEHIND THE LINE BEFORE GOING BACK TO THE WSW. SPEEDS
WILL INCREASE TO 15-20 KTS SUSTAINED BETWEEN 15-18Z. GUSTS WILL BE
BETWEEN 25-30 KTS.
KRM
&&
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 53 72 49 69 / 90 10 10 10
MKL 50 71 45 65 / 90 10 10 10
JBR 48 71 47 66 / 70 10 10 10
TUP 55 73 45 70 / 90 10 10 10
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...WIND ADVISORY UNTIL MIDNIGHT CDT TONIGHT FOR CLAY-CRAIGHEAD-
CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-MISSISSIPPI-
PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS.
MO...WIND ADVISORY UNTIL MIDNIGHT CDT TONIGHT FOR DUNKLIN-PEMISCOT.
MS...WIND ADVISORY UNTIL MIDNIGHT CDT TONIGHT FOR BENTON MS-COAHOMA-
DESOTO-LAFAYETTE-MARSHALL-PANOLA-QUITMAN-TALLAHATCHIE-TATE-
TUNICA-YALOBUSHA.
TN...WIND ADVISORY UNTIL MIDNIGHT CDT TONIGHT FOR CARROLL-CHESTER-
CROCKETT-DYER-FAYETTE-GIBSON-HARDEMAN-HAYWOOD-HENDERSON-
HENRY-LAKE-LAUDERDALE-MADISON-OBION-SHELBY-TIPTON-WEAKLEY.
&&
$$
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
634 PM CDT THU OCT 18 2012
.DISCUSSION...
SEE AVIATION.
&&
.AVIATION...
STRATO CU FIELD 4-7KFT IS GRADUALLY SHIFTING SOUTH ACROSS SE TX.
NE WINDS WILL DECREASE INLAND THIS EVENING AND BECOME N
TOMORROW. 33
&&
.PREV DISCUSSION... /ISSUED 327 PM CDT THU OCT 18 2012/
DISCUSSION...
CLOUDS ARE BEGINNING TO ERODE ACROSS SOUTHEAST TEXAS AND AM
EXPECTING SKIES TO BECOME MOSTLY CLEAR THIS EVENING. DRIER AIR
WILL CONTINUE TO FILTER INTO THE REGION AND OBSERVATIONS UPSTREAM
SHOW SFC DEW POINTS IN THE UPPER 20S TO LOWER 30S. WITH THE VERY
DRY AIR IN PLACE AND WINDS DECOUPLING...FEEL OVERNIGHT LOWS WILL
FALL INTO THE UPPER 40S AND LOWER 50S NORTH...MID 50S CENTRAL AND
MID 60S IMMEDIATE COAST. SURFACE HIGH PRESSURE WILL BRING MOSTLY
SUNNY SKIES AND WARM DAYTIME TEMPERATURES BOTH FRIDAY AND
SATURDAY. THE HIGH WILL SHIFT EAST ON SATURDAY AND ONSHORE WINDS
WILL BRING HIGHER HUMIDITY LEVELS BACK TO SOUTHEAST TEXAS. AN
UPPER LEVEL RIDGE AND A CORRESPONDING INCREASE IN 500 MB HEIGHTS
WILL ALLOW TEMPS TO WARM SUN/MON BUT THIS WARMING WILL BE TEMPERED
A BIT BY THE INCREASE IN MOISTURE AND CLOUD COVER. COULD BE SOME
STREAMER SHOWERS SUNDAY AND MONDAY AS FCST SOUNDINGS SHOW
SATURATION BENEATH A BUILDING CAP BUT FEEL RAIN CHANCES ARE TOO
SLIM TO MENTION AT THIS TIME. NOT EXPECTING MUCH DAY TO DAY CHANGE
THROUGH THE END OF NEXT WEEK AS UPPER LEVEL RIDGING IMPINGES ON
SOUTH TEXAS. WITH THE HIGH 500 MB HEIGHTS AND CONTINUED ONSHORE
FLOW...EXPECT UNSEASONABLY WARM TEMPERATURES FOR MOST OF NEXT
WEEK. 43
MARINE...
A TIGHT PRESSURE GRADIENT WILL HELP GENERATE WINDS TO ADVISORY
LEVELS THROUGH AT LEAST THIS EVENING. THE NAM12 AND RUC DIMINISH
THE WINDS TO SLIGHTLY BELOW ADVISORY LEVELS BY 06Z. WILL EXTEND
THE ADVISORY INTO THE EVENING FOR THE GULF WATERS.
HIGH PRESSURE WILL MOVE OVERHEAD LATER ON FRIDAY. EXPECT MODERATE
ONSHORE WINDS TO DEVELOP SATURDAY AFTERNOON. WIND SPEEDS MAY REACH
AT LEAST CAUTION LEVELS SATURDAY NIGHT INTO TUESDAY.
40
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 52 83 57 87 69 / 0 0 0 0 10
HOUSTON (IAH) 55 84 58 87 70 / 0 0 0 0 10
GALVESTON (GLS) 67 80 70 82 76 / 0 0 0 0 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 11 PM CDT THIS EVENING FOR THE
FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP
CHANNEL 20 NM TO 60 NM...WATERS FROM FREEPORT TO THE
MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND
TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH ISLAND TO
FREEPORT OUT 20 NM.
&&
$$
AVIATION/MARINE...33
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1246 PM CDT WED OCT 17 2012
.DISCUSSION...
18Z TAF UPDATE DISCUSSION BELOW.
&&
.AVIATION...
AREAWIDE SKIES CLEARING OUT TO VFR AHEAD OF TONIGHT`S FRONTAL
PASSAGE. FROPA IS TIMED TO PASS ACROSS THE NORTHERN HUBS BETWEEN
18/00-03Z...CENTRAL TERMINALS BETWEEN 18/03-06Z...AND SLOWING TO
THE COAST WITH WINDS GOING VRB IN THE 18/08-12Z TIME FRAME.
OVERALL...A DRY FRONTAL PASSAGE WITH THE BULK OF THE ENERGY AND
HIGHEST MOISTURE DISPLACED EAST OF THE MAJORITY OF HUBS. EARLY
MORNING VCSH IS NOT TOTALLY OUT OF THE QUESTION...BUT CURRENT
CONFIDENCE IS TOO LOW TO PLACE WITHIN THIS PACKAGE. CONFIDENCE IS
HIGHER THAT TERMINALS CLOSER TO THE COAST WILL EXPERIENCE EARLY
THURSDAY MORNING MVFR...POSSIBLY TEMPO IFR...CEILINGS AS THE
BOUNDARY HANGS UP JUST SHY OF THE SHORELINE. BRISK SOUTH-SOUTHWEST
WINDS TODAY WILL WEAKEN AND VEER PAST SUNSET...BECOMING MORE MODERATE
NORTH-NORTHEAST POST-15Z THURSDAY UNDER PARTIALLY CLEARING SKIES.
31
&&
.PREV DISCUSSION... /ISSUED 1055 AM CDT WED OCT 17 2012/
UPDATE...
SEE MORNING UPDATE.
DISCUSSION...
JUST A FEW CHANGES THIS MORNING AS HIGHER PW AIR LINGERS ALONG THE
COAST. RADAR IS SHOWING A FEW SHRA ALONG AND EAST OF HWY 59 SO
WILL ADD ISOLATED SHRA TODAY. WATER VAPOR IMAGERY SHOWS SOME DRIER
AIR WORKING EAST SO FEEL THE THREAT FOR SHRA WILL BE SHORT LIVED
AND PROBABLY END BY EARLY AFTERNOON. THAT SAID...THE LATEST RAP13
SHOWS SHRA CONTINUING ALL DAY OVER PARTS OF THE CENTRAL AND
EASTERN ZONES. WILL WATCH TRENDS AND HIGHER POPS MIGHT BE NEEDED
THIS AFTN IF THE RAP VERIFIES. WILL ALSO LOWER MAX TEMPS DUE TO A
COOL START...LINGERING CLOUD COVER AND MIXING FROM STRONGER WINDS.
NEW ZONES OUT BY 11 AM. 43
PREV DISCUSSION... /ISSUED 446 AM CDT WED OCT 17 2012/
DISCUSSION...
SHOULD MARKEDLY WARMER/DRIER ACROSS SE TX TODAY WITH THE PASSAGE
OF THAT STRONG SHORTWAVE LAST NIGHT. CLEARING SKIES/RETURN OF ON-
SHORE WINDS WILL HELP HI TEMPS TO TOP OFF INTO THE UPPER 80S AND
LOWER 90S THIS AFTN. HOWEVER RAIN CHCS STILL SET TO RETURN LATER
TONIGHT WITH THE PASSAGE OF THE COLD FRONT. FAVOURABLE UPPER JET
DYNAMICS ALONG WITH LIFT ALONG THE FRONT ITSELF SHOULD BE ENOUGH
FOR ISO/WIDELY SCT RAINS WITH FROPA. CURRENTLY THINKING THAT THE
HIGHER CHCS WILL BE OVER THE NERN CWA (WHERE LIFT IS STRONGEST).
FRONT SHOULD BE INTO THE NEARSHORE WATERS BY THURS MORNING AS WE
COOL OFF/DRY OUT ONCE AGAIN. A SLOW WARM UP THEN PROGGED THROUGH
THE END OF THE WEEK AS THE ASSOCIATED HIGH EVENTUALLY SETTLES IN
THE SERN U.S. THIS SHOULD ALLOW FOR THE RETURN OF ONSHORE WINDS/
LOW LEVEL MOISTURE OVER THE WEEKEND.
FAIRLY DECENT AGREEMENT WITH MODELS THROUGH THE START OF NEXT WK
AS A SOMEWHAT FLATTISH UPPER RIDGE DOMINATES THE PATTERN. BUT WE
ARE SEEING QUITE A BIT OF DISAGREEMENT FOR THE VERY LATTER STAGE
OF THE FCST CYCLE. ECMWF APPEARS TO BE MUCH MORE AGGRESSIVE/FAST
WITH THE APPROACH/DEVELOPMENT OF THE NEXT LONGWAVE TROF WHEN COM-
PARED TO THE GFS. SO WILL LIKELY KEEP WITH CURRENT EXTENDED FCST
FOR NOW AND SEE WHAT SHAKES OUT FOR LATER. 41
MARINE...
INCREASING SOUTHERLY FLOW TODAY WITH WINDS IN THE NEARSHORE
AREAS INCREASING TO 15 TO 20 KNOTS BEFORE RELAXING LATE THIS
AFTERNOON AND EVENING PRIOR TO THE ARRIVAL OF THE FRONT
THURSDAY MORNING. HAVE HOISTED A SCEC FOR THE NEARSHORE WATERS. WILL
HAVE TO KEEP AN EYE OUT FOR STRONG STORMS ALONG THE FRONTAL BOUNDARY
PASSAGE IN AND AROUND GALVESTON BAY AND HIGH ISLAND AREA WHERE MORE
FAVORABLE CAPE/SHEAR PROFILES SHOULD PREVAIL. AFTER THE FRONTAL
PASSAGE EXPECTING WINDS TO CLIMB TO 15 TO 20 KNOTS AND WILL LIKELY
NEED SCECS. WINDS GRADUALLY SWING TO THE SOUTHEAST AND EAST AS RIDGE
SLIDES EAST AND PARKS KEEPING A FAIRLY TIGHT GRADIENT OVER THE AREA
THIS WEEKEND.
45
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 58 80 52 82 56 / 10 10 10 10 10
HOUSTON (IAH) 65 82 54 83 56 / 20 20 10 10 10
GALVESTON (GLS) 73 81 66 80 67 / 20 20 10 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 7 PM CDT THIS EVENING
FOR THE FOLLOWING ZONES: MATAGORDA BAY...WATERS FROM
FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...
WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20
NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...
WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...31
AVIATION/MARINE...43
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1055 AM CDT WED OCT 17 2012
.UPDATE...
SEE MORNING UPDATE.
&&
.DISCUSSION...
JUST A FEW CHANGES THIS MORNING AS HIGHER PW AIR LINGERS ALONG THE
COAST. RADAR IS SHOWING A FEW SHRA ALONG AND EAST OF HWY 59 SO
WILL ADD ISOLATED SHRA TODAY. WATER VAPOR IMAGERY SHOWS SOME DRIER
AIR WORKING EAST SO FEEL THE THREAT FOR SHRA WILL BE SHORT LIVED
AND PROBABLY END BY EARLY AFTERNOON. THAT SAID...THE LATEST RAP13
SHOWS SHRA CONTINUING ALL DAY OVER PARTS OF THE CENTRAL AND
EASTERN ZONES. WILL WATCH TRENDS AND HIGHER POPS MIGHT BE NEEDED
THIS AFTN IF THE RAP VERIFIES. WILL ALSO LOWER MAX TEMPS DUE TO A
COOL START...LINGERING CLOUD COVER AND MIXING FROM STRONGER WINDS.
NEW ZONES OUT BY 11 AM. 43
&&
.PREV DISCUSSION... /ISSUED 446 AM CDT WED OCT 17 2012/
DISCUSSION...
SHOULD MARKEDLY WARMER/DRIER ACROSS SE TX TODAY WITH THE PASSAGE
OF THAT STRONG SHORTWAVE LAST NIGHT. CLEARING SKIES/RETURN OF ON-
SHORE WINDS WILL HELP HI TEMPS TO TOP OFF INTO THE UPPER 80S AND
LOWER 90S THIS AFTN. HOWEVER RAIN CHCS STILL SET TO RETURN LATER
TONIGHT WITH THE PASSAGE OF THE COLD FRONT. FAVOURABLE UPPER JET
DYNAMICS ALONG WITH LIFT ALONG THE FRONT ITSELF SHOULD BE ENOUGH
FOR ISO/WIDELY SCT RAINS WITH FROPA. CURRENTLY THINKING THAT THE
HIGHER CHCS WILL BE OVER THE NERN CWA (WHERE LIFT IS STRONGEST).
FRONT SHOULD BE INTO THE NEARSHORE WATERS BY THURS MORNING AS WE
COOL OFF/DRY OUT ONCE AGAIN. A SLOW WARM UP THEN PROGGED THROUGH
THE END OF THE WEEK AS THE ASSOCIATED HIGH EVENTUALLY SETTLES IN
THE SERN U.S. THIS SHOULD ALLOW FOR THE RETURN OF ONSHORE WINDS/
LOW LEVEL MOISTURE OVER THE WEEKEND.
FAIRLY DECENT AGREEMENT WITH MODELS THROUGH THE START OF NEXT WK
AS A SOMEWHAT FLATTISH UPPER RIDGE DOMINATES THE PATTERN. BUT WE
ARE SEEING QUITE A BIT OF DISAGREEMENT FOR THE VERY LATTER STAGE
OF THE FCST CYCLE. ECMWF APPEARS TO BE MUCH MORE AGGRESSIVE/FAST
WITH THE APPROACH/DEVELOPMENT OF THE NEXT LONGWAVE TROF WHEN COM-
PARED TO THE GFS. SO WILL LIKELY KEEP WITH CURRENT EXTENDED FCST
FOR NOW AND SEE WHAT SHAKES OUT FOR LATER. 41
MARINE...
INCREASING SOUTHERLY FLOW TODAY WITH WINDS IN THE NEARSHORE
AREAS INCREASING TO 15 TO 20 KNOTS BEFORE RELAXING LATE THIS
AFTERNOON AND EVENING PRIOR TO THE ARRIVAL OF THE FRONT
THURSDAY MORNING. HAVE HOISTED A SCEC FOR THE NEARSHORE WATERS. WILL
HAVE TO KEEP AN EYE OUT FOR STRONG STORMS ALONG THE FRONTAL BOUNDARY
PASSAGE IN AND AROUND GALVESTON BAY AND HIGH ISLAND AREA WHERE MORE
FAVORABLE CAPE/SHEAR PROFILES SHOULD PREVAIL. AFTER THE FRONTAL
PASSAGE EXPECTING WINDS TO CLIMB TO 15 TO 20 KNOTS AND WILL LIKELY
NEED SCECS. WINDS GRADUALLY SWING TO THE SOUTHEAST AND EAST AS RIDGE
SLIDES EAST AND PARKS KEEPING A FAIRLY TIGHT GRADIENT OVER THE AREA
THIS WEEKEND.
45
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 88 58 80 52 82 / 10 10 10 10 10
HOUSTON (IAH) 87 65 82 54 83 / 10 20 20 10 10
GALVESTON (GLS) 83 73 81 66 80 / 10 20 20 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 7 PM CDT THIS EVENING
FOR THE FOLLOWING ZONES: MATAGORDA BAY...WATERS FROM
FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...
WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20
NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...
WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...43
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
658 PM CDT THU OCT 18 2012
.SHORT TERM...TONIGHT THROUGH SUNDAY
254 PM CDT THU OCT 18 2012
CLOSED LOW AND ITS INFLUENCE ON THE AREA THROUGH FRIDAY EVENING IS
IMMEDIATE FORECAST CONCERN...THEN ATTENTION TURNS TO WARMING
SATURDAY AND ESPECIALLY SUNDAY.
LATEST LOOP OF WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW CLOSED LOW
CENTERED OVER THE MN/IA/WI COMMON BORDER. RADAR MOSAIC SHOWING
WIDESPREAD SHOWER ACTIVITY ACROSS THE FORECAST AREA THANKS TO
INFLUENCE OF DEEP COLD/CYCLONIC FLOW OVERHEAD. TEMPERATURES
SUFFERING AS WELL WITH READINGS AT 2 PM ONLY IN THE 40S.
LATEST NCEP MODELS AS WELL AS THE ECMWF/GEM ALL IN VERY GOOD
AGREEMENT WITH SYNOPTIC SETUP THROUGH SUNDAY.
LOOK OF THE CLOSED LOW TO REMAIN ANCHORED OVER THE REGION
TONIGHT...MAKING A SLOW PUSH EAST TOWARD LAKE MICHIGAN BY LATE
FRIDAY AFTERNOON. BUFKIT MODEL SOUNDINGS SHOWING DEEP LAYER OF
MOISTURE WITH GENERALLY WEAK LIFT OVER THE AREA TONIGHT FOR
SCATTERED SHOWERS/AREAS OF DRIZZLE. WITH LIGHT WINDS AND SATURATED
LOWER BOUNDARY LAYER UNDER THE LOW...ALSO EXPECTING SOME LIGHT FOG
ACROSS THE AREA WITH VISIBILITY GENERALLY IN THE 3-6SM RANGE.
925-850MB LAYER TEMPERATURES COOL ONLY A COUPLE DEGREES TONIGHT.
WITH CLOUD COVER/SCATTERED PRECIPITATION...LOWS TONIGHT SHOULD
BOTTOM OUT IN THE UPPER 30S TO LOWER 40S. PLAN ON SCATTERED SHOWERS
ONCE AGAIN FOR FRIDAY WITH COLD/DEEP CYCLONIC FLOW CONTINUING. NOT
MUCH RECOVERY EXPECTED IN TEMPERATURES AS WELL WITH HIGHS TOPPING
OFF IN THE UPPER 40S TO A FEW LOWER 50S. A FEW LINGERING SHOWERS
WILL BE POSSIBLE ACROSS NORTHEAST IOWA INTO FAR SOUTHWEST WISCONSIN
FRIDAY EVENING AS LAST TROUGH ASSOCIATED WITH THE CLOSED LOW ROTATES
THROUGH THAT AREA. OTHERWISE FOR THE REST OF THE OVERNIGHT HOURS
MODELS PUSH THE CLOSED LOW MORE INTO THE GREAT LAKES REGION WHILE A
RIDGE OF HIGH PRESSURE BUILDS IN FROM THE PLAINS. NAM 925MB RH FIELD
INDICATING PERHAPS A FEW BREAKS IN THE STRATUS/STRATOCUMULUS LATER
FRIDAY NIGHT. THIS IS ALSO INDICATED IN THE BUFKIT SOUNDING...BUT
THEN DEVELOPS QUITE A BIT OF LOW-LEVEL STRATUS TOWARD MORNING.
BELIEVE MOSTLY CLOUDY IS THE WAY TO GO AT THIS POINT IN TIME. WILL
HAVE TO WATCH THIS SCENARIO CLOSELY. IF THERE IS SOME
CLEARING...COULD END UP WITH QUITE A BIT OF FOG WITH COOL/MOIST
LOWER BOUNDARY LAYER.
CLEARING SKIES AND WARMING EXPECTED SATURDAY AS THE CLOSED LOW
CONTINUES TO MOVE EAST OF THE REGION AND RIDGE OF HIGH PRESSURE BUILD
OVERHEAD. HIGHS SATURDAY SHOULD RESPOND NICELY TO SUNSHINE AND
925-850MB TEMPERATURES WARMING INTO THE 5-7C RANGE. PLAN ON HIGHS
PUSHING WELL INTO THE 50S. WARMING WILL CONTINUE INTO SUNDAY IN
SOUTHERLY FLOW AHEAD OF A COLD FRONT MOVING INTO THE DAKOTAS/WESTERN
MN. NAM INDICATING 925-850MB LAYER TEMPERATURES IN THE 14-17C RANGE.
THIS SHOULD EQUATE TO HIGHS SUNDAY IN THE 60S TO PERHAPS A FEW LOWER
70S WHICH WOULD BE SOME 15-20 DEGREES ABOVE NORMAL.
.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY
254 PM CDT THU OCT 18 2012
LATEST GFS/ECMWF IN GOOD AGREEMENT THROUGH TUESDAY...THEN DIVERGE
SOMEWHAT WEDNESDAY AND THURSDAY WITH TIMING ISSUES WITH WAVES IN
SOUTHWEST FLOW ALOFT.
FOR SUNDAY NIGHT THROUGH TUESDAY...CYCLOGENESIS OVER THE CENTRAL
PLAINS TAKES PLACE WITH THE WAVE MOVING NORTHEAST TOWARD THE AREA.
BOTH MODELS SHOWING AMPLE AMOUNT OF 850MB MOISTURE TRANSPORT OUT OF
THE GULF AND INTO THE AREA AHEAD OF THE ADVANCING LOW AND WARM
FRONT. ALSO...MODELS PRODUCING ABOUT 300-600J/KG OF CAPE LATER
SUNDAY NIGHT INTO MONDAY FOR A GOOD CHANCE OF SHOWERS/EMBEDDED
THUNDERSTORMS. FOR WEDNESDAY AND THURSDAY...MODELS DIVERGE ON
AMOUNT OF CYCLOGENESIS AND TIMING OF LOW PRESSURE SYSTEMS MOVING
TOWARD THE AREA WITH SOUTHWEST FLOW ALOFT. TOOK A CONSENSUS APPROACH
FOR NOW WHICH YIELDS MID-RANGE POPS FOR SHOWERS/THUNDERSTORMS.
WILL HOPE FOR BETTER RESOLUTION IN THE MODELS WITH SUBSEQUENT RUNS.
EITHER WAY...LOOKS LIKE AN ACTIVE WEATHER WEEK SETTING UP WITH EVEN
THE OUT SIDE CHANCE OF STRONG-SEVERE THUNDERSTORMS DEPENDING ON
AVAILABLE CAPE/SHEAR. OTHERWISE...LOOKS LIKE TEMPERATURES WILL
REMAIN SOME 15 OR SO DEGREES ABOVE NORMAL.
&&
.AVIATION...TONIGHT AND FRIDAY
658 PM CDT THU OCT 18 2012
CHALLENGING AVIATION FORECAST WITH FOCUS ON IFR TO LIFR CEILINGS
AND IFR VISIBILITY RESTRICTIONS AT KRST/KLSE. STACKED CLOSED LOW
CURRENTLY WOBBLING ACROSS CENTRAL MINNESOTA...WITH A FEW DIFFERENT
LOBES OF ENERGY ROTATING AROUND. ABUNDANT LOW-LEVEL MOISTURE AND
LIGHT/VARIABLE SURFACE WINDS WILL ALLOW CEILINGS TO LOWER
OVERNIGHT TO IFR AT KRST...AND LOW-END MVFR AT KLSE. THERE ARE
INDICATIONS THAT EVEN LOWER CEILINGS COULD OCCUR IN THE 10Z-13Z
TIME FRAME...AS THE CORE OF THE LOW SITS OVERHEAD. VARIETY OF
MESO-MODEL SOLUTIONS...FORECAST SOUNDINGS...AND STATISTICAL
GUIDANCE SHOW THERE A DECENT CHANCE OF THIS HAPPENING.
HOWEVER...NOT SOLD ON THIS SOLUTION RIGHT NOW...AS SUBTLE
INCREASE IN WINDS ALOFT MAY PRECLUDE THIS HAPPENING. FOR
NOW...INCLUDED A TEMPO GROUP TO ADDRESS POSSIBILITY
CEILINGS/VISIBILITIES COULD BE BOUNCING IN AND OUT OF LIFR/IFR.
SCATTERED LIGHT RAIN SHOWERS AND/OR DRIZZLE WILL PERSIST FOR MUCH
OF THE PERIOD. A VERY SLOW...BUT GRADUAL...IMPROVEMENT IS EXPECTED
FRIDAY AFTERNOON AS THE LOW BEGINS ITS DEPARTURE EAST. CONDITIONS
WILL LIKELY REMAIN BELOW VFR UNTIL AFTER 00Z SATURDAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
254 PM CDT THU OCT 18 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM...DAS
AVIATION...ZT
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
324 PM CDT WED OCT 17 2012
.SHORT TERM...
.TONIGHT...FORECAST CONFIDENCE HIGH.
A SHORTWAVE MOVING ACROSS SOUTHERN AND CENTRAL WI IS CAUSING AN AREA
OF SHOWERS...POSSIBLY WITH A FEW EMBEDDED THUNDERSTORMS... TO MOVE
NORTHEAST ACROSS SOUTH CENTRAL WI THIS AFTERNOON. ANOTHER AREA OF
SHOWERS WERE MOVING INTO SOUTHWEST WI AROUND 230 PM/1930Z.
THEN THE NEXT SURGE OF MOISTURE COMING UP CENTRAL IL WILL REACH
SOUTHERN WI RIGHT AROUND THE SAME TIME AS THE SURFACE COLD FRONT. IT
WILL BE SATURATED THROUGH THE WHOLE COLUMN...YIELDING EFFICIENT
PRECIPITATION AND LOW CLOUDS. THE TIMING OF MODERATE TO HEAVY RAIN
WILL BE RIGHT AROUND 00Z ACROSS ALL OF THE FORECAST AREA...BEGINNING
AROUND 23Z IN THE WESTERN FORECAST AREA. THIS IS THE TIME THE UPPER
DIVERGENCE FROM THE 250MB JET RAPIDLY INCREASES DIRECTLY
OVERHEAD...THE OMEGA VALUES SPIKE...AND THE LEFT EXIT REGION OF THE
850MB JET PUSHES INTO THE AREA.
THERE WILL BE ABOUT A 3 HOUR PERIOD OF MODERATE TO HEAVY RAIN LIKELY
TOTALING 0.75 TO 1 INCH. RAP SOUNDINGS SHOW CAPE VALUES AROUND 100
J/KG FOR A TIME AND GIVEN THE STRONG DYNAMICS...STILL EXPECTING
ISOLATED THUNDER.
MODELS ARE NOW SHOWING DRY AIR IN THE MID AND UPPER LEVELS PUSHING
IN FROM THE WEST BEHIND THE FRONT RATHER QUICKLY. THERE IS
UNCERTAINTY IN HOW QUICKLY THE LOWEST LEVELS WILL DRY OUT. WE COULD
SEE VERY LOW CLOUDS AND DRIZZLE HANG AROUND THROUGH THE REST OF THE
NIGHT INTO THURSDAY MORNING...OR THE DRY AIR AND LOW DEW POINTS WILL
ADVECT INTO HERE AND CLOUD BASES WILL LIFT AND EVENTUALLY SCATTER
OUT MID THU MORNING.
.THURSDAY...FORECAST CONFIDENCE MEDIUM.
THERE SHOULD BE A BREAK IN PRECIP DURING THE MORNING HOURS. THEN
ANOTHER ROUND OF LIGHT RAIN SHOWERS SHOULD SPREAD ACROSS SOUTHERN WI
THU AFTERNOON AS THE UPPER LOW PARKS OVER CENTRAL WI AND VORT MAXES
ROTATE AROUND IT. STEEP LOW LEVEL LAPSE RATES AND COLD CLOUDS MAY
LEAD TO ENOUGH INSTABILITY TO GENERATE GRAUPEL AND A CLAP OF THUNDER
IN A FEW SHOWERS. LEFT THE MENTION OUT OF THE FORECAST FOR NOW...BUT
KNOW THAT IT IS A POSSIBILITY.
MAX TEMPS ON THU WILL ONLY REACH THE UPPER 40S TO AROUND 50 WITH
AMPLE CLOUD COVER AND INTERMITTENT SHOWERS. WINDS MAY BECOME GUSTY
FOR A TIME OUT OF THE SOUTHWEST...DEPENDING ON CLOUD COVER.
.THURSDAY NIGHT AND FRIDAY...FORECAST CONFIDENCE...MEDIUM TO HIGH
THE LARGE NEARLY STATIONARY UPPER LOW CENTERED OVER SOUTHEAST
WISCONSIN BEGINS TO FILL FRIDAY AS IT ONLY REACHES LAKE MICHIGAN
FRIDAY AFTERNOON. IN THE MID LEVELS AT 500 MB SEVERAL AREAS OF
CYCLONIC VORTICITY WRAP AROUND THE MID/UPPER LOW.
THE BEST CHANCE FOR MODERATE RAIN RAIN WILL BE THURSDAY EVENING
ESPECIALLY FAR SOUTHEAST...BUT EXPECT INTERMITTENT LIGHT RAIN
FOR THIS PERIOD WITH CLOUDY SKIES AND COOL TEMPERATURES. 850 MB RH
VALUES NEAR 100 PERCENT. DUE TO RATHER STEEP LOW LEVEL LAPSE RATES
OF 9.5 CELSIUS/KM AT 850 MB THE NAM HAS SOME WEAK ZERO TO 1 KM
CAPE OF AROUND 50 J/KG.
.FRIDAY NIGHT AND SATURDAY...FORECAST CONFIDENCE...MEDIUM TO HIGH
THE GFS IS QUICKER IN PUSHING THE UPPER LOW OFF TO THE NORTHEAST.
THE SLOWER 12Z NAM IS MORE LIKE THE 00Z ECMWF AND IS PREFERRED.
THEREFORE EXPECT THE UPPER LOW TO WEAKEN AND SLOWLY PROGRESS TO THE
EAST...REACHING LOWER MICHIGAN SATURDAY. SOUTHERN WISCONSIN WILL
BE IN THE NORTHWEST CYCLONIC FLOW OF THE UPPER LOW WITH DRYING
OCCURRING AT 700 MB. STILL EXPECT LINGERING STRATOCUMULUS CLOUDS
ESPECIALLY OVER SOUTHEAST WISCONSIN DUE TO LINGERING MOISTURE IN
THE LOW LEVELS.
.LONG TERM...
.SUNDAY THROUGH TUESDAY...FORECAST CONFIDENCE...MEDIUM
A WEAK UPPER RIDGE WILL BUILD INTO THE WISCONSIN AREA ON SUNDAY
WITH A SOUTHWEST FLOW MONDAY AND TUESDAY. THE 12Z GFS/00Z ECMWF
AND 06Z DGEX ALL TAKE A WEAK SHORTWAVE ACROSS THE KANSAS AREA
MONDAY PUSHING IT NORTHEAST INTO ILLINOIS AND POSSIBLY SOUTHERN
WISCONSIN ON TUESDAY.
THICKNESS VALUES WARM TO AROUND 564 DECAMETERS BY SUNDAY AFTERNOON
RESULTING IN MILD TEMPERATURES. THE MAIN FORECAST PROBLEM WILL BE
A DEVELOPING SURFACE TROUGH OF LOW PRESSURE OVER KANSAS THAT LIFTS
NORTHEAST TOWARD SOUTHERN WISCONSIN ON MONDAY. THE MODELS ALL
BRING LIGHT PRECIPITATION INTO SOUTHERN WISCONSIN ON
MONDAY...WHILE THE 00Z ECMWF AND 06Z DGEX LINGER THE TROUGH AND
PRECIPITATION ON TUESDAY. PREFER THE 00Z ECMWF/06Z DGEX SO WILL
CONTINUE TO PUT A CHANCE OF SHOWERS FOR MONDAY AND TUESDAY.
.WEDNESDAY AND THURSDAY...FORECAST CONFIDENCE...MEDIUM TO LOW
THE NEXT MID/UPPER TROUGH MOVES INTO THE WEST COAST OF THE U.S.
WEDNESDAY...RESULTING IN A WEAK RIDGE ACROSS THE MISSISSIPPI
VALLEY AND INTO SOUTHERN WISCONSIN EARLY WEDNESDAY AS THE WEST TO
SOUTHWEST FLOW BECOMES MORE SOUTHWEST. THE 12Z GFS BRINGS OUT A
STRONG TROUGH/UPPER LOW INTO THE NORTHERN PLAINS ON
THURSDAY...WHILE THE 00Z ECMWF WAS A LITTLE SLOWER BRINGING THE
TROUGH NORTHEAST. NOW THE 12Z ECMWF HAS TRENDED TOWARD THE 12Z GFS.
THIS WOULD BRING A CHANCE OF SHOWERS NEAR AN ADVANCING WARM FRONT
WEDNESDAY MORNING. EVEN THOUGH THE 12Z ECMWF HAS TRENDED TOWARD
THE 12Z GFS WITH THE STRONGER FASTER SHORTWAVE...THE 00Z ECMWF
AND 12Z STILL KEEPS SOUTHERN WISCONSIN IN A DRY WARM SECTOR
WEDNESDAY NIGHT AND THURSDAY MORNING UNTIL THE ADVANCING COLD
FRONT REACHES THE FORECAST AREA THURSDAY AFTERNOON. BOTH THE 12Z
GFS AND 12Z ECMWF NOW BRING A STRONG LOW INTO MINNESOTA THURSDAY.
HOWEVER LITTLE CONSISTENCY BETWEEN MODEL RUNS SO CONFIDENCE IS
STILL LOWER EVEN THOUGH BOTH THE GFS AND ECMWF ARE NOW IN BETTER
AGREEMENT.
&&
.AVIATION/00Z TAFS/...
A COLD FRONT STEMMING FROM LOW PRESSURE IN THE NORTHERN PLAINS...
STRETCHING FROM MINNESOTA DOWN TO MISSOURI...WILL PUSH EAST ACROSS
WISCONSIN AND ILLINOIS THIS EVENING. A LEADING SURGE OF ENERGY LED
TO SCATTERED SHOWERS ACROSS SOUTHERN WI THIS AFTERNOON.
THEN ABUNDANT MOISTURE WITH STRONG DYNAMICAL FORCING WILL STREAM
NORTH INTO SOUTHERN WISCONSIN LATE THIS AFTERNOON. WIDESPREAD
MODERATE TO HEAVY RAINFALL AND ISOLATED THUNDERSTORMS WILL EXPAND
RAPIDLY BETWEEN 23Z AND 01Z THIS EVENING AND LAST AROUND 3 HOURS. AN
ASSOCIATED COLD FRONT WILL REACH MADISON AROUND OR SHORTLY AFTER 00Z
THU...AND THE MILWAUKEE AREA BY AROUND 04Z THU. WINDS WILL SHIFT
FROM SOUTH SOUTHWEST...TO WEST NORTHWEST IN THE WAKE OF THE
FRONT...THEN GRADUALLY SHIFT BACK TO THE SOUTH TOWARD MORNING.
LOOK FOR VFR CONDITIONS TO RAPIDLY DETERIORATE BY EARLY EVENING...
AND EVENTUALLY GO DOWN TO IFR WITH THE RAIN THIS EVENING. IT IS
LIKELY THAT TAF SITES WILL GO BELOW ALTERNATE MINIMUMS FOR CIGS AND
VSBY FOR A TIME MAYBE AROUND MIDNIGHT ALONG WITH DRIZZLE AFTER THE
MAIN RAIN EVENT ENDS AND BEFORE THE DRIER AIR GETS HERE.
&&
.MARINE...A LARGE LOW PRESSURE SYSTEM STRETCHING FROM THE NORTHERN
PLAINS...THROUGH MISSOURI WILL MOVE EAST TONIGHT AND AN ASSOCIATED
COLD FRONT WILL PUSH THROUGH THE NEARSHORE WATERS LATER THIS EVENING
AND OVERNIGHT. SOUTH WINDS OF 15 TO 25 KNOTS WITH WAVES RANGING FROM
4 TO 7 FEET WILL GRADUALLY DIMINISH BEHIND THE COLD FRONT.
THEREAFTER... WINDS WILL SHIFT TO THE WEST NORTHWEST OVERNIGHT...AND
THEN BACK TO THE SOUTHWEST ON THURSDAY. THERE MAY BE A FEW GUSTS TO
25 KNOTS DURING THE DAY ON THURSDAY...BUT NOT EXPECTING A SMALL
CRAFT ADVISORY AT THIS TIME.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 11 PM CDT THIS EVENING FOR LMZ645-646.
SMALL CRAFT ADVISORY UNTIL 4 AM CDT THURSDAY FOR LMZ643-644.
&&
$$
TONIGHT/THURSDAY AND AVIATION/MARINE...MRC
THURSDAY NIGHT THROUGH WEDNESDAY...HENTZ
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1145 AM CDT WED OCT 17 2012
.UPDATE...
A SHORTWAVE MOVING INTO SOUTHERN WI WILL LIKELY BRING SCATTERED
SHOWERS AND A FEW THUNDERSTORMS TO SOUTHERN WI BETWEEN NOW AND 21Z.
THIS INITIAL SURGE WILL HAVE HIGHER CLOUD BASES...AROUND 6000 FEET.
THEN WE WILL WAIT FOR THE NEXT SURGE OF MOISTURE COMING UP FROM THE
SOUTHWEST AND COINCIDENT WITH THE SURFACE COLD FRONT. IT WILL BE
SATURATED THROUGH THE WHOLE COLUMN...YIELDING EFFICIENT
PRECIPITATION AND LOW CLOUDS. THE TIMING OF MODERATE TO HEAVY RAIN
WILL BE RIGHT AROUND 00Z ACROSS ALL OF THE FORECAST AREA...BEGINNING
AROUND 23Z IN THE WESTERN FORECAST AREA. THIS IS THE TIME THE UPPER
DIVERGENCE FROM THE 250MB JET RAPIDLY INCREASES DIRECTLY
OVERHEAD...THE OMEGA VALUES SPIKE...AND THE LEFT EXIT REGION OF THE
850MB JET PUSHES INTO THE AREA.
THERE WILL BE ABOUT A 3 HOUR PERIOD OF MODERATE TO HEAVY RAIN LIKELY
TOTALING 0.75 TO 1 INCH. RAP SOUNDINGS SHOW CAPE VALUES AROUND 100
J/KG FOR A TIME AND GIVEN THE STRONG DYNAMICS...STILL EXPECTING
ISOLATED THUNDER.
UPDATED FORECAST TO REFLECT A MORE SCATTERED NATURE OF SHOWERS EARLY
IN THE AFTERNOON...AND THEN THE STEADY RAIN AROUND 00Z THROUGH 03Z.
WILL BE TAPERING OFF THE RAIN QUICKLY AFTER MIDNIGHT AS THE LATEST
MODELS ARE SHOWING THE DRY AIR MOVING IN EARLIER. WE COULD SEE VERY
LOW CLOUDS AND DRIZZLE HANG AROUND THROUGH THE REST OF THE NIGHT AND
THURSDAY MORNING. THEN ANOTHER ROUND OF SHOWERS SHOULD SPREAD ACROSS
SOUTHERN WI THU AFTERNOON.
&&
.AVIATION/18Z TAFS/...LOOK FOR VFR CONDITIONS THROUGH EARLY
AFTERNOON...FOLLOWED BY RAPIDLY DETERIORATING CONDITIONS...
EVENTUALLY GOING DOWN TO IFR FOR TONIGHT INTO THURSDAY. IT IS LIKELY
THAT TAF SITES WILL GO BELOW ALTERNATE MINIMUMS FOR CIGS AND VSBY
FOR A TIME LATE TONIGHT ALONG WITH DRIZZLE AFTER THE MAIN RAIN EVENT
ENDS.
A LARGE LOW PRESSURE SYSTEM STRETCHING FROM THE NORTHERN PLAINS...
DOWN TO MISSOURI AND KANSAS WILL PUSH EAST TODAY. THERE WILL BE SOME
SCATTERED SHOWERS IN THE AREA THIS AFTERNOON. THEN ABUNDANT MOISTURE
WILL STREAM NORTH INTO SOUTHERN WISCONSIN LATE THIS AFTERNOON.
WIDESPREAD MODERATE TO HEAVY RAINFALL AND ISOLATED THUNDERSTORMS WILL
EXPAND ABRUPTLY BETWEEN 23Z AND 01Z THIS EVENING AND LAST AROUND 3
HOURS. AN ASSOCIATED COLD FRONT WILL REACH MADISON AROUND OR SHORTLY
AFTER 00Z THU...AND THE MILWAUKEE AREA BY AROUND 04Z THU. WINDS
WILL SHIFT FROM SOUTH SOUTHWEST...TO WEST NORTHWEST IN THE WAKE OF
THE FRONT.
DRY AIR IN THE MID AND UPPER LEVELS WILL QUICKLY MOVE IN BEHIND THE
COLD FRONT AFTER MIDNIGHT. THERE COULD BE LINGERING LOW LEVEL
MOISTURE LEADING TO LOW CLOUDS AND LIGHT FOG AND POSSIBLY DRIZZLE.
&&
.PREV DISCUSSION... /ISSUED 340 AM CDT WED OCT 17 2012/
TODAY AND TONIGHT...FORECAST CONFIDENCE...HIGH
ALL THE MODELS ARE IN VERY GOOD AGREEMENT THAT SOUTHERN WISCONSIN
WILL BE HIT WITH A WIDESPREAD AND RATHER GENEROUS RAINFALL OVER THE
NEXT 24 HOURS. THE BULK OF THE RAIN WILL HIT FROM MID AFTERNOON
THROUGH THE OVERNIGHT HOURS AND COULD EXCEED 1 INCH IN SOME SPOTS.
A MID LEVEL TROF WILL DIG INTO THE NORTHERN PLAINS TODAY AND QUICKLY
CLOSE OFF INTO A LARGE AND AMPLIFYING UPPER LOW CENTERED AROUND
SOUTHERN MINNESOTA LATER TONIGHT. A SHORT WAVE ROTATING AROUND THE
BASE OF THE LOW WILL FORCE THE UPPER LOW INTO A NEGATIVE TILT
ORIENTATION FOR A TIME THIS EVENING. THE DEEP UPWARD VERTICAL MOTION
BLOSSOMS AT THIS POINT AND WE SHOULD SEE THE RAINFALL BECOME MORE
WIDESPREAD AND HEAVIER AT THAT POINT. MOISTURE WILL BE IN PLACE WITH
PRECIPITABLE WATER VALUES OF 1-1.2 INCHES EXPECTED. BY EARLY
EVENING...THE COLD FRONT ASSOCIATED WITH THE DEEPENING SURFACE LOW
WILL BE NEAR MADISON ALREADY. SO THE HEAVIEST RAIN WILL LIKELY BE
FOUND FROM MADISON ON EASTWARD. GIVEN THE OVERWHELMING CONSENSUS ON
RAINFALL...HAVE BUMPED POPS OVER THE EASTERN HALF OF THE CWA TO 100
PERCENT. THERE CONTINUES TO BE SOME ELEVATED INSTABILITY...SO WILL
CONTINUE MENTION OF ISOLATED THUNDER.
THE FRONT WILL SPIN OFF TO THE NORTH AND OCCLUDE OVERNIGHT. WILL
CONTINUE HIGH POPS ACROSS THE FAR NORTH AND DIMINISH ACROSS THE
SOUTH AS THIS SYSTEM STARTS TO BECOME A STACKED AND STUBBORN CUTOFF
LOW FOR THE REMAINDER OF THE WEEK.
THURSDAY FRIDAY...FORECAST CONFIDENCE...MEDIUM TO HIGH
LARGE AND DEEP UPPER LOW TO MOVE SLOWLY FROM NEARLY RIGHT OVER THE
FORECAST AREA THURSDAY EVENING ONLY TO LOWER MICHIGAN BY FRIDAY
EVENING. NEEDLESS TO SAY...GOOD CHANCE FOR CLOUDS...RAIN...AND
COOLER TEMPERATURES FOR THE LATTER HALF OF THE WORK WEEK.
BEST CHANCE FOR SHOWERS THURSDAY AND THURSDAY NIGHT EXPECTED TO BE
ACROSS SOUTHERN PORTIONS OF THE FORECAST AREA CLOSER TO THE SURFACE
LOW. SHOULD SEE BEST CHANCE FOR SHOWERS IN THE EAST FRIDAY DUE TO
LAKE ENHANCEMENT UNDER EASTERLY FLOW...WITH SFC-850 MB TEMP
DIFFERENCE INCREASING TO AROUND 14C. TEMPS WILL BE BELOW NORMAL BOTH
THURSDAY AND FRIDAY...WITH HIGHS STRUGGLING INTO THE UPPER 40S OR
LOW 50S.
SATURDAY AND SUNDAY...FORECAST CONFIDENCE...MEDIUM TO HIGH
TEMPERATURES SHOULD WARM TO NEAR NORMAL SATURDAY THEN A FEW DEGREES
ABOVE NORMAL SUNDAY AS UPPER RIDGING BUILDS INTO THE AREA. SHOULD BE
DRY THROUGH THE WEEKEND.
MONDAY AND TUESDAY...FORECAST CONFIDENCE...LOW TO MEDIUM
MODELS JUMPING AROUND QUITE A BIT WITH THE FORECAST FOR EARLY NEXT
WEEK. MAIN ISSUE IS HOW LONG MILDER AIR WILL STICK AROUND AND
RESULTANT PRECIP CHANCES DUE TO WARM AIR ADVECTION AND EVENTUAL
ARRIVAL OF COOLER AIR. TEMPERATURES TRICKY TOO...AS 925 MB TEMPS
SUPPORT HIGHS MILDER THAN THE CURRENT FORECAST. DID NOT GET THAT
AGGRESSIVE WITH WARMING UP TEMPS DUE TO INCONSISTENCY IN THE
MODELS...ALONG WITH CLOUDS AND POSSIBLE PRECIP. WILL LIKELY NEED
TO WARM THINGS UP THOUGH IF MODELS DO STICK WITH THE CURRENT
MILDER SOLUTION.
WITH EXPECTED WARM AIR ADVECTION AND A WEAK WAVE OR TWO IN THE
FLOW...KEPT SHOWER CHANCES GOING. ECMWF AND GFS BOTH SHOWING SOME
ELEVATED INSTABILITY...SO ADDED SLIGHT CHANCE OF THUNDER INTO THE
FORECAST.
AVIATION/12Z TAFS/...LOOK FOR VFR CONDITIONS THROUGH EARLY
AFTERNOON...FOLLOWED BY RAPIDLY DETERIORATING CONDITIONS...
EVENTUALLY GOING DOWN TO IFR FOR TONIGHT INTO THURSDAY.
A LARGE LOW PRESSURE SYSTEM STRETCHING FROM THE NORTHERN
PLAINS...DOWN TO MISSOURI AND KANSAS WILL PUSH EAST TODAY. ABUNDANT
MOISTURE WILL STREAM NORTH INTO SOUTHERN WISCONSIN THIS AFTERNOON
WITH WIDESPREAD RAINFALL AND ISOLATED THUNDERSTORMS BY LATE
AFTERNOON AND EVENING. AN ASSOCIATED COLD FRONT WILL REACH MADISON
AROUND OR SHORTLY AFTER 00Z THU...AND THE MILWAUKEE AREA BY AROUND
06Z THU. WINDS WILL SHIFT FROM SOUTH SOUTHWEST...TO WEST NORTHWEST
IN THE WAKE OF THE FRONT.
MARINE...SOUTH WINDS OF 15 TO 25 KNOTS WILL CONTINUE TODAY AND
INTO THE EVENING WITH WAVES RANGING FROM 4 TO 7 FEET. A LARGE LOW
PRESSURE SYSTEM STRETCHING FROM THE NORTHERN PLAINS...THROUGH
MISSOURI THIS MORNING WILL MOVE SLOWLY EAST TODAY. AN ASSOCIATED
COLD FRONT WILL PUSH THROUGH THE NEARSHORE WATERS LATER THIS EVENING
AND OVERNIGHT. THEREAFTER...WINDS WILL SHIFT TO THE WEST
NORTHWEST.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 11 PM CDT THIS EVENING FOR LMZ645-646.
SMALL CRAFT ADVISORY UNTIL 4 AM CDT THURSDAY FOR LMZ643-644.
&&
$$
UPDATE...MRC
TODAY/TONIGHT AND AVIATION/MARINE...DAVIS
THURSDAY THROUGH TUESDAY...DDV
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
320 AM EDT FRI OCT 19 2012
.SYNOPSIS...
07Z WATER VAPOR AND H4 RAP ANALYSIS SHOWING A HIGHLY AMPLIFIED UPPER
LEVEL PATTERN IN PLACE OVER THE CONUS THIS MORNING. PATTERN IS
HIGHLIGHTED BY LONGWAVE RIDGING OVER THE INTER-MOUNTAIN WEST
FOLLOWED DOWNSTREAM BY A LARGE LONGWAVE TROUGH/UPPER LOW COVERING
THE CENTRAL AND EASTERN STATES. THE UPPER LOW IS SLOWLY MIGRATING
EASTWARD WHILE SITUATED OVER THE WESTERN GREAT LAKES. A GENERALLY
ZONAL PATTERN OVER THE FORECAST AREA ON THURSDAY HAS TRANSITIONED TO
A MORE CYCLONIC FLOW AS THE TROUGH AXIS APPROACHES ALONG THE
NORTHERN GULF COAST. UNLIKE THE MOIST ENVIRONMENTS CHARACTERIZED TO
THE EAST OF MANY OF OUR UPPER TROUGH PASSAGES...THE TROPOSPHERIC
ENVIRONMENT AHEAD OF THIS TROUGH IS MUCH DRIER OVER THE FL
PENINSULA. THE 00Z KTBW SOUNDING WAS SURPRISINGLY DRY WITH A PW OF
ONLY AROUND 1" AND A DEEP LAYER OF DEWPOINT DEPRESSION GREATER THAN
40C. WV IMAGERY DOES SHOW A NARROW BAND OF SOMEWHAT DEEPER MOISTER
ALONG AN APPROACHING FRONT...HOWEVER IT WOULD TAKE QUITE A LOT TO
OVERCOME THIS DEGREE OF DRY AIR AND RESULT IN ANY SIGNIFICANT PRECIP
COVERAGE. AT THIS POINT...IT IS DOUBTFUL THIS WILL OCCUR.
AT THE SURFACE...AS MENTIONED ABOVE...A SURFACE COLD FRONT IS SLOWLY
ADVANCING SOUTH AND EAST FROM THE FL BIG BEND/NE GULF OF MEXICO. THE
DRY AIR AND LACK OF OVERALL SYNOPTIC FORCING IS RESULTING IN ONLY A
VERY NARROW "ROPE" OF SHOWERS FORCED BY THE LOW LEVEL FOCUS AHEAD OF
THE FRONT. THIS LACK OF ORGANIZED CONVECTION SHOULD GENERALLY BE THE
RULE AS THE FRONT PROGRESSES SOUTHWARD THROUGH THE FORECAST AREA THE
NEXT 24-30 HOURS.
&&
.SHORT TERM (TODAY THROUGH SUNDAY)...
TODAY...UPPER TROUGH WILL CONTINUE TO SHARPEN INTO THE EASTERN THIRD
OF THE NATION AS A STRONGER PIECE OF SHORTWAVE ENERGY DROPS DOWN
INTO THE TROUGHS BASE. THE ATMOSPHERIC PUSH ASSOCIATED WITH THIS
ENERGY WILL KEEP THE SURFACE COLD FRONT SLOWLY DROPPING SOUTHWARD
THROUGH EARLY AFTERNOON...AND THEN BEGIN A MORE RAPID ADVANCE THIS
EVENING AND OVERNIGHT. NARROW BAND OF SCT SHOWERS/ISOLATED THUNDER
ASSOCIATED WITH THE LOW LEVEL FOCUS ALONG THE BOUNDARY ITSELF IS
EXPECTED TO REACH THE NORTHERN NATURE COAST ZONES (LEVY/CITRUS)
TOWARD DAWN OR SHORTLY THEREAFTER...AND THEN VERY SLOWLY PIVOT
SOUTHWARD DOWN THE NATURE COAST THROUGH THE DAY. WHILE THE FRONT
SHOULD SUPPORT THIS SCT BAND OF SHOWERS THROUGH THE DAY...THE IMPACT
WILL BE QUITE LOW/BRIEF...AND THEREFORE WILL KEEP POPS ON THE LOW
SIDE WITH ITS PASSAGE. ELSEWHERE...SEEING A FEW SHOWERS DOWN TOWARD
FT MYERS EARLY THIS MORNING ALONG A WEAK SURFACE TROUGH. GUIDANCE
SUGGEST THIS WIDELY SCT ACTIVITY WILL PERSIST THROUGH MID-MORNING
AND THEN DISSIPATE. LATER IN THE AFTERNOON/EARLY EVENING HOURS...A
FEW SHOWERS/STORMS WILL BE POSSIBLE OVER INTERIOR ZONES TO THE SOUTH
OF I-4 ASSOCIATED WITH THE SURFACE TROUGH AND SOME ENHANCED
SEA-BREEZE CONVERGENCE. THAT IS A LOT OF DISCUSSION ABOUT RAIN...BUT
DO NOT ANTICIPATE A WET DAY FOR ANY LOCATION. THE SHOWERS...
REGARDLESS OF FORCING MECHANISM SHOULD BE BRIEF.
TONIGHT...FRONT CONTINUES SOUTHWARD PASSING THE I-4 CORRIDOR AROUND
MIDNIGHT AND APPROACHING OUR FAR SOUTHERN ZONES AROUND SUNRISE.
SIGNIFICANT DRYING ALOFT ALONG WITH MINIMAL SYNOPTIC SUPPORT WILL
KEEP ANY SHOWERS ALONG THE BOUNDARY ISOLATED AT BEST. COOLER AND
DRIER AIR WILL BEGIN FILTERING INTO THE NORTHERN HALF OF THE
AREA...ESPECIALLY DURING THE SECOND HALF OF THE NIGHT. WHILE
OVERNIGHT LOW TEMPS WILL REMAIN IN THE MIDDLE 60S TO AROUND 70S
SOUTH OF I-4...TEMPS WILL DROP QUICKLY FURTHER TO THE NORTH. MOS
CONSENSUS SUGGEST NORTHERN NATURE COAST ZONES WILL DROP INTO THE 50S
AWAY FROM THE IMMEDIATE COAST AND EVEN LOWER/MID 50S UP TOWARD
CHIEFLAND.
SATURDAY...FRONT EXITS THE FORECAST AREA EARLY IN THE MORNING. WILL
KEEP A SLIGHT CHANCE POP AROUND FORT MYERS TILL 15Z...AND THEN END
THE ACTIVITY. MUCH DRIER AIR WILL CONTINUE TO ARRIVE ON A NORTHERLY
BREEZE AND WILL BE QUITE NOTICEABLE...ESPECIALLY NORTH OF
CHARLOTTE/LEE COUNTIES. HIGH TEMPERATURES WILL RANGE FROM AROUND 80
FAR NORTH TO THE MID 80S SOUTH. SKIES WILL BE MOSTLY SUNNY THROUGH
THE DAY FROM TAMPA BAY NORTHWARD AND BECOME MOSTLY SUNNY FURTHER
SOUTH.
SATURDAY NIGHT...DRY CONDITIONS AND LIGHT WINDS ASSOCIATED WITH
NEARBY HIGH PRESSURE ARE EXPECTED TO RESULT IN A COOL NIGHT. MOS
CONSENSUS SUGGESTS MANY LOCATIONS AWAY FROM THE IMMEDIATE COAST WILL
SEE TEMPERATURES IN THE 50S BY SUNRISE SUNDAY MORNING. NORMALLY
COLDER LOCATIONS FROM BROOKSVILLE NORTHWARD HAVE A LEGITIMATE SHOT
AT SEEING TEMPS DIP INTO THE UPPER 40S. BRRRR!
SUNDAY..."CHAMBER OF COMMERCE" WEATHER TO ROUND OUT THE WEEKEND.
BUILDING HEIGHTS OVER TOP THE SURFACE RIDGE WILL RESULT IN NEAR ZERO
RAIN CHANCES...ABUNDANT SUNSHINE...LOW DEWPOINTS...AND AFTERNOON
HIGH TEMPS IN THE LOWER TO MIDDLE 80S. THESE TEMPS WILL REPRESENT A
DIURNAL SWING OF UP TO 35 DEGREES.
&&
.LONG TERM (SUNDAY NIGHT THROUGH NEXT THURSDAY)...
NOT TOO MUCH TO TALK ABOUT IN THE EXTENDED PORTION OF THE FORECAST.
A SURFACE RIDGE OF HIGH PRESSURE WILL REMAIN NORTH OF THE REGION
THROUGH THE PERIOD. UPPER-LEVEL RIDGING WILL EXTEND FROM THE GULF OF
MEXICO... NORTHEASTWARD INTO THE MID-ATLANTIC STATES. THE
UPPER-LEVEL RIDGE WILL KEEP THE AIRMASS VERY DRY ALOFT WHILE THE
EASTERLY FLOW SOUTH OF THE SURFACE RIDGE BRINGS MOISTURE BACK IN
BELOW ABOUT TEN THOUSAND FEET. THE MOISTURE DEPTH COULD BE ENOUGH TO
SEE A FEW SHOWERS HERE AND THERE ON WEDNESDAY...BUT OVERALL RAIN
CHANCES WILL BE LOW AND WILL NOT MENTION IN THE FORECAST.
THE SHALLOW COOL AIRMASS WILL STILL BE IN PLACE SUNDAY NIGHT
ALLOWING FOR ANOTHER COOL MORNING ON MONDAY. AFTER THAT WE WILL SEE
TEMPERATURES RETURN TO NEAR NORMAL MONDAY AFTERNOON...THEN BACK TO
BEING A BIT ABOVE NORMAL FOR TUESDAY THROUGH THURSDAY.
&&
.AVIATION...
NEED TO WATCH SHOWERS MAKING THEIR WAY INTO CHARLOTTE HARBOR NEAR
PGD. OTHERWISE LOOK FOR MAINLY VFR CONDITIONS WITH SOME MVFR OR
PERHAPS IFR CONDITIONS IN PATCHY FOG AND LOW CLOUDS...ESPECIALLY AT
PGD AND LAL THROUGH 13Z.
&&
.MARINE...
A COLD FRONT WILL SINK SOUTH ACROSS THE EASTERN GULF OF MEXICO
THROUGH TONIGHT. A LARGE RIDGE OF HIGH PRESSURE WILL THEN BUILD INTO
THE SOUTHEASTERN STATES AND EASTERN GULF BY THE SECOND HALF OF THE
WEEKEND. WINDS WILL TURN NORTHERLY BEHIND THE FRONT TONIGHT AND
SATURDAY AND THEN INCREASE OUT OF THE NORTHEAST SUNDAY AND THE
EARLY PORTION OF NEXT WEEK.
&&
.FIRE WEATHER...
A COLD FRONT WILL SETTLE SOUTHWARD THROUGH THE REGION TODAY AND
TONIGHT ALLOWING A MUCH DRIER LOW LEVEL AIRMASS TO FILTER IN FROM
THE NORTH BY SATURDAY. THE MAIN PUSH OF DRIER AIR WILL NOT BEGIN
ARRIVING UNTIL TONIGHT AND RELATIVE HUMIDITY WILL REMAIN ABOVE
CRITICAL LEVELS FOR ALL ZONES TODAY. THE DRIEST CONDITIONS ON
SATURDAY WILL OCCUR FROM TAMPA BAY NORTHWARD WHERE SEVERAL HOURS OF
RELATIVE HUMIDITY BELOW 35 PERCENT ARE FORECAST. MINIMUM VALUES IN
THE MIDDLE AND UPPER 20S ARE EXPECTED NORTH OF THE I-4 CORRIDOR.
DESPITE THE DRY AIR...DISPERSION INDICES ARE EXPECTED TO REMAIN
BELOW 75 AND ERC VALUES ARE LOW. THEREFORE...NO RED FLAG CONDITIONS
ARE EXPECTED. MANY LOCATION...EVEN SOUTH OF TAMPA BAY ARE FORECAST
TO REACH MINIMUM RELATIVE HUMIDITY VALUES BETWEEN 30 AND 35 PERCENT
SUNDAY AFTERNOON. A SLOW INCREASE IN ATLANTIC MOISTURE WILL THEN
BEGIN DURING THE EARLY PORTION OF NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 86 69 83 61 / 20 20 0 0
FMY 87 71 86 63 / 20 20 20 0
GIF 89 65 84 58 / 20 20 10 0
SRQ 85 69 83 60 / 10 20 10 0
BKV 87 61 83 47 / 20 20 0 0
SPG 86 72 83 67 / 20 20 0 0
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/MARINE/FIRE WX...MROCZKA
LONG TERM/AVIATION...JILLSON
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
407 AM EDT FRI OCT 19 2012
.SYNOPSIS...
A COLD FRONT WILL MOVE OFF THE COAST THIS MORNING. HIGH PRESSURE WILL
THEN EXPAND OVER THE REGION THROUGH LATE NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
PRE-DAWN...AT THE SURFACE 07Z ANALYSIS INDICATES THE COLD FRONT WAS
NEAR A LINE FROM AUGUSTA TO MACON GEORGIA WITH MUCH DRIER DEW
POINTS TO THE W AT KCSG AND NATL. A POTENT 90 KT 500 MB JET SEGMENT
ACROSS N GEORGIA AND UPSTATE SOUTH CAROLINA. THE AIR MASS OVER SE
GEORGIA AND SOUTHERN SOUTH CAROLINA HAS BEEN VERY MILD OVERNIGHT
BUT NOT EXTREMELY UNSTABLE IN TANDEM WITH 35 KT OF DEEP LAYERED
SHEAR. CONVECTIVE RAINS IN BATCHES RUNNING OUT AHEAD OF THE FRONT
WITH A FEW COLDER TOPS ON SATELLITE DEVELOPING TO THE S OF THE
ALTAMAHA RIVER AND SCATTERED DOWNPOURS MOVING E OF THE I-95
CORRIDOR IN SE SOUTH CAROLINA. THERE IS A NARROW WINDOW FOR
ISOLATED STRONG THUNDERSTORMS GIVEN THE LATEST RUC ANALYSIS AND
3-HR DATA...BUT THE OPPORTUNITY IS NARROW. WE HAVE A CHANCE OF
SHOWERS ONGOING WITH SLIGHT CHANCE THUNDER DECREASING OVER INLAND
ZONES TOWARD DAYBREAK AS THE FRONT CLOSES IN.
TODAY...THE DEEP UPPER LOW OVER THE UPPER MIDWEST CONTINUES TO BE
THE FEATURE OF NOTE. MODELS IN GOOD AGREEMENT WITH SHIFTING THE
COLD FRONT OFF THE COAST THIS MORNING WITH A PUNCH OF MUCH DRIER
AIR IN IT/S WAKE POISED TO END THE RAIN CHANCES AND DELIVER CLEARING
SKIES. ELEVATED OVERNIGHT 925 MB DEW POINTS NEAR 17C ARE FORECAST
TO BE SUPPLANTED BY -1C TO 6C DEW POINTS BY EARLY THIS AFTERNOON.
DEEPER LAYERED MOISTURE ALSO BECOMES VERY DRY AND WE THINK SUNNY
SKIES WILL PREVAIL ALL AREAS BY AFTERNOON. MUCH LOWER SURFACE DEW
POINTS LATER TODAY WILL ACCOMPANY HIGH TEMPS IN THE LOWER 80S
THANKS TO DECENT DOWNSLOPE AND LACK OF SUSTAINED COLD AIR ADVECTION.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
AN UPPER DISTURBANCE ACROSS THE GREAT PLAINS STATES THIS MORNING
IS FORECAST TO DIG RAPIDLY SE INTO THE MID SOUTH REGION LATER
TODAY THEN SHARPEN A PROGRESSIVE SHORT WAVE OVER GEORGIA AND THE
CAROLINAS TONIGHT. DEEP LAYERED DRIER AIR UNFAVORABLE FOR MUCH IN
THE WAY OF CLOUD DEVELOPMENT OTHER THAN OFF THE COAST. LOW LEVEL
FLOW WILL BACK TO SW IN RESPONSE TO THIS FEATURE AND WE MADE VERY
LITTLE CHANGE TO TONIGHT/S LOWS IN THE UPPER 40S WELL INLAND TO
50-55 CLOSER TO THE COAST.
THE BROAD UPPER TROUGH WILL SHIFT EAST OF THE AREA BY LATE SATURDAY
BEFORE A STRONG UPPER RIDGE BUILDS IN FROM THE WEST THROUGH EARLY
NEXT WEEK. AT THE SURFACE...COOL AND DRY HIGH PRESSURE WILL BUILD
IN. ALTHOUGH THICKNESSES WOULD ONLY GIVE US HIGHS IN THE LOWER 70S
SATURDAY AND SUNDAY...PRONOUNCED DOWNSLOPE FLOW SHOULD NUDGE THOSE
READINGS INTO THE MIDDLE 70S. BY MONDAY THE 850 MB RIDGE WILL BE
DIRECTLY OVERHEAD...ALLOWING FOR AN INCREASE IN THICKNESSES WHICH
WILL PUSH HIGH TEMPS TOWARD 80 DEGREES. STRONG RADIATIONAL COOLING
EXPECTED DURING THE OVERNIGHT PERIODS UNDER CLEAR SKIES...LIGHT
WINDS AND LOW DEWPOINTS. LOW TEMPERATURES ARE EXPECTED TO BE SEVERAL
DEGREES BELOW NORMAL WITH MIDDLE 40S TO LOWER 50S.
&&
.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
PERSISTENT UPPER RIDGE AND SURFACE HIGH PRESSURE SHOULD MAINTAIN
MOSTLY DRY CONDITIONS THROUGH NEXT FRIDAY. ONLY SLIGHT INDICATIONS
OF A WEAK COASTAL TROUGH NEXT THURSDAY OR FRIDAY AS THE SURFACE HIGH
SHIFTS OFF THE EASTERN SEABOARD. MAINTAINED DRY CONDITIONS AT THIS
TIME BUT A FEW SHOWERS CANNOT BE RULED OUT...MAINLY ACROSS SOUTHEAST
GEORGIA. THIS PATTERN WILL SUPPORT HIGH TEMPERATURES SLIGHTLY ABOVE
SEASONAL NORMALS.
&&
.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
SCATTERED SHOWERS AND POSSIBLY AN ISOLATED THUNDERSTORM COULD
IMPACT THE TERMINALS AHEAD OF AN APPROACHING COLD FRONT...AND
VICINITY SHOWERS ARE INCLUDED IN THE TAF/S ONLY MAINLY DURING THE
EARLY OVERNIGHT HOURS THROUGH ABOUT DAYBREAK. WE HAVE MADE ONLY
MINOR TIMING ADJUSTMENTS TO TEMPO PERIODS FOR SHOWERS AT KCHS WITH
AN 06Z-09Z INCLUSION AT KSAV GIVEN LATEST RADAR TRENDS. THE FRONT
WILL PUSH OFFSHORE BY FRIDAY MORNING...WITH SKIES CLEARING IN ITS
WAKE.
EXTENDED AVIATION OUTLOOK...VFR WEATHER WILL PREVAIL.
&&
.MARINE...
A COLD FRONTAL PASSAGE THIS MORNING WILL BRING A WIND SHIFT FROM
S AND SW TO THE W AND NW. SURGES WILL OCCUR PRIOR TO MID MORNING
WITH A LIGHT FLOW LESS THAN 10 KT LIKELY THIS AFTERNOON.
TONIGHT... AN UPPER LEVEL DISTURBANCE WILL BACK LOW LEVEL WINDS
TO THE SW BEFORE SHIFTING WNW LATE. ANOTHER SURGE IS ANTICIPATED
LATE TONIGHT WITH A 15G20 KT POTENTIAL OVER OUTER WATERS BEYOND
15-20 MILES OFFSHORE. SEAS WILL BE IN THE 2 TO 4 FT RANGE...
HIGHEST WELL OFFSHORE.
HIGH PRESSURE WILL REMAIN JUST NORTH OF THE AREA THROUGH THE MIDDLE
OF NEXT WEEK WITH WINDS GENERALLY 15 KT OR LESS AND SEAS 4 FT OR
LESS.
&&
.TIDES/COASTAL FLOODING...
TIDE LEVELS WILL REMAIN HIGH TODAY DUE TO THE PERIGEAN
SPRING TIDES AND SLIGHTLY ELEVATED SEAS. LITTLE DEVIATION FROM THE
PREDICTED LEVELS WILL BE NEEDED TO GENERATE SHALLOW COASTAL
FLOODING WITH THE HIGH TIDE AROUND MIDDAY. WE THINK THE FLOW BECOMING
W IN THE WAKE OF THE COLD FRONT THIS MORNING WILL LIKELY DIMINISH THE
OVERALL RISK FOR TIDE LEVELS TOUCHING 7.0 MLLW AT DOWNTOWN CHARLESTON.
&&
.EQUIPMENT...
THE KCLX UPGRADE TO DUAL POLARIZATION IS UNDERWAY. AS A RESULT
RADAR DATA WILL NOT BE AVAILABLE DURING THE INSTALLATION AND
TESTING PHASE OF THE UPGRADE WHICH COULD LAST UP TO 2 WEEKS. USERS
ARE URGED TO UTILIZE ADJACENT RADARS DURING THE UPGRADE...WHICH
INCLUDE KLTX...KCAE...KJGX...KVAX AND KJAX.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...JRL
LONG TERM...JRL
AVIATION...
MARINE...JRL
TIDES/COASTAL FLOODING...
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
223 AM CDT FRI OCT 19 2012
.DISCUSSION...
925 PM CDT
A MASSIVE STACKED LOW PRESSURE CONTINUES TO PIVOT ACROSS THE UPPER
MIDWEST AND WESTERN GREAT LAKES TONIGHT. TO EXPRESS HOW
IMPRESSIVELY DEEP THIS LOW IS...THIS SYSTEM HAS DIPPED THE
TROPOPAUSE DOWN TO NEAR 400 MB ON AREA RAOBS...WITH 250 MB
TEMPERATURES 13C DEGREES WARMER IN THE CENTER OF THE CIRCULATION
/DUE TO STRATOSPHERIC FOLDING/. MULTIPLE MID AND LOW-LEVEL
CIRCULATIONS CONTINUE TO TWIRL AROUND EACH OTHER. SEVERAL SUCH
MID-LEVEL IMPULSES ARE IN A WRAPAROUND TONGUE OF MOISTURE AND
GRADUAL ASCENT OVER THE AREA THIS EVE. THIS IS FORECAST TO
CONTINUE ON RAP ISENTROPIC FIELDS INTO OVERNIGHT AND GRADUALLY
SHIFT EAST AS THE LOW CENTER EXPANDS INTO THE NORTHWEST FORECAST
AREA. GENERAL DRIZZLE WITH NUMEROUS TO WIDESPREAD SHOWERS HAVE BEEN
THE PREVAILING RAIN MODE. EARLIER PRIOR TO SUNSET THERE WERE A
FEW 40 DBZ ECHOES NEAR THE FREEZING LEVEL...AND A FEW PUBLIC
REPORTS OF GRAUPEL WERE REPORTED IN ROCKFORD. FOR THE REMAINDER OF
TONIGHT THE PRECIP TYPE SHOULD BE DRIZZLE AND LIGHT TO MODERATE
SHOWERS. ON FRIDAY THE POTENTIAL FOR GRAUPEL WILL AGAIN RE-
INCREASE. IN ADDITION...WITH THE LOW CENTER AND A DIMINISHING WIND
FIELD APPROACHING LAKE MICHIGAN...ANY POTENTIAL CONVERGENCE AREA
WILL LIKELY SERVE AS FOCI FOR WATERSPOUTS...INCLUDING NEAR THE
SHORES.
AS FOR TEMPERATURES...THEY SHOULD REMAIN NEARLY STEADY...DROPPING
ONLY ABOUT 2-4 DEGREES THE REMAINDER OF TONIGHT. SOME LIGHT FOG IS
POSSIBLE TOWARDS THE ROCKFORD AREA AS THE WINDS BECOME LIGHT LATE.
MTF
//PREV DISCUSSION...
341 PM CDT
MAIN FORECAST CONCERNS CONTINUE WITH SHOWERS/POSSIBLE THUNDER THIS
AFTERNOON...AND SHOWERS TO PERSIST THROUGH FRIDAY.
LATEST WATER VAPOR IMAGERY SHOWING LARGE CLOSED UPPER LEVEL SYSTEM
OVER THE MIDWEST THIS AFTERNOON...WITH SEVERAL STRONG MID LEVEL
FEATURES WRAPPING AROUND THIS SYSTEM. THIS FORCING IN THE PRESENCE
OF STEEP LAPSE RATES...PER AMDAR SOUNDINGS AND RAP ANALYSIS...HAS
ALLOWED SHOWERS TO BLOSSOM ACROSS NORTHERN ILLINOIS. ISOLATED
CONVECTIVE ELEMENTS HAVE ALSO BEGUN TO DEVELOP OUT AHEAD OF THIS
MAIN PRECIP SHIELD ACROSS NORTHEAST ILLINOIS AND NORTHWEST INDIANA
WHERE STEEPER LAPSE RATES CURRENTLY RESIDE. EXPECT THESE
CONVECTIVE ELEMENTS TO BE THE MORE NORM THROUGH THE REMAINDER OF
THE AFTERNOON AS MAIN PRECIP SHIELD CONTINUES TO SHIFT ACROSS THE
AREA. ITS IN THESE CONVECTIVE ELEMENTS THAT HEAVIER SHOWERS AND
LOWER VIS COULD OCCUR...AND ALSO WHERE THE POSSIBILITY OF
THUNDER/SMALL HAIL STILL MAY OCCUR.
UPPER LEVEL LOW WILL CONTINUE TO SLOWLY MEANDER TO THE EAST
OVERNIGHT...WITH PRECIP EXPECTED TO PERSIST FOR MUCH OF THE CWA
TONIGHT. ALTHOUGH WITH MID LEVEL FEATURES/FORCING SHIFTING
EASTWARD TONIGHT...MAIN AXIS OF PRECIP SHOULD ALSO SHIFT.
NEVERTHELESS...EXPECT AT LEAST LIGHT SHOWERS OR DRIZZLE TO
CONTINUE OVERNIGHT ACROSS THE ENTIRE CWA WITH TEMPS SLOWLY
LOWERING TO AROUND 40 ACROSS NORTHERN ILLINOIS AND THE LOWER 40S
FOR THE REMAINDER OF THE CWA...AS EXPANSIVE CLOUD SHIELD REMAINS
OVERHEAD. UPPER LEVEL LOW CENTER AND COLDEST TEMPS WILL BE
OVERHEAD ON FRIDAY...WITH A SIMILAR SETUP EXPECTED ONCE AGAIN.
SHOWERS WILL BE POSSIBLE ALONG WITH A SLIGHT CHANCE FOR
THUNDERSTORMS/SMALL HAIL ONCE AGAIN IN THE AFTERNOON...WHEN LAPSE
RATES ARE ONCE AGAIN EXPECTED TO BE THE STEEPEST. TEMPS WILL
STRUGGLE TO CLIMB MUCH AS THIS CLOUD SHIELD WILL REMAIN
OVERHEAD...WITH TEMPS IN THE UPPER 40S TO AROUND 50 EXPECTED.
GUIDANCE IN FAIR AGREEMENT WITH TAKING THIS UPPER LEVEL LOW EAST
OF THE AREA BY FRIDAY NIGHT AND EARLY SATURDAY MORNING. SO
CONTINUED TREND OF LOWERING POPS THROUGH FRIDAY NIGHT BUT WITH
THESE SYSTEMS GENERALLY MOVING SLOWER THAN MODEL GUIDANCE...WASNT
TOO AGGRESSIVE WITH LOWERING THE POPS AS STRAY SHOWERS MAY
LINGERING WITH CYCLONIC FLOW STILL IN PLACE.
AS UPPER LEVEL SYSTEM CONTINUES TO DRIFT EAST ON SATURDAY...HEIGHT
RISES ON THE BACKSIDE OF THIS SYSTEM WILL SET THE STAGE FOR A
PERIOD OF UPPER LEVEL RIDGING. WHAT THIS WILL MEAN FOR THE
REMAINDER OF THE WEEKEND WILL BE CLEARING SKIES AND QUIET WEATHER
WITH AN INCREASE IN TEMPS. EXPECT WINDS TO FLOP BACK TO THE
SOUTH/SOUTHWEST LATE SATURDAY WITH WAA USHERING IN SOME WARMTH
ACROSS THE REGION. THIS WAA AND SUNNY SKIES WILL HELP TEMPS RISE
WITH FORECAST HIGHS EXPECTED TO BE IN THE UPPER 60S TO LOW 70S ON
SUNDAY. THIS WARMTH WILL CONTINUE ON MONDAY WITH A SLIGHT INCREASE
IN TEMPS...AS THEY RISE TO THE LOW TO MID 70S. ALTHOUGH WITH THE
RIDGE AXIS OVERHEAD...THIS WILL BRING A SETUP FOR STEERING FLOW TO
BRING ABOUT SOME MID LEVEL ENERGY AND ACTIVE WEATHER FOR NEXT
WEEK.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* CIGS TRENDING TO IFR. PSBL IFR THRU MID-MORNING.
* PATCHY LGT DZ THRU OVERNIGHT AND MID-MORNING.
* S WINDS BECOMING SW/W WINDS BY MIDDAY AROUND 10-12KT. OCCASIONAL
GUSTS TO 16 KT.
* PSBL LGT SHRA MIDDAY THRU EARLY AFTN.
BEACHLER
//DISCUSSION...UPDATED 06Z...
STRONG AUTUMN WEATHER SYSTEM CONTINUES TO BE THE MAIN REASON FOR
REDUCED CIGS AND AREAS OF RA. WIDESPREAD AREAS OF IFR CIGS HAVE
STEADILY DEVELOPED AND WILL REMAIN THROUGH THE NEXT 12 HOURS. IT
APPEARS ONCE THE STEADIER RA PUSHES EAST OF THE NORTHEAST
IL/NORTHWEST IN AIRFIELDS THAT PATCHY DZ WILL OCCUR FOR THE
REMAINDER OF THE OVERNIGHT. THE CENTER OF CIRCULATION REMAINS
POSITIONED NORTHWEST OF THE AREA...WHICH HAS ALLOWED WINDS TO
REMAIN SOUTHERLY. IT APPEARS BY MID-MORNING THE SURFACE LOW
PRESSURE WILL SLIDE SOUTHEAST AND ALLOW WINDS TO TURN
SOUTHWESTERLY. AT THIS POINT CIGS MAY TRY TO PUSH UP
SLIGHTLY...HOWEVER A VERY LOW CONFIDENCE AT THIS POINT AND HAVE
OPTED TO KEEP CIGS DOWN AT LOW END MVFR CONDS. IT DOES NOT APPEAR
THAT ANY MAINTAINED IMPROVEMENT TO THE CIGS WILL OCCUR UNTIL
MIDDAY OR THE EARLY AFTN HOURS. WINDS WILL THEN TURN WESTERLY AND
POSSIBLY NORTHWEST BY A FEW HOURS AFTER SUNSET. DRY AIR WILL THEN
BEGIN TO FILTER IN...WHICH COULD AID IN PUSHING CIGS BACK TOWARDS
VFR.
BEACHLER
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE IN WIND DIR/SPEED.
* HIGH CONFIDENCE IN CIGS BEING REDUCED.
* HIGH CONFIDENCE VSBYS WILL REMAIN MVFR OR BETTER.
* MEDIUM CONFIDENCE IN CIGS REMAINING AT LOW END MVFR PSBL IFR.
* HIGH CONFIDENCE IN SHRA TRENDING TOWARDS PATCHY DZ THRU
DAYBREAK.
BEACHLER
//OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z...
* SATURDAY AND SUNDAY...VFR. WX NIL.
* MONDAY THROUGH WEDNESDAY...CHANCE OF TSRA/SHRA.
KJB
&&
.MARINE...
221 AM CDT
POTENT AUTUMN SYSTEM CONTINUES TO BE THE MAIN PLAYER IN THE WEATHER
ACROSS LAKE MICHIGAN TODAY...AND IT APPEARS THIS WILL CONTINUE
THROUGH THE NEXT COUPLE OF DAYS. FOR THE SECOND HALF OF THE WEEKEND
A BRIEF LULL IN ACTIVITY OVER THE LAKE...BEFORE YET ANOTHER SYSTEM
BEGINS TO DEVELOP AND BRING INCREASING SOUTHERLY WINDS FOR MONDAY.
STRONG LOW PRESSURE WILL SLOWLY SLIDE EAST ACROSS SOUTHERN WISCONSIN
TODAY...PUSHING OVER LAKE MICHIGAN EARLY THIS EVENING. IT DOES NOT
APPEAR TO CARRY MUCH OF A GRADIENT WITH THIS LOW AT THE
ONSET...HOWEVER AS THE LOW PRESSURE STEADILY PUSHES EAST OVER LOWER
MICHIGAN THE GRADIENT ON THE BACKSIDE WILL STEADILY INCREASE. AT
THIS TIME IT APPEARS WINDS WILL REMAIN UNDER GALE
CRITERIA...ALTHOUGH A FEW GALE GUSTS TO 35 KT MAY OCCUR DURING THE
PRE-DAWN HOURS SAT. OTHERWISE WEST WINDS WILL BECOME NORTHWEST AND
GENERALLY BE IN THE 20 TO 25 KT RANGE. THIS DIRECTION FAVORS AN
OPTIMAL FETCH SETUP FOR THE INDIANA NEARSHORE WATERS IN SEEING
BUILDING WAVES AND REACHING SMALL CRAFT ADVISORY CRITERIA. WINDS MAY
BE STRONG ENOUGH FOR THE ILLINOIS SHORE TO WARRANT A SMALL CRAFT AS
WELL.
WITH AN ELONGATED HIGH PRESSURE PUSHING ACROSS THE OHIO RIVER
VALLEY...STRETCHING AN INFLUENCE NORTH TO THE STRAITS OF MACKINAW
SUN...THIS SHOULD BRING DIMINISHING WINDS TO LAKE MICHIGAN. WAVES
WILL RELAX AND GO BELOW SMALL CRAFT CONDITIONS SUN. AS THE FOCUS
TURNS TOWARDS YET ANOTHER LOW PRESSURE SYSTEM POISED TO PUSH INTO
THE CENTRAL PLAINS EARLY MON. THIS SYSTEM APPEARS TO BRING GUSTY
WINDS BACK TO THE REGION AND MAINLY SOUTHERN LAKE MICHIGAN MON
MIDDAY. WINDS WILL APPROACH SMALL CRAFT CRITERIA...ALTHOUGH THIS
CURRENTLY IS A LOW CONFIDENCE.
THIS EARLY WEEK LOW PRESSURE SYSTEM WILL STALL ACROSS THE NORTHERN
GREAT LAKES...WITH ANOTHER SYSTEM POSSIBLY DEVELOPING LATER IN THE
WEEK.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 5 AM FRIDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1235 AM CDT FRI OCT 19 2012
.DISCUSSION...
925 PM CDT
A MASSIVE STACKED LOW PRESSURE CONTINUES TO PIVOT ACROSS THE UPPER
MIDWEST AND WESTERN GREAT LAKES TONIGHT. TO EXPRESS HOW
IMPRESSIVELY DEEP THIS LOW IS...THIS SYSTEM HAS DIPPED THE
TROPOPAUSE DOWN TO NEAR 400 MB ON AREA RAOBS...WITH 250 MB
TEMPERATURES 13C DEGREES WARMER IN THE CENTER OF THE CIRCULATION
/DUE TO STRATOSPHERIC FOLDING/. MULTIPLE MID AND LOW-LEVEL
CIRCULATIONS CONTINUE TO TWIRL AROUND EACH OTHER. SEVERAL SUCH
MID-LEVEL IMPULSES ARE IN A WRAPAROUND TONGUE OF MOISTURE AND
GRADUAL ASCENT OVER THE AREA THIS EVE. THIS IS FORECAST TO
CONTINUE ON RAP ISENTROPIC FIELDS INTO OVERNIGHT AND GRADUALLY
SHIFT EAST AS THE LOW CENTER EXPANDS INTO THE NORTHWEST FORECAST
AREA. GENERAL DRIZZLE WITH NUMEROUS TO WIDESPREAD SHOWERS HAVE BEEN
THE PREVAILING RAIN MODE. EARLIER PRIOR TO SUNSET THERE WERE A
FEW 40 DBZ ECHOES NEAR THE FREEZING LEVEL...AND A FEW PUBLIC
REPORTS OF GRAUPEL WERE REPORTED IN ROCKFORD. FOR THE REMAINDER OF
TONIGHT THE PRECIP TYPE SHOULD BE DRIZZLE AND LIGHT TO MODERATE
SHOWERS. ON FRIDAY THE POTENTIAL FOR GRAUPEL WILL AGAIN RE-
INCREASE. IN ADDITION...WITH THE LOW CENTER AND A DIMINISHING WIND
FIELD APPROACHING LAKE MICHIGAN...ANY POTENTIAL CONVERGENCE AREA
WILL LIKELY SERVE AS FOCI FOR WATERSPOUTS...INCLUDING NEAR THE
SHORES.
AS FOR TEMPERATURES...THEY SHOULD REMAIN NEARLY STEADY...DROPPING
ONLY ABOUT 2-4 DEGREES THE REMAINDER OF TONIGHT. SOME LIGHT FOG IS
POSSIBLE TOWARDS THE ROCKFORD AREA AS THE WINDS BECOME LIGHT LATE.
MTF
//PREV DISCUSSION...
341 PM CDT
MAIN FORECAST CONCERNS CONTINUE WITH SHOWERS/POSSIBLE THUNDER THIS
AFTERNOON...AND SHOWERS TO PERSIST THROUGH FRIDAY.
LATEST WATER VAPOR IMAGERY SHOWING LARGE CLOSED UPPER LEVEL SYSTEM
OVER THE MIDWEST THIS AFTERNOON...WITH SEVERAL STRONG MID LEVEL
FEATURES WRAPPING AROUND THIS SYSTEM. THIS FORCING IN THE PRESENCE
OF STEEP LAPSE RATES...PER AMDAR SOUNDINGS AND RAP ANALYSIS...HAS
ALLOWED SHOWERS TO BLOSSOM ACROSS NORTHERN ILLINOIS. ISOLATED
CONVECTIVE ELEMENTS HAVE ALSO BEGUN TO DEVELOP OUT AHEAD OF THIS
MAIN PRECIP SHIELD ACROSS NORTHEAST ILLINOIS AND NORTHWEST INDIANA
WHERE STEEPER LAPSE RATES CURRENTLY RESIDE. EXPECT THESE
CONVECTIVE ELEMENTS TO BE THE MORE NORM THROUGH THE REMAINDER OF
THE AFTERNOON AS MAIN PRECIP SHIELD CONTINUES TO SHIFT ACROSS THE
AREA. ITS IN THESE CONVECTIVE ELEMENTS THAT HEAVIER SHOWERS AND
LOWER VIS COULD OCCUR...AND ALSO WHERE THE POSSIBILITY OF
THUNDER/SMALL HAIL STILL MAY OCCUR.
UPPER LEVEL LOW WILL CONTINUE TO SLOWLY MEANDER TO THE EAST
OVERNIGHT...WITH PRECIP EXPECTED TO PERSIST FOR MUCH OF THE CWA
TONIGHT. ALTHOUGH WITH MID LEVEL FEATURES/FORCING SHIFTING
EASTWARD TONIGHT...MAIN AXIS OF PRECIP SHOULD ALSO SHIFT.
NEVERTHELESS...EXPECT AT LEAST LIGHT SHOWERS OR DRIZZLE TO
CONTINUE OVERNIGHT ACROSS THE ENTIRE CWA WITH TEMPS SLOWLY
LOWERING TO AROUND 40 ACROSS NORTHERN ILLINOIS AND THE LOWER 40S
FOR THE REMAINDER OF THE CWA...AS EXPANSIVE CLOUD SHIELD REMAINS
OVERHEAD. UPPER LEVEL LOW CENTER AND COLDEST TEMPS WILL BE
OVERHEAD ON FRIDAY...WITH A SIMILAR SETUP EXPECTED ONCE AGAIN.
SHOWERS WILL BE POSSIBLE ALONG WITH A SLIGHT CHANCE FOR
THUNDERSTORMS/SMALL HAIL ONCE AGAIN IN THE AFTERNOON...WHEN LAPSE
RATES ARE ONCE AGAIN EXPECTED TO BE THE STEEPEST. TEMPS WILL
STRUGGLE TO CLIMB MUCH AS THIS CLOUD SHIELD WILL REMAIN
OVERHEAD...WITH TEMPS IN THE UPPER 40S TO AROUND 50 EXPECTED.
GUIDANCE IN FAIR AGREEMENT WITH TAKING THIS UPPER LEVEL LOW EAST
OF THE AREA BY FRIDAY NIGHT AND EARLY SATURDAY MORNING. SO
CONTINUED TREND OF LOWERING POPS THROUGH FRIDAY NIGHT BUT WITH
THESE SYSTEMS GENERALLY MOVING SLOWER THAN MODEL GUIDANCE...WASNT
TOO AGGRESSIVE WITH LOWERING THE POPS AS STRAY SHOWERS MAY
LINGERING WITH CYCLONIC FLOW STILL IN PLACE.
AS UPPER LEVEL SYSTEM CONTINUES TO DRIFT EAST ON SATURDAY...HEIGHT
RISES ON THE BACKSIDE OF THIS SYSTEM WILL SET THE STAGE FOR A
PERIOD OF UPPER LEVEL RIDGING. WHAT THIS WILL MEAN FOR THE
REMAINDER OF THE WEEKEND WILL BE CLEARING SKIES AND QUIET WEATHER
WITH AN INCREASE IN TEMPS. EXPECT WINDS TO FLOP BACK TO THE
SOUTH/SOUTHWEST LATE SATURDAY WITH WAA USHERING IN SOME WARMTH
ACROSS THE REGION. THIS WAA AND SUNNY SKIES WILL HELP TEMPS RISE
WITH FORECAST HIGHS EXPECTED TO BE IN THE UPPER 60S TO LOW 70S ON
SUNDAY. THIS WARMTH WILL CONTINUE ON MONDAY WITH A SLIGHT INCREASE
IN TEMPS...AS THEY RISE TO THE LOW TO MID 70S. ALTHOUGH WITH THE
RIDGE AXIS OVERHEAD...THIS WILL BRING A SETUP FOR STEERING FLOW TO
BRING ABOUT SOME MID LEVEL ENERGY AND ACTIVE WEATHER FOR NEXT
WEEK.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* CIGS TRENDING TO IFR. PSBL IFR THRU MID-MORNING.
* PATCHY LGT DZ THRU OVERNIGHT AND MID-MORNING.
* S WINDS BECOMING SW/W WINDS BY MIDDAY AROUND 10-12KT. OCCASIONAL
GUSTS TO 16 KT.
* PSBL LGT SHRA MIDDAY THRU EARLY AFTN.
BEACHLER
//DISCUSSION...UPDATED 06Z...
STRONG AUTUMN WEATHER SYSTEM CONTINUES TO BE THE MAIN REASON FOR
REDUCED CIGS AND AREAS OF RA. WIDESPREAD AREAS OF IFR CIGS HAVE
STEADILY DEVELOPED AND WILL REMAIN THROUGH THE NEXT 12 HOURS. IT
APPEARS ONCE THE STEADIER RA PUSHES EAST OF THE NORTHEAST
IL/NORTHWEST IN AIRFIELDS THAT PATCHY DZ WILL OCCUR FOR THE
REMAINDER OF THE OVERNIGHT. THE CENTER OF CIRCULATION REMAINS
POSITIONED NORTHWEST OF THE AREA...WHICH HAS ALLOWED WINDS TO
REMAIN SOUTHERLY. IT APPEARS BY MID-MORNING THE SURFACE LOW
PRESSURE WILL SLIDE SOUTHEAST AND ALLOW WINDS TO TURN
SOUTHWESTERLY. AT THIS POINT CIGS MAY TRY TO PUSH UP
SLIGHTLY...HOWEVER A VERY LOW CONFIDENCE AT THIS POINT AND HAVE
OPTED TO KEEP CIGS DOWN AT LOW END MVFR CONDS. IT DOES NOT APPEAR
THAT ANY MAINTAINED IMPROVEMENT TO THE CIGS WILL OCCUR UNTIL
MIDDAY OR THE EARLY AFTN HOURS. WINDS WILL THEN TURN WESTERLY AND
POSSIBLY NORTHWEST BY A FEW HOURS AFTER SUNSET. DRY AIR WILL THEN
BEGIN TO FILTER IN...WHICH COULD AID IN PUSHING CIGS BACK TOWARDS
VFR.
BEACHLER
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE IN WIND DIR/SPEED.
* HIGH CONFIDENCE IN CIGS BEING REDUCED.
* HIGH CONFIDENCE VSBYS WILL REMAIN MVFR OR BETTER.
* MEDIUM CONFIDENCE IN CIGS REMAINING AT LOW END MVFR PSBL IFR.
* HIGH CONFIDENCE IN SHRA TRENDING TOWARDS PATCHY DZ THRU
DAYBREAK.
BEACHLER
//OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z...
* SATURDAY AND SUNDAY...VFR. WX NIL.
* MONDAY THROUGH WEDNESDAY...CHANCE OF TSRA/SHRA.
KJB
&&
.MARINE...
253 PM CDT
A LARGE UPPER LEVEL LOW WILL CONTINUE TO SPIN OVER OVER SOUTHERN
WISCONSIN AND SOUTHERN LAKE MICHIGAN TONIGHT AND FRIDAY BEFORE
GRADUALLY SHIFTING OFF TO THE EAST INTO SATURDAY. ONE AREA OF LOW
PRESSURE CONTINUES TO SPIN OVER THE ARROWHEAD OF MINNESOTA WITH A
SECONDARY CIRCULATION OVER WEST CENTRAL WISCONSIN. THE TWO LOWS WILL
MERGE AND WEAKEN TONIGHT AND THEN MOVE EASTWARD ACROSS SOUTHERN LAKE
MICHIGAN FRIDAY AND FRIDAY NIGHT. IN THE MEANTIME...THE PRESSURE
GRADIENT REMAINS STRONG LEADING TO 30 KT SOUTH TO SOUTHWEST WINDS
ACROSS THE LAKE...WITH SOME 35 KT GALES OCCURRING AT TIMES LATE THIS
AFTERNOON AND POSSIBLY EARLY THIS EVENING. SPEEDS LOOK TO REMAIN
STEADY THROUGH THE EVENING BUT THEN BEGIN TO SLOWLY DIMINISH AS THE
LOW BROADENS AND WEAKENS RESULTING IN A WEAKER PRESSURE GRADIENT.
THE DOWNWARD TREND SHOULD CONTINUE FRIDAY WITH WIND DIRECTION
BECOMING MORE COMPLEX AS THE LOW CROSSES THE SOUTHERN PART OF THE
LAKE. SOUTHWEST WINDS WILL OCCUR TO THE SOUTH OF THE LOW WHILE WINDS
TURN SOUTHEAST...THEN EAST...THEN NORTHEAST NORTH OF THE LOW ACROSS
THE NORTHERN HALF TO TWO-THIRDS OF THE LAKE FRIDAY. ONCE THE LOW
SHIFTS EAST FRIDAY EVENING NORTH TO NORTHWEST WINDS WILL TAKE OVER
WITH SOME MODEST INCREASE IN SPEEDS LIKELY AS THE PRESSURE GRADIENT
RECOVERS BUT THE LOW ITSELF WILL REMAIN IN A WEAKENED STATE. IN
ADDITION...WITH THE UPPER LOW PRESENT AND COLDER AIR ACROSS THE
LAKE...THERE WILL BE A GOOD CHANCE FOR WATERSPOUTS THROUGH
FRIDAY...WITH A FEW THUNDERSTORMS POSSIBLE AS WELL.
THE NORTHWEST WINDS WILL CONTINUE INTO INTO SATURDAY BEFORE TURNING
WESTERLY THEN SOUTHWESTERLY SATURDAY EVENING AS A RIDGE OF HIGH
PRESSURE BUILDS FROM SOUTHERN LAKE MICHIGAN INTO WESTERN WISCONSIN.
THE RIDGE SHIFTS EAST MONDAY ALLOWING WINDS TO TURN SOUTHEASTERLY AS
LOW PRESSURE SPREADS ACROSS THE CENTRAL AND NORTHERN PLAINS FOR THE
MIDDLE PART OF THE WEEK. SOUTH TO SOUTHEAST WINDS WILL LIKELY
INCREASE AS THE PRESSURE GRADIENT STRENGTHENS AS THE LOW TRACKS
NORTHEAST ACROSS THE UPPER MISSISSIPPI RIVER VALLEY AND LAKE
SUPERIOR. BEYOND THAT A FRONTAL BOUNDARY SHOULD CROSS THE LAKE AND
BRING A RETURN TO NORTHERLY WINDS FOR LATE WEEK.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 5 AM FRIDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1138 PM CDT THU OCT 18 2012
.AVIATION...
MVFR TO BRIEF IFR CONDITIONS WILL CONTINUE OVERNIGHT WITH
GENERALLY LIGHT WINDS AS SURFACE AND UPPER LOW PRESSURE SLOWLY
MOVE OVER THE LOCAL AREA. POCKETS OF LIGHT RAIN...DRIZZLE AND SOME
FOG ARE LIKELY THROUGH 15Z...FOLLOWED BY SCATTERED SHOWERS.
CONDITIONS SHOULD IMPROVE FROM THE VARIABLE MVFR/IFR TO CONSISTENT
MVFR BY MID MORNING FRIDAY...LASTING INTO FRIDAY EVENING.
NORTHWEST WINDS WILL INCREASE TOWARDS 15Z AT ALL SITES...WITH
SUSTAINED WINDS OF 10 TO 15 KTS POSSIBLE.
THE OVERNIGHT DRIZZLE AND FOG MAY LIMIT VISIBILITIES TO UNDER 3
MILES FOR SHORT TIMES...WITH CIGS OF 500 TO 1000 FT AS WELL.
&&
.PREV DISCUSSION... /ISSUED 432 PM CDT THU OCT 18 2012/
UPDATE...
UPDATED FOR 100 PERCENT COVERAGE OF RAINFALL IN THE PERSISTENT
BAND OF RAIN OVER THE CWA THE REMAINDER OF THE AFTERNOON. ALSO
INCREASED POPS SOMEWHAT OVER THE SOUTH HALF THIS EVENING DUE TO
WIDESPREAD COVERAGE. RAINFALL AMOUNTS FROM TODAY AND EARLY EVENING
SHOULD RANGE FROM 0.1 TO 0.2 IN MOST LOCATIONS.
ERVIN
PREV DISCUSSION... /ISSUED 352 PM CDT THU OCT 18 2012/
SYNOPSIS...
12Z UA ANALYSIS HAS AN 850MB LOW ALONG THE MN/WI BORDER NORTHEAST
OF KMSP. THE 850MB COLD FRONT RAN FROM THE LOW INTO LOWER MICHIGAN
AND THEN SOUTH TO SOUTHEAST ARKANSAS AND THEN INTO CENTRAL TEXAS.
SEVERAL TROFS RAN BEHIND THE COLD FRONT FROM WI/IL BACK THROUGH
IOWA AND NEBRASKA. SATELLITE/RADAR TRENDS THROUGH MID AFTERNOON
SHOW EXTENSIVE WRAP AROUND CLOUDS ACROSS THE AREA WITH LIGHT RAIN
AND DRIZZLE ACROSS THE AREA.
18Z SFC ANALYSIS PLACES THE SFC LOW NEAR KMSP WITH AN OCCLUDED
FRONT NORTHEAST TO ANOTHER SFC LOW OVER WESTERN LAKE SUPERIOR.
NUMEROUS WEAK TROFS RAN FROM WI/IL BACK THROUGH IOWA AND INTO
NEBRASKA. DEW POINTS WERE MAINLY IN THE 30S AND 40S ACROSS THE
MIDWEST.
SHORT TERM...TONIGHT AND FRIDAY...
ISENTROPIC UPGLIDE WILL CONTINUE ACROSS THE AREA LATE THIS
AFTERNOON RESULTING IN A LIGHT RAIN. HOWEVER...DOWNGLIDE WAS
OCCURRING ACROSS NORTHERN AND EXTREME NORTHEAST IOWA RESULTING IN
DRY CONDITIONS. TRENDS FROM THE RAP INDICATE THIS DOWNGLIDE WILL
MOVE INTO THE NORTHWEST TO NORTHERN CWFA EARLY THIS EVENING
BRIEFLY ENDING THE RAIN. THE MORE SUBSTANTIAL RAIN WILL PUSH TO
THE SOUTHERN THIRD TO 40 PERCENT OF THE CWFA.
BY LATE EVENING AND CONTINUING OVERNIGHT WEAK UPGLIDE WILL AGAIN
MOVE INTO THE NORTHERN CWFA WHILE THE MORE SUBSTANTIAL RAIN
CONTINUES TO SINK SOUTH. THUS LIGHT RAIN/DRIZZLE WILL AGAIN
DEVELOP ACROSS THE NORTHERN CWFA. AFTER MIDNIGHT WINDS ACROSS THE
NORTHERN PARTS OF THE CWFA DROP OFF SUGGESTING SOME PATCHY FOG MAY
DEVELOP PRIOR TO SUNRISE.
ON FRIDAY SPOTTY LIGHT RAIN/DRIZZLE WILL CONTINUE EARLY IN THE
MORNING WITH SOME PATCHY FOG POSSIBLE ACROSS THE NORTH. ISENTROPIC
UPGLIDE AGAIN BECOMES RE-ESTABLISHED BY LATE MORNING AND THROUGH
THE AFTERNOON. THUS...LIGHT RAIN IN CENTRAL IOWA WILL AGAIN ADVECT
INTO THE WESTERN CWFA AND CONTINUE MOVING EAST THROUGH THE
AFTERNOON HOURS. RIGHT NOW MAX TEMPERATURES FOR FRIDAY ARE IN THE
UPPER 40S TO LOWER 50S. HOWEVER...THESE MAY STILL BE TOO WARM AND
ACTUAL TEMPERATURES COULD BE SIMILAR TO THURSDAY. 08
LONG TERM...FRIDAY NIGHT THROUGH NEXT THURSDAY...
UPPER LOW WILL GRADUALLY RELINQUISH CONTROL OF OUR WEATHER FRIDAY
NIGHT INTO SATURDAY AS IT CONTINUES TO PUSHLY SLOWLY EAST ACROSS
THE GREAT LAKES REGION. AREAS OF LIGHT RAIN AND DRIZZLE LOOK TO
SHUT DOWN FRIDAY EVENING WITH SUBSIDENCE BUILDING FOR OVERNIGHT.
DESPITE THE SUBSIDENCE HAVE REMAINED MORE ON PESSIMISTIC SIDE ON
SKY COVER AND CLEARING TRENDS FRIDAY NIGHT INTO SATURDAY...GIVEN
ABUNDANT LOW LEVEL MOISTURE (AIDED BY PAST FEW DAYS OF RAIN)
BENEATH INVERSION... LOWER SUN ANGLE... AND EXTENSIVE CLOUD SHIELD
AROUND UPPER LOW DEPICTED WELL BY THE NAM MODEL WHICH IS MOST
AGGRESSIVE WITH MAINTAINING CLOUDS. AS RESULT... CONTINUE TO BE
NEAR WARM SIDE OF GUIDANCE ON LOWS FRIDAY NIGHT AND NEAR BLEND OR
COOL SIDE OF GUIDANCE FOR HIGHS ON SATURDAY.
PATTERN ALOFT SET TO TRANSITION TO SOUTHWEST FLOW OVER THE REGION
BY LATE IN THE WEEKEND... WITH THE MEDIUM RANGE MODELS GENERALLY
AGREEING ON MAINTAINING SOUTHWEST FLOW ALOFT THROUGH MUCH OF NEXT
WEEK. THIS REGIME FAVORS ABOVE NORMAL TEMPS ALONG WITH BOUTS OF
UNSETTLED WEATHER. THE CHALLENGE LIES IN THE DETAILS OF THE
FORECAST AS THE MODELS DIVERGE ON ENERGY EJECTING FROM WESTERN
TROUGH... ESPECIALLY BY TUESDAY AND CONTINUING INTO THURSDAY... WHICH
HAS IMPACT ON MOVEMENT OF FRONTAL ZONE AND SUBSEQUENT TEMPERATURE
FORECAST. GIVEN THE UNCERTAINTY... STAYED LARGELY WITH MODEL CONSENSUS
ON TEMPS/POPS FOR MONDAY THROUGH THURSDAY. DPROG/DT OF BOTH ECMWF
AND GFS SHOW CONTINUED SLOWING AND FURTHER NORTHWEST TREND WITH FRONTAL
ZONE IN GENERAL BY TUESDAY INTO THURSDAY. IF TRENDS PERSIST WOULD
EXPECT DECREASE IN RAIN CHANCES AND FURTHER WARMING ON TEMPS TO MUCH
ABOVE NORMAL FOR SOME OR MOST OF THIS PERIOD TUESDAY INTO THURSDAY.
TRANSITION TO MUCH COLDER REGIME IS STILL DEPICTED BY BOTH ECMWF AND
GFS BEYOND THE SCOPE OF CURRENT EXTENDED. MAIN CHALLENGE APPEARS TO
BE JUST EXACTLY WHEN THIS TRANSITION OCCURS. 05
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
455 AM EDT FRI OCT 19 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 449 AM EDT FRI OCT 19 2012
UPPER LOW REMAINS NEARBY THIS MORNING...CENTERED OVER WI/NORTHERN
IL. AT THE SFC...PRIMARY SFC LOW HAS NOW FOCUSED FARTHER SOUTH WITH
POSITION OVER NORTHWEST ILLINOIS. AN OCCLUDED FRONT IS ARCING FROM
THE LOW TO THE NORTH OF LK SUPERIOR WHILE COLD FRONT IS PLOWING
TOWARD ATLANTIC SEABOARD WITH SOME CONVECTION. RADAR LOOP OVER THE
WESTERN GREAT LAKES REGION SHOWS CONCENTRATED AREAS OF SHOWERS OVER
MINNESOTA...NORTHERN INDIANA...AND LIFTING NORTH ACROSS LK MICHIGAN.
OVER UPR MICHIGAN...ARE JUST SEEING A SMATTERING OF LGT SHOWERS OVER
CNTRL CWA THOUGH THE SHOWERS OVER LK MICHIGAN ARE POISED TO IMPACT
SCNTRL CWA EARLY THIS MORNING.
SFC LOW MOVES FROM NORTHERN ILLINOIS TO VCNTY LK HURON THIS EVENING.
WV LOOP AND RUC ANALYSIS INDICATE SHORTWAVES TO THE SOUTH OF UPR
MICHIGAN ON FRONT EDGE OF UPPER LOW ARE LIFTING NORTH THIS MORNING.
PRIMARY SHORTWAVE OVER INDIANA LIFTS ACROSS LOWER MICHIGAN TODAY AS
UPPER LOW SLOWLY MOVES EAST. RUC/GEM-REGIONAL HAVE DECENT HANDLE ON
LOCATION OF CURRENT SHOWERS AND BOTH SHOW MAIN AREA OF SHOWERS
STAYING OVER LOWER MICHIGAN THROUGH THE DAY. HOWEVER...AS THE
SHORTWAVE LIFTS NORTH...H85 WINDS BACK FROM SOUTHERLY TO MORE
EASTERLY...ALLOWING INCREASE IN H85 MOISTURE TRANSPORT ACROSS
CENTRAL AND EASTERN ZONES. COMBINATION OF THE ADDITIONAL MOISTURE
AND WEAK LIFT ON PERIFERY OF STRONGER SHORTWAVES LIFTING ACROSS
LOWER MICHIGAN SHOULD LEAD TO INCREASING COVERAGE OF SHOWERS FOR THE
EAST HALF OF CWA. SCATTERED WORDING WORKS FOR MOST AREAS TODAY. ONLY
EXCEPTION IS OVER THE KEWEENAW WHERE CHANCES STAY A BIT LOWER AS
THEY ARE FARTHER DISPLACED FROM THE FORCING. JUST A SLIGHT RISE IN
925MB TEMPS THROUGH THE DAY AS LOW-LEVEL WINDS BECOME MORE NORTH OF
EAST BY LATE DAY. EXPECT HIGHS TO REACH UPR 40S NORTH CENTRAL AND
INTO THE 50S ELSEWHERE. WHATEVER WEAK LIFT IS LEFT EVADES IN THE
EVENING...LEAVING 925-850MB MOISTURE BUT NOT MUCH FORCING. CUT OUT
POPS TOWARD MIDNIGHT FOR ALL AREAS. WEAKLY CYCLONIC NORTHEAST
LOW-LEVEL WINDS COULD KEEP BKN CLOUDS IN MOST OF THE NIGHT OVER
UPSLOPE AREAS OF WESTERN AND NORTH CENTRAL CWA. MIN TEMPS JUST
SLIGHTLY COOLER THAN TONIGHT...UPR 30S TO MID 40S.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 449 AM EDT FRI OCT 19 2012
NAM SHOWS A CLOSED 500 MB LOW OVER SE LOWER MICHIGAN IN AN EMBEDDED
DEEP TROUGH OVER THE EASTERN U.S. WITH A TROUGH OVER SW CANADA AND A
BROAD RIDGE OVER THE SOUTHERN ROCKIES INTO THE PLAINS ON SAT. THE
NAM BUILDS THE RIDGE INTO THE UPPER GREAT LAKES SAT NIGHT THROUGH
SUN NIGHT. WITH THE RIDGE IN THE AREA...LOOKS TO STAY DRY THIS
PERIOD AS THE CLOSED 500 MB LOW PULLS OFF TO THE EAST AND TAKES ITS
RAIN WITH IT AND WE WAIT FOR SYSTEMS TO EJECT OUT OF THE BROAD 500
MB TROUGH THAT WILL SET UP TO THE WEST. OVERALL...DID NOT MAKE TOO
MANY CHANGES TO THE GOING FORECAST FOR TEMPERATURES OR WEATHER.
IN THE EXTENDED...GFS AND ECMWF SHOW A 500 MB RIDGE OVER THE ERN
U.S. WITH A BROAD 500 MB TROUGH OVER THE WESTERN U.S. 12Z MON. UPPER
AIR FLOW STAYS OUT SW-NE THROUGH WED WITH LITTLE MOVEMENT TO THE
RIDGE OR THE TROUGH. ECMWF SHOWS A SHORTWAVE TROUGH EJECTING INTO
THE UPPER GREAT LAKES 12Z THU WHILE THE GFS IS SLOWER WITH IT. LOOKS
TO BE WARM AND WET THROUGH THE PERIOD WITH A CHANCE OF RAIN EACH
DAY. TEMPERATURES WILL CONTINUE TO BE ABOVE NORMAL. GETS KIND OF
TRICKY LATER ON FOR WINDS IN THE EXTENDED...ESPECIALLY THURSDAY AS
THE GFS AND ECMWF ARE 180 DEGREES OPPOSITE FOR WIND DIRECTIONS...BUT
ARE STRONG ON THE WINDS. KEPT PERSISTENCE FORECAST IN FOR NOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 135 AM EDT FRI OCT 19 2012
VERY CHALLENGING FCST WITH SLOW MOVING CLOSED LO PRES DRIFTING E
THRU THE LOWER GRT LKS. ALTHOUGH DISTURBANCES ROTATING ARND THIS
MAIN LO WL BRING PERIODS OF -SHRA...LLVL DRY ADVECTION WL PREVENT
CIGS/VSBYS FM FALLING AS LO AS MIGHT OTRW BE THE CASE. WITH DIURNAL
COOLING EARLY THIS MRNG...EXPECT MVFR CONDITIONS TO PREDOMINATE.
ALTHOUGH SOME DAYTIME HEATING ON FRI WL ALLOW CONDITIONS TO IMPROVE
TO VFR FOR AT LEAST A TIME...SUSPECT MVFR CONDITIONS WL REDEVELOP IN
THE EVNG WITH DIURNAL COOLING...ESPECIALLY AT IWD/SAW WITH MORE OF
AN UPSLOPE NE WIND.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 449 AM EDT FRI OCT 19 2012
SE WINDS TO 25 KTS TO START THE DAY THEN WINDS DIMINISH TO LESS THAN
20 KTS LATER TONIGHT INTO SATURDAY. COULD SEE NW WINDS REACH 25 KTS
SATURDAY OVER EASTERN PORTIONS OF LK SUPERIOR AS HIGH PRESSURE
BUILDS TOWARD SLOWLY EXITING LOW PRESSURE OVER QUEBEC...LEADING TO
TEMPORARY TIGHTER PRESSURE GRADIENT. EXPECT WINDS TO DIMINISH ON
SATURDAY NIGHT ONCE THE RIDGE MOVES OVERHEAD. WINDS WILL REMAIN AT
20 KTS OR LESS THROUGH EARLY NEXT WEEK WITH WEAK PRESSURE GRADIENT
IN PLACE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...07
AVIATION...KC
MARINE...JLA
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
333 AM CDT FRI OCT 19 2012
.SHORT TERM...
ISSUED AT 320 AM CDT FRI OCT 19 2012
(TODAY AND TONIGHT)
THE EXPANSIVE UPPER LOW CURRENTLY CENTERED IN WISCONSIN CONTINUES
TO MEANDER EASTWARD. A NUMBER OF WEAK IMPULSES PINWHEELING AROUND
THE VORTEX HAVE BEEN PRODUCING AREAS OF RAIN/SHOWERS. THE VAST
MAJORITY OF THE ACTIVITY THUS FAR WITHIN THE LSX CWA HAS BEEN
LOCATED ALONG AND NORTH OF I-70...AND HAS BEEN LIGHT AND NON-
MEASURABLE. REGIONAL RADARS SUGGEST THAT THE COVERAGE UPSTREAM HAS
BEGUN TO DIMINISH SOME. THE LATEST FORECASTS OF THE HRRR AND
DETERMINISTIC MODELS CONTINUE THIS TREND THOUGH THE MORNING AND
INTO THE AFTERNOON AS THE SYSTEM MOVES SLOWLY EASTWARD. STRATUS...GUSTY
WEST WINDS...AND POCKETS OF PRECIPITATION WILL MAKE FOR A COOL DAY
WITH WELL BELOW AVERAGE TEMPERATURES. THE UPPER LOW AND ATTENDANT
UPPER TROF WILL CONTINUE EASTWARD TONIGHT AND THE NWP MODEL SUITE
IS WELL CLUSTERED SHOWING THE UPPER LOW INVOF SRN MI WITH THE
UPPER TROF AXIS INTO THE TX PANHANDLE BY 12Z SAT. LOW LEVEL RH
PROGS SHOW THAT CLOUDS WILL PERSIST TONIGHT AND THIS SHOULD HELP
OVERNIGHT TEMPERATURES IN THE LOW-MID 40S.
GLASS
&&
.LONG TERM...
ISSUED AT 320 AM CDT FRI OCT 19 2012
(SATURDAY THROUGH SUNDAY)
THE UPPER AIR PATTERN WILL UNDERGO A CHANGE DURING THE PERIOD AS
THE UPPER LOW/TROF LIFT NEWD...WITH THE TROF SHIFTING INTO THE
WESTERN ATLANTIC BY SUNDAY EVENING. HEIGHTS ALOFT WILL RISE SOME
90 TO 120 M IN RESPONSE TO THE PROGRESSION...WITH A WEAK UPPER
RIDGE SHIFTING THROUGH THE MS VALLEY ON SUNDAY. SATURDAY WILL BE A
DAY OF TRANSITION AS CLOUDS ERODE AND A WEAK SURFACE RIDGE SLIDES
ACROSS THE CWA RESULTING IN MODERATING TEMPERATURES. A BIG WARM-UP
IS ON TAP SUNDAY IN RESPONSE TO THE HEIGHT RISES ALOFT AND GOOD
LOW LEVEL WAA.
(SUNDAY NIGHT THROUGH THURSDAY)
ABOVE AVERAGE TEMPERATURES AND A PERIOD OF POTENTIALLY STORMY
WEATHER ARE ON TAP FOR THE UPCOMING WEEK. SWLY UPPER FLOW WILL
DOMINATE THROUGH THE MS VALLEY WITH A DEEP BROAD UPPER TROF
CENTERED JUST OFF THE WEST COAST THROUGH AT LEAST MID WEEK. A 30+
KT SWLY LLJ WILL RAMP UP ON SUNDAY NIGHT AND THIS WILL RESULT IN
STRONG MOISTURE TRANSPORT AND CONVERGENCE BACK INTO THE AREA. THIS
MOISTENING COMBINED WITH THE EASTWARD ADVECTION OF STEEPER MID
LEVEL LAPSE RATES/THE EML WILL RESULT IN ELEVATED INSTABILITY WITH
POTENTIAL FOR ELEVATED SHOWERS AND THUNDERSTORMS IN THE WAA
REGIME SUNDAY NIGHT INTO MONDAY MORNING. AN IMPULSE LIFTING NEWD OUT OF
THE SRN PLAINS AND ACROSS THE AREA MONDAY AFTERNOON AND NIGHT IN
THE SW FLOW ALOFT WILL MAINTAIN THE THREAT OF SHOWERS AND
THUNDERSTORMS.
GLASS
&&
.AVIATION...
ISSUED AT 1205 AM CDT FRI OCT 19 2012
LOWER CIGS HAVE CONTINUED TO PUSH SWD THRU NRN MO AND CNTRL IL
THIS EVENING AND ARE ON COURSE TO IMPACT TERMINALS NEAR THE I-70
CORRIDOR OVER THE NEXT FEW HOURS. HAVE GAINED ENOUGH CONFIDENCE
WITH DEVELOPMENT OF IFR CIGS OVER IN SERN IA TO ADD THEM INTO KUIN
OVERNIGHT. BANDS OF LIGHT RAIN WILL CONTINUE TO MOVE THRU AND WILL
RESULT IN NUMEROUS SPRINKLES WITH POCKETS OF BRIEF HEAVIER SHRA
BUT HANDLED THIS FOR NOW WITH VCSH. RAIN THREAT SHOULD GRADUALLY
RECEDE ON FRIDAY...BUT NOT BEFORE GETTING SOME RE-INVIGORATION
FROM DIURNAL INFLUENCES TO PROLONG IT A BIT MORE BEFORE FINALLY
EXITING LATE IN THE DAY. SFC WNDS HAVE GONE GUSTY THIS EVENING
WITH SOME HIGHER WIND ALOFT MIXING DOWN WITH THE EXPANSION OF THE
LIGHT RAIN. THESE GUSTY WLY SFC WNDS WILL CONTINUE UNTIL SUNDOWN
FRIDAY.
SPECIFICS FOR KSTL...VFR CIGS LOWERING TO MVFR WITHIN THE NEXT FEW
HOURS AND THEN REMAINING THRU LATE FRIDAY AFTERNOON AND MAY LINGER
BEYOND INTO FRIDAY EVENING...OCNL SPRINKLES WITH VCSH TO CONTINUE
INTO THE MORNING HOURS OF FRIDAY...QUESTIONABLE HOW MUCH RE-
DEVELOPMENT OF SHRA WILL OCCUR FRIDAY MIDDAY-AFTN AND HOW CLOSE
IT WILL BE TO TERMINAL...CIGS SHOULD RISE ON FRIDAY BUT CURRENTLY
BELIEVE THEY WILL BE AOB 3KFT STILL...UNTIL LOSS OF SUNSHINE WILL
RESULT IN SOME BREAKUP AND RETURN TO VFR. SOME MODEL SOLUTIONS
RETURN THE LO CIGS FRIDAY NIGHT BUT FOR NOW REMAINING OPTIMISTIC.
ONE FLY IN THE OINTMENT IS THAT CIGS MAY BRIEFLY DIP BELOW 2KFT
AROUND 12Z BUT NOT CONFIDENT ENOUGH TO PLACE IN TAF WITH THIS
ISSUANCE.
TES
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1205 AM CDT FRI OCT 19 2012
.UPDATE...
ISSUED AT 947 PM CDT THU OCT 18 2012
UPDATING TO BUMP UP POPS FOR THE REST OF THE NIGHT FOR THE ENTIRE
AREA...ESPECIALLY ALONG AND NORTH OF THE I-70/I-64 CORRIDOR IN
MISSOURI AND ILLINOIS RESPECTIVELY. AREA OF LIGHT RAIN IS MOVING
EAST-SOUTHEAST THROUGH EASTERN MISSOURI AND SOUTHWEST ILLINOIS AT
THIS TIME...AND HRRR TAKES THE RAIN CURRENTLY OVER SOUTHWEST IOWA
AND DROPS IT SOUTHEAST INTO OUR AREA AFTER MIDNIGHT INTO FRIDAY
MORNING. THE HRRR IS HANDLING THE CURRENT PRECIP VERY WELL...SO
HAVE NO REASON TO DOUBT IT AT THIS TIME.
CARNEY
&&
.SHORT TERM...
ISSUED AT 341 PM CDT THU OCT 18 2012
(TONIGHT)
GUSTY WINDS SHOULD DIMINISH AFTER SUNSET HOWEVER SUSTAINED WINDS
SHOULD REMAIN ABOVE 10 KTS OVERNIGHT DUE TO A FAIRLY TIGHT PRESSURE
GRADIENT BETWEEN A LOW PRESSURE SYSTEM NEAR THE GRTLKS AND A SFC
HIGH OVER TX. SEVERAL VORT LOBES ROTATING AROUND THE GRTLKS LOW
PRESSURE CENTER WILL SUPPORT BANDS OF ISO-SCT SHRA ACROSS MOST OF
THE CWA TONIGHT WITH THE HIGHEST COVERAGE EXPECTED ACROSS THE NRN
CWA.
KANOFSKY
&&
.LONG TERM...
ISSUED AT 328 PM CDT THU OCT 18 2012
(FRIDAY THROUGH THURSDAY)
UPPER LEVEL LOW TO CONTINUE TO SPIN OVER THE GREAT LAKES REGION ON
FRIDAY WITH IT SLOWLY SHIFTING TO THE EAST. SO WRAP AROUND CLOUDS
AND LIGHT SHOWERS TO PERSIST ESPECIALLY FRIDAY MORNING...MAINLY
ALONG AND NORTHEAST OF A MEXICO MO TO SPARTA IL LINE. THEN THE
SHOWERS TO TAPER OFF DURING THE AFTERNOON AND EARLY EVENING HOURS ON
FRIDAY. COLDER AIR TO CONTINUE FILTERING IN WITH HIGHS ONLY IN THE
50S. LOWS FRIDAY NIGHT WILL BE IN THE LOW 40S.
THEN BY MIDDAY ON SATURDAY...CLOUDS TO CLEAR OUT WITH WEAK SURFACE
RIDGE BUILDING IN. TEMPS TO BEGIN TO WARM BACK UP...INTO THE LOW TO
MID 60S. BY SUNDAY...SOUTHERLY FLOW TO RETURN WITH TEMPS IN THE LOW
TO MID 70S...MAYBE EVEN UPPER 70S OVER CENTRAL MO.
THEN NEXT WEATHER SYSTEM APPROACHES THE REGION SUNDAY NIGHT.
EXTENDED MODELS HAVE DIFFERING OPINIONS ON HOW TO HANDLE THE FRONTAL
BOUNDARY...BUT ALL SEEM TO HINT AT STALLING IT OUT JUST NORTHWEST OF
FORECAST AREA. FOR NOW HAVE CHANCE POPS FOR SHOWERS AND
THUNDERSTORMS FOR PORTIONS OF THE FORECAST AREA MONDAY THROUGH
TUESDAY. ANOTHER ROUND OF SHOWERS POSSIBLE WEDNESDAY NIGHT AND
THURSDAY...BUT TIMING AND COVERAGE HARD TO PIN DOWN. OTHERWISE...
TEMPS TO REMAIN ABOVE NORMAL THROUGH THE PERIOD.
BYRD
&&
.AVIATION...
ISSUED AT 1205 AM CDT FRI OCT 19 2012
LOWER CIGS HAVE CONTINUED TO PUSH SWD THRU NRN MO AND CNTRL IL
THIS EVENING AND ARE ON COURSE TO IMPACT TERMINALS NEAR THE I-70
CORRIDOR OVER THE NEXT FEW HOURS. HAVE GAINED ENOUGH CONFIDENCE
WITH DEVELOPMENT OF IFR CIGS OVER IN SERN IA TO ADD THEM INTO KUIN
OVERNIGHT. BANDS OF LIGHT RAIN WILL CONTINUE TO MOVE THRU AND WILL
RESULT IN NUMEROUS SPRINKLES WITH POCKETS OF BRIEF HEAVIER SHRA
BUT HANDLED THIS FOR NOW WITH VCSH. RAIN THREAT SHOULD GRADUALLY
RECEDE ON FRIDAY...BUT NOT BEFORE GETTING SOME RE-INVIGORATION
FROM DIURNAL INFLUENCES TO PROLONG IT A BIT MORE BEFORE FINALLY
EXITING LATE IN THE DAY. SFC WNDS HAVE GONE GUSTY THIS EVENING
WITH SOME HIGHER WIND ALOFT MIXING DOWN WITH THE EXPANSION OF THE
LIGHT RAIN. THESE GUSTY WLY SFC WNDS WILL CONTINUE UNTIL SUNDOWN
FRIDAY.
SPECIFICS FOR KSTL...VFR CIGS LOWERING TO MVFR WITHIN THE NEXT FEW
HOURS AND THEN REMAINING THRU LATE FRIDAY AFTERNOON AND MAY LINGER
BEYOND INTO FRIDAY EVENING...OCNL SPRINKLES WITH VCSH TO CONTINUE
INTO THE MORNING HOURS OF FRIDAY...QUESTIONABLE HOW MUCH RE-
DEVELOPMENT OF SHRA WILL OCCUR FRIDAY MIDDAY-AFTN AND HOW CLOSE
IT WILL BE TO TERMINAL...CIGS SHOULD RISE ON FRIDAY BUT CURRENTLY
BELIEVE THEY WILL BE AOB 3KFT STILL...UNTIL LOSS OF SUNSHINE WILL
RESULT IN SOME BREAKUP AND RETURN TO VFR. SOME MODEL SOLUTIONS
RETURN THE LO CIGS FRIDAY NIGHT BUT FOR NOW REMAINING OPTIMISTIC.
ONE FLY IN THE OINTMENT IS THAT CIGS MAY BRIEFLY DIP BELOW 2KFT
AROUND 12Z BUT NOT CONFIDENT ENOUGH TO PLACE IN TAF WITH THIS
ISSUANCE.
TES
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
254 AM EDT FRI OCT 19 2012
.SYNOPSIS...
LOW PRESSURE MOVING SLOWLY EASTWARD THROUGH THE GREAT LAKES WILL
KEEP UNSETTLED WEATHER IN OUR AREA FOR MUCH OF THE WEEKEND.
SHOWERS FROM THE LOW WILL BE SCATTERED OVER THE REGION INTO
SUNDAY...ALONG WITH GRADUALLY COOLER AIR.
&&
.NEAR TERM /THROUGH TODAY/...
FNT DEAD CNTR OVER THE FCST AREA ATTM WITH A BRIEF AREA OF RW+ AND
AN ISLTD LGTNG STRIKES OVER NE PA. LATEST HRRR AND NAM RUNS ARE QUITE
PROGRESSIVE WITH THE FNT PUSHING IT AND THE HEAVIEST RAIN EAST OF
THE FCST AREA BY 12Z...DESPITE THE DVLPG SFC LOW OVER THE MID
ATLANTIC STATES. DEEP MOISTURE AHD OF THE FNT WITH A GULF
CONNECTION AND PWATS NEAR 180% OF NRML FOR THIS TIME OF YEAR.
AREAS AHD OF THE FNT WILL CONT TO SEE HEAVY RAIN WITH THE GOOD
FRCG OF THE FNT.
HRRR AND NAM SHOWS SOME PCPN BEING TOSSED BACK BHD THE FNT LTR
THIS MRNG AS THE LOW MVES NEWRD...SO WILL KEEP HIER POPS OVER THE
ERN ZONES THRU MUCH OF THE DAY DESPITE THE ERWRD MVMT OF THE
BNDRY.
SINCE THE LATEST MODEL FCSTS KEEP THE FNT PROGRESSIVE THRU THE
FCST AREA...HEAVY RAINS SHD NOT BE A PRBLM...WITH STORM TTLS WELL
BLO FFG AND HEADWATERS GUID. WILL KEEP A LOW CHANCE OF THUNDER IN
THE EAST AND SOUTH WITH THE INSTABILITY ALOFT WITH THE FNT...AND
THE ADDED LIFT OF THE APRCHG WV.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY/...
LOW PLODS SLOWLY EAST AS IT GRADUALLY FILLS. DRY SLOT BHD THE FNT
TODAY IS QUICKLY REPLACED WITH THE DEEP MOISTURE ASSOCIATED WITH
THE UPR LOW. VERTICALLY STACKED LOW IS POSITIONED NEAR BUF BY 00Z
SUN. THIS WILL KEEP INSTABILITY AND MOISTURE OVER THE AREA...ALONG
WITH A GRADUAL COOLING AS THE COLD CORE APRCHS. DOES NOT APPEAR TO
BE ENUF INSTABILITY FOR TRWS ATTM...ALTHOUGH AN ISLTD WEAK STORM
CANNOT BE RULED OUT SAT AFTN...ESP WITH ANY HTG.
BY SUN...PROGRESSIVE LOW IS NORTH OF THE ST LAWRENCE VLY AND
SOMEWHAT DRIER AIR IS MVG BACK IN FROM THE OH VLY. ENUF LEFTIOVER
MOISTURE MAY ALLOW FOR A FEW SCT SHWRS OVER THE NRN ZONES...ESP
OVER THE HIER TERRAIN. ANY PCPN WILL BE LGT.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
DURING THE EXTENDED PERIOD MEDIUM RANGE MODELS ARE IN AGREEMENT
THAT THE UPPER LEVEL TROF OVER THE NORTHEAST WILL BE REPLACED BY
RISING HEIGHTS AND DEVELOPMENT OF AN UPPER LEVEL RIDGE. AT THE
SURFACE THINGS ARE A BIT MORE TRICKY WITH LOW PRES MOVING THROUGH
THE UPPER GREAT LAKES WITH POSSIBLE FROPA TUESDAY NIGHT. GENERALLY
FOLLOWED HPC GUIDANCE.
SUNDAY EVENING WILL INCLUDE SLIGHT CHC POPS FAR NRN CWA ON BACK
SIDE OF UPPER LEVEL TROF THEN DRY. DRY WEATHER IS EXPECTED
MONDAY THROUGH MUCH OF MONDAY NIGHT THEN CHC/SLIGHT CHC POPS
TUESDAY THROUGH WEDNESDAY DUE TO PASSING COLD FRONT AND NORTHWEST
FLOW BEHIND BOUNDARY. DRY WEATHER WILL RETURN WED NIGHT/THURSDAY
AS SFC HIGH BUILDS DOWN FROM CANADA. TEMPS WILL BE 5-10 DEGREES
ABOVE NORMAL.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
WARM FRONTAL PRECIPITATION IS LIFTING ACROSS THE TERMINALS EARLY
THIS MORNING. A FEW RUMBLES OF THUNDER ARE BEING REPORTED, THOUGH
THE DENSITY IS TOO SPARSE TO INCLUDE IN THE TAFS AT THIS POINT.
RAIN SHOWERS WILL BE HEAVY AT TIMES THROUGH 9Z, WITH MAINLY MVFR
CEILING AND VISIBILITY RESTRICTIONS. HOWEVER BRIEF IFR IS POSSIBLE
IN DOWNPOURS.
WHAT HAPPENS IN THE WAKE OF THE PRECIPITATION IS MORE UNCERTAIN.
MODEL GUIDANCE LOOKS UNREALISTIC WITH WIDESPREAD IFR CONDITIONS.
HOWEVER WESTERN PA AND SOUTHWESTERN NY OBS ARE STARTING TO SHOW
DENSE FOG FORMATION. BELIEVE THE BEST CHANCE FOR IFR FOG
RESTRICTIONS WILL BE BETWEEN 8Z AND 12Z AT BGM/ELM/ITH. THERE IS
LESS OF A CHANCE UP THE LAKE PLAIN TOWARD SYR/RME WHERE THE
TERRAIN WILL ALLOW FOR BETTER LOW LEVEL MIXING WINDS.
A BROKEN 1500-2500 DECK IS FORECAST FOR TODAY, POSSIBLY GOING
SCATTERED DURING THE LATE AFTERNOON.
OUTLOOK...
FRI NIGHT THROUGH SAT...MVFR RESTRICTIONS EXPECTED IN OCNL -SHRA.
SUN AND MON...MAINLY VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DGM
NEAR TERM...DGM
SHORT TERM...DGM
LONG TERM...RRM
AVIATION...DJP
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
134 AM EDT FRI OCT 19 2012
.SYNOPSIS...
A STRONG WEATHER SYSTEM WILL IMPACT THE REGION TONIGHT, WITH RAIN,
HEAVY AT TIMES, GRADUALLY OVERSPREADING THE AREA TONIGHT. RAIN
WILL END FROM WEST TO EAST FRIDAY MORNING TO MIDDAY. UNSETTLED
SHOWERY WEATHER WILL THEN CONTINUE THROUGH THE UPCOMING WEEKEND.
&&
.NEAR TERM /THROUGH TODAY/...
10 PM UPDATE...
CHANGES TO THE TIMING TO SPEED UP THE ONSET OF RAIN IN THE SOUTH.
ALSO ADDED THUNDER BECAUSE THUNDER JUST UPSTREAM IN MIDDLETOWN.
TEMPERATURES AT THEIR LOWS NOW SO ADJUSTED UP THE HOURLY TEMPS.
PREVIOUS DISCUSSION...
LATEST VIS SATELLITE IMAGERY CONTINUES TO SHOW CLOUDS STREAMING
NORTHEAST FROM THE LWR OHIO VALLEY THIS AFTERNOON AS COLD/OCCLUDED
FRONTAL BOUNDARY ADVANCES EAST. ALOFT...WATER VAPOR IMAGERY
SHOWING A DEEPLY WOUND- UP UPPER LOW ACROSS THE UPPER MISS RVR VLY
WITH RUC POTENTIAL VORTICITY COMPOSITES INDICATING THE THE UPPER
PV ANOMALY EXTENDS DOWN TO NEAR 500 MB ACROSS THE OHIO/MISS RVR
CONFLUENCE REGION. THIS LEAD WAVE WILL CONTINUE MOVING NORTHEAST
OVERNIGHT WHICH WILL ULTIMATELY HELP PROPEL THE AFOREMENTIONED
COLD/OCCLUDED FRONT EAST INTO OUR FCST AREA. LATEST RADAR TRENDS
NOW SHOWING INITIAL FRONTAL WAVE RAIN BAND SLOWLY LIFTING
NORTHEAST THROUGH EASTERN OHIO THIS AFTERNOON WHICH WITH TIME
SHOULD BEGIN ENTERING OUR WESTERN ZONES AFTER 00Z THIS EVENING.
CLOSER TO THE SFC...A STRONG PRESSURE GRADIENT BETWEEN THIS DEEPLY
WOUND-UP SYSTEM AND DEPARTING HIGH PRESSURE OFF THE EAST COAST HAS
ALLOWED FOR STRONG SOUTHEASTERLY WINDS THIS AFTERNOON WITH LATEST
OBSERVATIONS SHOWING GUSTS AS HIGH AS 35 KTS ACROSS THE REGION.
AS HAS THE BEEN THE CONCERN IN RECENT DAYS...12Z MODEL GUIDANCE
CONTINUES TO ADVERTISE FAVORABLE CONDITIONS FOR A DECENT RAINFALL
EVENT ACROSS MUCH OF CENTRAL NY AND NE PA BEGINNING TONIGHT AS
INITIAL PV ANOMALY AND SFC FRONT TRANSLATE NORTHEAST OVER THE AREA.
AHEAD OF THESE FEATURES...STRONG MOISTURE ADVECTION CHARACTERIZED
H925 V-WIND COMPONENTS ON THE ORDER OF 2-3 STANDARD DEVIATIONS ABOVE
NORMAL WILL HELP INCREASE PWAT VALUES TO WELL OVER 1 INCH ACROSS THE
EASTERN ZONES BY 12Z FRI. AS THIS OCCURS...MODELS NOW SHOWING A
SECONDARY FRONTAL WAVE AND CORRESPONDING WARM FRONT MOVING NORTH
ALONG THE OCCLUDED FRONT OVERNIGHT WHICH WILL EFFECTIVELY HELP
STALL THE MAIN OCCLUDED FRONT WITH TIME ACROSS OUR FCST AREA EARLY
FRI. BY 15Z...MODELS INDICATE THAT THE TRIPLE POINT WILL RESIDE
OVER OR REGION WITH EASTERN ZONES EFFECTIVELY BECOMING PLACED IN
MODIFYING WARM SECTOR AIR. MODELS CONTINUE TO SUGGEST THE
DEVELOPMENT OF WEAK INSTABILITY AFTER 12Z FRI AS DEW POINTS CLIMB
INTO THE MIDDLE TO UPPER 50S...AND POSSIBLY LOWER 60S ACROSS OUR
FAR SOUTHEAST. MEANWHILE ALOFT...MODELS STILL ADVERTISING THE
ENTRANCE OF A MID-LEVEL JET BY LATE MORNING WHICH WILL INCREASE
THE VERTICAL WIND SHEAR PROFILE ACROSS THE REGION. CONSIDERING
THAT SUCH STRONG WIND FIELD WILL BE IN PLACE (0-6 KM BULK SHEAR
WELL OVER 50 KTS)...DEVELOPING CONVECTION COULD EASILY BE SHEARED
APART AS IT FIRES. THAT SAID...WITH STRONGER INSTABILITY SUGGESTED
WITH TODAY/S RUNS...HAVE ELECTED TO REINTRODUCE A THUNDER MENTION
FOR FRI FROM THE LWR WYOMING VLY NORTH THROUGH THE POCONOS AND
CATSKILLS.
WITH RESPECT TO FCST QPF AMOUNTS...HPC GUIDANCE CONTINUES TO
ADVERTISE CLOSE TO 2" ACROSS THE EASTERN POCONOS AND CATSKILLS
WHERE MOIST SOUTHEAST WINDS WILL INTERACT WITH UPSLOPE TERRAIN
INFLUENCES. FOR NOW HAVE FOLLOWED BOTH HPC AND RFC QPF GUIDANCE
WHICH KEEPS THE HIGHEST AMOUNTS ACROSS THE EASTERN HALF OF THE
CWA. BY LATE MORNING...MODELS INDICATE THAT A WELL DEVELOPED DRY
SLOT WILL BEGIN WORKING INTO OUR WESTERN ZONES WHICH SHOULD RESULT
IN RAIN COMING TO AN END FROM WEST TO EAST DURING THE LATE
MORNING/EARLY AFTERNOON HRS.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY/...
UNSETTLED WX EXPECTED TO CONTINUE RIGHT THROUGH THE WEEKEND AS
UPPER LOW CONTINUES TO PINWHEEL ACROSS THE REGION BOTH FRIDAY
NIGHT AND SATURDAY. FOR ALL INTENSIVE PURPOSES...MAIN RAIN BAND
SHOULD BE EXITING TO THE EAST BY FRIDAY EVENING AS NORTHWARD
MOVING FRONTAL WAVE FRIDAY AFTERNOON FINALLY EXITS TO THE
NORTHEAST. WITH AFOREMENTIONED DRY SLOT LINGERING...HAVE MAINTAINED
SLGT CHC TO CHC MENTION FOR POPS FRI NGT. FOR SATURDAY...UPPER
WAVE TO INCH EVER SO CLOSER TO THE REGION WITH THE NEXT ROUND OF
SHORTWAVE ENERGY EXPECTED TO LEAD TO ADDITIONAL SHWRS LATE SAT
MORNING/AFTERNOON. RIGHT NOW BEST POTENTIAL FOR REDEVELOPING SHWRS
APPEAR ACROSS THE NORTHERN ZONES WHERE COLD TEMPS ALOFT WILL
COMBINE WITH BEST FORCING FOR ASCENT FROM THE MAIN SFC LOW FCST
TO LIFT FROM THE CENTRAL LAKES INTO SOUTHERN ONTARIO.
UPPER LOW TO FINALLY BEGIN LIFTING NORTHEAST OF THE REGION SAT
NIGHT/EARLY SUN AS HEIGHTS BUILD ACROSS THE NORTHERN MISS RVR
VLY/SOUTHERN CANADIAN PRAIRIE PROVINCES. BEHIND THE FEATURE...H85
TEMPS ONLY DROP TO NEAR 0C WHICH MAY RESULT IN SCATTERED LAKE
EFFECT RAIN SHWRS JUST TO OUR NORTH IN SUSTAINED SOUTHWEST LOW-
LEVEL FLOW.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
DURING THE EXTENDED PERIOD MEDIUM RANGE MODELS ARE IN AGREEMENT
THAT THE UPPER LEVEL TROF OVER THE NORTHEAST WILL BE REPLACED BY
RISING HEIGHTS AND DEVELOPMENT OF AN UPPER LEVEL RIDGE. AT THE
SURFACE THINGS ARE A BIT MORE TRICKY WITH LOW PRES MOVING THROUGH
THE UPPER GREAT LAKES WITH POSSIBLE FROPA TUESDAY NIGHT. GENERALLY
FOLLOWED HPC GUIDANCE.
SUNDAY EVENING WILL INCLUDE SLIGHT CHC POPS FAR NRN CWA ON BACK
SIDE OF UPPER LEVEL TROF THEN DRY. DRY WEATHER IS EXPECTED
MONDAY THROUGH MUCH OF MONDAY NIGHT THEN CHC/SLIGHT CHC POPS
TUESDAY THROUGH WEDNESDAY DUE TO PASSING COLD FRONT AND NORTHWEST
FLOW BEHIND BOUNDARY. DRY WEATHER WILL RETURN WED NIGHT/THURSDAY
AS SFC HIGH BUILDS DOWN FROM CANADA. TEMPS WILL BE 5-10 DEGREES
ABOVE NORMAL.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
WARM FRONTAL PRECIPITATION IS LIFTING ACROSS THE TERMINALS EARLY
THIS MORNING. A FEW RUMBLES OF THUNDER ARE BEING REPORTED, THOUGH
THE DENSITY IS TOO SPARSE TO INCLUDE IN THE TAFS AT THIS POINT.
RAIN SHOWERS WILL BE HEAVY AT TIMES THROUGH 9Z, WITH MAINLY MVFR
CEILING AND VISIBILITY RESTRICTIONS. HOWEVER BRIEF IFR IS POSSIBLE
IN DOWNPOURS.
WHAT HAPPENS IN THE WAKE OF THE PRECIPITATION IS MORE UNCERTAIN.
MODEL GUIDANCE LOOKS UNREALISTIC WITH WIDESPREAD IFR CONDITIONS.
HOWEVER WESTERN PA AND SOUTHWESTERN NY OBS ARE STARTING TO SHOW
DENSE FOG FORMATION. BELIEVE THE BEST CHANCE FOR IFR FOG
RESTRICTIONS WILL BE BETWEEN 8Z AND 12Z AT BGM/ELM/ITH. THERE IS
LESS OF A CHANCE UP THE LAKE PLAIN TOWARD SYR/RME WHERE THE
TERRAIN WILL ALLOW FOR BETTER LOW LEVEL MIXING WINDS.
A BROKEN 1500-2500 DECK IS FORECAST FOR TODAY, POSSIBLY GOING
SCATTERED DURING THE LATE AFTERNOON.
OUTLOOK...
FRI NIGHT THROUGH SAT...MVFR RESTRICTIONS EXPECTED IN OCNL -SHRA.
SUN AND MON...MAINLY VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...CMG/TAC
NEAR TERM...CMG/TAC
SHORT TERM...CMG
LONG TERM...RRM
AVIATION...DJP
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
150 AM EDT FRI OCT 19 2012
.SYNOPSIS...
AN APPROACHING COLD FRONT WILL BRING A CHANCE OF SHOWERS AND
ISOLATED THUNDERSTORMS THROUGH MIDDAY FRIDAY. DRIER AND SLIGHTLY
COOLER AIR WILL OVERSPREAD THE REGION THIS WEEKEND. HIGH PRESSURE
WILL BRING FAIR WEATHER AND A WARMING TREND EARLY NEXT
WEEK...ALONG WITH ABOVE NORMAL TEMPERATURES THROUGH MID WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1:45 AM FRIDAY...LIGHT SHOWER ACTIVITY BEGINNING TO BREAK
OUT THROUGHOUT THE CWA WITH A LINE OF HEAVIER SHOWERS APPROACHING
OUR FAR NORTHWESTERN COUNTIES. FORECAST IN GOOD SHAPE...PREVIOUS
DISCUSSION BELOW:
BOWLING BALL LOW PRESSURE BARRELING ACROSS THE MIDWEST IS DRIVING
A POTENT SFC COLD FRONT TO THE WINDWARD SIDE OF THE APPALACHIANS
AT THE MOMENT. THIS COLD FRONT WILL CROSS THE APPALACHIANS AND
REACH THE CENTRAL CAROLINAS BY EARLY FRIDAY...AND OFF THE ILM CWA
COAST BY MIDDAY FRIDAY AND ENDING THE 40 PERCENT THREAT FOR
CONVECTION.
WV/11-3.9 MICRON IR IMAGERY SHOW TWO AREAS OF ENHANCED MOISTURE
MOVING ACROSS THE SOUTHEAST LATE THIS EVENING. THE FIRST...WHICH
IS THE MID-UPPER LEVEL CLOUD DECK ACROSS THE CENTRAL AND EASTERN
PORTIONS OF THE FA...WHICH IS A DEBRIS CLOUD FIELD FROM
A REMNANT UPSTREAM SQUALL LINE THAT WEAKENED CONSIDERABLY THIS
AFTERNOON AND EARLY EVENING. WILL CONTINUE THE MAINLY DRY
LATE EVENING AND OVERNIGHT FORECAST. A SECOND AREA OF ENHANCED
MOISTURE JUST AHEAD OF THE FRONT WILL PARTIALLY MERGE WITH THE
1ST AREA OF MOISTURE OVERNIGHT. A WEAK MID-LEVEL S/W TROF ROTATING
AROUND THE MASSIVE CUTOFF UPPER LOW CENTERED OVER THE GREAT LAKES...
WILL BE IN THE NEIGHBORHOOD DURING THE PRE-DAWN HRS. THE DYNAMICS
FROM THIS...MOISTURE AVAILABILITY...AND THE SFC FEATURES...WILL
END PRODUCE A DEVELOPING/MOVING BAND/LINE OF SHOWERS WITH ISOLATED
TSTMS CROSSING THE ILM CWA. THE LATEST HRRR HAS BECOME MORE
OBSESSIVE WITH THIS OUTCOME OVERNIGHT...WITH A MORE ROBUST NE-SW LINE
ACROSS THE WESTERN CWA BY 07-08Z...AND REACHING THE COAST BY 10-13Z
FRI. STILL LOOKING AT SUB-SEVERE WIND GUSTS POSSIBLE.
TEMPS OVERNIGHT WILL BE TEMPERED BY CONTINUED SOUTHERLY FLOW AND
CLOUD COVER...FALLING ONLY SLOWLY AHEAD OF THE FRONT...THEN MORE
RAPIDLY IN THE EXTREME WEST AS THE FRONT MOVES FROM WEST TO EAST.
MINS TONIGHT LOOK TO BE JUST BELOW 60 IN THE EXTREME NW...TO THE MID
60S AT THE COAST.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY NIGHT/...
AS OF 3 PM THURSDAY...COLUMN MOISTURE WILL REMAIN SUFFICIENT FOR
SHOWERS THROUGH AT LEAST LATE MORNING AS A MODERATELY WEAK COLD
FRONT TRAVERSES THE FORECAST AREA. SHOWERS HOWEVER MAY LINGER
THROUGH FRIDAY AFTERNOON ALONG THE COASTAL/EASTERN ZONES WITH
HEATING AND RESIDUAL MOISTURE TO 12000 FEET. BY FRIDAY EVENING
IT APPEARS ANY CONVECTION WILL SHUT DOWN DUE TO FURTHER DRYING
AND DIURNAL COOLING.
DESPITE THE DRYING REGIME...NORTH WINDS WILL NOT BE REALIZED UNTIL
LAGGING HIGH PRESSURE BUILDS FROM THE GULF COAST STATES AND AN
UPPER TROUGH AXIS MOVES OFFSHORE. THUS DRYING WILL BE OUTPACING
THE WEAK COOL AIR ADVECTION. THE AIR MASS CHANGE WILL BE MORE
EVIDENT LATE SATURDAY AS THE HIGH PRESSURE CENTER LIFTS INTO THE
CENTRAL APPALACHIANS...AND IMPARTS NORTH WINDS.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 3 PM THURSDAY...SURFACE HIGH PRESSURE WILL COMBINE WITH
BUILDING 500MB RIDGE TO CREATE SUNNY AND WARMING TEMPS THROUGH THE
EXTENDED. WEAK S/W WILL BE EXITING AT THE START OF THE PERIOD
CREATING SUBSIDENCE THROUGH THE COLUMN. ALTHOUGH WE WILL SEE
WALL-TO-WALL SUNSHINE SUNDAY...WEAK CAA ON LEE SIDE OF ADVANCING
HIGH PRESSURE WILL KEEP TEMPS RIGHT AROUND CLIMO.
THEREAFTER...SURFACE HIGH SLOWLY DRIFTS EAST TOWARDS THE WATERS
WHILE MID LEVEL RIDGING BULGES UP FROM THE GULF OF MEXICO. ALTHOUGH
BOUTS OF HIGH LEVEL CI WILL PERIODICALLY AFFECT SKY COVER...MON-THU
WILL FEATURE NEARLY COMPLETE SUNSHINE WITH MAX TEMPS RISING EACH
DAY...FROM MID 70S MONDAY TO AROUND 80 WED/THU. NEARLY IDEAL
RADIATIONAL COOLING AT NIGHT SUGGESTS MINS WILL FALL TO AROUND OR
SLIGHTLY BELOW CLIMO EACH NIGHT.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 06Z...A COLD FRONT WILL MOVE THROUGH THE KFLO/KLBT TERMINALS
EARLY THIS MORNING...REACHING THE COASTAL TERMINALS AROUND SUNRISE.
RAIN/SHOWERS WILL CONTINUE TO DEVELOP AHEAD OF THE FRONT AND SHOULD
MOVE INTO THE KFLO/KLBT TERMS OVER THE NEXT SEVERAL HOURS. GENERALLY
VFR EXPECTED WITH TEMPO PERIODS OF MVFR. ANY IFR WITH THE HEAVIER
SHOWERS SHOULD BE OF TOO SHORT OF A DURATION TO MENTION. AFTER THE
RAIN ENDS AND THE FRONT MOVES THROUGH THERE IS MODERATE CONFIDENCE
OF POST FRONTAL IFR/LIFR CONDITIONS DEVELOPING IN FOG AND LOW
STRATUS. THIS SHOULD LAST 2-3 HOURS OR UNTIL STRONGER WINDS AND
DRIER AIR BEHIND THE FRONT MOVES IN LIFTING CONDITIONS TO VFR. AS
THE RAIN AFFECTS THE COASTAL TERMINALS IN THE PRE-DAWN HOURS EXPECT
THE SAME GENERAL VFR/TEMPO MVFR CONDITIONS...POSSIBLY BRIEF IFR...
ALTHOUGH THE RAIN MAY BE OF SHORTER DURATION. MODERATE CONFIDENCE OF
A PERIOD OF POST FRONTAL IFR/MVFR CEILINGS OCCURRING BEFORE STRONGER
WINDS AND DRIER AIR BEHIND THE FRONT MOVES IN LIFTING CONDITIONS TO
VFR. WEST-SOUTHWEST TO WEST NORTHWEST WINDS EXPECTED AFTER 13-15Z
UNDER VFR CONDITIONS WITH WINDS BECOMING SOUTHWEST BY AFTERNOON. VFR
CONDITIONS WILL CONTINUE INTO THE EVENING HOURS WITH WINDS DIMINISHING.
EXTENDED OUTLOOK...LOW CONFIDENCE OF PRE-DAWN FOG/SUB-VFR VSBYS
MONDAY AND TUESDAY MORNINGS. OTHERWISE VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1:45 AM FRIDAY...SW WINDS NOW IN THE 10 TO 15 KT RANGE WITH
SEAS OF 3 TO 4 FT. ALL GOING AS PLANNED...PREVIOUS DISCUSSION
FOLLOWS BELOW:
SOUTH-SOUTHWEST WINDS WILL GRADUALLY VEER TO THE SW ALTOGETHER AND
INCREASE TO AROUND 15 KTS AHEAD OF AN ADVANCING COLD FRONT
OVERNIGHT. AS THE WINDS PICK UP SEAS WILL BUILD SLIGHTLY...FROM
THE CURRENT 3 FT...TO 3-4 FT...THANKS TO AN INCREASED CONTRIBUTION
FROM THE 4-5 SECOND WIND CHOP. A SLIGHTLY DECREASING 3 FT 10-11
SEC EASTERLY GROUND SWELL WILL EXIST WITHIN THE SPECTRUM.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 PM THURSDAY...A WEAK COLD FRONT WILL CROSS THE WATERS LATE
MORNING TO EARLY AFTERNOON BARELY SHIFTING WINDS...MAINLY FROM SW
TO WSW IN THE AFTERNOON. WSW-W WINDS LOOK TO PREVAIL SATURDAY 15
KNOTS OR LESS AND NO ADVISORIES OR CAUTION STATEMENTS ARE EXPECTED
BOTH FRIDAY AND SATURDAY. HIGH PRESSURE BUILDING FROM THE GULF
COAST STATES INTO THE CENTRAL APPALACHIANS WILL BRING WINDS TO
THE NW AND NNW LATE SATURDAY NIGHT...BUT WELL BELOW ADVISORY WIND
SPEEDS. SEAS MAINLY 2 TO 4 FEET THROUGH THE PERIOD IN A MIX OF SE
WAVES 2-3 FEET AT 10 SECONDS AND 1-2 FOOT SW WIND-WAVES AND CHOP.
LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 3 PM THURSDAY...HIGH PRESSURE WILL RIDGE ACROSS THE WATERS
THROUGH THE EXTENDED...CREATING MOSTLY LIGHT N/NE WINDS EACH DAY.
THE EXCEPTION WILL BE ON SUNDAY...WHEN A WEAK NORTHERLY SURGE WILL
CONTINUE AHEAD OF THE ADVANCING HIGH...CREATING NORTHERLY WINDS OF
10-15 KTS BEFORE EASING BY SUNDAY NIGHT TO LESS THAN 10 KTS. SEAS
WILL BE 2-3 FT SUNDAY...FALLING TO 1-2 FT MON/TUE AS WINDS EASE AND
ONLY A WEAK SE SWELL PERSISTS WITHIN THE WAVE SPECTRUM.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MJC
NEAR TERM...DCH/REK
SHORT TERM...MJC
LONG TERM...JDW
AVIATION...MRR
MARINE...DCH/MJC/REK/JDW
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
520 AM EDT FRI OCT 19 2012
.SYNOPSIS...
UPPER LEVEL LOW PRESSURE NEAR CHICAGO WILL SLOWLY MOVE EAST ACROSS
THE AREA THROUGH SATURDAY NIGHT. HIGH PRESSURE WILL THEN BUILD
NORTHEAST INTO THE REGION SUNDAY THEN SETTLE NEAR THE CAROLINA COAST
FOR MONDAY AND TUESDAY. A COLD FRONT WILL DROP SOUTHEAST AND STALL
OVER THE AREA FOR TUESDAY NIGHT AND WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM FRIDAY EVENING/...
DOING 630 AM UPDATE EARLY. HAVE ADDED EARLY MORNING MENTION OF
PATCHY FOG FOR THE YNG TO GKJ AREA. ALSO HAVE ADDED CHC OF SPRINKLES
TO CENTRAL PART OF AREA WHERE BAND OF CLOUDS CURRENTLY PRESENT AND
THEN PROG THIS EAST DURING THE REST OF THE MORNING. HRRR HAS BEEN
HINTING AT SPRINKLES FOR THIS AREA AND LATEST RADAR PIX STARTING TO
SHOW SOME INCREASE IN RETURNS.
THE MODELS ARE IN FAIRLY GOOD AGREEMENT IN MOVING THE UPPER LOW NEAR
CHICAGO SLOWLY EAST TODAY. RAIN AND SHRA POOLED UNDER THE UPPER LOW
WILL GET AN EASTWARD PUSH TODAY AS SHORTWAVE ENERGY AND A SURFACE
TROUGH ROTATE AROUND THE UPPER LOW. THE WESTERN PART OF THE CWA
LOOKS CATEGORICAL FOR MEASURABLE PRECIP WITH THE CENTRAL PART LIKELY
AND MAYBE JUST A CHANCE FOR THE EAST AS THE BETTER ENERGY DOES NOT
GET THERE UNTIL TONIGHT. PRECIP AMOUNTS WILL GENERALLY BE LIGHT WITH
MOST PLACES SEEING AROUND A TENTH OF AN INCH OR LESS WEST AND A FEW
HUNDREDTHS OR LESS EAST.
THE WARMER TEMPS SHOULD BE IN THE EAST WHERE CLOUDS WILL TAKE LONGER
TO FILL IN TODAY.
&&
.SHORT TERM /6 PM FRIDAY EVENING THROUGH MONDAY NIGHT/...
PER THE PREVIOUS DISCUSSION...THE UPPER AND SURFACE FORCING WILL
WORK EAST ACROSS THE CWA TONIGHT AND SATURDAY WITH A FAIRLY
WIDESPREAD COOL RAIN. EVEN THOUGH THE COLDEST PART OF THE AIRMASS
WILL BE OVER THE AREA BY DAYBREAK SAT...THE EXTENSIVE CLOUD COVER
SHOULD KEEP TEMPS IN A 40 TO 45 DEGREE RANGE. HOWEVER...ON SAT THESE
SAME CLOUDS WILL HOLD HIGH TEMPS TO ONLY 50 TO 55 FOR MOST PLACES.
AS THE TROUGH MOVES EAST OF THE AREA SAT NIGHT...DRIER AIR WILL
START TO SPREAD IN FROM THE WEST. THE RAIN THREAT WILL SHIFT INTO
JUST THE SNOWBELT BY LATE SAT NIGHT THEN TAPER OFF IN THE SNOWBELT
SUNDAY AS THE PUSH OF DRIER AIR CONTINUES AND LAKE EFFECT CONDITIONS
LESSEN.
HIGH PRESSURE RIDGED NORTH INTO THE AREA SHOULD PROVIDE DRY WEATHER
FOR SUN NIGHT AND MON. TEMPS WILL MODERATE WITH THE ADDED SUNSHINE
AND WARM ADVECTION. MONDAY NIGHT IS MORE QUESTIONABLE AS THE MODELS
INDICATE A BACKDOOR COLD FRONT SAGGING INTO OR NEAR THE AREA. CHANCE
POPS...MAINLY NEAR LAKE ERIE STILL SEEMS REASONABLE.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
ONLY MINOR CHANGES TO THE LONG TERM THIS MORNING. A NEARLY
STATIONARY BOUNDARY WILL BE JUST NORTH OF THE AREA TUESDAY AND
WEDNESDAY. THIS WILL KEEP PLENTY OF CLOUDS AND A THREAT FOR SHOWERS
GOING EACH PERIOD FROM TUESDAY THROUGH WEDNESDAY NIGHT. THE
BOUNDARY IS FORECAST TO MOVE SLIGHTLY NORTH ON THURSDAY SO WILL PULL
THE MENTION OF PRECIP OUT OF THE FORECAST. A COLD FRONT WILL BEGIN
TO APPROACH FROM THE WEST AT THE VERY END OF THE PERIOD. THE AREA
WILL REMAIN IN THE WARM SECTOR THE ENTIRE PERIOD SO EXPECT HIGHS TO
BE MAINLY IN THE LOWER 70S ALL THREE DAYS.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
MID LEVEL CLOUDS WILL CONTINUE TO SPREAD EAST ACROSS THE AREA
OVERNIGHT. LATEST MODELS SLOWER BRINGING PRECIP INTO THE AREA.
IT WILL LIKELY BE CLOSE TO 15Z BEFORE THE FIRST SHOWERS REACH KTOL
AND KFDY AND INTO EARLY AFTERNOON BEFORE THEY REACH KCLE. STEADIER
PRECIP WILL ARRIVE TOWARD EVENING FROM WEST TO EAST. EXPECT CIGS
AND VSBYS TO DIP TO MVFR AS THIS OCCURS. S TO SE FLOW WILL BECOME
SW THIS AFTERNOON. SOME GUSTS TO 25 KNOTS POSSIBLE THIS
AFTERNOON...ESPECIALLY IN THE WEST.
.OUTLOOK...NON VFR FRIDAY NIGHT AND CONTINUING SATURDAY.
&&
.MARINE...
LOW PRESSURE REMAINS OVER EASTERN IA THIS MORNING. THIS LOW IS
FORECAST TO GRADUALLY WEAKEN AND TO PASS TO THE NORTH OF THE LAKE
TONIGHT. S FLOW WILL BECOME SW TODAY AND TONIGHT. SPEEDS WILL
INCREASE LATE TONIGHT AND SATURDAY MORNING AND MAY NEED A SMALL
CRAFT FOR THE EASTERN TWO THIRDS OF THE LAKE. A TROUGH FROM THE LOW
WILL CROSS THE LAKE ON SATURDAY AND THIS WILL CAUSE THE FLOW TO
BECOME WEST. HIGH PRESSURE WILL TRY TO BUILD IN FROM THE SOUTH ON
SUNDAY WITH THE RIDGE AXIS JUST EAST OF THE LAKE ON MONDAY WHICH WILL
CAUSE THE FLOW TO AGAIN BECOME S TO SW. A WARM FRONT IS EXPECTED TO
DEVELOP TO THE NORTH OF THE LAKE ON MONDAY NIGHT AND SOME WARM AIR
ADVECTION SHOWERS COULD OCCUR BY EARLY TUESDAY. THE LAKE WILL
REMAIN IN THE WARM SECTOR FOR THE REMAINDER OF THE PERIOD. AS A
RESULT SW FLOW AT UNDER 15 KNOTS WILL CONTINUE.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...ADAMS
NEAR TERM...ADAMS
SHORT TERM...ADAMS
LONG TERM...KUBINA
AVIATION...KUBINA
MARINE...KUBINA
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
305 AM EDT FRI OCT 19 2012
.SYNOPSIS...
A DEEP LOW PRESSURE SYSTEM WILL LINGER TO OUR NORTHWEST AS A COLD
FRONT MOVES OFF THE ATLANTIC COAST ON FRIDAY. DRY HIGH PRESSURE WILL
THEN BUILD IN BEHIND THE FRONT OVER THE WEEKEND AND REMAIN IN PLACE
WELL INTO NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
0515 UTC UPDATE...POPS WERE UPDATED PER RADAR TRENDS IN THE KCLT
AREA. SKY COVER HAS BEEN UPDATED TO ACCOUNT STRATUS COVERAGE FROM
OBSERVATIONS. AREAS OF FOG WERE ADJUSTED BASED ON OBSERVATIONS
TRENDS AS WELL. WINDS WERE UPDATED WITH A TWO TO ONE BLEND OF THE
00Z NAM AND 00Z ADJMAV...THE WEIGHTING TOWARD THE FORMER TO CAPTURE
GUSTIER WINDS AT HIGH ELEVATIONS. TEMPERATURES WERE UPDATED WITH A
BLEND OF THE LATEST ADJMAV AND ADJMET.
EVENING UPDATE...THE RADAR STILL SHOWS A STORM BEING MAINTAINED
ACROSS RABUN COUNTY HEADING INTO NC JUST AHEAD OF THE COLD FRONT.
THIS STORM COULD BECOME FAIRLY STRONG...BUT DONT ANTICIPATE SEVERE
LEVELS. THE REMNANT STORM ACROSS THE NC PIEDMONT IS JUST NOW EXITING
THE CWFA. SOME LINGERING SMALL SCALE -SHRA MAY CONTINUE
OVERNIGHT...YET ANYTHING STRONG OR LONG LIVED IS NOT LIKELY. THE
MAIN CONCERN OVERNIGHT WILL BE THE THREAT OF FG AND JUST HOW DENSE
IT MAY BECOME. SOME AREAS ARE EXPERIENCING DENSE FG CURRENTLY AROUND
KAND AND KPJ...BUT THINK THE MAJORITY OF AREAS WILL SEE PATCHY
MODERATE FG. THIS SITUATION WILL NEED TO BE MONITORED OVERNIGHT
HOWEVER AS THE ERN ZONES HAVE RECEIVED A MODEST AMOUNT OF RAINFALL
IN THE PAST 6 HRS...WINDS HAVE BECOME CALM AND SKIES ARE BECOMING
CLEARER.
THIS AFTERNOON...STRATUS OVER THE MOUNTAINS AND HIGHER UPSTATE
TERRAIN SHOULD GRADUALLY MIX OUT FROM THE EDGES INWARD. SCATTERED
CUMULUS WILL LIKELY FILL IN THE AREAS SHORTLY AFTER CLEARING OCCURS.
SURFACE FRONT STILL ACROSS THE MID TN VALLEY NOW PRODUCING SOME
LIGHT PRECIP WITH A FEW SCATTERED CONVECTIVE CELLS OVER NE TN. THIS
IS VERY SIMILAR TO DEPICTION ON 15Z HRRR RUN. THE NE TN ACTIVITY
AFFECTS MAINLY THE NRN PORTION OF THE CWA IN THAT DEPICTION WHILE
THE LIGHTER MORE STRATIFORM ACTIVITY DOES NOT MAKE IT ACROSS THE
MOUNTAINS. THIS SUPPORTS EARLIER DECISION TO KEEP CHANCE POPS IN THE
NRN CWA NEAR THE SUPPORT FROM THE UPPER TROUGH. IN THE FAR EASTERN
CWA WHERE SKIES CLEARED EARLIER AND THERE HAS BEEN MORE TIME TO
DESTABILIZE...PROG SOUNDINGS SHOW 500 J OR SO OF CAPE WHICH
WARRANTED A CHC MENTION THERE. DEPENDING ON HOW SOON THE STRATUS
CLEAR OUT IN THE WEST AND DESTABILIZATION OCCURS...SUBSEQUENT
REVISIONS MAY NEED TO BE MADE TO INCREASE POPS IN THAT AREA.
FRONT SHOULD BE EAST OF THE CWA BY MID EVENING AND CLEAR SKIES
SHOULD PROGRESS EASTWARD. TEMPS SHOULD BE NEAR NORMAL AS WINDS WILL
KEEP THE AREA FROM EXPERIENCING PRIME RADIATIONAL COOLING AND ALSO
LIKELY KEEPING FOG AT BAY. SFC DEWPOINTS SHOULD GRADUALLY DROP
OVERNIGHT WHICH WILL INHIBIT FOG FORMATION AS WELL.
CLEAR SKIES AND COOL AIR ALOFT WILL CAUSE DEEP MIXING ON FRIDAY.
THIS WILL ALLOW STRONG WINDS TO MIX DOWN TO THE SURFACE...GENERALLY
IN THE 20 TO 25 KT RANGE...BUT SOMEWHAT HIGHER OVER THE MOUNTAINS.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 230 AM FRIDAY...A DEEP UPPER LOW PRESSURE OVER THE EASTERN
GREAT LAKES REGION WILL SHIFT NORTHEAST AND REACH NORTHERN NEW
ENGLAND ON SUNDAY. HIGH PRESSURE WILL GRADUALLY BUILD IN FROM THE
WEST ON SATURDAY AND REMAIN IN PLACE THROUGH SUNDAY. THIS WILL BRING
MOSTLY DRY CONDITIONS WITH COOLER TEMPERATURES TO OUR CWA THROUGH
THE PERIOD. TEMPERATURES WILL BE AROUND 3-4 DEGREES BELOW NORMAL
WITH AFTERNOON HIGHS IN THE UPPER 60S OVER THE PIEDMONT SAT/SUN.
OVERNIGHT LOWS WILL BE IN THE LOW TO MID 40S OVER THE PIEDMONT WITH
MID TO UPPER 30S IN THE MTNS. THERE WILL BE ENOUGH WINDS TO PRECLUDE
WIDESPREAD FROST IN THE MTNS/FOOTHILLS THROUGH THE PERIOD.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 200 AM EDT FRIDAY...THE MEDIUM RANGE FORECAST PICKS UP AT 12Z
MONDAY WITH AN UPPER LEVEL RIDGE OF HIGH PRESSURE BUILDING OVER THE
EASTERN CONUS WHILE AN UPPER LOW PRESSURE SYSTEM SPINNING OFF THE
PACIFIC NORTHWEST COAST. THE LATEST MODELS ARE IN GOOD AGREEMENT
WITH THE UPPER RIDGE OF HIGH PERSISTING OVER THE REGION THROUGHOUT
THE MEDIUM RANGE PERIOD.
AT THE SURFACE...BROAD SURFACE HIGH PRESSURE WILL REMAIN ANCHORED
OVER THE EASTERN STATES MONDAY THROUGH FRIDAY. THIS WILL RESULT IN
MOSTLY DRY WEATHER WITH TEMPERATURES SLIGHTLY ABOVE NORMAL THROUGH
THE PERIOD.
&&
.AVIATION /07Z FRIDAY THROUGH TUESDAY/...
AT KCLT...THE CONVECTIVE LINE TO THE SE IS EXPECTED TO MOVE OFF TO
THE EAST OVERNIGHT. THE MORE PESSIMISTIC CASE FROM A BLEND OF THE
MAV...MET AND LAMP WOULD YIELD LOW VFR FOG TOWARD DAYBREAK...AND
WITHER NO COG OR A LOW VFR ONE. SW WINDS WILL INCREASE TO OVER 10
KNOTS AND BECOME GUSTY TODAY...WHILE SKY COVER CLEARS OUT. WINDS
BECOME LIGHT SW AGAIN TONIGHT.
ELSEWHERE...OBSERVATIONS SHOW STRATUS AND FOG LURKING IN THE AREA.
MODEL FORECASTS HAVE NOT PICKED UP ON THIS...AND FAVOR IMPROVING
CONDITIONS AS DRIER AIR WORKS IN FROM THE WEST. THE FORECAST WILL
FAVOR A SLOWER AND MORE GRADUAL IMPROVEMENT...WITH IFR CIGS AND VSBY
AT MOST SITES BEFORE DAYBREAK. RAPID IMPROVEMENT IS EXPECTED AFTER
DAWN AS SW WINDS BECOME QUITE GUSTY...HASTENING MIXING. WINDS BECOME
LIGHT TONIGHT...VEERING TO THE NW AT KAVL.
OUTLOOK...EXPECT VFR CONDITIONS TO CONTINUE THROUGH THE WEEKEND. THE
EXCEPTION WILL BE EARLY MORNING MOUNTAIN VALLEY FOG DURING THAT
TIMEFRAME.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JOH
NEAR TERM...JAT
SHORT TERM...JOH
LONG TERM...JOH
AVIATION...JAT
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
116 AM EDT FRI OCT 19 2012
.SYNOPSIS...
A DEEP LOW PRESSURE SYSTEM WILL LINGER TO OUR NORTHWEST AS A COLD
FRONT MOVES OFF THE ATLANTIC COAST ON FRIDAY. DRY HIGH PRESSURE WILL
THEN BUILD IN BEHIND THE FRONT OVER THE WEEKEND AND REMAIN IN PLACE
WELL INTO NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
0515 UTC UPDATE...POPS WERE UPDATED PER RADAR TRENDS IN THE KCLT
AREA. SKY COVER HAS BEEN UPDATED TO ACCOUNT STRATUS COVERAGE FROM
OBSERVATIONS. AREAS OF FOG WERE ADJUSTED BASED ON OBSERVATIONS
TRENDS AS WELL. WINDS WERE UPDATED WITH A TWO TO ONE BLEND OF THE
00Z NAM AND 00Z ADJMAV...THE WEIGHTING TOWARD THE FORMER TO CAPTURE
GUSTIER WINDS AT HIGH ELEVATIONS. TEMPERATURES WERE UPDATED WITH A
BLEND OF THE LATEST ADJMAV AND ADJMET.
EVENING UPDATE...THE RADAR STILL SHOWS A STORM BEING MAINTAINED
ACROSS RABUN COUNTY HEADING INTO NC JUST AHEAD OF THE COLD FRONT.
THIS STORM COULD BECOME FAIRLY STRONG...BUT DONT ANTICIPATE SEVERE
LEVELS. THE REMNANT STORM ACROSS THE NC PIEDMONT IS JUST NOW EXITING
THE CWFA. SOME LINGERING SMALL SCALE -SHRA MAY CONTINUE
OVERNIGHT...YET ANYTHING STRONG OR LONG LIVED IS NOT LIKELY. THE
MAIN CONCERN OVERNIGHT WILL BE THE THREAT OF FG AND JUST HOW DENSE
IT MAY BECOME. SOME AREAS ARE EXPERIENCING DENSE FG CURRENTLY AROUND
KAND AND KPJ...BUT THINK THE MAJORITY OF AREAS WILL SEE PATCHY
MODERATE FG. THIS SITUATION WILL NEED TO BE MONITORED OVERNIGHT
HOWEVER AS THE ERN ZONES HAVE RECEIVED A MODEST AMOUNT OF RAINFALL
IN THE PAST 6 HRS...WINDS HAVE BECOME CALM AND SKIES ARE BECOMING
CLEARER.
THIS AFTERNOON...STRATUS OVER THE MOUNTAINS AND HIGHER UPSTATE
TERRAIN SHOULD GRADUALLY MIX OUT FROM THE EDGES INWARD. SCATTERED
CUMULUS WILL LIKELY FILL IN THE AREAS SHORTLY AFTER CLEARING OCCURS.
SURFACE FRONT STILL ACROSS THE MID TN VALLEY NOW PRODUCING SOME
LIGHT PRECIP WITH A FEW SCATTERED CONVECTIVE CELLS OVER NE TN. THIS
IS VERY SIMILAR TO DEPICTION ON 15Z HRRR RUN. THE NE TN ACTIVITY
AFFECTS MAINLY THE NRN PORTION OF THE CWA IN THAT DEPICTION WHILE
THE LIGHTER MORE STRATIFORM ACTIVITY DOES NOT MAKE IT ACROSS THE
MOUNTAINS. THIS SUPPORTS EARLIER DECISION TO KEEP CHANCE POPS IN THE
NRN CWA NEAR THE SUPPORT FROM THE UPPER TROUGH. IN THE FAR EASTERN
CWA WHERE SKIES CLEARED EARLIER AND THERE HAS BEEN MORE TIME TO
DESTABILIZE...PROG SOUNDINGS SHOW 500 J OR SO OF CAPE WHICH
WARRANTED A CHC MENTION THERE. DEPENDING ON HOW SOON THE STRATUS
CLEAR OUT IN THE WEST AND DESTABILIZATION OCCURS...SUBSEQUENT
REVISIONS MAY NEED TO BE MADE TO INCREASE POPS IN THAT AREA.
FRONT SHOULD BE EAST OF THE CWA BY MID EVENING AND CLEAR SKIES
SHOULD PROGRESS EASTWARD. TEMPS SHOULD BE NEAR NORMAL AS WINDS WILL
KEEP THE AREA FROM EXPERIENCING PRIME RADIATIONAL COOLING AND ALSO
LIKELY KEEPING FOG AT BAY. SFC DEWPOINTS SHOULD GRADUALLY DROP
OVERNIGHT WHICH WILL INHIBIT FOG FORMATION AS WELL.
CLEAR SKIES AND COOL AIR ALOFT WILL CAUSE DEEP MIXING ON FRIDAY.
THIS WILL ALLOW STRONG WINDS TO MIX DOWN TO THE SURFACE...GENERALLY
IN THE 20 TO 25 KT RANGE...BUT SOMEWHAT HIGHER OVER THE MOUNTAINS.
&&
.SHORT TERM /TONIGHT THROUGH 6 PM SATURDAY/...
AS OF 200 PM THURSDAY...A DEEP UPPER LOW OVER THE GREAT LAKES WILL
BEGIN TO SLOWLY SHIFT NORTHEAST AND REACH NORTHERN NEW ENGLAND ON
SUNDAY. MODEL GUIDANCE KEEPS THE DEEPER MOISTURE ASSOCIATED WITH THE
LARGE LOW TO THE NORTH OF THE AREA. HENCE...EXCEPT FOR SOME CLOUDS
ACROSS THE NC MOUNTAINS FRI NIGHT...GENERALLY CLEAR CONDITIONS ARE
ANTICIPATED SAT THROUGH SUN AS SURFACE HIGH PRESSURE GRADUALLY
BUILDS EAST OVER THE REGION.
MOS GUIDANCE IS RATHER CHILLY OVER THE MOUNTAINS FOR BOTH FRI NIGHT
AND SAT NIGHT WITH GENERALLY MID 30S FOR LOWS. THERE MAY BE ENOUGH
WIND/CLOUDS FRI NIGHT TO PRECLUDE WIDESPREAD FROST...BUT CONDITIONS
SAT NIGHT WILL FAVOR WIDESPREAD FROST AS HIGH PRESSURE SETTLES OVER
THE AREA. MAX TEMPS WILL BE NEAR CLIMO PER A MOS BLEND.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
AS OF 215 PM THURSDAY...LOOKS LIKE THE MEDIUM RANGE WILL BE QUIET
WITH TEMPS ABOVE CLIMO. ALL THE MEDIUM RANGE MODELS BUILD AN UPPER
RIDGE OVER THE EASTERN U.S. THE FIRST PART OF THE NEW WORK WEEK AND
IT THEN HOLDS SWAY INTO THE END OF THE WEEK. A BACKDOOR COLD FRONT
MAY APPROACH THU PER HPC/GFS GUIDANCE...BUT THE 00Z ECM KEEPS IT WELL NORTH
OF THE FORECAST AREA. THEREFORE...EXPECT SURFACE HIGH PRESSURE TO
PROVIDE MOSTLY CLEAR CONDITIONS THROUGH THE PERIOD WITH THE
AFOREMENTIONED SEASONALLY WARM CONDITIONS.
&&
.AVIATION /05Z FRIDAY THROUGH TUESDAY/...
AT KCLT...THE CONVECTIVE LINE TO THE SE IS EXPECTED TO MOVE OFF TO
THE EAST OVERNIGHT. THE MORE PESSIMISTIC CASE FROM A BLEND OF THE
MAV...MET AND LAMP WOULD YIELD LOW VFR FOG TOWARD DAYBREAK...AND
WITHER NO COG OR A LOW VFR ONE. SW WINDS WILL INCREASE TO OVER 10
KNOTS AND BECOME GUSTY TODAY...WHILE SKY COVER CLEARS OUT. WINDS
BECOME LIGHT SW AGAIN TONIGHT.
ELSEWHERE...OBSERVATIONS SHOW STRATUS AND FOG LURKING IN THE AREA.
MODEL FORECASTS HAVE NOT PICKED UP ON THIS...AND FAVOR IMPROVING
CONDITIONS AS DRIER AIR WORKS IN FROM THE WEST. THE FORECAST WILL
FAVOR A SLOWER AND MORE GRADUAL IMPROVEMENT...WITH IFR CIGS AND VSBY
AT MOST SITES BEFORE DAYBREAK. RAPID IMPROVEMENT IS EXPECTED AFTER
DAWN AS SW WINDS BECOME QUITE GUSTY...HASTENING MIXING. WINDS BECOME
LIGHT TONIGHT...VEERING TO THE NW AT KAVL.
OUTLOOK...EXPECT VFR CONDITIONS TO CONTINUE THROUGH THE WEEKEND. THE
EXCEPTION WILL BE EARLY MORNING MOUNTAIN VALLEY FOG DURING THAT
TIMEFRAME.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.FIRE WEATHER...
MAXIMUM TEMPERATURES IN THE 60S ACROSS THE MTNS AND 70S FOOTHILLS
AND PIEDMONT ON FRIDAY WILL COMBINE WITH DRIER DEW POINTS ACROSS THE
REGION TO PUSH AFTERNOON RH VALUES DOWN INTO THE 25 TO 30 PERCENT
RANGE FRI AFTN. IN ADDITION...BREEZY SW WINDS ARE EXPECTED THROUGH
THE DAY WITH OCCASIONAL GUSTS IN THE 25 TO 30 KT RANGE. DEPENDING
UPON HOW MUCH RAIN FALLS AHEAD OF THE FRONT PASSING THIS
AFTN/EVENING...FUELS COULD BE DRY ENOUGH TO CREATE HEIGHTENED FIRE
DANGER IN SOME AREAS FRI AFTN. RAIN CHANCES ARE BEST OVER THE NRN
MOUNTAINS AND ERN PIEDMONT. THIS WILL NEED TO BE MONITORED CLOSELY
THROUGH THU.
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...PAT
NEAR TERM...JAT/SBK/WIMBERLEY
SHORT TERM...LG
LONG TERM...LG
AVIATION...JAT/SBK
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1141 PM CDT THU OCT 18 2012
.SHORT TERM...TONIGHT THROUGH SUNDAY
254 PM CDT THU OCT 18 2012
CLOSED LOW AND ITS INFLUENCE ON THE AREA THROUGH FRIDAY EVENING IS
IMMEDIATE FORECAST CONCERN...THEN ATTENTION TURNS TO WARMING
SATURDAY AND ESPECIALLY SUNDAY.
LATEST LOOP OF WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW CLOSED LOW
CENTERED OVER THE MN/IA/WI COMMON BORDER. RADAR MOSAIC SHOWING
WIDESPREAD SHOWER ACTIVITY ACROSS THE FORECAST AREA THANKS TO
INFLUENCE OF DEEP COLD/CYCLONIC FLOW OVERHEAD. TEMPERATURES
SUFFERING AS WELL WITH READINGS AT 2 PM ONLY IN THE 40S.
LATEST NCEP MODELS AS WELL AS THE ECMWF/GEM ALL IN VERY GOOD
AGREEMENT WITH SYNOPTIC SETUP THROUGH SUNDAY.
LOOK OF THE CLOSED LOW TO REMAIN ANCHORED OVER THE REGION
TONIGHT...MAKING A SLOW PUSH EAST TOWARD LAKE MICHIGAN BY LATE
FRIDAY AFTERNOON. BUFKIT MODEL SOUNDINGS SHOWING DEEP LAYER OF
MOISTURE WITH GENERALLY WEAK LIFT OVER THE AREA TONIGHT FOR
SCATTERED SHOWERS/AREAS OF DRIZZLE. WITH LIGHT WINDS AND SATURATED
LOWER BOUNDARY LAYER UNDER THE LOW...ALSO EXPECTING SOME LIGHT FOG
ACROSS THE AREA WITH VISIBILITY GENERALLY IN THE 3-6SM RANGE.
925-850MB LAYER TEMPERATURES COOL ONLY A COUPLE DEGREES TONIGHT.
WITH CLOUD COVER/SCATTERED PRECIPITATION...LOWS TONIGHT SHOULD
BOTTOM OUT IN THE UPPER 30S TO LOWER 40S. PLAN ON SCATTERED SHOWERS
ONCE AGAIN FOR FRIDAY WITH COLD/DEEP CYCLONIC FLOW CONTINUING. NOT
MUCH RECOVERY EXPECTED IN TEMPERATURES AS WELL WITH HIGHS TOPPING
OFF IN THE UPPER 40S TO A FEW LOWER 50S. A FEW LINGERING SHOWERS
WILL BE POSSIBLE ACROSS NORTHEAST IOWA INTO FAR SOUTHWEST WISCONSIN
FRIDAY EVENING AS LAST TROUGH ASSOCIATED WITH THE CLOSED LOW ROTATES
THROUGH THAT AREA. OTHERWISE FOR THE REST OF THE OVERNIGHT HOURS
MODELS PUSH THE CLOSED LOW MORE INTO THE GREAT LAKES REGION WHILE A
RIDGE OF HIGH PRESSURE BUILDS IN FROM THE PLAINS. NAM 925MB RH FIELD
INDICATING PERHAPS A FEW BREAKS IN THE STRATUS/STRATOCUMULUS LATER
FRIDAY NIGHT. THIS IS ALSO INDICATED IN THE BUFKIT SOUNDING...BUT
THEN DEVELOPS QUITE A BIT OF LOW-LEVEL STRATUS TOWARD MORNING.
BELIEVE MOSTLY CLOUDY IS THE WAY TO GO AT THIS POINT IN TIME. WILL
HAVE TO WATCH THIS SCENARIO CLOSELY. IF THERE IS SOME
CLEARING...COULD END UP WITH QUITE A BIT OF FOG WITH COOL/MOIST
LOWER BOUNDARY LAYER.
CLEARING SKIES AND WARMING EXPECTED SATURDAY AS THE CLOSED LOW
CONTINUES TO MOVE EAST OF THE REGION AND RIDGE OF HIGH PRESSURE BUILD
OVERHEAD. HIGHS SATURDAY SHOULD RESPOND NICELY TO SUNSHINE AND
925-850MB TEMPERATURES WARMING INTO THE 5-7C RANGE. PLAN ON HIGHS
PUSHING WELL INTO THE 50S. WARMING WILL CONTINUE INTO SUNDAY IN
SOUTHERLY FLOW AHEAD OF A COLD FRONT MOVING INTO THE DAKOTAS/WESTERN
MN. NAM INDICATING 925-850MB LAYER TEMPERATURES IN THE 14-17C RANGE.
THIS SHOULD EQUATE TO HIGHS SUNDAY IN THE 60S TO PERHAPS A FEW LOWER
70S WHICH WOULD BE SOME 15-20 DEGREES ABOVE NORMAL.
.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY
254 PM CDT THU OCT 18 2012
LATEST GFS/ECMWF IN GOOD AGREEMENT THROUGH TUESDAY...THEN DIVERGE
SOMEWHAT WEDNESDAY AND THURSDAY WITH TIMING ISSUES WITH WAVES IN
SOUTHWEST FLOW ALOFT.
FOR SUNDAY NIGHT THROUGH TUESDAY...CYCLOGENESIS OVER THE CENTRAL
PLAINS TAKES PLACE WITH THE WAVE MOVING NORTHEAST TOWARD THE AREA.
BOTH MODELS SHOWING AMPLE AMOUNT OF 850MB MOISTURE TRANSPORT OUT OF
THE GULF AND INTO THE AREA AHEAD OF THE ADVANCING LOW AND WARM
FRONT. ALSO...MODELS PRODUCING ABOUT 300-600J/KG OF CAPE LATER
SUNDAY NIGHT INTO MONDAY FOR A GOOD CHANCE OF SHOWERS/EMBEDDED
THUNDERSTORMS. FOR WEDNESDAY AND THURSDAY...MODELS DIVERGE ON
AMOUNT OF CYCLOGENESIS AND TIMING OF LOW PRESSURE SYSTEMS MOVING
TOWARD THE AREA WITH SOUTHWEST FLOW ALOFT. TOOK A CONSENSUS APPROACH
FOR NOW WHICH YIELDS MID-RANGE POPS FOR SHOWERS/THUNDERSTORMS.
WILL HOPE FOR BETTER RESOLUTION IN THE MODELS WITH SUBSEQUENT RUNS.
EITHER WAY...LOOKS LIKE AN ACTIVE WEATHER WEEK SETTING UP WITH EVEN
THE OUT SIDE CHANCE OF STRONG-SEVERE THUNDERSTORMS DEPENDING ON
AVAILABLE CAPE/SHEAR. OTHERWISE...LOOKS LIKE TEMPERATURES WILL
REMAIN SOME 15 OR SO DEGREES ABOVE NORMAL.
&&
.AVIATION...THROUGH 06Z SATURDAY
1141 PM CDT THU OCT 18 2012
LITTLE OVERALL CHANGE IS EXPECTED TO OCCUR THROUGH THE PERIOD. THE
BROAD AREA OF SURFACE LOW PRESSURE...CURRENTLY CENTERED OVER
NORTHEAST IOWA...WILL CONTINUE TO SINK SLOWLY SOUTHEAST THROUGH
FRIDAY. THE UPPER LEVEL LOW WILL DO THE SAME WITH THE 19.00Z NAM
CONTINUING TO SHOW A COUPLE MORE SHORT WAVE TROUGH ROTATING AROUND
THE UPPER LEVEL LOW AND ACROSS THE AREA DURING THE DAY. THESE
WAVES PRODUCE VERY LITTLE PV ADVECTION IN THE 500-300 MB LAYER SO
THEY ARE ONLY EXPECTED TO SLIGHTLY ENHANCE THE LIFT. AS THE WHOLE
SYSTEM SINKS SLOWLY AWAY...THE CYCLONIC FLOW WILL BE WEAKENING AS
WILL THE ISENTROPIC UP GLIDE AS THE BETTER WARM AIR ADVECTION
MOVES TO THE SOUTH. HAVE THUS REMOVED THE MENTION OF ANY SUSTAINED
LIGHT RAIN AND LIMITED THE VCSH TO THE DAYLIGHT HOURS FRIDAY. AREA
OF MVFR CLOUDS OVER CENTRAL WISCONSIN IS MOVING SOUTHWEST AND IS
EXPECTED TO BE INTO KLSE AROUND 06Z. HAVE CONTINUED TO SHOW THESE
REACHING KRST OVERNIGHT BUT CONFIDENCE IS NOT THAT HIGH AS THE
TRAJECTORY COULD TAKE THEM SOUTH OF THERE. CONFIDENCE IS ALSO NOT
HIGH ON FOG FORMATION OVERNIGHT AS THERE WILL BE LITTLE
TEMPERATURE CHANGE AND FOG HAS YET TO DEVELOP DESPITE THE LIGHT
WINDS AND HIGH MOISTURE LEVELS AND UPDATES MAY BE NEEDED TO REMOVE
THIS IF IT DOES NOT FORM. WILL BE PESSIMISTIC ON SHOWING ANY
CLEARING FRIDAY EVENING AS THE NAM 850 MB RELATIVE HUMIDITY STAYS
HIGH WELL INTO SATURDAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
254 PM CDT THU OCT 18 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM...DAS
AVIATION...04
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1037 AM CDT FRI OCT 19 2012
.UPDATE...
A MAJOR REVISION HAS BEEN DONE TO THE FCST.
SATELLITE SHOWS A LARGE HOLE HAS DEVELOPED ACROSS EASTERN IOWA
WITH NUMEROUS SMALL HOLES AS WELL. THE RAP ALONG WITH OTHER MODELS
HAVE BEEN SHOWING LARGE AMOUNTS OF SUBSIDENCE OVER THE AREA BUT
THE ONLY HOLES THAT HAVE DEVELOPED ARE OVER THE CWFA.
LIKEWISE...RADAR TRENDS SHOW NOT MUCH IN THE WAY OF SHRA ACTIVITY
EXCEPT EAST OF THE MISSISSIPPI.
SO...ASSUMING THE MOST RECENT TRENDS FROM THE RAP ARE CORRECT MOST
OF THE AREA WILL REMAIN PRECIP FREE FOR THE REMAINDER OF THE
MORNING. THE RAP DOES SLOWLY FILL IN THE HOLES IN THE CLOUD COVER
AS THE DAY PROGRESSES. THIS FILLING MAKES SENSE GIVEN THE COLD
POCKET ALOFT.
ON THE 300K THETA SFC BROAD ISENTROPIC LIFT DEVELOPS DURING THE
AFTERNOON HOURS SO ISOLATED TO SCATTERED SHRA SHOULD ONCE AGAIN
DEVELOP.
GIVEN THE RAPIDLY EVOLVING NATURE...ADDITIONAL UPDATES DURING THE
DAY WILL LIKELY BE NEEDED. ..08..
&&
.AVIATION...
DOWNWARD MOTION HAS ALLOWED A LARGE HOLE TO DVLP ACRS EASTERN IOWA
RESULTING IN VFR CONDITIONS AT KCID. THE RAP MODEL SHOWS THIS HOLE
MOVING EAST BUT EVENTUALLY FILLING THROUGH 21Z/19. ISOLATED TO
SCATTERED SHRA SHOULD DVLP AFT 18Z/19 AS AN UPPER LEVEL
DISTURBANCE MOVES INTO THE AREA. THUS CONDITIONS SHOULD IMPROVE TO
MVFR OR VFR AT ALL TAF SITES BEFORE DROPPING BACK TO MVFR/IFR
CONDITIONS. ..08..
&&
PREV DISCUSSION... /ISSUED 302 AM CDT FRI OCT 19 2012/
SYNOPSIS...
IMPRESSIVE UPPER LOW SPINNING OVER THE MIDWEST AND WAS CENTERED
IN EXTREME SOUTHERN WISCONSIN. THE SURFACE LOW WAS NEAR KDBQ.
DOPPLER RADAR INDICATED AREAS OF DRIZZLE AND POCKETS OF LIGHT RAIN
IN THE DVN CWA. LIGHT TO MODERATE RAIN WAS LOCATED IN SOUTHWEST MN
AND INTO WESTERN IA. CLOUD COVER WAS EXTENSIVE ACROSS THE MIDWEST
WITH CLEAR SKIES FOUND WAY BACK IN THE WESTERN PLAINS. CURRENT
TEMPERATURES IN THE CWA WERE MAINLY IN THE 40S. WINDS WERE HOWLING
IN THE DAKOTAS AND INTO NEB...KS AND MO WITH SOME GUSTS TO 40 KNOTS.
HAASE
SHORT TERM...TODAY AND TONIGHT...
FORECAST FOCUS ON RAIN TODAY THEN ENDING TONIGHT. CONTINUED WELL
BELOW NORMAL TEMPERATURES.
TODAY...STACKED LOW WILL SLOWLY PUSH EASTWARD BUT FORCING IS NOT
AS STRONG AS YESTERDAY AS THE SYSTEM SLOWLY FILLS. HOWEVER AREAS
OF DRIZZLE AND LIGHT RAIN THIS MORNING WITH SHOWERS LIKELY THIS
AFTERNOON WILL STILL BE EXPECTED. DUE TO THE WEAKENING OF THE
SYSTEM RAINFALL AMOUNTS WILL BE LIGHTER THAN YESTERDAY...ON THE
ORDER OF 0.15 INCH OR LESS. WITH EXTENSIVE LOW CLOUDS TEMPERATURES
SHOULD BE LOWER THAN GUIDANCE AND WILL KEEP HIGHS ONLY IN THE
UPPER 40S TO LOWER 50S AT MOST LOCATIONS. WEST TO NORTHWEST WINDS
WILL GUST TO AROUND 25 MPH IN OUR SOUTHERN CWA WHERE THE TIGHTER
GRADIENT SOUTH OF THE LOW EXISTS.
TONIGHT...THE UPPER LOW GETS NUDGED FARTHER EAST AND BY 12Z
SATURDAY SHOULD BE IN THE EASTERN GREAT LAKES REGION. THIS
OCCURRING WHILE A STRONG 100+ KT UPPER LEVEL JET RAMS INTO THE
NORTHERN ROCKIES AS AN INTENSE LOW DIVES SOUTHWARD ALONG THE
BRITISH COLUMBIA COAST. ANY LINGERING RAIN WILL END THIS EVENING
FOLLOWED BY GRADUAL DECREASING CLOUDS. THESE BREAKS IN THE CLOUDS
SHOULD ALLOW TEMPERATURES TO BOTTOM OUT IN THE UPPER 30S TO LOWER
40S BY MORNING.
HAASE
LONG TERM...SATURDAY THROUGH THURSDAY...
WARMING TREND WITH CHANCE OF SHOWERS AND POSSIBLY ISOLATED STORMS
NEXT WEEK.
OVERVIEW...INITIALIZATION AND VERIFICATION GOOD WITH MINOR ISSUES
WITH UPSTREAM PACIFIC ENERGY. LITTLE SENSIBLE WEATHER DIFFERENCES
THIS FAR OUT. VERIFICATION SUPPORTS NORMAL BLEND OF MODELS WEIGHTED
TOWARD GFS. KEY ISSUE WILL BE LOW CLOUD POTENTIAL DEVELOPING SUNDAY
NIGHT AND MONDAY WITH GULF MOISTURE ARRIVING.
SATURDAY AND SUNDAY...FAIR SKIES...LIGHT WINDS AND A WARMING TREND
WITH HIGHS CLOSE TO 60F MOST AREAS SATURDAY AND UPPER 60S TO LOWER
70S ON SUNDAY. SATURDAY NIGHT...LIGHT WIND SUPPORTS COOLER MINS WITH
LATER SHIFTS POSSIBLY NEEDING TO TRIM A FEW MORE DEGREES OFF PROGGED
UPPER 30S TO LOWER 40S.
SUNDAY NIGHT...HAVE LOW POPS WITH SUGGESTION MAY HAVE HIGH ENOUGH
DEWPOINTS FOR LOW CLOUDS AND POSSIBLY FOG AND EVEN LIGHT DRIZZLE
FOR LATER SHIFTS TO REASSESS. MILD LOWS OF 55 TO 60 DEGREES AND
POSSIBLY LOWER 60S LOOK REASONABLE.
MONDAY THROUGH THURSDAY...FRONTAL BOUNDARY TO STALL NORTH OF AREA
WITH MODERATE SW UPPER LEVEL FLOW SUGGESTING A CHANCE OF SHOWERS AND
ISOLATED STORMS. LIMITED INSTABILITY AND FORCING PRECLUDES ANY
POTENTIAL FOR SEVERE STORMS ATTM WITH MUCAPE AOB 1200 J/KG. ABOVE
NORMAL TO WELL ABOVE NORMAL TEMPERATURES WITH HIGHS UPPER 60S TO
MIDDLE 70S DEPENDING ON AMOUNT OF CLOUDS. LOWS TO ALSO TO CONTINUE
QUITE MILD...MAINLY THE UPPER 50S TO LOWER 60S. POOR CONFIDENCE ON
TIMING OF WHEN NEXT FRONT TO PASS WITH D-PROG-DT TRENDS SUPPORTING
NEXT FRIDAY.
NICHOLS
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAY ME
1138 AM EDT FRI OCT 19 2012
.SYNOPSIS...
LOW PRESSURE WILL MOVE VERY SLOWLY EAST FROM THE GREAT LAKES TODAY
THROUGH SATURDAY. A COLD FRONT EXTENDING TO THE SOUTH AND EAST OF
THIS LOW WILL PUSH TOWARD NEW ENGLAND TODAY AND TONIGHT THEN
SLOWLY MOVE THROUGH THE REGION ON SATURDAY. EXPECT CLOUDS AND SCATTERED
MAINLY MOUNTAIN SHOWERS WITH AN UPPER LOW SATURDAY NIGHT INTO
MONDAY. HIGH PRESSURE WILL BUILD BY TO OUR SOUTH ON TUESDAY. A
WARM FRONT WILL BRING CLOUDS AND A CHANCE OF PRECIPITATION TO THE
AREA TUESDAY NIGHT INTO THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...
HAVE BACKED OFF ON POPS FOR THE NEXT FEW HRS. MAIN BANDS OF PCPN
CONT TO STREAM MAINLY W OF THE BORDER OF ME/NH. THIS TIMING IS IN
LINE WITH THE LATEST HRRR RUN.
SOME MINOR TWEAKS TO THE GRIDS THIS MORNING WITH TIMING OF THE
PCPN AND INCREASING WIND FIELDS. WILL MAKE ADJUSTMENTS TO THE
LATEST REC FCST BASED ON CURRENT CONDS. OTRW...NO SIGNIF CHANGES
THIS PACKAGE.
PREV DISC...
WILL UPDATE TO INPUT LATEST OBSERVED DATA. MAIN CHANGE WILL
BE TO UPDATE CHC OF RA THIS MORNING PER LATEST RADAR
LOOP...INCREASING THE CHC OVER OUR SRN MOST ZONES AND DECREASING
IT TO THE N.
PREVIOUS DISCUSSION...THE SLOW MOVING COLD FRONT...AND A WARM
FRONT TO THE SOUTH... WILL COMBINE TO BRING RA AND WIND TO THE
FCST AREA TDA...DEVELOPING FROM SW TO NE THIS MORNING OVER NH AND
SW MAINE AND OVER OUR NE ZONES AROUND MIDDAY. AREAS OF F AND -DZ
WILL PRECEDE THE RA THIS MORNING. E OR SE WINDS PICK UP DURING THE
AFTERNOON. RAINFALL AMOUNTS OF HALF AN INCH UPWARDS TO AN INCH ARE
PSBL TDA...MAINLY ACROSS SE NH TO THE FOOTHILLS OF MAINE. LESSER
AMOUNTS ACROSS FAR WRN NH...NRN NH AND THE MT ZONES OF WRN MAINE.
GENERALLY USED GFS40...A BLEND OF MAV/MET MOS GUIDANCE AND RFC/HPC
QPF FOR THE NEAR TERM FCST.
&&
.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
THE SLOW MOVING CD FNT CONTINUES TO APPROACH TNGT AS RA AND WIND
CONT. THE WIND LETS UP LATER TNGT AS THE PRES GRADIENT EASES UP...
BUT THE RA CONTINUES WITH UP TO AN INCH OF QPF PSBL OVER SRN AND
CENTRAL ZONES. THE FNT MOVES SLOWLY THRU ON SATURDAY WITH PRCP
TAPERING OFF...OR ENDING...WITH SOME PARTIAL CLEARING PSBL. THE
IMPROVING WX REACHES NH FIRST THE SLOWLY WORKS ITS WAY ACROSS SRN
AND WRN MAINE WHERE ANY CLEARING WOULD BE LESS LIKELY. TEMPS
SHOULD WARM UP BEHIND THE FNT...ESPECIALLY IF ANY CLEARING OCCURS.
MOS GUIDANCE GIVES HIGHS IN THE 60S...WITH HIGHS OF 70 TO 75 OVER
MUCH OF NH AND EVEN INTO ADJACENT WRN MAINE.
GENERALLY USED GFS40...BLEND OF MAV/MET MOS GUIDANCE AND RFC/HPC
QPF FOR THE SHORT TERM FCST.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
GFS/ECMWF ARE IN GENERAL AGREEMENT ABOUT LONGWAVE PATTERN WHILE
SIGNIFICANT TIMING DIFFERENCES EXIST WITH INDIVIDUAL SHORTWAVES.
OVERALL...MEAN JET POSITION WILL KEEP COLD AIR BOTTLED UP WELL TO
OUR NORTH WITH TEMPERATURES TO AVERAGE ABOVE NORMAL THIS PERIOD. THE
UPPER LOW WILL CROSS THE REGION SATURDAY NIGHT INTO MONDAY BEFORE
EXITING INTO THE MARITIMES. RISING HEIGHTS AND RIDGING THEN
FOLLOWS FOR THE MIDWEEK PERIOD. IN THE DAILIES...EXPECT CLOUDS AND
SCATTERED MAINLY MOUNTAIN SHOWERS IN CYCLONIC FLOW SATURDAY NIGHT
INTO MONDAY. HIGH PRESSURE WILL BUILD BY TO OUR SOUTH ON TUESDAY. A
WARM FRONT WILL BRING CLOUDS AND A CHANCE OF PRECIPITATION TO THE
AREA TUESDAY NIGHT INTO THURSDAY.
&&
.AVIATION /16Z FRIDAY THROUGH TUESDAY/...
SHORT TERM /THROUGH SATURDAY/...IFR/LIFR DEVELOPS THRU THIS
MORNING AND CONTINUES THRU TNGT...THEN IMPROVES AS THE CD FNT
MOVES THRU ON SATURDAY. LLWS ADDED TO TAFS FOR THIS AFTERNOON
INTO TNGT AS STRONG S SE LOW LVL JET UP TO 50 KT DEVELOPS AT 2000
FT. THE KHIE MTR IS NOT AVAILABLE DUE TO COMMS PROBLEMS WITH THE
ASOS UNIT. HAVE APPENDED "AMD NOT SKED" TO THE TAF.
LONG TERM...
SAT NIGHT - MON...LCL MVFR PSBL IN MOUNTAIN SHOWERS.
&&
.MARINE...
SHORT TERM /TODAY THROUGH SATURDAY/...WILL UPDATE TO INPUT LATEST
OBSERVED DATA WHICH WILL RESULT IN LITTLE IF ANY CHANGES TO THE
PREVIOUS FCST. WILL CONT THE GLW FOR THE OPEN WATERS AND THE SCA
FOR THE BAYS. MODELS BRING A STRONG LOW LVL JET UP TO 50 KT AT
2000 FT ACROSS THE WATERS DURING THIS TIME FRAME AND EXPECT GUSTS
OF 35 TO 40 KT TO MIX DOWN. WINDS DROP OFF SATURDAY AS THE
GRADIENT DECREASES QUICKLY AS THE CD FNT SLOWLY MOVES THRU. SEAS
WILL BE SLOW TO SUBSIDE SO THE GLW WILL LIKELY BE REPLACED WITH AN
SCA FOR SATURDAY.
LONG TERM...
SUN - MON...A SMALL CRAFT FOR WINDS AND SEAS IS POSSIBLE.
&&
.HYDROLOGY...
USED RFC/HPC QPF WHICH ARE IN VERY GOOD AGREEMENT. THE NAM QPF
APPEARS WAY OVERDONE WITH 3 INCH MAX WHILE GFS AND 12Z ECMWF SHOW
MAX OF 1 TO 1.5 INCH OVER SRN ZONES WHICH APPEARS MORE LIKELY. THE
RFC/HPC QPF STORM TOTAL IS A GOOD COMPROMISE WITH MAX AMOUNTS OVER
1.5 INCHES BUT LESS THAN 2 INCHES AND FALL FROM SRN MAINE AND SE
NH TO THE FOOTHILLS. THIS MUCH QPF IS WELL BELOW FLASH FLOOD
GUIDANCE AND PRELIMINARY RFC RIVER FCST KEEPING ALL POINT FCST
BELOW FLOOD STAGE THOUGH IT DOES SHOW SHARP RISES AND WOODSTOCK IN
NH GETS CLOSE TO FLOOD STAGE.
&&
.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES WILL CONT OVER THE NEXT TWO DAYS. WITH
INCREASING ONSHORE FLOW TDA AND TNGT ALONG WITH BUILDING SEAS
THERE WILL BE STORM SURGE ON TOP OF THE HIGH TIDE WHICH COULD PUSH
THE TIDE CLOSE TO FLOOD STAGE...THOUGH IT IS EXPECTED TO STAY
BELOW FLOOD STAGE. STILL THE WAVE ACTION COULD LEAD TO SOME
SPLASHOVER AND BEACH EROSION PROBLEMS...MAINLY DURING THE
AFTERNOON HIGH TIDE TDA AND MAINLY FROM PWM TO PSM. WINDS AND SEAS
WILL BE LOWERING SLOWLY ON SATURDAY AS THE HIGH TIDE IS LOWER THAN
TODAY. THUS NOT EXPECTING ANY PROBLEMS WITH THE HIGH TIDE ON
SATURDAY. THE PREDICTED HIGH TIDE AT PORTLAND IS 11.2 FT AT 227 PM
TDA AND 10.8 FT AT 326 PM SATURDAY. THE TIDAL FLOOD STAGE AT
PORTLAND IS 12.0 FT.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EDT SATURDAY FOR ANZ151-153.
GALE WARNING FROM 4 PM THIS AFTERNOON TO 7 AM EDT SATURDAY FOR
ANZ150-152-154.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
757 AM EDT FRI OCT 19 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 449 AM EDT FRI OCT 19 2012
UPPER LOW REMAINS NEARBY THIS MORNING...CENTERED OVER WI/NORTHERN
IL. AT THE SFC...PRIMARY SFC LOW HAS NOW FOCUSED FARTHER SOUTH WITH
POSITION OVER NORTHWEST ILLINOIS. AN OCCLUDED FRONT IS ARCING FROM
THE LOW TO THE NORTH OF LK SUPERIOR WHILE COLD FRONT IS PLOWING
TOWARD ATLANTIC SEABOARD WITH SOME CONVECTION. RADAR LOOP OVER THE
WESTERN GREAT LAKES REGION SHOWS CONCENTRATED AREAS OF SHOWERS OVER
MINNESOTA...NORTHERN INDIANA...AND LIFTING NORTH ACROSS LK MICHIGAN.
OVER UPR MICHIGAN...ARE JUST SEEING A SMATTERING OF LGT SHOWERS OVER
CNTRL CWA THOUGH THE SHOWERS OVER LK MICHIGAN ARE POISED TO IMPACT
SCNTRL CWA EARLY THIS MORNING.
SFC LOW MOVES FROM NORTHERN ILLINOIS TO VCNTY LK HURON THIS EVENING.
WV LOOP AND RUC ANALYSIS INDICATE SHORTWAVES TO THE SOUTH OF UPR
MICHIGAN ON FRONT EDGE OF UPPER LOW ARE LIFTING NORTH THIS MORNING.
PRIMARY SHORTWAVE OVER INDIANA LIFTS ACROSS LOWER MICHIGAN TODAY AS
UPPER LOW SLOWLY MOVES EAST. RUC/GEM-REGIONAL HAVE DECENT HANDLE ON
LOCATION OF CURRENT SHOWERS AND BOTH SHOW MAIN AREA OF SHOWERS
STAYING OVER LOWER MICHIGAN THROUGH THE DAY. HOWEVER...AS THE
SHORTWAVE LIFTS NORTH...H85 WINDS BACK FROM SOUTHERLY TO MORE
EASTERLY...ALLOWING INCREASE IN H85 MOISTURE TRANSPORT ACROSS
CENTRAL AND EASTERN ZONES. COMBINATION OF THE ADDITIONAL MOISTURE
AND WEAK LIFT ON PERIFERY OF STRONGER SHORTWAVES LIFTING ACROSS
LOWER MICHIGAN SHOULD LEAD TO INCREASING COVERAGE OF SHOWERS FOR THE
EAST HALF OF CWA. SCATTERED WORDING WORKS FOR MOST AREAS TODAY. ONLY
EXCEPTION IS OVER THE KEWEENAW WHERE CHANCES STAY A BIT LOWER AS
THEY ARE FARTHER DISPLACED FROM THE FORCING. JUST A SLIGHT RISE IN
925MB TEMPS THROUGH THE DAY AS LOW-LEVEL WINDS BECOME MORE NORTH OF
EAST BY LATE DAY. EXPECT HIGHS TO REACH UPR 40S NORTH CENTRAL AND
INTO THE 50S ELSEWHERE. WHATEVER WEAK LIFT IS LEFT EVADES IN THE
EVENING...LEAVING 925-850MB MOISTURE BUT NOT MUCH FORCING. CUT OUT
POPS TOWARD MIDNIGHT FOR ALL AREAS. WEAKLY CYCLONIC NORTHEAST
LOW-LEVEL WINDS COULD KEEP BKN CLOUDS IN MOST OF THE NIGHT OVER
UPSLOPE AREAS OF WESTERN AND NORTH CENTRAL CWA. MIN TEMPS JUST
SLIGHTLY COOLER THAN TONIGHT...UPR 30S TO MID 40S.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 449 AM EDT FRI OCT 19 2012
NAM SHOWS A CLOSED 500 MB LOW OVER SE LOWER MICHIGAN IN AN EMBEDDED
DEEP TROUGH OVER THE EASTERN U.S. WITH A TROUGH OVER SW CANADA AND A
BROAD RIDGE OVER THE SOUTHERN ROCKIES INTO THE PLAINS ON SAT. THE
NAM BUILDS THE RIDGE INTO THE UPPER GREAT LAKES SAT NIGHT THROUGH
SUN NIGHT. WITH THE RIDGE IN THE AREA...LOOKS TO STAY DRY THIS
PERIOD AS THE CLOSED 500 MB LOW PULLS OFF TO THE EAST AND TAKES ITS
RAIN WITH IT AND WE WAIT FOR SYSTEMS TO EJECT OUT OF THE BROAD 500
MB TROUGH THAT WILL SET UP TO THE WEST. OVERALL...DID NOT MAKE TOO
MANY CHANGES TO THE GOING FORECAST FOR TEMPERATURES OR WEATHER.
IN THE EXTENDED...GFS AND ECMWF SHOW A 500 MB RIDGE OVER THE ERN
U.S. WITH A BROAD 500 MB TROUGH OVER THE WESTERN U.S. 12Z MON. UPPER
AIR FLOW STAYS OUT SW-NE THROUGH WED WITH LITTLE MOVEMENT TO THE
RIDGE OR THE TROUGH. ECMWF SHOWS A SHORTWAVE TROUGH EJECTING INTO
THE UPPER GREAT LAKES 12Z THU WHILE THE GFS IS SLOWER WITH IT. LOOKS
TO BE WARM AND WET THROUGH THE PERIOD WITH A CHANCE OF RAIN EACH
DAY. TEMPERATURES WILL CONTINUE TO BE ABOVE NORMAL. GETS KIND OF
TRICKY LATER ON FOR WINDS IN THE EXTENDED...ESPECIALLY THURSDAY AS
THE GFS AND ECMWF ARE 180 DEGREES OPPOSITE FOR WIND DIRECTIONS...BUT
ARE STRONG ON THE WINDS. KEPT PERSISTENCE FORECAST IN FOR NOW.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 755 AM EDT FRI OCT 19 2012
CHALLENGING FCST AS SLOW MOVING CLOSED LO PRES IS STILL DRIFTING E
THRU THE LOWER GRT LKS. ALTHOUGH DISTURBANCES ROTATING ARND THIS
MAIN LO WL BRING PERIODS OF -SHRA...LLVL DRY ADVECTION WILL ONLY
ALLOW MVFR CONDITIONS TO PREDOMINATE. DAYTIME HEATING COULD ALLOW
CIGS TO RISE UP SLIGHTLY TODAY...BUT MVFR CONDITIONS WL REDEVELOP IN
THE EVNG WITH DIURNAL COOLING...ESPECIALLY AT IWD/SAW WITH MORE OF
AN UPSLOPE NE WIND.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 449 AM EDT FRI OCT 19 2012
SE WINDS TO 25 KTS TO START THE DAY THEN WINDS DIMINISH TO LESS THAN
20 KTS LATER TONIGHT INTO SATURDAY. COULD SEE NW WINDS REACH 25 KTS
SATURDAY OVER EASTERN PORTIONS OF LK SUPERIOR AS HIGH PRESSURE
BUILDS TOWARD SLOWLY EXITING LOW PRESSURE OVER QUEBEC...LEADING TO
TEMPORARY TIGHTER PRESSURE GRADIENT. EXPECT WINDS TO DIMINISH ON
SATURDAY NIGHT ONCE THE RIDGE MOVES OVERHEAD. WINDS WILL REMAIN AT
20 KTS OR LESS THROUGH EARLY NEXT WEEK WITH WEAK PRESSURE GRADIENT
IN PLACE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...07
AVIATION...JLA
MARINE...JLA
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
1053 AM CDT FRI OCT 19 2012
.UPDATE...
ISSUED AT 1036 AM CDT FRI OCT 19 2012
SHORTWAVES ROTATING AROUND A DEEP UPPER LOW WILL BRING SCT SHRA
AND DRIZZLE TO PARTS OF THE AREA THROUGH THE AFTERNOON. ONE OF THE
CHALLENGES WITH MONITORING SHORT TERM WX TRENDS TODAY IS THAT THE
LOWEST ELEVATION ANGLE OF THE RADAR BEAM IS OVERSHOOTING MOST OF
THE PCPN BEYOND APPROXIMATELY 40 NMI. FOR EXAMPLE...LIGHT RAIN OR
DRIZZLE WAS LOWERING VSBYS TO AROUND 4 MI AT KUIN BETWEEN 14-15Z
HOWEVER THE 0.5 DEGREE ELEVATION SCANS DEPICTED NO PCPN ANYWHERE
NEAR KUIN. THERE MAY BE SOME BRIEF PDS OF CLEARING AND A FEW
GLIMPSES OF SUNSHINE DUE TO SUBSIDENCE ALOFT HOWEVER CLOUDS ARE
EXPECTED TO BUILD BACK IN FAIRLY QUICKLY.
KANOFSKY
&&
.SHORT TERM...
ISSUED AT 320 AM CDT FRI OCT 19 2012
(TODAY AND TONIGHT)
THE EXPANSIVE UPPER LOW CURRENTLY CENTERED IN WISCONSIN CONTINUES
TO MEANDER EASTWARD. A NUMBER OF WEAK IMPULSES PINWHEELING AROUND
THE VORTEX HAVE BEEN PRODUCING AREAS OF RAIN/SHOWERS. THE VAST
MAJORITY OF THE ACTIVITY THUS FAR WITHIN THE LSX CWA HAS BEEN
LOCATED ALONG AND NORTH OF I-70...AND HAS BEEN LIGHT AND NON-
MEASURABLE. REGIONAL RADARS SUGGEST THAT THE COVERAGE UPSTREAM HAS
BEGUN TO DIMINISH SOME. THE LATEST FORECASTS OF THE HRRR AND
DETERMINISTIC MODELS CONTINUE THIS TREND THOUGH THE MORNING AND
INTO THE AFTERNOON AS THE SYSTEM MOVES SLOWLY EASTWARD. STRATUS...GUSTY
WEST WINDS...AND POCKETS OF PRECIPITATION WILL MAKE FOR A COOL DAY
WITH WELL BELOW AVERAGE TEMPERATURES. THE UPPER LOW AND ATTENDANT
UPPER TROF WILL CONTINUE EASTWARD TONIGHT AND THE NWP MODEL SUITE
IS WELL CLUSTERED SHOWING THE UPPER LOW INVOF SRN MI WITH THE
UPPER TROF AXIS INTO THE TX PANHANDLE BY 12Z SAT. LOW LEVEL RH
PROGS SHOW THAT CLOUDS WILL PERSIST TONIGHT AND THIS SHOULD HELP
OVERNIGHT TEMPERATURES IN THE LOW-MID 40S.
GLASS
&&
.LONG TERM...
ISSUED AT 320 AM CDT FRI OCT 19 2012
(SATURDAY THROUGH SUNDAY)
THE UPPER AIR PATTERN WILL UNDERGO A CHANGE DURING THE PERIOD AS
THE UPPER LOW/TROF LIFT NEWD...WITH THE TROF SHIFTING INTO THE
WESTERN ATLANTIC BY SUNDAY EVENING. HEIGHTS ALOFT WILL RISE SOME
90 TO 120 M IN RESPONSE TO THE PROGRESSION...WITH A WEAK UPPER
RIDGE SHIFTING THROUGH THE MS VALLEY ON SUNDAY. SATURDAY WILL BE A
DAY OF TRANSITION AS CLOUDS ERODE AND A WEAK SURFACE RIDGE SLIDES
ACROSS THE CWA RESULTING IN MODERATING TEMPERATURES. A BIG WARM-UP
IS ON TAP SUNDAY IN RESPONSE TO THE HEIGHT RISES ALOFT AND GOOD
LOW LEVEL WAA.
(SUNDAY NIGHT THROUGH THURSDAY)
ABOVE AVERAGE TEMPERATURES AND A PERIOD OF POTENTIALLY STORMY
WEATHER ARE ON TAP FOR THE UPCOMING WEEK. SWLY UPPER FLOW WILL
DOMINATE THROUGH THE MS VALLEY WITH A DEEP BROAD UPPER TROF
CENTERED JUST OFF THE WEST COAST THROUGH AT LEAST MID WEEK. A 30+
KT SWLY LLJ WILL RAMP UP ON SUNDAY NIGHT AND THIS WILL RESULT IN
STRONG MOISTURE TRANSPORT AND CONVERGENCE BACK INTO THE AREA. THIS
MOISTENING COMBINED WITH THE EASTWARD ADVECTION OF STEEPER MID
LEVEL LAPSE RATES/THE EML WILL RESULT IN ELEVATED INSTABILITY WITH
POTENTIAL FOR ELEVATED SHOWERS AND THUNDERSTORMS IN THE WAA
REGIME SUNDAY NIGHT INTO MONDAY MORNING. AN IMPULSE LIFTING NEWD OUT OF
THE SRN PLAINS AND ACROSS THE AREA MONDAY AFTERNOON AND NIGHT IN
THE SW FLOW ALOFT WILL MAINTAIN THE THREAT OF SHOWERS AND
THUNDERSTORMS.
GLASS
&&
.AVIATION...
ISSUED AT 626 AM CDT FRI OCT 19 2012
LARGE LOW SYSTEM WILL CONTINUE TO SPREAD CLOUDS ACROSS THE REGION
TODAY AS WELL AS LIGHT PRECIP THIS MORNING. LATEST RADAR TRENDS AS
WELL AS GUIDANCE SUGGEST RA WILL GRADUALLY COME TO AN END THIS
MORNING. A LOT OF UNCERTAINTY REMAINS REGARDING THE ENDING OF
PRECIP. ONLY MINOR CHANGES TO THE PREV TAFS...BUT OVERALL DELAYED
CIGS LIFTING UNTIL LATE THIS AFTERNOON OR INTO THE EVENING HOURS.
THIS MAY BE TOO OPTIMISTIC AS CIGS MAY LOWER AGAIN TONIGHT AS THE
BOUNDARY LAYER COOLS WITH NO INSOLATION ANTICIPATED TODAY.
REGARDLESS...CLOUDS SHUD MOVE OUT OF THE AREA NEAR THE END OF THE
TAF PERIOD. STRONG AND GUSTY WLY WINDS WILL DIMINISH LATE TONIGHT
AND VEER SLIGHTLY TO NWLY.
SPECIFICS FOR KSTL...ONGOING RA IS EXPECTED TO DIMINISH THIS
MORNING...THO EXACT TIMING REMAINS UNCERTAIN. CIGS SHUD REMAIN IN
THE MVFR RANGE THRU THIS AFTERNOON AND INTO THIS EVENING. SOME
UNCERTAINTY REMAINS WITH TIMING OF CIGS LIFTING...AS CIGS MAY
LOWER AGAIN TONIGHT AS THE BOUNDARY LAYER COOLS. STRONG WLY WINDS
SHUD DIMINISH THIS EVENING AND VEER SLIGHTLY LATE TONIGHT.
TILLY
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
637 AM CDT FRI OCT 19 2012
.SHORT TERM...
ISSUED AT 320 AM CDT FRI OCT 19 2012
(TODAY AND TONIGHT)
THE EXPANSIVE UPPER LOW CURRENTLY CENTERED IN WISCONSIN CONTINUES
TO MEANDER EASTWARD. A NUMBER OF WEAK IMPULSES PINWHEELING AROUND
THE VORTEX HAVE BEEN PRODUCING AREAS OF RAIN/SHOWERS. THE VAST
MAJORITY OF THE ACTIVITY THUS FAR WITHIN THE LSX CWA HAS BEEN
LOCATED ALONG AND NORTH OF I-70...AND HAS BEEN LIGHT AND NON-
MEASURABLE. REGIONAL RADARS SUGGEST THAT THE COVERAGE UPSTREAM HAS
BEGUN TO DIMINISH SOME. THE LATEST FORECASTS OF THE HRRR AND
DETERMINISTIC MODELS CONTINUE THIS TREND THOUGH THE MORNING AND
INTO THE AFTERNOON AS THE SYSTEM MOVES SLOWLY EASTWARD. STRATUS...GUSTY
WEST WINDS...AND POCKETS OF PRECIPITATION WILL MAKE FOR A COOL DAY
WITH WELL BELOW AVERAGE TEMPERATURES. THE UPPER LOW AND ATTENDANT
UPPER TROF WILL CONTINUE EASTWARD TONIGHT AND THE NWP MODEL SUITE
IS WELL CLUSTERED SHOWING THE UPPER LOW INVOF SRN MI WITH THE
UPPER TROF AXIS INTO THE TX PANHANDLE BY 12Z SAT. LOW LEVEL RH
PROGS SHOW THAT CLOUDS WILL PERSIST TONIGHT AND THIS SHOULD HELP
OVERNIGHT TEMPERATURES IN THE LOW-MID 40S.
GLASS
&&
.LONG TERM...
ISSUED AT 320 AM CDT FRI OCT 19 2012
(SATURDAY THROUGH SUNDAY)
THE UPPER AIR PATTERN WILL UNDERGO A CHANGE DURING THE PERIOD AS
THE UPPER LOW/TROF LIFT NEWD...WITH THE TROF SHIFTING INTO THE
WESTERN ATLANTIC BY SUNDAY EVENING. HEIGHTS ALOFT WILL RISE SOME
90 TO 120 M IN RESPONSE TO THE PROGRESSION...WITH A WEAK UPPER
RIDGE SHIFTING THROUGH THE MS VALLEY ON SUNDAY. SATURDAY WILL BE A
DAY OF TRANSITION AS CLOUDS ERODE AND A WEAK SURFACE RIDGE SLIDES
ACROSS THE CWA RESULTING IN MODERATING TEMPERATURES. A BIG WARM-UP
IS ON TAP SUNDAY IN RESPONSE TO THE HEIGHT RISES ALOFT AND GOOD
LOW LEVEL WAA.
(SUNDAY NIGHT THROUGH THURSDAY)
ABOVE AVERAGE TEMPERATURES AND A PERIOD OF POTENTIALLY STORMY
WEATHER ARE ON TAP FOR THE UPCOMING WEEK. SWLY UPPER FLOW WILL
DOMINATE THROUGH THE MS VALLEY WITH A DEEP BROAD UPPER TROF
CENTERED JUST OFF THE WEST COAST THROUGH AT LEAST MID WEEK. A 30+
KT SWLY LLJ WILL RAMP UP ON SUNDAY NIGHT AND THIS WILL RESULT IN
STRONG MOISTURE TRANSPORT AND CONVERGENCE BACK INTO THE AREA. THIS
MOISTENING COMBINED WITH THE EASTWARD ADVECTION OF STEEPER MID
LEVEL LAPSE RATES/THE EML WILL RESULT IN ELEVATED INSTABILITY WITH
POTENTIAL FOR ELEVATED SHOWERS AND THUNDERSTORMS IN THE WAA
REGIME SUNDAY NIGHT INTO MONDAY MORNING. AN IMPULSE LIFTING NEWD OUT OF
THE SRN PLAINS AND ACROSS THE AREA MONDAY AFTERNOON AND NIGHT IN
THE SW FLOW ALOFT WILL MAINTAIN THE THREAT OF SHOWERS AND
THUNDERSTORMS.
GLASS
&&
.AVIATION...
ISSUED AT 626 AM CDT FRI OCT 19 2012
LARGE LOW SYSTEM WILL CONTINUE TO SPREAD CLOUDS ACROSS THE REGION
TODAY AS WELL AS LIGHT PRECIP THIS MORNING. LATEST RADAR TRENDS AS
WELL AS GUIDANCE SUGGEST RA WILL GRADUALLY COME TO AN END THIS
MORNING. A LOT OF UNCERTAINTY REMAINS REGARDING THE ENDING OF
PRECIP. ONLY MINOR CHANGES TO THE PREV TAFS...BUT OVERALL DELAYED
CIGS LIFTING UNTIL LATE THIS AFTERNOON OR INTO THE EVENING HOURS.
THIS MAY BE TOO OPTIMISTIC AS CIGS MAY LOWER AGAIN TONIGHT AS THE
BOUNDARY LAYER COOLS WITH NO INSOLATION ANTICIPATED TODAY.
REGARDLESS...CLOUDS SHUD MOVE OUT OF THE AREA NEAR THE END OF THE
TAF PERIOD. STRONG AND GUSTY WLY WINDS WILL DIMINISH LATE TONIGHT
AND VEER SLIGHTLY TO NWLY.
SPECIFICS FOR KSTL...ONGOING RA IS EXPECTED TO DIMINISH THIS
MORNING...THO EXACT TIMING REMAINS UNCERTAIN. CIGS SHUD REMAIN IN
THE MVFR RANGE THRU THIS AFTERNOON AND INTO THIS EVENING. SOME
UNCERTAINTY REMAINS WITH TIMING OF CIGS LIFTING...AS CIGS MAY
LOWER AGAIN TONIGHT AS THE BOUNDARY LAYER COOLS. STRONG WLY WINDS
SHUD DIMINISH THIS EVENING AND VEER SLIGHTLY LATE TONIGHT.
TILLY
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
950 AM EDT FRI OCT 19 2012
.SYNOPSIS...
A FRONT WILL SLOWLY PASS THROUGH THE AREA TODAY WITH WIDESPREAD
SHOWERS EXPECTED IN CENTRAL NEW YORK, EAST OF I81 AND OVER
NORTHEAST PENNSYLVANIA. ISOLATED THUNDERSTORMS WILL ALSO OCCUR IN
THE ABOVE MENTIONED AREA. LOW PRESSURE MOVING SLOWLY EASTWARD
THROUGH THE GREAT LAKES WILL KEEP UNSETTLED WEATHER IN OUR AREA
FOR MUCH OF THE WEEKEND. SHOWERS FROM THE LOW WILL BE SCATTERED
OVER THE REGION INTO SUNDAY...ALONG WITH GRADUALLY COOLER AIR.
&&
.NEAR TERM /THROUGH TONIGHT/...
945 AM UPDATE...LOCAL RADARS SHOW SHOWERS ACROSS CENTRAL NY
MAINLY EAST OF I81 AND NORTHEAST PA. OCCLUDED FRONT STRETCHED FROM
THE SYR AREA SOUTH ACROSS BGM INTO THE WYOMING VALLEY. SFC WAVE
ALONG BOUNDARY OVER SE PA WILL ACT TO SLOW THE PROGRESS OF THIS
FRONT THROUGH EARLY AFTERNOON ALONG WITH KEEPING ACTIVITY IN SAME
LOCATION UNTIL EASTWARD PROGRESS COMMENCES AGAIN. WEAK INSTABILITY
ALONG WITH FRONTAL LIFT WILL KEEP THE THREAT FOR THUNDERSTORMS
ALONG AND EAST OF BOUNDARY THROUGH THIS AFTERNOON. HIGH PWATS
INDICATE ANY STRONGER RETURNS ON RADAR WILL BE ASSOCIATED WITH
HEAVY DOWNPOURS AND THIS IS CONFIRMED BY OBSERVATIONS.
PREVIOUS DISC...
FNT DEAD CNTR OVER THE FCST AREA ATTM WITH A BRIEF AREA OF RW+
AND AN ISLTD LGTNG STRIKES OVER NE PA. LATEST HRRR AND NAM RUNS
ARE QUITE PROGRESSIVE WITH THE FNT PUSHING IT AND THE HEAVIEST
RAIN EAST OF THE FCST AREA BY 12Z...DESPITE THE DVLPG SFC LOW OVER
THE MID ATLANTIC STATES. DEEP MOISTURE AHD OF THE FNT WITH A GULF
CONNECTION AND PWATS NEAR 180% OF NRML FOR THIS TIME OF YEAR.
AREAS AHD OF THE FNT WILL CONT TO SEE HEAVY RAIN WITH THE GOOD
FRCG OF THE FNT.
HRRR AND NAM SHOWS SOME PCPN BEING TOSSED BACK BHD THE FNT LTR
THIS MRNG AS THE LOW MVES NEWRD...SO WILL KEEP HIER POPS OVER THE
ERN ZONES THRU MUCH OF THE DAY DESPITE THE ERWRD MVMT OF THE
BNDRY.
SINCE THE LATEST MODEL FCSTS KEEP THE FNT PROGRESSIVE THRU THE
FCST AREA...HEAVY RAINS SHD NOT BE A PRBLM...WITH STORM TTLS WELL
BLO FFG AND HEADWATERS GUID. WILL KEEP A LOW CHANCE OF THUNDER IN
THE EAST AND SOUTH WITH THE INSTABILITY ALOFT WITH THE FNT...AND
THE ADDED LIFT OF THE APRCHG WV.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
LOW PLODS SLOWLY EAST AS IT GRADUALLY FILLS. DRY SLOT BHD THE FNT
TODAY IS QUICKLY REPLACED WITH THE DEEP MOISTURE ASSOCIATED WITH
THE UPR LOW. VERTICALLY STACKED LOW IS POSITIONED NEAR BUF BY 00Z
SUN. THIS WILL KEEP INSTABILITY AND MOISTURE OVER THE AREA...ALONG
WITH A GRADUAL COOLING AS THE COLD CORE APRCHS. DOES NOT APPEAR TO
BE ENUF INSTABILITY FOR TRWS ATTM...ALTHOUGH AN ISLTD WEAK STORM
CANNOT BE RULED OUT SAT AFTN...ESP WITH ANY HTG.
BY SUN...PROGRESSIVE LOW IS NORTH OF THE ST LAWRENCE VLY AND
SOMEWHAT DRIER AIR IS MVG BACK IN FROM THE OH VLY. ENUF LEFTIOVER
MOISTURE MAY ALLOW FOR A FEW SCT SHWRS OVER THE NRN ZONES...ESP
OVER THE HIER TERRAIN. ANY PCPN WILL BE LGT.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
DURING THE EXTENDED PERIOD MEDIUM RANGE MODELS ARE IN AGREEMENT
THAT THE UPPER LEVEL TROF OVER THE NORTHEAST WILL BE REPLACED BY
RISING HEIGHTS AND DEVELOPMENT OF AN UPPER LEVEL RIDGE. AT THE
SURFACE THINGS ARE A BIT MORE TRICKY WITH LOW PRES MOVING THROUGH
THE UPPER GREAT LAKES WITH POSSIBLE FROPA TUESDAY NIGHT. GENERALLY
FOLLOWED HPC GUIDANCE.
SUNDAY EVENING WILL INCLUDE SLIGHT CHC POPS FAR NRN CWA ON BACK
SIDE OF UPPER LEVEL TROF THEN DRY. DRY WEATHER IS EXPECTED
MONDAY THROUGH MUCH OF MONDAY NIGHT THEN CHC/SLIGHT CHC POPS
TUESDAY THROUGH WEDNESDAY DUE TO PASSING COLD FRONT AND NORTHWEST
FLOW BEHIND BOUNDARY. DRY WEATHER WILL RETURN WED NIGHT/THURSDAY
AS SFC HIGH BUILDS DOWN FROM CANADA. TEMPS WILL BE 5-10 DEGREES
ABOVE NORMAL.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
730 AM UPDATE...
THE FIRST MAIN AREA OF RAIN SHOWERS IS EXITING THE REGION TO THE
EAST OF THE TERMINALS. KAVP HAS A THUNDERSTORM NOW THAT MAY LAST
AN HOUR BEFORE A BREAK. SCATTERED SHOWER ACTIVITY IN THE FINGER
LAKES AND CENTRAL SOUTHERN TIER OF NY WILL EXPAND AND FILL IN AS
IT MOVES SLOWLY NORTHEAST. SHOWERS WILL CONTINUE TODAY,
ESPECIALLY PRIOR TO NOON.
SKY COVER IS ERRATIC IN THE INTERIM. BEFORE THE SHOWERS COME IN
BGMA ND SYR BOUNCING BETWEEN IFR AND VFR. WITH THE SHOWERS CIGS
BETWEEN MVFR AND VFR. CIGS AS LOW AS 1500 FT.
MODELS SUGGEST A TEMPORARY DRYING OF THE ATMOSPHERE BETWEEN 20Z
AND 00Z, SO THE CURRENT TERMINAL FORECASTS SCATTER OUT THE MVFR
CLOUD COVER PRIOR TO SUNSET.
OUTLOOK...
SAT...MVFR RESTRICTIONS EXPECTED IN OCNL -SHRA.
SUN AND MON...MAINLY VFR.
TUE...BECOMING MVFR WITH SHOWERS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DGM/RRM
NEAR TERM...DGM/RRM
SHORT TERM...DGM
LONG TERM...RRM
AVIATION...DJP/TAC
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
804 AM EDT FRI OCT 19 2012
.SYNOPSIS...
LOW PRESSURE MOVING SLOWLY EASTWARD THROUGH THE GREAT LAKES WILL
KEEP UNSETTLED WEATHER IN OUR AREA FOR MUCH OF THE WEEKEND.
SHOWERS FROM THE LOW WILL BE SCATTERED OVER THE REGION INTO
SUNDAY...ALONG WITH GRADUALLY COOLER AIR.
&&
.NEAR TERM /THROUGH TONIGHT/...
FNT DEAD CNTR OVER THE FCST AREA ATTM WITH A BRIEF AREA OF RW+ AND
AN ISLTD LGTNG STRIKES OVER NE PA. LATEST HRRR AND NAM RUNS ARE
QUITE PROGRESSIVE WITH THE FNT PUSHING IT AND THE HEAVIEST RAIN
EAST OF THE FCST AREA BY 12Z...DESPITE THE DVLPG SFC LOW OVER THE
MID ATLANTIC STATES. DEEP MOISTURE AHD OF THE FNT WITH A GULF
CONNECTION AND PWATS NEAR 180% OF NRML FOR THIS TIME OF YEAR.
AREAS AHD OF THE FNT WILL CONT TO SEE HEAVY RAIN WITH THE GOOD
FRCG OF THE FNT.
HRRR AND NAM SHOWS SOME PCPN BEING TOSSED BACK BHD THE FNT LTR
THIS MRNG AS THE LOW MVES NEWRD...SO WILL KEEP HIER POPS OVER THE
ERN ZONES THRU MUCH OF THE DAY DESPITE THE ERWRD MVMT OF THE
BNDRY.
SINCE THE LATEST MODEL FCSTS KEEP THE FNT PROGRESSIVE THRU THE
FCST AREA...HEAVY RAINS SHD NOT BE A PRBLM...WITH STORM TTLS WELL
BLO FFG AND HEADWATERS GUID. WILL KEEP A LOW CHANCE OF THUNDER IN
THE EAST AND SOUTH WITH THE INSTABILITY ALOFT WITH THE FNT...AND
THE ADDED LIFT OF THE APRCHG WV.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
LOW PLODS SLOWLY EAST AS IT GRADUALLY FILLS. DRY SLOT BHD THE FNT
TODAY IS QUICKLY REPLACED WITH THE DEEP MOISTURE ASSOCIATED WITH
THE UPR LOW. VERTICALLY STACKED LOW IS POSITIONED NEAR BUF BY 00Z
SUN. THIS WILL KEEP INSTABILITY AND MOISTURE OVER THE AREA...ALONG
WITH A GRADUAL COOLING AS THE COLD CORE APRCHS. DOES NOT APPEAR TO
BE ENUF INSTABILITY FOR TRWS ATTM...ALTHOUGH AN ISLTD WEAK STORM
CANNOT BE RULED OUT SAT AFTN...ESP WITH ANY HTG.
BY SUN...PROGRESSIVE LOW IS NORTH OF THE ST LAWRENCE VLY AND
SOMEWHAT DRIER AIR IS MVG BACK IN FROM THE OH VLY. ENUF LEFTIOVER
MOISTURE MAY ALLOW FOR A FEW SCT SHWRS OVER THE NRN ZONES...ESP
OVER THE HIER TERRAIN. ANY PCPN WILL BE LGT.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
DURING THE EXTENDED PERIOD MEDIUM RANGE MODELS ARE IN AGREEMENT
THAT THE UPPER LEVEL TROF OVER THE NORTHEAST WILL BE REPLACED BY
RISING HEIGHTS AND DEVELOPMENT OF AN UPPER LEVEL RIDGE. AT THE
SURFACE THINGS ARE A BIT MORE TRICKY WITH LOW PRES MOVING THROUGH
THE UPPER GREAT LAKES WITH POSSIBLE FROPA TUESDAY NIGHT. GENERALLY
FOLLOWED HPC GUIDANCE.
SUNDAY EVENING WILL INCLUDE SLIGHT CHC POPS FAR NRN CWA ON BACK
SIDE OF UPPER LEVEL TROF THEN DRY. DRY WEATHER IS EXPECTED
MONDAY THROUGH MUCH OF MONDAY NIGHT THEN CHC/SLIGHT CHC POPS
TUESDAY THROUGH WEDNESDAY DUE TO PASSING COLD FRONT AND NORTHWEST
FLOW BEHIND BOUNDARY. DRY WEATHER WILL RETURN WED NIGHT/THURSDAY
AS SFC HIGH BUILDS DOWN FROM CANADA. TEMPS WILL BE 5-10 DEGREES
ABOVE NORMAL.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
730 AM UPDATE...
THE FIRST MAIN AREA OF RAIN SHOWERS IS EXITING THE REGION TO THE
EAST OF THE TERMINALS. KAVP HAS A THUNDERSTORM NOW THAT MAY LAST
AN HOUR BEFORE A BREAK. SCATTERED SHOWER ACTIVITY IN THE FINGER
LAKES AND CENTRAL SOUTHERN TIER OF NY WILL EXPAND AND FILL IN AS
IT MOVES SLOWLY NORTHEAST. SHOWERS WILL CONTINUE TODAY,
ESPECIALLY PRIOR TO NOON.
SKY COVER IS ERRATIC IN THE INTERIM. BEFORE THE SHOWERS COME IN
BGMA ND SYR BOUNCING BETWEEN IFR AND VFR. WITH THE SHOWERS CIGS
BETWEEN MVFR AND VFR. CIGS AS LOW AS 1500 FT.
MODELS SUGGEST A TEMPORARY DRYING OF THE ATMOSPHERE BETWEEN 20Z
AND 00Z, SO THE CURRENT TERMINAL FORECASTS SCATTER OUT THE MVFR
CLOUD COVER PRIOR TO SUNSET.
OUTLOOK...
SAT...MVFR RESTRICTIONS EXPECTED IN OCNL -SHRA.
SUN AND MON...MAINLY VFR.
TUE...BECOMING MVFR WITH SHOWERS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DGM
NEAR TERM...DGM
SHORT TERM...DGM
LONG TERM...RRM
AVIATION...DJP/TAC
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
614 AM EDT FRI OCT 19 2012
.SYNOPSIS...
LOW PRESSURE MOVING SLOWLY EASTWARD THROUGH THE GREAT LAKES WILL
KEEP UNSETTLED WEATHER IN OUR AREA FOR MUCH OF THE WEEKEND.
SHOWERS FROM THE LOW WILL BE SCATTERED OVER THE REGION INTO
SUNDAY...ALONG WITH GRADUALLY COOLER AIR.
&&
.NEAR TERM /THROUGH TONIGHT/...
FNT DEAD CNTR OVER THE FCST AREA ATTM WITH A BRIEF AREA OF RW+ AND
AN ISLTD LGTNG STRIKES OVER NE PA. LATEST HRRR AND NAM RUNS ARE QUITE
PROGRESSIVE WITH THE FNT PUSHING IT AND THE HEAVIEST RAIN EAST OF
THE FCST AREA BY 12Z...DESPITE THE DVLPG SFC LOW OVER THE MID
ATLANTIC STATES. DEEP MOISTURE AHD OF THE FNT WITH A GULF
CONNECTION AND PWATS NEAR 180% OF NRML FOR THIS TIME OF YEAR.
AREAS AHD OF THE FNT WILL CONT TO SEE HEAVY RAIN WITH THE GOOD
FRCG OF THE FNT.
HRRR AND NAM SHOWS SOME PCPN BEING TOSSED BACK BHD THE FNT LTR
THIS MRNG AS THE LOW MVES NEWRD...SO WILL KEEP HIER POPS OVER THE
ERN ZONES THRU MUCH OF THE DAY DESPITE THE ERWRD MVMT OF THE
BNDRY.
SINCE THE LATEST MODEL FCSTS KEEP THE FNT PROGRESSIVE THRU THE
FCST AREA...HEAVY RAINS SHD NOT BE A PRBLM...WITH STORM TTLS WELL
BLO FFG AND HEADWATERS GUID. WILL KEEP A LOW CHANCE OF THUNDER IN
THE EAST AND SOUTH WITH THE INSTABILITY ALOFT WITH THE FNT...AND
THE ADDED LIFT OF THE APRCHG WV.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
LOW PLODS SLOWLY EAST AS IT GRADUALLY FILLS. DRY SLOT BHD THE FNT
TODAY IS QUICKLY REPLACED WITH THE DEEP MOISTURE ASSOCIATED WITH
THE UPR LOW. VERTICALLY STACKED LOW IS POSITIONED NEAR BUF BY 00Z
SUN. THIS WILL KEEP INSTABILITY AND MOISTURE OVER THE AREA...ALONG
WITH A GRADUAL COOLING AS THE COLD CORE APRCHS. DOES NOT APPEAR TO
BE ENUF INSTABILITY FOR TRWS ATTM...ALTHOUGH AN ISLTD WEAK STORM
CANNOT BE RULED OUT SAT AFTN...ESP WITH ANY HTG.
BY SUN...PROGRESSIVE LOW IS NORTH OF THE ST LAWRENCE VLY AND
SOMEWHAT DRIER AIR IS MVG BACK IN FROM THE OH VLY. ENUF LEFTIOVER
MOISTURE MAY ALLOW FOR A FEW SCT SHWRS OVER THE NRN ZONES...ESP
OVER THE HIER TERRAIN. ANY PCPN WILL BE LGT.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
DURING THE EXTENDED PERIOD MEDIUM RANGE MODELS ARE IN AGREEMENT
THAT THE UPPER LEVEL TROF OVER THE NORTHEAST WILL BE REPLACED BY
RISING HEIGHTS AND DEVELOPMENT OF AN UPPER LEVEL RIDGE. AT THE
SURFACE THINGS ARE A BIT MORE TRICKY WITH LOW PRES MOVING THROUGH
THE UPPER GREAT LAKES WITH POSSIBLE FROPA TUESDAY NIGHT. GENERALLY
FOLLOWED HPC GUIDANCE.
SUNDAY EVENING WILL INCLUDE SLIGHT CHC POPS FAR NRN CWA ON BACK
SIDE OF UPPER LEVEL TROF THEN DRY. DRY WEATHER IS EXPECTED
MONDAY THROUGH MUCH OF MONDAY NIGHT THEN CHC/SLIGHT CHC POPS
TUESDAY THROUGH WEDNESDAY DUE TO PASSING COLD FRONT AND NORTHWEST
FLOW BEHIND BOUNDARY. DRY WEATHER WILL RETURN WED NIGHT/THURSDAY
AS SFC HIGH BUILDS DOWN FROM CANADA. TEMPS WILL BE 5-10 DEGREES
ABOVE NORMAL.
&&
.AVIATION /10Z FRIDAY THROUGH TUESDAY/...
THE MAIN AREA OF PRECIPITATION HAS EXITED THE REGION EAST OF THE
TERMINALS. SCATTERED SHOWER ACTIVITY WILL CONTINUE TODAY,
ESPECIALLY PRIOR TO NOON.
SKY COVER IS ERRATIC IN THE INTERIM. MIXING ON THE BACK SIDE OF
THE FRONT IS BATTLING AGAINST A MOIST LOWER ATMOSPHERE. THE
MAJORITY OF THE TERMINALS WILL BOUNCE BETWEEN A BROKEN 2000 FT DECK
AND A BROKEN 6000 FT DECK THROUGH THE MORNING HOURS.
MODELS SUGGEST A TEMPORARY DRYING OF THE ATMOSPHERE BETWEEN 20Z
AND 00Z, SO THE CURRENT TERMINAL FORECASTS SCATTER OUT THE CLOUD
COVER PRIOR TO SUNSET.
OUTLOOK...
SAT...MVFR RESTRICTIONS EXPECTED IN OCNL -SHRA.
SUN AND MON...MAINLY VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DGM
NEAR TERM...DGM
SHORT TERM...DGM
LONG TERM...RRM
AVIATION...DJP
AREA FORECAST DISCUSSION...UPDATED
NWS NEWPORT/MOREHEAD CITY NC
1046 AM EDT FRI OCT 19 2012
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE AREA TODAY. HIGH PRESSURE WILL
BUILD OVER THE REGION THROUGH WEDNESDAY. ANOTHER COLD FRONT WILL
APPROACH FROM THE NORTH ON THURSDAY.
&&
.NEAR TERM /TODAY/...
AS OF 1035 AM FRI...ONLY MINOR ADJUSTMENTS TO POPS/WX/TEMPS/DEWPOINTS
TO REFLECT RECENT TRENDS IN OBS/SATELLITE/RADAR. FOR TODAY...A DEEP
VERTICALLY STACKED LOW PRES SYSTEM WILL SLOWLY MOVE EWD ACROSS THE
GREAT LAKES INTO TONIGHT WHILE AN ATTENDANT COLD FRONT PUSHES
OFF THE EASTERN SEABOARD. THE FRONT IS CURRENTLY PUSHING ACROSS
THE COASTAL PLAIN COUNTIES WITH SCATTERED SHOWERS AHEAD OF THE
FRONT. HRRR AND NSSL WRF INDICATE THE THREAT FOR STRONG TO
MARGINALLY SEVERE STORMS CONTINUES TO DIMINISH RAPIDLY. THE FRONT
WILL PUSH ACROSS ERN NC THROUGH THE AFTERNOON HOURS WITH WINDS
BECOMING SWLY AFTER FROPA. HIGHS TODAY WILL BE IN THE M/U70S.
&&
.SHORT TERM /TONIGHT/...
AS OF 4 AM FRI...THE FRONT WILL MOVE WELL OFFSHORE TONIGHT WITH A
MUCH DRIER AIRMASS BUILDING INTO THE REGION BRINGING MAINLY CLEAR
SKIES...ALTHOUGH A WEAK VORT LOBE MOVE THROUGH THE FLOW ALOFT LATE
TONIGHT AND MAY BRING A FEW MID LEVEL CLOUDS MAINLY NEAR THE
COAST. TEMPS ARE EXPECTED TO DROP TO AROUND 50 WELL INLAND AND
M50S CLOSER TO THE COAST TO M60S OBX.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
AS OF 300 AM FRIDAY...HIGH AND DRY CONDITIONS EXPECTED THROUGH
FORECAST PERIOD. PRIMARY COLD FRONT AND SHRT WV WILL BE EXITING OFF
COAST EARLY SAT MORNING...THEN SECONDARY FRONT WITH UPR TROF AXIS
WILL MOVE THROUGH SAT NIGHT. SOME HIGH CLOUDS EXPECTED AHEAD OF TROF
AXIS BUT DRY WESTERLY FLOW WILL PRECLUDE ANY PCPN. RIDGING SFC AND
ALOFT WILL THEN PREVAIL OVER AREA SUN-WED. ECMWF A BIT FASTER THAN
GFS WITH NEXT SHRT WV AFFECTING AREA THU...BUT MSTR WILL CONTINUE TO
BE TOO LIMITED FOR PCPN DEVELOPMENT.
AFTER A MILD DAY ON SAT...SLIGHTLY BELOW NORMAL TEMPS EXPECTED SUN
AND MON WITH CAA. GRADUAL WARMING EXPECTED REST OF PERIOD WITH TEMPS
POSSIBLY 5-10 DEGS ABOVE NORMAL ON THU.
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
SHORT TERM /THROUGH FRIDAY NIGHT/...
AS OF 730 AM FRI...MOIST SLY FLOW CONTINUES AHEAD OF A COLD
FRONT MOVING ACROSS THE CENTRAL PIEDMONT EARLY THIS MORNING.
AREA OF SHOWERS QUICKLY WEAKENING AS THEY APPROACH ERN NC AND
EXPECT ONLY ISO SHOWERS THIS MORNING AND THREAT FOR STRONG STORMS
QUICKLY DIMINISHING. PATCHY FOG CONTINUES ACROSS THE AREA AND
EXPECT AREAS OF IFR/LIFR THROUGH 14Z. THE FRONT WILL PUSH EAST OF
THE TAF SITES THIS AFTERNOON BRINGING CLEARING SKIES AND A MUCH
DRIER AIRMASS INTO THE REGION WITH VFR CONDITIONS DOMINATING FRI
NIGHT.
LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 300 AM FRIDAY...VFR WILL PREVAIL DURING PERIOD WITH HIGH AND
DRY CONDITIONS. SOME EARLY MORNING FOG PSBL MAINLY MON AND
TUE...ESPECIALLY AT KPGV AND KEWN DUE TO STEAM-TYPE FOG FROM NEARBY
WATER SOURCES.
&&
.MARINE...
SHORT TERM /TONIGHT AND FRIDAY/...
AS OF 1040 AM FRI...LATEST SURFACE AND BUOY OBSERVATIONS INDICATE
WEST TO SOUTHWEST WINDS 5-10 KNOTS WITH SEAS 3-5 FT SOUTH OF
DIAMOND SHOALS AND 5-7 FT NORTH. CONDITIONS ACROSS THE SOUTHERN
WATERS HAVE CONTINUED BELOW 6 FT FOR THE PAST FEW HOURS SO HAVE
CANCELLED THE SCA FOR THOSE WATERS. A COLD FRONT IS APPROACHING
FROM THE W TODAY WITH S/SWLY FLOW MAINLY AROUND 10-15 KT ACROSS
THE WATERS THROUGH THIS AFTERNOON. SEAS BUILT TO AS HIGH AS 5-8 FT
OVERNIGHT AND WILL MAINTAIN SCA ACROSS THE COASTAL WATERS THROUGH
TODAY. THE COLD FRONT IS PROGGED TO MOVE ACROSS THE WATERS THIS
AFTERNOON AND MAY SEE A FEW STRONGER STORMS IN ADVANCE OF THE
FRONT. NOT MUCH OF A WIND SHIFT AFTER FROPA WITH W/SW WINDS AROUND
10-15 KT. WAVEWATCH DROPS SEAS BELOW 6 FT ALL WATERS AROUND 00Z SAT.
LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 300 AM FRIDAY...PER PREVIOUS FCST THINKING AND GOOD MODEL
AGREEMENT AND CONSISTENCY...STRONGER WINDS WITH CAA WILL OCCUR
BEHIND SECONDARY FRONT MOVING THROUGH AREA SAT NIGHT...WITH PERIOD
OF 15-20 KTS LIKELY LATE SAT NIGHT INTO SUN MORNING. WINDS WILL
DIMINISH REST OF PERIOD WITH SFC HIGH PRES CENTER BUILDING OVER AREA
FROM WEST. GOOD BOATING CONDITIONS LIKELY FOR MON AFTN INTO TUE.
MINOR ADJUSTMENTS TO SEAS FCST...BASED ON BLEND OF LATEST WW3 AND
SWAN. HEIGHTS 3-5 FT WILL PERSIST SAT INTO SUN...THEN SUBSIDE TO
MAINLY 2 FT OR LESS BY TUE.
RIP CURRENTS...COMBO OF LONG PERIOD SE SWELL...HIGH ASTRONOMICAL
TIDES AND BREEZY SW WINDS WILL PRODUCE HIGH THREAT OF RIP CURRENTS
FROM CAPE LOOKOUT TO CAPE HATTERAS TODAY...AND MODERATE THREAT REST
OF BEACHES.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...BEACH HAZARDS STATEMENT UNTIL 8 PM EDT THIS EVENING FOR NCZ095-
103-104.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR AMZ150-
152-154.
&&
$$
SYNOPSIS...CTC/SK
NEAR TERM...SK/DAG
SHORT TERM...SK
LONG TERM...JME
AVIATION...JME/SK
MARINE...JME/SK/DAG
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1035 AM EDT FRI OCT 19 2012
.SYNOPSIS...
DRIER AND SLIGHTLY COOLER AIR WILL OVERSPREAD THE REGION THIS
WEEKEND. HIGH PRESSURE WILL BRING FAIR WEATHER AND A WARMING TREND
EARLY NEXT WEEK...ALONG WITH ABOVE NORMAL TEMPERATURES THROUGH MID
WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 10:35 AM FRIDAY...THE FRONT...ACCORDING TO SURFACE OBSERVATIONS
PRIMARILY DEWPOINT DISCONTINUITIES...LIES BETWEEN WHITEVILLE AND
LUMBERTON EXTENDING SOUTHWARD. THIS CAN BE SEEN ON VISIBLE SATELLITE
IMAGERY AS WELL. THE LINE OF SHOWERS AND ISOLATED THUNDERSTORMS THAT
MOVED ACROSS EARLIER IS WELL OFFSHORE. THE 1200 UTC NAM AND HRRR DO
SHOW SOME SHOWERS DEVELOPING ALONG THE COAST BY 1700/1800 UTC ALONG
THE BOUNDARY WHILE THE 0600 GFS IS MORE PROGRESSIVE. WILL CONTINUE
TO KEEP FORECAST DRY WITH SKIES BECOMING SUNNY. TWEAKED TEMPERATURES
JUST SLIGHTLY DOWNWARD TO MATCH HOURLY OBSERVATIONS BUT MIDDLE TO
UPPER 70S FOR HIGHS APPEAR TO BE ON TRACK.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM FRIDAY...SURFACE HIGH BUILDS IN AS COLD FRONT MOVES AWAY
FROM THE COAST ON SAT. PASSAGE OF MID LEVEL TROUGH AXIS SAT NIGHT
INTO SUN WILL SIGNAL THE START OF A CHANGE IN THE PATTERN ALOFT. 5H
TROUGHING YIELDS TO BUILDING 5H RIDGE SUN INTO SUN NIGHT. COLD AIR
IS SLOW TO ARRIVE WITH COLD ADVECTION NOT COMMENCING UNTIL SAT
NIGHT. TEMPERATURES WILL BE ABOVE CLIMO FOR SAT BUT ARRIVAL OF COLD
AIR LATE SAT NIGHT MAY LEAD TO A LARGE TEMP GRADIENT SUN MORNING.
INLAND AREAS WILL BE NEAR CLIMO WHILE CLOSER TO THE COAST LOWS WILL
END UP ABOVE CLIMO. COLDER AIR IN PLACE SUN/SUN WILL KEEP TEMPS NEAR
TO SLIGHTLY BELOW CLIMO.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 3 AM FRIDAY...SURFACE HIGH PRESSURE AND BUILDING 5H RIDGE WILL
DOMINATE THE PERIOD...KEEPING THE REGION DRY. TEMPERATURES START OUT
NEAR CLIMO WITH HIGH PRESSURE CENTERED TO THE WEST. HIGHS START TO
WARM AS THE CENTER OF THE HIGH SHIFTS SOUTHEAST...SETTING UP OVER
THE REGION FOR THE MIDDLE OF THE WEEK. LATE IN THE PERIOD A WEAK
BACKDOOR COLD FRONT TRIES TO MOVE ACROSS THE AREA. UNSURE HOW
SUCCESSFUL THIS FEATURE WILL BE AT THIS TIME...BUT GIVEN FULL SUN
AND VARYING AMOUNTS OF SUBSIDENCE UNDER THE 5H RIDGE THINK HIGHS
WILL REMAIN ABOVE CLIMO SHOULD IT PUSH SOUTH OF THE AREA. LOWS WILL
BE A LITTLE TRICKIER AS GOOD TO EXCELLENT RADIATIONAL COOLING
CONDITIONS FOR AT LEAST PART IF NOT ALL OF THE PERIOD. LOWS WILL
CREEP UP FROM CLIMO LATE IN THE PERIOD...THOUGH SHOULD IDEAL
RADIATIONAL COOLING CONDITIONS CONTINUE NUMBERS COULD END UP SEVERAL
DEGREES COOLER.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
AS OF 12Z...SHOWERS AND STORMS AHEAD OF AN APPROACHING COLD FRONT
HAVE BECOME MORE DISORGANIZED OVER THE PAST COUPLE HOURS. SHOWERS
ARE LINGERING ALONG THE COAST...AND KILM COULD SEE TEMPO PERIODS OF
MVFR/IFR CONDITIONS WITH HEAVIER SHOWERS. IFR VISIBILITIES AT KLBT
SHOULD LIFT BACK TO MVFR/VFR LEVELS WITHIN THE NEXT HOUR OR SO. ONCE
THE COLD FRONT CLEARS THE CWA IN THE NEXT COUPLE OF HOURS...GRADUAL
CLEARING EXPECTED THIS AFTERNOON AND EVENING. VFR CONDITIONS LIKELY
THIS AFTERNOON THROUGH THE REST OF THE TAF PERIOD. W/SW WINDS AROUND
5 KNOTS THIS MORNING INCREASING TO 10 KNOTS IN THE AFTERNOON HOURS.
EXTENDED OUTLOOK...LOW CONFIDENCE OF FOG/REDUCED VSBYS MON AND TUE
MORNING. OTHERWISE VFR CONDITIONS SHOULD PREVAIL THROUGH THE
FORECAST PERIOD.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 10:35 AM FRIDAY...NO CHANGES TO THE COASTAL WATERS FORECAST WITH
THE MID MORNING UPDATE. A SOUTHWEST FLOW WILL CONTINUE THIS
AFTERNOON AND EVENING WITH SPEEDS GRADUALLY DIMINISHING. 10-15 KNOTS
TODAY WITH AROUND TEN TONIGHT. SEAS ARE ON TRACK AS WELL WITH JUST
OVER THREE FEET AT 41110 AND 41013.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM FRIDAY...HIGH PRESSURE BUILDING FROM THE WEST SAT INTO
SAT NIGHT WILL RESULT IN WINDS VEERING FROM SOUTHWEST AT THE START
OF THE TO THE PERIOD TO NORTHWEST SAT NIGHT. ARRIVAL OF COLD
ADVECTION WILL ADD A FEW KT TO WIND SPEEDS SAT NIGHT AND INCREASE
GUST STRENGTH. HOWEVER SPEEDS WILL REMAIN BELOW ANY ADVISORY
CRITERIA. NORTHERLY FLOW SUN WILL BECOME NORTHEAST SUN NIGHT AS HIGH
PRESSURE TO THE WEST EXPANDS NORTH. SPEEDS THROUGH THE PERIOD WILL
BE 10 TO 15 KT WITH A BRIEF PERIOD OF SOLID 15 KT POSSIBLE SAT
NIGHT. SEAS 2 TO 4 FT SAT/SAT NIGHT WILL DECREASE TO 2 TO 3 FT FOR
SUN/SUN NIGHT. SEAS WILL BE A COMBINATION OF A SOUTHWEST WIND WAVE
AND A WEAK SOUTHEAST SWELL.
LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 3 AM FRIDAY...HIGH PRESSURE WILL REMAIN OVER THE WATERS
THROUGH THE PERIOD RESULTING IN LIGHT NORTH TO NORTHEAST FLOW. WINDS
10 KT OR LESS WILL RESULT IN SEAS RUNNING 1 TO 2 FT MON AND TUE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SHK
NEAR TERM...SHK
SHORT TERM...III
LONG TERM...III
AVIATION...REK/BJR
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
754 AM EDT FRI OCT 19 2012
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE AREA TODAY. HIGH PRESSURE WILL
BUILD OVER THE REGION THROUGH WEDNESDAY. ANOTHER COLD FRONT WILL
APPROACH FROM THE NORTH ON THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 730 AM FRI...A DEEP VERTICALLY STACKED LOW PRES SYSTEM WILL
SLOWLY MOVE EWD ACROSS THE GREAT LAKES TODAY AND TONIGHT WHILE AN
ATTENDANT COLD FRONT PUSHES OFF THE EASTERN SEABOARD. THE FRONT IS
CURRENTLY PUSHING ACROSS THE CENTRAL NC PIEDMONT. AREA OF SHOWERS
AHEAD OF THE FRONT IS QUICKLY WEAKENING AS THEY MOVE INTO ERN NC
AS PROGGED BY NSSL WRF AND HRRR MODELS AND THE THREAT FOR STRONG
TO MARGINALLY SEVERE STORMS IS DIMINISHING RAPIDLY. THE FRONT
WILL PUSH ACROSS ERN NC LATE MORNING THROUGH THE AFTERNOON HOURS
WITH WINDS BECOMING SWLY AFTER FROPA. HIGHS TODAY WILL BE IN THE
M/U70S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/...
AS OF 4 AM FRI...THE FRONT WILL MOVE WELL OFFSHORE TONIGHT WITH A
MUCH DRIER AIRMASS BUILDING INTO THE REGION BRINGING MAINLY CLEAR
SKIES...ALTHOUGH A WEAK VORT LOBE MOVE THROUGH THE FLOW ALOFT LATE
TONIGHT AND MAY BRING A FEW MID LEVEL CLOUDS MAINLY NEAR THE
COAST. TEMPS ARE EXPECTED TO DROP TO AROUND 50 WELL INLAND AND
M50S CLOSER TO THE COAST TO M60S OBX.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
AS OF 300 AM FRIDAY...HIGH AND DRY CONDITIONS EXPECTED THROUGH
FORECAST PERIOD. PRIMARY COLD FRONT AND SHRT WV WILL BE EXITING OFF
COAST EARLY SAT MORNING...THEN SECONDARY FRONT WITH UPR TROF AXIS
WILL MOVE THROUGH SAT NIGHT. SOME HIGH CLOUDS EXPECTED AHEAD OF TROF
AXIS BUT DRY WESTERLY FLOW WILL PRECLUDE ANY PCPN. RIDGING SFC AND
ALOFT WILL THEN PREVAIL OVER AREA SUN-WED. ECMWF A BIT FASTER THAN
GFS WITH NEXT SHRT WV AFFECTING AREA THU...BUT MSTR WILL CONTINUE TO
BE TOO LIMITED FOR PCPN DEVELOPMENT.
AFTER A MILD DAY ON SAT...SLIGHTLY BELOW NORMAL TEMPS EXPECTED SUN
AND MON WITH CAA. GRADUAL WARMING EXPECTED REST OF PERIOD WITH TEMPS
POSSIBLY 5-10 DEGS ABOVE NORMAL ON THU.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
SHORT TERM /THROUGH FRIDAY NIGHT/...
AS OF 730 AM FRI...MOIST SLY FLOW CONTINUES AHEAD OF A COLD
FRONT MOVING ACROSS THE CENTRAL PIEDMONT EARLY THIS MORNING.
AREA OF SHOWERS QUICKLY WEAKENING AS THEY APPROACH ERN NC AND
EXPECT ONLY ISO SHOWERS THIS MORNING AND THREAT FOR STRONG STORMS
QUICKLY DIMINISHING. PATCHY FOG CONTINUES ACROSS THE AREA AND
EXPECT AREAS OF IFR/LIFR THROUGH 14Z. THE FRONT WILL PUSH EAST OF
THE TAF SITES THIS AFTERNOON BRINGING CLEARING SKIES AND A MUCH
DRIER AIRMASS INTO THE REGION WITH VFR CONDITIONS DOMINATING FRI
NIGHT.
LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 300 AM FRIDAY...VFR WILL PREVAIL DURING PERIOD WITH HIGH AND
DRY CONDITIONS. SOME EARLY MORNING FOG PSBL MAINLY MON AND
TUE...ESPECIALLY AT KPGV AND KEWN DUE TO STEAM-TYPE FOG FROM NEARBY
WATER SOURCES.
&&
.MARINE...
SHORT TERM /TONIGHT AND FRIDAY/...
AS OF 4 AM FRI...A COLD FRONT IS APPROACHING FROM THE W TODAY WITH
S/SWLY FLOW MAINLY AROUND 10-15 KT ACROSS THE WATERS THIS MORNING.
SEAS HAVE BUILT AS HIGH AS 5-8 FT ACROSS THE WATERS OVERNIGHT AND
WILL MAINTAIN SCA ACROSS THE COASTAL WATERS THROUGH TODAY. THE
COLD FRONT IS PROGGED TO MOVE ACROSS THE WATERS THIS AFTERNOON AND
MAY SEE A FEW STRONGER STORMS IN ADVANCE OF THE FRONT. NOT MUCH OF
A WIND SHIFT AFTER FROPA WITH W/SW WINDS AROUND 10-15 KT.
WAVEWATCH DROPS SEAS BELOW 6 FT ALL WATERS AROUND 00Z SAT.
LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 300 AM FRIDAY...PER PREVIOUS FCST THINKING AND GOOD MODEL
AGREEMENT AND CONSISTENCY...STRONGER WINDS WITH CAA WILL OCCUR
BEHIND SECONDARY FRONT MOVING THROUGH AREA SAT NIGHT...WITH PERIOD
OF 15-20 KTS LIKELY LATE SAT NIGHT INTO SUN MORNING. WINDS WILL
DIMINISH REST OF PERIOD WITH SFC HIGH PRES CENTER BUILDING OVER AREA
FROM WEST. GOOD BOATING CONDITIONS LIKELY FOR MON AFTN INTO TUE.
MINOR ADJUSTMENTS TO SEAS FCST...BASED ON BLEND OF LATEST WW3 AND
SWAN. HEIGHTS 3-5 FT WILL PERSIST SAT INTO SUN...THEN SUBSIDE TO
MAINLY 2 FT OR LESS BY TUE.
RIP CURRENTS...COMBO OF LONG PERIOD SE SWELL...HIGH ASTRONOMICAL
TIDES AND BREEZY SW WINDS WILL PRODUCE HIGH THREAT OF RIP CURRENTS
FROM CAPE LOOKOUT TO CAPE HATTERAS TODAY...AND MODERATE THREAT REST
OF BEACHES.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...BEACH HAZARDS STATEMENT THROUGH THIS EVENING FOR NCZ095-103-
104.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR AMZ150-
152-154-156-158.
&&
$$
SYNOPSIS...CTC/SK
NEAR TERM...SK
SHORT TERM...SK
LONG TERM...JME
AVIATION...JME/SK
MARINE...CTC/JME/SK
AREA FORECAST DISCUSSION...UPDATED
NWS CLEVELAND OH
924 AM EDT FRI OCT 19 2012
.SYNOPSIS...
UPPER LEVEL LOW PRESSURE NEAR CHICAGO WILL SLOWLY MOVE EAST ACROSS
THE AREA THROUGH SATURDAY NIGHT. HIGH PRESSURE WILL THEN BUILD
NORTHEAST INTO THE REGION SUNDAY THEN SETTLE NEAR THE CAROLINA COAST
FOR MONDAY AND TUESDAY. A COLD FRONT WILL DROP SOUTHEAST AND STALL
OVER THE AREA FOR TUESDAY NIGHT AND WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
FEW CHANGES FOR 930 UPDATE. SLOWED DOWN TIMING OF RAIN SLIGHTLY AS
RAINFALL THAT IS REACHING THE GROUND ONLY A HUNDREDTH OR TWO PER
HOUR. WILL TAKE A LITTLE TIME TO SATURATE THE ATTM. SINCE SLOWED
PRECIP ALSO BUMPED UP TEMPS A DEGREE OR TWO.
DOING 630 AM UPDATE EARLY. HAVE ADDED EARLY MORNING MENTION OF
PATCHY FOG FOR THE YNG TO GKJ AREA. ALSO HAVE ADDED CHC OF SPRINKLES
TO CENTRAL PART OF AREA WHERE BAND OF CLOUDS CURRENTLY PRESENT AND
THEN PROG THIS EAST DURING THE REST OF THE MORNING. HRRR HAS BEEN
HINTING AT SPRINKLES FOR THIS AREA AND LATEST RADAR PIX STARTING TO
SHOW SOME INCREASE IN RETURNS.
THE MODELS ARE IN FAIRLY GOOD AGREEMENT IN MOVING THE UPPER LOW NEAR
CHICAGO SLOWLY EAST TODAY. RAIN AND SHRA POOLED UNDER THE UPPER LOW
WILL GET AN EASTWARD PUSH TODAY AS SHORTWAVE ENERGY AND A SURFACE
TROUGH ROTATE AROUND THE UPPER LOW. THE WESTERN PART OF THE CWA
LOOKS CATEGORICAL FOR MEASURABLE PRECIP WITH THE CENTRAL PART LIKELY
AND MAYBE JUST A CHANCE FOR THE EAST AS THE BETTER ENERGY DOES NOT
GET THERE UNTIL TONIGHT. PRECIP AMOUNTS WILL GENERALLY BE LIGHT WITH
MOST PLACES SEEING AROUND A TENTH OF AN INCH OR LESS WEST AND A FEW
HUNDREDTHS OR LESS EAST.
THE WARMER TEMPS SHOULD BE IN THE EAST WHERE CLOUDS WILL TAKE LONGER
TO FILL IN TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
PER THE PREVIOUS DISCUSSION...THE UPPER AND SURFACE FORCING WILL
WORK EAST ACROSS THE CWA TONIGHT AND SATURDAY WITH A FAIRLY
WIDESPREAD COOL RAIN. EVEN THOUGH THE COLDEST PART OF THE AIRMASS
WILL BE OVER THE AREA BY DAYBREAK SAT...THE EXTENSIVE CLOUD COVER
SHOULD KEEP TEMPS IN A 40 TO 45 DEGREE RANGE. HOWEVER...ON SAT THESE
SAME CLOUDS WILL HOLD HIGH TEMPS TO ONLY 50 TO 55 FOR MOST PLACES.
AS THE TROUGH MOVES EAST OF THE AREA SAT NIGHT...DRIER AIR WILL
START TO SPREAD IN FROM THE WEST. THE RAIN THREAT WILL SHIFT INTO
JUST THE SNOWBELT BY LATE SAT NIGHT THEN TAPER OFF IN THE SNOWBELT
SUNDAY AS THE PUSH OF DRIER AIR CONTINUES AND LAKE EFFECT CONDITIONS
LESSEN.
HIGH PRESSURE RIDGED NORTH INTO THE AREA SHOULD PROVIDE DRY WEATHER
FOR SUN NIGHT AND MON. TEMPS WILL MODERATE WITH THE ADDED SUNSHINE
AND WARM ADVECTION. MONDAY NIGHT IS MORE QUESTIONABLE AS THE MODELS
INDICATE A BACKDOOR COLD FRONT SAGGING INTO OR NEAR THE AREA. CHANCE
POPS...MAINLY NEAR LAKE ERIE STILL SEEMS REASONABLE.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
ONLY MINOR CHANGES TO THE LONG TERM THIS MORNING. A NEARLY
STATIONARY BOUNDARY WILL BE JUST NORTH OF THE AREA TUESDAY AND
WEDNESDAY. THIS WILL KEEP PLENTY OF CLOUDS AND A THREAT FOR SHOWERS
GOING EACH PERIOD FROM TUESDAY THROUGH WEDNESDAY NIGHT. THE
BOUNDARY IS FORECAST TO MOVE SLIGHTLY NORTH ON THURSDAY SO WILL PULL
THE MENTION OF PRECIP OUT OF THE FORECAST. A COLD FRONT WILL BEGIN
TO APPROACH FROM THE WEST AT THE VERY END OF THE PERIOD. THE AREA
WILL REMAIN IN THE WARM SECTOR THE ENTIRE PERIOD SO EXPECT HIGHS TO
BE MAINLY IN THE LOWER 70S ALL THREE DAYS.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
MID LEVEL CLOUDS ARE ABOUT TO REACH NW PA. FOG AT KYNG SHOULD LIFT
SHORTLY. LATEST MODELS BRING PRECIP INTO NW OH AROUND 15Z. WILL
TRY TO TIME IT EAST ACROSS THE REMAINDER OF THE AREA. THE PRECIP
SHOULD REACH KERI BY EARLY EVENING. STEADY PRECIP IS EXPECTED
OVERNIGHT WITH CIGS AND VSBYS DIPPING TO MVFR. SOME PATCHY IFR
CIGS ARE POSSIBLE AT THE VERY END OF THE TAF PERIOD. SOME GUSTS
TO 25 KNOTS POSSIBLE THIS AFTERNOON...ESPECIALLY IN THE WEST.
.OUTLOOK...NON VFR CONTINUING SATURDAY.
&&
.MARINE...
LOW PRESSURE REMAINS OVER EASTERN IA THIS MORNING. THIS LOW IS
FORECAST TO GRADUALLY WEAKEN AND TO PASS TO THE NORTH OF THE LAKE
TONIGHT. S FLOW WILL BECOME SW TODAY AND TONIGHT. SPEEDS WILL
INCREASE LATE TONIGHT AND SATURDAY MORNING AND MAY NEED A SMALL
CRAFT FOR THE EASTERN TWO THIRDS OF THE LAKE. A TROUGH FROM THE LOW
WILL CROSS THE LAKE ON SATURDAY AND THIS WILL CAUSE THE FLOW TO
BECOME WEST. HIGH PRESSURE WILL TRY TO BUILD IN FROM THE SOUTH ON
SUNDAY WITH THE RIDGE AXIS JUST EAST OF THE LAKE ON MONDAY WHICH WILL
CAUSE THE FLOW TO AGAIN BECOME S TO SW. A WARM FRONT IS EXPECTED TO
DEVELOP TO THE NORTH OF THE LAKE ON MONDAY NIGHT AND SOME WARM AIR
ADVECTION SHOWERS COULD OCCUR BY EARLY TUESDAY. THE LAKE WILL
REMAIN IN THE WARM SECTOR FOR THE REMAINDER OF THE PERIOD. AS A
RESULT SW FLOW AT UNDER 15 KNOTS WILL CONTINUE.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...ADAMS
NEAR TERM...ADAMS/DJB
SHORT TERM...ADAMS
LONG TERM...KUBINA
AVIATION...KUBINA
MARINE...KUBINA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
734 AM EDT FRI OCT 19 2012
.SYNOPSIS...
UPPER LEVEL LOW PRESSURE NEAR CHICAGO WILL SLOWLY MOVE EAST ACROSS
THE AREA THROUGH SATURDAY NIGHT. HIGH PRESSURE WILL THEN BUILD
NORTHEAST INTO THE REGION SUNDAY THEN SETTLE NEAR THE CAROLINA COAST
FOR MONDAY AND TUESDAY. A COLD FRONT WILL DROP SOUTHEAST AND STALL
OVER THE AREA FOR TUESDAY NIGHT AND WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
DOING 630 AM UPDATE EARLY. HAVE ADDED EARLY MORNING MENTION OF
PATCHY FOG FOR THE YNG TO GKJ AREA. ALSO HAVE ADDED CHC OF SPRINKLES
TO CENTRAL PART OF AREA WHERE BAND OF CLOUDS CURRENTLY PRESENT AND
THEN PROG THIS EAST DURING THE REST OF THE MORNING. HRRR HAS BEEN
HINTING AT SPRINKLES FOR THIS AREA AND LATEST RADAR PIX STARTING TO
SHOW SOME INCREASE IN RETURNS.
THE MODELS ARE IN FAIRLY GOOD AGREEMENT IN MOVING THE UPPER LOW NEAR
CHICAGO SLOWLY EAST TODAY. RAIN AND SHRA POOLED UNDER THE UPPER LOW
WILL GET AN EASTWARD PUSH TODAY AS SHORTWAVE ENERGY AND A SURFACE
TROUGH ROTATE AROUND THE UPPER LOW. THE WESTERN PART OF THE CWA
LOOKS CATEGORICAL FOR MEASURABLE PRECIP WITH THE CENTRAL PART LIKELY
AND MAYBE JUST A CHANCE FOR THE EAST AS THE BETTER ENERGY DOES NOT
GET THERE UNTIL TONIGHT. PRECIP AMOUNTS WILL GENERALLY BE LIGHT WITH
MOST PLACES SEEING AROUND A TENTH OF AN INCH OR LESS WEST AND A FEW
HUNDREDTHS OR LESS EAST.
THE WARMER TEMPS SHOULD BE IN THE EAST WHERE CLOUDS WILL TAKE LONGER
TO FILL IN TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
PER THE PREVIOUS DISCUSSION...THE UPPER AND SURFACE FORCING WILL
WORK EAST ACROSS THE CWA TONIGHT AND SATURDAY WITH A FAIRLY
WIDESPREAD COOL RAIN. EVEN THOUGH THE COLDEST PART OF THE AIRMASS
WILL BE OVER THE AREA BY DAYBREAK SAT...THE EXTENSIVE CLOUD COVER
SHOULD KEEP TEMPS IN A 40 TO 45 DEGREE RANGE. HOWEVER...ON SAT THESE
SAME CLOUDS WILL HOLD HIGH TEMPS TO ONLY 50 TO 55 FOR MOST PLACES.
AS THE TROUGH MOVES EAST OF THE AREA SAT NIGHT...DRIER AIR WILL
START TO SPREAD IN FROM THE WEST. THE RAIN THREAT WILL SHIFT INTO
JUST THE SNOWBELT BY LATE SAT NIGHT THEN TAPER OFF IN THE SNOWBELT
SUNDAY AS THE PUSH OF DRIER AIR CONTINUES AND LAKE EFFECT CONDITIONS
LESSEN.
HIGH PRESSURE RIDGED NORTH INTO THE AREA SHOULD PROVIDE DRY WEATHER
FOR SUN NIGHT AND MON. TEMPS WILL MODERATE WITH THE ADDED SUNSHINE
AND WARM ADVECTION. MONDAY NIGHT IS MORE QUESTIONABLE AS THE MODELS
INDICATE A BACKDOOR COLD FRONT SAGGING INTO OR NEAR THE AREA. CHANCE
POPS...MAINLY NEAR LAKE ERIE STILL SEEMS REASONABLE.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
ONLY MINOR CHANGES TO THE LONG TERM THIS MORNING. A NEARLY
STATIONARY BOUNDARY WILL BE JUST NORTH OF THE AREA TUESDAY AND
WEDNESDAY. THIS WILL KEEP PLENTY OF CLOUDS AND A THREAT FOR SHOWERS
GOING EACH PERIOD FROM TUESDAY THROUGH WEDNESDAY NIGHT. THE
BOUNDARY IS FORECAST TO MOVE SLIGHTLY NORTH ON THURSDAY SO WILL PULL
THE MENTION OF PRECIP OUT OF THE FORECAST. A COLD FRONT WILL BEGIN
TO APPROACH FROM THE WEST AT THE VERY END OF THE PERIOD. THE AREA
WILL REMAIN IN THE WARM SECTOR THE ENTIRE PERIOD SO EXPECT HIGHS TO
BE MAINLY IN THE LOWER 70S ALL THREE DAYS.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
MID LEVEL CLOUDS ARE ABOUT TO REACH NW PA. FOG AT KYNG SHOULD LIFT
SHORTLY. LATEST MODELS BRING PRECIP INTO NW OH AROUND 15Z. WILL
TRY TO TIME IT EAST ACROSS THE REMAINDER OF THE AREA. THE PRECIP
SHOULD REACH KERI BY EARLY EVENING. STEADY PRECIP IS EXPECTED
OVERNIGHT WITH CIGS AND VSBYS DIPPING TO MVFR. SOME PATCHY IFR
CIGS ARE POSSIBLE AT THE VERY END OF THE TAF PERIOD. SOME GUSTS
TO 25 KNOTS POSSIBLE THIS AFTERNOON...ESPECIALLY IN THE WEST.
.OUTLOOK...NON VFR CONTINUING SATURDAY.
&&
.MARINE...
LOW PRESSURE REMAINS OVER EASTERN IA THIS MORNING. THIS LOW IS
FORECAST TO GRADUALLY WEAKEN AND TO PASS TO THE NORTH OF THE LAKE
TONIGHT. S FLOW WILL BECOME SW TODAY AND TONIGHT. SPEEDS WILL
INCREASE LATE TONIGHT AND SATURDAY MORNING AND MAY NEED A SMALL
CRAFT FOR THE EASTERN TWO THIRDS OF THE LAKE. A TROUGH FROM THE LOW
WILL CROSS THE LAKE ON SATURDAY AND THIS WILL CAUSE THE FLOW TO
BECOME WEST. HIGH PRESSURE WILL TRY TO BUILD IN FROM THE SOUTH ON
SUNDAY WITH THE RIDGE AXIS JUST EAST OF THE LAKE ON MONDAY WHICH WILL
CAUSE THE FLOW TO AGAIN BECOME S TO SW. A WARM FRONT IS EXPECTED TO
DEVELOP TO THE NORTH OF THE LAKE ON MONDAY NIGHT AND SOME WARM AIR
ADVECTION SHOWERS COULD OCCUR BY EARLY TUESDAY. THE LAKE WILL
REMAIN IN THE WARM SECTOR FOR THE REMAINDER OF THE PERIOD. AS A
RESULT SW FLOW AT UNDER 15 KNOTS WILL CONTINUE.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...ADAMS
NEAR TERM...ADAMS
SHORT TERM...ADAMS
LONG TERM...KUBINA
AVIATION...KUBINA
MARINE...KUBINA
AREA FORECAST DISCUSSION
NWS NEW YORK NY
514 PM EDT FRI OCT 19 2012
.SYNOPSIS...
PRIMARY LOW PRESSURE OVER THE MIDWEST...AND A WEAK SECONDARY LOW
OVER THE MID ATLANTIC REGION...WILL LIFT A WARM FRONT INTO THE
REGION THIS EVENING...AND THEN BRING A WEAK COLD FRONT ACROSS
SATURDAY MORNING. THE PRIMARY LOW WILL THEN WEAKEN AS IT MOVES
THROUGH SOUTHEAST CANADA THIS WEEKEND. HIGH PRESSURE WILL BUILD
INTO THE AREA SUNDAY THROUGH TUESDAY. A COLD FRONT WILL MOVE
THROUGH TUESDAY NIGHT INTO WEDNESDAY. ANOTHER HIGH WILL BEGIN TO
BUILD FROM THE NORTH ON THURSDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
OCCLUDED 998 MB LOW WAS NEAR CHICAGO AT 19Z. WEAK SFC WAVE OVER
THE UPPER MIDWEST AT 15Z. WEAK SFC WAVE REMAINS NEAR BALTIMORE...WITH
A WEAK WARM FRONT EXTENDING E TO PHILADELPHIA AND TO THE CENTRAL
NJ COAST.
BANDS OF MODERATE RAIN HAVE REDEVELOPED ACROSS LONG ISLAND/CT IN
THE LEFT FRONT QUAD OF A LOW LEVEL JET APPROACHING SOUTHERN NEW
ENGLAND...WHERE LOW LEVEL CONVERGENCE AND UPPER LEVEL DIVERGENCE
ARE MAXIMIZED. LLJ SHOULD LIFT NE BY 22Z-23Z...THEN LATEST RAP
INDICATES ANOTHER FAVORABLE LL CONVERGENCE/UL DIVERGENCE COUPLET
SHOULD MOVE ACROSS ERN LONG ISLAND/CT FOR A FEW HOURS BEGINNING LATE
THIS EVENING. ELSEWHERE...EARLIER HRRR INDICATED THAT SCT SHOWERS
MAY CONTINUE TO FORM NW OF NYC INTO THIS EVENING ON EDGE OF MID
LEVEL DRY SLOT.
AFTER ANY PRECIP ENDS...LIGHT WINDS AND ABUNDANT LL MOISTURE
SHOULD LEAD TO FOG FORMATION OVERNIGHT. LOCALLY DENSE FOG MAY BE
POSSIBLE INLAND AND ACROSS ERN LONG ISLAND LATE TONIGHT.
LOWS TONIGHT ARE CLOSE TO A GUIDANCE BLEND...NEAR 60 IN NYC TO THE
50S ELSEWHERE.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
EARLY MORNING FOG SHOULD BURN OFF QUICKLY AS WEAK FRONT ENTERS THE
REGION AND STRONGER SW FLOW COMMENCES...WITH MOSTLY CLEAR SKIES
FOR THE AFTERNOON AND NIGHT. BREEZY CONDS SHOULD DEVELOP IN THE
AFTERNOON AS THE PRIMARY LOW LIFTS INTO SE CANADA AND THE PRESSURE
GRADIENT TIGHTENS. HIGHS SHOULD BE A COUPLE DEG EITHER SIDE OF
70...WARMEST IN NYC METRO...LONG ISLAND AND THE CT RIVER VALLEY.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
UPPER LEVEL LOW LIFTS NORTH INTO SE CANADA THROUGH THE DAY ON
SUNDAY. A FEW STRONG VORTICITY MAXIMA WILL ROTATE IN BEHIND IT
WITH A DEPARTING STRONG UPPER LEVEL JET STREAK. MOST OF THE
INSTABILITY WILL BE TO THE NORTH OF OUR AREA...ALONG WITH DRIER
AIR MOVING INTO THE CWA...SO HAVE THEREFORE LEFT POPS OUT OF THE
FORECAST FOR SUNDAY. WESTERLY WINDS WILL PICK UP BRIEFLY ON SUNDAY
AS THE UPPER LEVEL LOW LIFTS NORTH AND HIGH PRESSURE BUILDS IN.
A LARGE AREA OF SURFACE HIGH PRESSURE AND AN UPPER LEVEL RIDGE
QUICKLY MOVES IN BEHIND THE UPPER LOW SUNDAY NIGHT. THE HIGH
PRESSURE AREA DOMINATES THE WEATHER THROUGH THE WEEK PROVIDING JUST
ABOVE NORMAL TEMPERATURES AND LIGHT WINDS TO THE AREA. ONLY CHANCE
FOR PRECIP IN THE PERIOD IS ON TUESDAY WHICH IS ASSOCIATED WITH A
WARM FRONT EXTENDING EASTWARD OUT OF A LOW PRESSURE SYSTEM IN THE
MIDWEST. UNCERTAINTY BETWEEN THE MODELS ON THE UPPER FLOW AT THIS
TIME CAUSES SOME UNCERTAINTY ON THE TIMING AND PLACEMENT OF THE
PRECIP ASSOCIATED WITH THE FRONT. GFS IS INDICATING A WEAK SHORTWAVE
DEVELOPING TUESDAY WHICH WILL AID IN PRECIP THROUGH WED MORNING.
ECMWF DEVELOPS A DEEPER SHORTWAVE WEDNESDAY MORNING...INDICATING
MORE PRECIP FOR THE WEDNESDAY THROUGH WEDNESDAY NIGHT TIME FRAME. AT
THIS TIME...HAVE CHANCE POPS TUESDAY NIGHT THROUGH WEDNESDAY TO
ACCOUNT FOR THIS UNCERTAINTY.
BEHIND THE WARM FRONT ON TUESDAY...RIDGING ALOFT BUILDS IN WITH
UNCERTAINTY BETWEEN THE MODELS ON THE UPPER FLOW AGAIN. ECMWF IS
QUICK WITH THE PASSAGE OF A COLD FRONT WITH LITTLE UPPER SUPPORT AND
LOW CHANCES OF RAIN. GFS LAGS BEHIND WITH A MUCH DEEPER UPPER LOW
OVER MINNESOTA WHICH WOULD KEEP THE RAIN AWAY FROM THE AREA DURING
THIS PERIOD. TEMPERATURES REMAIN JUST ABOVE NORMAL THURSDAY AND
FRIDAY WITH THE HIGH PRESSURE AT THE SURFACE LINGERING OVER THE AREA.
&&
.AVIATION /21Z FRIDAY THROUGH WEDNESDAY/...
A WEAK COLD FRONT W OF THE REGION WILL SLOWLY MOVE E THROUGH
TONIGHT AND PASS THROUGH EARLY SATURDAY MORNING.
MAINLY MVFR CONDITIONS ACROSS NYC/NJ TERMINALS AND IFR CONDS
ELSEWHERE LIKELY THIS EVENING. AFTER DARK...EXPECT CIGS/VSBY TO
TREND DOWNWARD AGAIN AS LOW CLOUDS/FOG BEGIN TO REDEVELOP. VIS MAY
DROP LOWER THAN INDICATED IN TAFS FOR A PERIOD LATE TONIGHT.
WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS POSSIBLE ACROSS
WESTERN INTO THIS EVENING. BEST CHANCE IS KSWF. CONFIDENCE ON
TSRA IS NOT HIGH ENOUGH FOR EXPLICIT MENTION IN TAFS.
SOME UNCERTAINTY AS TO HOW LOW CONDITIONS WILL GET TONIGHT...BUT
SOME IFR IS POSSIBLE. WITH LIGHT SRLY OR LGT/VRB SFC FLOW THROUGH
THE NIGHT...HAVE GONE MORE PESSIMISTIC WITH THE FORECAST. COLD
FRONT MOVES THROUGH 10-12Z SATURDAY WITH WINDS SHIFTING TO SW AND
IMPROVEMENT TO VFR.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS
CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: AMENDMENTS LIKELY FOR VARIABLE
CEILINGS/VSBY. HIGH CONFIDENCE IN SFC WINDS BECMG MORE SRLY
THROUGH THE EVENING WITH GUSTS SUBSIDING. IFR CONDITIONS POSSIBLE
AFTER MIDNIGHT.
KLGA FCSTER COMMENTS: AMENDMENTS LIKELY FOR VARIABLE
CEILINGS/VSBY. HIGH CONFIDENCE IN SFC WINDS BECMG MORE SRLY
THROUGH THE EVENING WITH GUSTS SUBSIDING. IFR CONDITIONS POSSIBLE
AFTER MIDNIGHT.
KEWR FCSTER COMMENTS: AMENDMENTS LIKELY FOR VARIABLE
CEILINGS/VSBY. HIGH CONFIDENCE IN SFC WINDS BECMG MORE SRLY
THROUGH THE EVENING WITH GUSTS SUBSIDING. IFR CONDITIONS POSSIBLE
AFTER MIDNIGHT.
KTEB FCSTER COMMENTS: AMENDMENTS LIKELY FOR VARIABLE
CEILINGS/VSBY. HIGH CONFIDENCE IN SFC WINDS BECMG MORE THROUGH
THE EVENING WITH GUSTS SUBSIDING. IFR CONDITIONS POSSIBLE AFTER
MIDNIGHT.
KHPN FCSTER COMMENTS: AMENDMENTS LIKELY FOR VARIABLE
CEILINGS/VSBY. HIGH CONFIDENCE IN SFC WINDS BECMG MORE SRLY
THROUGH THE EVENING. CHANCE FOR VIS 1/2SM OR LESS LATE TONIGHT.
KISP FCSTER COMMENTS: AMENDMENTS LIKELY FOR VARIABLE
CEILINGS/VSBY. HIGH CONFIDENCE IN SFC WINDS BECMG MORE SRLY
THROUGH THE EVENING WITH GUSTS SUBSIDING. MODERATE TO HIGH
CONFIDENCE IN IFR CONDITIONS AFTER MIDNIGHT.
.OUTLOOK FOR 18Z SATURDAY THROUGH WEDNESDAY...
.SAT AFTERNOON-TUESDAY...VFR. GUSTY NW WINDS PSBL SUN-MON.
.WEDNESDAY...SUB VFR PSBL IN SCT SHRA.
&&
.MARINE...
SCA HAS BEEN EXTENDED INTO SAT-SAT NIGHT FOR THE OCEAN. SWELLS 5-7
FT SWELLS SHOULD CONTINUE TONIGHT...AND SUBSIDE ONLY SLIGHTLY TO
4-6 FT SAT INTO SAT NIGHT. INCREASING SW FLOW SAT MAY GUST TO 25
KT ON THE OCEAN AND ERN SOUND BY SAT EVENING AS THE PRESSURE
GRADIENT TIGHTENS BETWEEN LOW PRESSURE OVER SE CANADA AND BUILDING
HIGH PRESSURE TO THE SW.
THE PRESSURE GRADIENT SHOULD REMAIN TIGHT ENOUGH TO KEEP OCEAN
SEAS ABOVE 5 FT ON SUNDAY AND GUSTS AROUND 25 KT IN A W-NW FLOW.
THESE SHOULD LINGER THROUGH MON MORNING...WITH WINDS AND SEAS
GRADUALLY DIMINISHING.
HIGH PRESSURE WILL THEN REMAIN OVER THE AREA THROUGH THE WEEK.
SUB-SCA CONDITIONS ARE EXPECTED.
&&
.HYDROLOGY...
ADDITIONAL BASIN AVG RAINFALL OF UP TO 1/4 INCH POSSIBLE
TONIGHT...MAINLY ACROSS LONG ISLAND/SOUTHERN CT...WITH LOCAL AMTS
DOUBLE THAT. NO SIG PRECIPITATION EXPECTED THEREAFTER.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT SATURDAY FOR ANZ355.
SMALL CRAFT ADVISORY UNTIL 6 AM EDT SUNDAY FOR ANZ350-353.
&&
$$
SYNOPSIS...GOODMAN
NEAR TERM...GOODMAN
SHORT TERM...GOODMAN
LONG TERM...FIG/LN
AVIATION...
MARINE...FIG/GOODMAN/LN
HYDROLOGY...FIG/GOODMAN
AREA FORECAST DISCUSSION
NWS NEW YORK NY
414 PM EDT FRI OCT 19 2012
.SYNOPSIS...
PRIMARY LOW PRESSURE OVER THE MIDWEST...AND A WEAK SECONDARY LOW
OVER THE MID ATLANTIC REGION...WILL LIFT A WARM FRONT INTO THE
REGION THIS EVENING...AND THEN BRING A WEAK COLD FRONT ACROSS
SATURDAY MORNING. THE PRIMARY LOW WILL THEN WEAKEN AS IT MOVES
THROUGH SOUTHEAST CANADA THIS WEEKEND. HIGH PRESSURE WILL BUILD
INTO THE AREA SUNDAY THROUGH TUESDAY. A COLD FRONT WILL MOVE
THROUGH TUESDAY NIGHT INTO WEDNESDAY. ANOTHER HIGH WILL BEGIN TO
BUILD FROM THE NORTH ON THURSDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
OCCLUDED 998 MB LOW WAS NEAR CHICAGO AT 19Z. WEAK SFC WAVE OVER
THE UPPER MIDWEST AT 15Z. WEAK SFC WAVE REMAINS NEAR BALTIMORE...WITH
A WEAK WARM FRONT EXTENDING E TO PHILADELPHIA AND TO THE CENTRAL
NJ COAST.
BANDS OF MODERATE RAIN HAVE REDEVELOPED ACROSS LONG ISLAND/CT IN
THE LEFT FRONT QUAD OF A LOW LEVEL JET APPROACHING SOUTHERN NEW
ENGLAND...WHERE LOW LEVEL CONVERGENCE AND UPPER LEVEL DIVERGENCE
ARE MAXIMIZED. LLJ SHOULD LIFT NE BY 22Z-23Z...THEN LATEST RAP
INDICATES ANOTHER FAVORABLE LL CONVERGENCE/UL DIVERGENCE COUPLET
SHOULD MOVE ACROSS ERN LONG ISLAND/CT FOR A FEW HOURS BEGINNING LATE
THIS EVENING. ELSEWHERE...EARLIER HRRR INDICATED THAT SCT SHOWERS
MAY CONTINUE TO FORM NW OF NYC INTO THIS EVENING ON EDGE OF MID
LEVEL DRY SLOT.
AFTER ANY PRECIP ENDS...LIGHT WINDS AND ABUNDANT LL MOISTURE
SHOULD LEAD TO FOG FORMATION OVERNIGHT. LOCALLY DENSE FOG MAY BE
POSSIBLE INLAND AND ACROSS ERN LONG ISLAND LATE TONIGHT.
LOWS TONIGHT ARE CLOSE TO A GUIDANCE BLEND...NEAR 60 IN NYC TO THE
50S ELSEWHERE.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
EARLY MORNING FOG SHOULD BURN OFF QUICKLY AS WEAK FRONT ENTERS THE
REGION AND STRONGER SW FLOW COMMENCES...WITH MOSTLY CLEAR SKIES
FOR THE AFTERNOON AND NIGHT. BREEZY CONDS SHOULD DEVELOP IN THE
AFTERNOON AS THE PRIMARY LOW LIFTS INTO SE CANADA AND THE PRESSURE
GRADIENT TIGHTENS. HIGHS SHOULD BE A COUPLE DEG EITHER SIDE OF
70...WARMEST IN NYC METRO...LONG ISLAND AND THE CT RIVER VALLEY.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
UPPER LEVEL LOW LIFTS NORTH INTO SE CANADA THROUGH THE DAY ON
SUNDAY. A FEW STRONG VORTICITY MAXIMA WILL ROTATE IN BEHIND IT
WITH A DEPARTING STRONG UPPER LEVEL JET STREAK. MOST OF THE
INSTABILITY WILL BE TO THE NORTH OF OUR AREA...ALONG WITH DRIER
AIR MOVING INTO THE CWA...SO HAVE THEREFORE LEFT POPS OUT OF THE
FORECAST FOR SUNDAY. WESTERLY WINDS WILL PICK UP BRIEFLY ON SUNDAY
AS THE UPPER LEVEL LOW LIFTS NORTH AND HIGH PRESSURE BUILDS IN.
A LARGE AREA OF SURFACE HIGH PRESSURE AND AN UPPER LEVEL RIDGE
QUICKLY MOVES IN BEHIND THE UPPER LOW SUNDAY NIGHT. THE HIGH
PRESSURE AREA DOMINATES THE WEATHER THROUGH THE WEEK PROVIDING JUST
ABOVE NORMAL TEMPERATURES AND LIGHT WINDS TO THE AREA. ONLY CHANCE
FOR PRECIP IN THE PERIOD IS ON TUESDAY WHICH IS ASSOCIATED WITH A
WARM FRONT EXTENDING EASTWARD OUT OF A LOW PRESSURE SYSTEM IN THE
MIDWEST. UNCERTAINTY BETWEEN THE MODELS ON THE UPPER FLOW AT THIS
TIME CAUSES SOME UNCERTAINTY ON THE TIMING AND PLACEMENT OF THE
PRECIP ASSOCIATED WITH THE FRONT. GFS IS INDICATING A WEAK SHORTWAVE
DEVELOPING TUESDAY WHICH WILL AID IN PRECIP THROUGH WED MORNING.
ECMWF DEVELOPS A DEEPER SHORTWAVE WEDNESDAY MORNING...INDICATING
MORE PRECIP FOR THE WEDNESDAY THROUGH WEDNESDAY NIGHT TIME FRAME. AT
THIS TIME...HAVE CHANCE POPS TUESDAY NIGHT THROUGH WEDNESDAY TO
ACCOUNT FOR THIS UNCERTAINTY.
BEHIND THE WARM FRONT ON TUESDAY...RIDGING ALOFT BUILDS IN WITH
UNCERTAINTY BETWEEN THE MODELS ON THE UPPER FLOW AGAIN. ECMWF IS
QUICK WITH THE PASSAGE OF A COLD FRONT WITH LITTLE UPPER SUPPORT AND
LOW CHANCES OF RAIN. GFS LAGS BEHIND WITH A MUCH DEEPER UPPER LOW
OVER MINNESOTA WHICH WOULD KEEP THE RAIN AWAY FROM THE AREA DURING
THIS PERIOD. TEMPERATURES REMAIN JUST ABOVE NORMAL THURSDAY AND
FRIDAY WITH THE HIGH PRESSURE AT THE SURFACE LINGERING OVER THE AREA.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
A WEAK COLD FRONT W OF THE REGION WILL SLOWLY MOVE E THROUGH
TONIGHT AND PASS THROUGH EARLY SATURDAY MORNING.
MAINLY MVFR CONDITIONS CONT EARLY THIS AFTERNOON. STEADY RAIN IS
PUSHING N OF NYC TERMINALS AND MAINLY JUST EXPECTING SCT -SHRA FOR
THE NEXT SEVERAL HRS FOR NYC AND POINTS E. STEADIER RAIN WILL CONT
FOR KSWF.
VIS SATELLITE SHOWS SOME CLEARING TO VFR ALONG/JUST OFFSHORE THE
NJ COAST. THERE IS A SMALL CHC NYC TERMINALS...ESP JFK/LGA MAY SEE
OCNL VFR CONDITIONS FOR SEVERAL HRS LATE THIS AFTERNOON...BUT
CONFIDENCE NOT HIGH ENOUGH TO INCLUDE IN THE TAFS AT THIS POINT.
AFTER DARK...EXPECT CIGS/VSBY TO TREND DOWNWARD AGAIN AS LOW
CLOUDS/FOG BEGIN TO REDEVELOP. VIS MAY DROP LOWER THAN INDICATED IN
TAFS FOR A PERIOD LATE TONIGHT.
SOME UNCERTAINTY AS TO HOW LOW CONDITIONS WILL GET TONIGHT...BUT
SOME IFR IS POSSIBLE. WITH LIGHT SRLY OR LGT/VRB SFC FLOW THROUGH
THE NIGHT...HAVE GONE MORE PESSIMISTIC WITH THE FORECAST. COLD
FRONT MOVES THROUGH 10-12Z SATURDAY WITH WINDS SHIFTING TO SW AND
IMPROVEMENT TO VFR.
...NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS
CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: AMENDMENTS LIKELY FOR VARIABLE
CEILINGS/VSBY. HIGH CONFIDENCE IN SFC WINDS BECMG MORE SRLY BY
LATE AFTERNOON WITH GUSTS SUBSIDING.
KLGA FCSTER COMMENTS: AMENDMENTS LIKELY FOR VARIABLE
CEILINGS/VSBY. HIGH CONFIDENCE IN SFC WINDS BECMG MORE SRLY BY
LATE AFTERNOON WITH GUSTS SUBSIDING.
KEWR FCSTER COMMENTS: AMENDMENTS LIKELY FOR VARIABLE
CEILINGS/VSBY. HIGH CONFIDENCE IN SFC WINDS BECMG MORE SRLY BY
LATE AFTERNOON WITH GUSTS SUBSIDING.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH
IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: AMENDMENTS LIKELY FOR VARIABLE
CEILINGS/VSBY. HIGH CONFIDENCE IN SFC WINDS BECMG MORE SRLY BY
LATE AFTERNOON WITH GUSTS SUBSIDING.
KHPN FCSTER COMMENTS: AMENDMENTS LIKELY FOR VARIABLE
CEILINGS/VSBY. HIGH CONFIDENCE IN SFC WINDS BECMG MORE SRLY BY
LATE AFTERNOON WITH GUSTS SUBSIDING. CHANCE FOR VIS 1/2SM OR LESS
LATE TONIGHT.
KISP FCSTER COMMENTS: AMENDMENTS LIKELY FOR VARIABLE
CEILINGS/VSBY. HIGH CONFIDENCE IN SFC WINDS BECMG MORE SRLY BY
LATE AFTERNOON WITH GUSTS SUBSIDING.
.OUTLOOK FOR 18Z SATURDAY THROUGH WEDNESDAY...
.SAT AFTERNOON-TUESDAY...VFR. GUSTY NW WINDS PSBL SUN-MON.
.WEDNESDAY...SUB VFR PSBL IN SCT SHRA.
&&
.MARINE...
SCA HAS BEEN EXTENDED INTO SAT-SAT NIGHT FOR THE OCEAN. SWELLS 5-7
FT SWELLS SHOULD CONTINUE TONIGHT...AND SUBSIDE ONLY SLIGHTLY TO
4-6 FT SAT INTO SAT NIGHT. INCREASING SW FLOW SAT MAY GUST TO 25
KT ON THE OCEAN AND ERN SOUND BY SAT EVENING AS THE PRESSURE
GRADIENT TIGHTENS BETWEEN LOW PRESSURE OVER SE CANADA AND BUILDING
HIGH PRESSURE TO THE SW.
THE PRESSURE GRADIENT SHOULD REMAIN TIGHT ENOUGH TO KEEP OCEAN
SEAS ABOVE 5 FT ON SUNDAY AND GUSTS AROUND 25 KT IN A W-NW FLOW.
THESE SHOULD LINGER THROUGH MON MORNING...WITH WINDS AND SEAS
GRADUALLY DIMINISHING.
HIGH PRESSURE WILL THEN REMAIN OVER THE AREA THROUGH THE WEEK.
SUB-SCA CONDITIONS ARE EXPECTED.
&&
.HYDROLOGY...
ADDITIONAL BASIN AVG RAINFALL OF UP TO 1/4 INCH POSSIBLE
TONIGHT...MAINLY ACROSS LONG ISLAND/SOUTHERN CT...WITH LOCAL AMTS
DOUBLE THAT. NO SIG PRECIPITATION EXPECTED THEREAFTER.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...COASTAL FLOOD ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR
CTZ009-010.
NY...COASTAL FLOOD ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR
NYZ071-073-078-176-177.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT SATURDAY FOR ANZ355.
SMALL CRAFT ADVISORY UNTIL 6 AM EDT SUNDAY FOR ANZ350-353.
&&
$$
SYNOPSIS...GOODMAN
NEAR TERM...GOODMAN
SHORT TERM...GOODMAN
LONG TERM...FIG/LN
AVIATION...GS
MARINE...FIG/GOODMAN/LN
HYDROLOGY...FIG/GOODMAN
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
258 PM CDT FRI OCT 19 2012
.SYNOPSIS...
12Z UA ANALYSIS HAS THE UPPER LOW OVER WISCONSIN WITH NUMEROUS
TROFS FROM THE OHIO VALLEY BACK INTO THE PLAINS AND UPPER MIDWEST.
SATELLITE/RADAR TRENDS THROUGH MID AFTERNOON SHOWS THE INITIAL
SUBSIDENCE HAS FILLED BACK IN WITH DIURNAL CLOUDS. A VORT MAX
ROTATING SOUTHEAST OUT OF MINNESOTA IS HELPING TO GENERATE NEW
SHOWERS/SPRINKLES.
18Z SFC ANALYSIS HAS A LOW OVER SOUTHERN LAKE MICHIGAN WEST OF
KBIV. NUMEROUS TROFS RAN FROM THE LOW FROM THE LOWER OHIO VALLEY
BACK UP THROUGH WISCONSIN AND MINNESOTA. DEW POINTS WERE IN THE
30S AND 40S ACROSS THE MIDWEST.
&&
.SHORT TERM...LATE THIS AFTERNOON THROUGH SATURDAY...
THE VORT MAX HELPING TO GENERATE THE SHRA ACTIVITY ACROSS THE CWFA
IS FURTHER TO THE NORTH/EAST THAN WHAT THE RAP WAS SUGGESTING
EARLIER TODAY. BASED ON THE CURRENT AND EXTRAPOLATED POSITION OF
THE SHRA ACTIVITY...THERE SHOULD BE AN AREA OF CONCENTRATED
SHOWERS BETWEEN KDBQ/KALO TO THE SOUTHEAST LATE THIS AFTERNOON.
SAID ACTIVITY WILL CONTINUE INTO THE EARLY EVENING FROM NORTHEAST
OF KIOW DOWN TOWARDS KGBG BEFORE DISSIPATING LATER THIS EVENING.
AROUND THIS BAND OF CONCENTRATED SHRA ACTIVITY ISOLATED TO LOW END
SCATTERED DIURNAL SHRA WILL BE SEEN THAT DISSIPATE SHORTLY AFTER
SUNSET.
BASED ON THE LUMPY NATURE OF THE CLOUDS ON SATELLITE...SUBSIDENCE
AND THE SETTING SUN WILL RESULT IN A CLEARING POCKET THAT DEVELOPS
ACROSS MN AND WESTERN WISCONSIN THAT SHOULD BEGIN ROTATING SOUTH
AND THEN SOUTHEAST ACROSS THE CWFA BY LATE EVENING WITH PARTIAL
CLEARING CONTINUING OVERNIGHT. WINDS WILL DIMINISH BUT NOT AS MUCH
AS LAST NIGHT. HOWEVER...IN SHELTERED AREAS AND SOME RIVER VALLEYS
THERE IS A POTENTIAL FOR PATCHY FOG TO DEVELOP LATE TONIGHT.
IF FOG DEVELOPS LATE TONIGHT IT WILL LINGER INTO EARLY SATURDAY
MORNING BEFORE BURNING OFF.
SATURDAY WILL BE A MUCH NICER DAY WITH SUNSHINE...POSSIBLY
FILTERED...WITH TEMPERATURES CLOSE TO NORMAL. 08
.LONG TERM...SATURDAY NIGHT THROUGH NEXT FRIDAY...
FLOW PATTERN ALOFT WILL TRANSITION TO SOUTHWESTERLY FLOW BY EARLY
IN THE WEEK. HEIGHT RISES... GOOD LOW LEVEL WARM ADVECTION AND
ABUNDANT SUNSHINE SHOULD COMBINE TO BRING ABOUT A NICE BOOST IN
TEMPS ON SUNDAY... WITH HIGHS MOSTLY IN THE UPPER 60S TO LOWER 70S
ON GUSTY S/SE WINDS.
SUN NGT THROUGH MON WILL BRING THE FIRST OF SEVERAL RAIN CHANCES
THROUGHOUT THE EXTENDED... AS 30+ KT LOW LEVEL JET AND ATTENDANT
MOISTURE TRANSPORT AND CONVERGENCE AIMED OVER THE REGION BY LATE SUN
EVE INTO MON AM AHEAD OF AN UPPER LEVEL DISTURBANCE LIFTING OUT
OF THE CENTRAL PLAINS. ISOLD/SCTD ELEVATED STORMS SEEM REASONABLE
WITH BOTH NAM AND GFS MODELS ADVECTING STEEP PLUME OF MID LEVEL
LAPSE RATES IN EXCESS OF 7 C/KM IN 700-500 MB LAYER BY 12Z MON. IN
ADDITION... CANT RULE OUT SEEING SOME FOG AND DRIZZLE WITH SUCH
STRONG LOW LEVEL MOISTURE TRANSPORT WITH SFC DEWPTS CLIMBING THROUGH
THE 50S INTO 60S. ALSO... EXPECTING NON DIURNAL TEMP TREND WITH
TEMPS STEADY TO RISING OVRNGT SUN NGT. RAIN CHANCES WILL PERSIST
MON NGT INTO TUE WITH SUGGESTIONS OF ADDITIONAL UPPER LEVEL ENERGY
LIFTING OUT OF THE PLAINS AHEAD OF WESTERN CONUS TROUGH.
OUR REGION WILL CONTINUE TO RESIDE IN SOUTHWESTERLY FLOW ALOFT THROUGH
AT LEAST MIDWEEK WITH BROAD... DEEP TROUGH CENTERED OFF THE PACIFIC
NORTHWEST COAST. THIS WILL RESULT IN CONTINUATION OF ABOVE TO MUCH
ABOVE NORMAL TEMPS WHILE STAYING UNSETTLED... ALTHOUGH SUGGESTION OF
LOWER RISK OF PCPN TUE INTO WED WITH MAIN FRONTAL ZONE LOCATED TO
OUR NORTH/WEST. ANTICIPATE FLOW PATTERN ALOFT TO FLATTEN OR TRANSITION
TO SEMI-ZONAL LATE WEEK AS MORE SUBSTANTIAL ENERGY EJECTS FROM
WESTERN TROUGH. THIS WILL SEND THE BOUNDARY BACK THROUGH AS COLD
FRONT ACCOMPANIED BY SHOWERS AND STORMS WED NGT THROUGH THU BASED ON
THE RECENT MODEL TRENDS OR DPROG/DT OF UKMET... ECMWF AND GFS.
MOST AREAS LIKELY TO SEE 0.25 TO 0.75 INCH OF RAIN WITH AREAS OF 1+
INCHES BETWEEN THE TWO MAIN PCPN WINDOWS OF SUN NGT-MON NGT AND WED NGT-
THU NGT. MCCLURE
&&
.AVIATION... /ISSUED 1243 PM CDT FRI OCT 19 2012/
CONDITIONS WILL VARY BETWEEN MVFR AND PERIODS OF VFR THROUGH
00Z/20. DIURNAL HEATING COMBINED WITH THE UPPER LEVEL DISTURBANCE
IS STARTING TO DVLP SHRA ACROSS IOWA THAT WILL CONTINUE TO MOVE
SOUTHEAST. KCID/KBRL HAS THE BEST CHANCE AT SEEING RAIN WITH MVFR
CONDITIONS. KDBQ/KMLI MAY SEE A SHRA. AFT 00Z/20 CIGS WILL SLOWLY
LIFT ABV 3 KFT AGL AS CLOUDS BREAK UP. LIGHT WINDS AND CLEARING
SKIES WILL ALLOW MVFR FG TO DVLP WITH THE POTENTIAL FOR IFR OR
LIFR FG PRIOR TO SUNRISE SATURDAY. 08
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
08/MCCLURE
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1243 PM CDT FRI OCT 19 2012
.UPDATE...
SATELLITE TRENDS SHOW THE HOLES ARE FILLING IN DUE TO DIURNAL
HEATING AND THE COLD POOL ALOFT. SPRINKLES/SHRA ARE MOVING SOUTH
FROM MINNESOTA. THE RECENT RAP TRENDS CONTINUE TO SHOW ISENTROPIC
UP GLIDE WHICH SHOULD ALLOW SHRA TO DEVELOP THROUGH THE AFTERNOON
HOURS. THE SHRA ACTIVITY SHOULD BE MORE ISOLATED TO SCATTERED BUT
THERE IS A POSSIBILITY OF A BAND OF LIGHT RAIN DEVELOPING OVER THE
SOUTHWEST HALF OF THE CWFA.
DIFFERENTIAL HEATING FROM THE HOLES IN THE CLOUDS HAS ALLOWED
TEMPERATURES TO GET WARMER THAN FCST SO MAX TEMPS WERE ADJUSTED
ACCORDINGLY. ..08..
&&
.AVIATION...
CONDITIONS WILL VARY BETWEEN MVFR AND PERIODS OF VFR THROUGH
00Z/20. DIURNAL HEATING COMBINED WITH THE UPPER LEVEL DISTURBANCE
IS STARTING TO DVLP SHRA ACROSS IOWA THAT WILL CONTINUE TO MOVE
SOUTHEAST. KCID/KBRL HAS THE BEST CHANCE AT SEEING RAIN WITH MVFR
CONDITIONS. KDBQ/KMLI MAY SEE A SHRA. AFT 00Z/20 CIGS WILL SLOWLY
LIFT ABV 3 KFT AGL AS CLOUDS BREAK UP. LIGHT WINDS AND CLEARING
SKIES WILL ALLOW MVFR FG TO DVLP WITH THE POTENTIAL FOR IFR OR
LIFR FG PRIOR TO SUNRISE SATURDAY. ..08..
&&
.PREV DISCUSSION... /ISSUED 1037 AM CDT FRI OCT 19 2012/
UPDATE...
A MAJOR REVISION HAS BEEN DONE TO THE FCST.
SATELLITE SHOWS A LARGE HOLE HAS DEVELOPED ACROSS EASTERN IOWA
WITH NUMEROUS SMALL HOLES AS WELL. THE RAP ALONG WITH OTHER MODELS
HAVE BEEN SHOWING LARGE AMOUNTS OF SUBSIDENCE OVER THE AREA BUT
THE ONLY HOLES THAT HAVE DEVELOPED ARE OVER THE CWFA.
LIKEWISE...RADAR TRENDS SHOW NOT MUCH IN THE WAY OF SHRA ACTIVITY
EXCEPT EAST OF THE MISSISSIPPI.
SO...ASSUMING THE MOST RECENT TRENDS FROM THE RAP ARE CORRECT MOST
OF THE AREA WILL REMAIN PRECIP FREE FOR THE REMAINDER OF THE
MORNING. THE RAP DOES SLOWLY FILL IN THE HOLES IN THE CLOUD COVER
AS THE DAY PROGRESSES. THIS FILLING MAKES SENSE GIVEN THE COLD
POCKET ALOFT.
ON THE 300K THETA SFC BROAD ISENTROPIC LIFT DEVELOPS DURING THE
AFTERNOON HOURS SO ISOLATED TO SCATTERED SHRA SHOULD ONCE AGAIN
DEVELOP.
GIVEN THE RAPIDLY EVOLVING NATURE...ADDITIONAL UPDATES DURING THE
DAY WILL LIKELY BE NEEDED. ..08..
AVIATION...
DOWNWARD MOTION HAS ALLOWED A LARGE HOLE TO DVLP ACRS EASTERN IOWA
RESULTING IN VFR CONDITIONS AT KCID. THE RAP MODEL SHOWS THIS HOLE
MOVING EAST BUT EVENTUALLY FILLING THROUGH 21Z/19. ISOLATED TO
SCATTERED SHRA SHOULD DVLP AFT 18Z/19 AS AN UPPER LEVEL
DISTURBANCE MOVES INTO THE AREA. THUS CONDITIONS SHOULD IMPROVE TO
MVFR OR VFR AT ALL TAF SITES BEFORE DROPPING BACK TO MVFR/IFR
CONDITIONS. ..08..
PREV DISCUSSION... /ISSUED 302 AM CDT FRI OCT 19 2012/
SYNOPSIS...
IMPRESSIVE UPPER LOW SPINNING OVER THE MIDWEST AND WAS CENTERED
IN EXTREME SOUTHERN WISCONSIN. THE SURFACE LOW WAS NEAR KDBQ.
DOPPLER RADAR INDICATED AREAS OF DRIZZLE AND POCKETS OF LIGHT RAIN
IN THE DVN CWA. LIGHT TO MODERATE RAIN WAS LOCATED IN SOUTHWEST MN
AND INTO WESTERN IA. CLOUD COVER WAS EXTENSIVE ACROSS THE MIDWEST
WITH CLEAR SKIES FOUND WAY BACK IN THE WESTERN PLAINS. CURRENT
TEMPERATURES IN THE CWA WERE MAINLY IN THE 40S. WINDS WERE HOWLING
IN THE DAKOTAS AND INTO NEB...KS AND MO WITH SOME GUSTS TO 40 KNOTS.
HAASE
SHORT TERM...TODAY AND TONIGHT...
FORECAST FOCUS ON RAIN TODAY THEN ENDING TONIGHT. CONTINUED WELL
BELOW NORMAL TEMPERATURES.
TODAY...STACKED LOW WILL SLOWLY PUSH EASTWARD BUT FORCING IS NOT
AS STRONG AS YESTERDAY AS THE SYSTEM SLOWLY FILLS. HOWEVER AREAS
OF DRIZZLE AND LIGHT RAIN THIS MORNING WITH SHOWERS LIKELY THIS
AFTERNOON WILL STILL BE EXPECTED. DUE TO THE WEAKENING OF THE
SYSTEM RAINFALL AMOUNTS WILL BE LIGHTER THAN YESTERDAY...ON THE
ORDER OF 0.15 INCH OR LESS. WITH EXTENSIVE LOW CLOUDS TEMPERATURES
SHOULD BE LOWER THAN GUIDANCE AND WILL KEEP HIGHS ONLY IN THE
UPPER 40S TO LOWER 50S AT MOST LOCATIONS. WEST TO NORTHWEST WINDS
WILL GUST TO AROUND 25 MPH IN OUR SOUTHERN CWA WHERE THE TIGHTER
GRADIENT SOUTH OF THE LOW EXISTS.
TONIGHT...THE UPPER LOW GETS NUDGED FARTHER EAST AND BY 12Z
SATURDAY SHOULD BE IN THE EASTERN GREAT LAKES REGION. THIS
OCCURRING WHILE A STRONG 100+ KT UPPER LEVEL JET RAMS INTO THE
NORTHERN ROCKIES AS AN INTENSE LOW DIVES SOUTHWARD ALONG THE
BRITISH COLUMBIA COAST. ANY LINGERING RAIN WILL END THIS EVENING
FOLLOWED BY GRADUAL DECREASING CLOUDS. THESE BREAKS IN THE CLOUDS
SHOULD ALLOW TEMPERATURES TO BOTTOM OUT IN THE UPPER 30S TO LOWER
40S BY MORNING.
HAASE
LONG TERM...SATURDAY THROUGH THURSDAY...
WARMING TREND WITH CHANCE OF SHOWERS AND POSSIBLY ISOLATED STORMS
NEXT WEEK.
OVERVIEW...INITIALIZATION AND VERIFICATION GOOD WITH MINOR ISSUES
WITH UPSTREAM PACIFIC ENERGY. LITTLE SENSIBLE WEATHER DIFFERENCES
THIS FAR OUT. VERIFICATION SUPPORTS NORMAL BLEND OF MODELS WEIGHTED
TOWARD GFS. KEY ISSUE WILL BE LOW CLOUD POTENTIAL DEVELOPING SUNDAY
NIGHT AND MONDAY WITH GULF MOISTURE ARRIVING.
SATURDAY AND SUNDAY...FAIR SKIES...LIGHT WINDS AND A WARMING TREND
WITH HIGHS CLOSE TO 60F MOST AREAS SATURDAY AND UPPER 60S TO LOWER
70S ON SUNDAY. SATURDAY NIGHT...LIGHT WIND SUPPORTS COOLER MINS WITH
LATER SHIFTS POSSIBLY NEEDING TO TRIM A FEW MORE DEGREES OFF PROGGED
UPPER 30S TO LOWER 40S.
SUNDAY NIGHT...HAVE LOW POPS WITH SUGGESTION MAY HAVE HIGH ENOUGH
DEWPOINTS FOR LOW CLOUDS AND POSSIBLY FOG AND EVEN LIGHT DRIZZLE
FOR LATER SHIFTS TO REASSESS. MILD LOWS OF 55 TO 60 DEGREES AND
POSSIBLY LOWER 60S LOOK REASONABLE.
MONDAY THROUGH THURSDAY...FRONTAL BOUNDARY TO STALL NORTH OF AREA
WITH MODERATE SW UPPER LEVEL FLOW SUGGESTING A CHANCE OF SHOWERS AND
ISOLATED STORMS. LIMITED INSTABILITY AND FORCING PRECLUDES ANY
POTENTIAL FOR SEVERE STORMS ATTM WITH MUCAPE AOB 1200 J/KG. ABOVE
NORMAL TO WELL ABOVE NORMAL TEMPERATURES WITH HIGHS UPPER 60S TO
MIDDLE 70S DEPENDING ON AMOUNT OF CLOUDS. LOWS TO ALSO TO CONTINUE
QUITE MILD...MAINLY THE UPPER 50S TO LOWER 60S. POOR CONFIDENCE ON
TIMING OF WHEN NEXT FRONT TO PASS WITH D-PROG-DT TRENDS SUPPORTING
NEXT FRIDAY.
NICHOLS
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAY ME
606 PM EDT FRI OCT 19 2012
.SYNOPSIS...
LOW PRESSURE WILL MOVE VERY SLOWLY EAST FROM THE GREAT LAKES THROUGH
SATURDAY. A COLD FRONT EXTENDING TO THE SOUTH AND EAST OF THIS LOW
WILL PUSH TOWARD NEW ENGLAND SATURDAY. EXPECT CLOUDS AND
SCATTERED SHOWERS WITH AN UPPER LOW SATURDAY NIGHT INTO MONDAY.
HIGH PRESSURE WILL BUILD BY TO OUR SOUTH ON TUESDAY. A WARM FRONT
WILL BRING CLOUDS AND A CHANCE OF PRECIPITATION TO THE AREA
TUESDAY NIGHT INTO THURSDAY. A COLD FRONT WILL APPROACH THE REGION
LATE FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
600 PM UPDATE...
MADE SOME MINOR ADJUSTMENTS TO THE POPS AND SLIGHTLY LOWERED QPF
NORTH OF THE MOUNTAINS DUE TO SHADOW EFFECTS. UPDATED TEMPERATURES
BASED ON CURRENT OBSERVATIONS AND TRENDS.
PREVIOUS DISCUSSION...
PCPN HAS BEEN HAVING A DIFFICULT TIME MAKING ITS PROGRESSION TO
THE E TODAY. HAVE BACKED OFF ON POPS FOR THE REST OF THE
AFTN...THEN QUICKLY INCREASE THE POPS THEREAFTER. LATEST HRRR RUN
HAS THE BULK OF THE PCPN ENTERING MAINE AFT 21Z.
PERIODS OF RAIN WILL CONTINUE TONIGHT. PREFER THE GFS SOLN TODAY
AS HIGHEST QPF WILL BE ALIGNED ALONG THE MTNS IN E-CNTRL NH AND
FOOTHILLS IN MAINE.
SOUTHEAST GRADIENT...HIGH PRECIPITABLE WATERS AND AN INCREASING
DEW POINTS JUST TO OUR SOUTH WILL ALLOW THE RAIN TO BECOME HEAVY
AT TIMES STARTING THIS EVENING. LARGE UPPER LEVEL VORTEX WILL CONT
TO SLOWLY MARCH EAST OVERNIGHT. EXPECT AREAS OF FOG TO REDEVELOP
WITH PATCHY DRIZZLE.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
AFTER PERIODS OF RAIN VERY EARLY ON SATURDAY...MAINLY OVER EASTERN
SECTIONS...A DRY SLOW WILL ROTATE INTO THE REGION. IN FACT...A
BLEND OF MAV/MET MOS YIELDS TEMPS INT EH LOWER 70S OVER SOUTHERN
NH. COOLER READINGS WILL OCCUR OVER EASTERN SECTIONS WHICH WILL
HAVE THE MOST LOW CLOUD COVER AND WINDS OFF THE CHILLY GULF OF
MAINE.
BY SATURDAY NIGHT...THE UPPER LOW WILL APPROACH NORTHERN SECTIONS.
EXPECT SCT SHOWERS IN THE MTNS. WINDS WILL SWITCH TO THE SW BY
LATE AT NIGHT.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
AN UPPER TROF MOVES THRU NEW ENGLAND SUNDAY WITH AN ASSOCIATED
COLD FRONT MAY BRING SOME SCT SHWRS TO THE MTNS WITH DRY CONDS
ELSEWHERE OVER SRN/ERN AREAS DUE TO THE DOWN SLOPING WNWLY WINDS. A
DRY WEATHER PATTERN DEVELOPS DURING THE WEEK AS A DRY WNWLY FLOW
DEVELOPS THRU THE AS AN UPPER RIDGE BUILDS TO THE WEST OF NEW ENGL.
TEMPS WILL BEGIN THE WEEK COOL BUT A WARMING TREND IS EXPECTED
OVER THE MIDDLE TO LATTER PART OF THE WEEK. GENERALLY USED A BLEND
OF THE ADJUSTED GMOS TEMPS.
&&
.AVIATION /22Z FRIDAY THROUGH WEDNESDAY/...
SHORT TERM...IFR/LIFR CONDS CONTS TO DEVELOP LATE THIS AFTN AND
CONTINUES THRU TNGT...THEN IMPROVES AS THE COLD FNT MOVES THRU ON
SATURDAY. LLWS ADDED TO TAFS FOR INTO TNGT AS STRONG S SE LOW LVL
JET UP TO 50 KT DEVELOPS AT 2000 FT. THE KHIE MTR IS NOW BACK.
LONG TERM...
MAINLY VFR.
&&
.MARINE...
SHORT TERM...WILL UPDATE TO INPUT LATEST OBSERVED DATA WHICH WILL
RESULT IN LITTLE IF ANY CHANGES TO THE PREVIOUS FCST. WILL CONT
THE GLW FOR THE OPEN WATERS AND THE SCA FOR THE BAYS. MODELS BRING
A STRONG LOW LVL JET UP TO 50 KT AT 2000 FT ACROSS THE WATERS
DURING THIS TIME FRAME AND EXPECT GUSTS OF 35 KT TO BRIEFLY MIX
DOWN. WINDS DROP OFF SATURDAY AS THE GRADIENT DECREASES QUICKLY AS
THE CD FNT SLOWLY MOVES THRU. SEAS WILL BE SLOW TO SUBSIDE SO THE
GLW WILL LIKELY BE REPLACED WITH AN SCA FOR SATURDAY.
LONG TERM...
SUNDAY THRU MONDAY PSBL SCA WNWLY WINDS.
&&
.HYDROLOGY...
USED RFC/HPC QPF WHICH ARE IN VERY GOOD AGREEMENT. THE NAM QPF
APPEARS WAY OVERDONE WITH 3 INCH MAX WHILE GFS AND 12Z ECMWF SHOW
MAX OF 1 TO 1.5 INCH OVER SRN ZONES WHICH APPEARS MORE LIKELY. THE
RFC/HPC QPF STORM TOTAL IS A GOOD COMPROMISE WITH MAX AMOUNTS OVER
1.5 INCHES BUT LESS THAN 2 INCHES AND FALL FROM E-CNTRL NH TO THE
WRN FOOTHILLS OF ME. THIS MUCH QPF IS WELL BELOW FLASH FLOOD
GUIDANCE AND PRELIMINARY RFC RIVER FCST KEEPING ALL POINT FCST
BELOW FLOOD STAGE THOUGH IT DOES SHOW SOME SHARP RISES OVER
CENTRAL NH.
&&
.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES WILL CONT THROUGH SATURDAY. WITH
INCREASING ONSHORE FLOW TNGT ALONG WITH MODESTLY BUILDING SEAS
THERE WILL BE STORM SURGE ON TOP OF THE HIGH TIDE WHICH COULD PUSH
THE TIDE CLOSE TO...BUT KEEP IT BELOW FLOOD STAGE. STILL THE WAVE
ACTION COULD LEAD TO SOME MODEST SPLASH OVER AND BEACH EROSION
PROBLEMS...TONIGHT AND SATURDAY.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EDT SATURDAY FOR ANZ151-153.
GALE WARNING UNTIL 7 AM EDT SATURDAY FOR ANZ150-152-154.
&&
$$
NEAR TERM...KISTNER
AREA FORECAST DISCUSSION
NWS GRAY ME
229 PM EDT FRI OCT 19 2012
.SYNOPSIS...
LOW PRESSURE WILL MOVE VERY SLOWLY EAST FROM THE GREAT LAKES THROUGH
SATURDAY. A COLD FRONT EXTENDING TO THE SOUTH AND EAST OF THIS LOW
WILL PUSH TOWARD NEW ENGLAND SATURDAY. EXPECT CLOUDS AND
SCATTERED SHOWERS WITH AN UPPER LOW SATURDAY NIGHT INTO MONDAY.
HIGH PRESSURE WILL BUILD BY TO OUR SOUTH ON TUESDAY. A WARM FRONT
WILL BRING CLOUDS AND A CHANCE OF PRECIPITATION TO THE AREA
TUESDAY NIGHT INTO THURSDAY. A COLD FRONT WILL APPROACH THE REGION
LATE FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
PCPN HAS BEEN HAVING A DIFFICULT TIME MAKING ITS PROGRESSION TO
THE E TODAY. HAVE BACKED OFF ON POPS FOR THE REST OF THE
AFTN...THEN QUICKLY INCREASE THE POPS THEREAFTER. LATEST HRRR RUN
HAS THE BULK OF THE PCPN ENTERING MAINE AFT 21Z.
PERIODS OF RAIN WILL CONTINUE TONIGHT. PREFER THE GFS SOLN TODAY
AS HIGHEST QPF WILL BE ALIGNED ALONG THE MTNS IN E-CNTRL NH AND
FOOTHILLS IN MAINE.
SOUTHEAST GRADIENT...HIGH PRECIPITABLE WATERS AND AN INCREASING
DEW POINTS JUST TO OUR SOUTH WILL ALLOW THE RAIN TO BECOME HEAVY
AT TIMES STARTING THIS EVENING. LARGE UPPER LEVEL VORTEX WILL CONT
TO SLOWLY MARCH EAST OVERNIGHT. EXPECT AREAS OF FOG TO REDEVELOP
WITH PATCHY DRIZZLE.
&&
.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
AFTER PERIODS OF RAIN VERY EARLY ON SATURDAY...MAINLY OVER EASTERN
SECTIONS...A DRY SLOW WILL ROTATE INTO THE REGION. IN FACT...A
BLEND OF MAV/MET MOS YIELDS TEMPS INT EH LOWER 70S OVER SOUTHERN
NH. COOLER READINGS WILL OCCUR OVER EASTERN SECTIONS WHICH WILL
HAVE THE MOST LOW CLOUD COVER AND WINDS OFF THE CHILLY GULF OF
MAINE.
BY SATURDAY NIGHT...THE UPPER LOW WILL APPROACH NORTHERN SECTIONS.
EXPECT SCT SHOWERS IN THE MTNS. WINDS WILL SWITCH TO THE SW BY
LATE AT NIGHT.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
AN UPPER TROF MOVES THRU NEW ENGLAND SUNDAY WITH AN ASSOCIATED
COLD FRONT MAY BRING SOME SCT SHWRS TO THE MTNS WITH DRY CONDS
ELSWHR OVER SRN/ERN AREAS DUE TO THE DOWNSLOPING WNWLY WINDS. A
DRY WEATHER PATTERN DEVELOPS DURING THE WEEK AS A DRY WNWLY FLOW
DEVLOPS THRU THE AS AN UPPER RIDGE BUILDS TO THE WEST OF NEW ENGL.
TEMPS WILL BEGIN THE WEEK COOL BUT A WARMING TREND IS EXPECTED
OVER THE MIDDLE TO LATTER PART OF THE WEEK. GENERALLY USED A BLEND
OF THE ADJUSTED GMOS TEMPS.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
SHORT TERM...IFR/LIFR CONDS CONTS TO DEVELOP LATE THIS AFTN AND
CONTINUES THRU TNGT...THEN IMPROVES AS THE COLD FNT MOVES THRU ON
SATURDAY. LLWS ADDED TO TAFS FOR INTO TNGT AS STRONG S SE LOW LVL
JET UP TO 50 KT DEVELOPS AT 2000 FT. THE KHIE MTR IS NOW BACK.
LONG TERM...
MAINLY VFR.
&&
.MARINE...
SHORT TERM...WILL UPDATE TO INPUT LATEST OBSERVED DATA WHICH WILL
RESULT IN LITTLE IF ANY CHANGES TO THE PREVIOUS FCST. WILL CONT
THE GLW FOR THE OPEN WATERS AND THE SCA FOR THE BAYS. MODELS BRING
A STRONG LOW LVL JET UP TO 50 KT AT 2000 FT ACROSS THE WATERS
DURING THIS TIME FRAME AND EXPECT GUSTS OF 35 KT TO BRIEFLY MIX
DOWN. WINDS DROP OFF SATURDAY AS THE GRADIENT DECREASES QUICKLY AS
THE CD FNT SLOWLY MOVES THRU. SEAS WILL BE SLOW TO SUBSIDE SO THE
GLW WILL LIKELY BE REPLACED WITH AN SCA FOR SATURDAY.
LONG TERM...
SUNDAY THRU MONDAY PSBL SCA WNWLY WINDS.
&&
.HYDROLOGY...
USED RFC/HPC QPF WHICH ARE IN VERY GOOD AGREEMENT. THE NAM QPF
APPEARS WAY OVERDONE WITH 3 INCH MAX WHILE GFS AND 12Z ECMWF SHOW
MAX OF 1 TO 1.5 INCH OVER SRN ZONES WHICH APPEARS MORE LIKELY. THE
RFC/HPC QPF STORM TOTAL IS A GOOD COMPROMISE WITH MAX AMOUNTS OVER
1.5 INCHES BUT LESS THAN 2 INCHES AND FALL FROM E-CNTRL NH TO THE
WRN FOOTHILLS OF ME. THIS MUCH QPF IS WELL BELOW FLASH FLOOD
GUIDANCE AND PRELIMINARY RFC RIVER FCST KEEPING ALL POINT FCST
BELOW FLOOD STAGE THOUGH IT DOES SHOW SOME SHARP RISES OVER
CENTRAL NH.
&&
.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES WILL CONT THROUGH SATURDAY. WITH
INCREASING ONSHORE FLOW TNGT ALONG WITH MODESTLY BUILDING SEAS
THERE WILL BE STORM SURGE ON TOP OF THE HIGH TIDE WHICH COULD PUSH
THE TIDE CLOSE TO...BUT KEEP IT BELOW FLOOD STAGE. STILL THE WAVE
ACTION COULD LEAD TO SOME MODEST SPLASHOVER AND BEACH EROSION
PROBLEMS...TONIGHT AND SATURDAY.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EDT SATURDAY FOR ANZ151-153.
GALE WARNING UNTIL 7 AM EDT SATURDAY FOR ANZ150-152-154.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
548 PM EDT FRI OCT 19 2012
.SYNOPSIS...
AN UPPER LOW WILL MOVE ACROSS THE GREAT LAKES TONIGHT INTO TOMORROW
AND BRING SHOWERS AND COOLER TEMPERATURES TO THE REGION. HIGH
PRESSURE WILL THEN BUILD IN FROM THE SOUTHWEST...ALLOWING FOR A
DRY SUNDAY AND MODERATING TEMPERATURES FOR EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
WITH 545PM UPDATE...HAVE BUMPED UP POPS ACROSS EASTERN OHIO OVER
THE NEXT FEW HOURS WITH RAIN ALREADY MOVING INTO ZANESVILLE.
BLENDED THIS INTO FORECAST THROUGH MIDNIGHT...WITH NO CHANGES MADE
AFTERWARDS. PREVIOUS DISCUSSION FOLLOWS.
THE LATEST RAP ANALYSIS INDICATES A LARGE CLOSED LOW CENTERED
OVER LAKE MICHIGAN WITH ITS BROAD AND MOIST CYCLONIC FLOW EXTENDING
EASTWARD INTO THE OHIO VALLEY. WEAK 500MB VORT ENERGY IS LOCATED
ACROSS EASTERN OHIO WITH STRONGER SYNOPTIC FORCING WITH THE
SYSTEM FURTHER UPSTREAM IN ILLINOIS AIDING MORE WIDESPREAD PRECIP
IN INDIANA. AT THE SURFACE...THE LOW IS CENTERED IN A SIMILAR
LOCATION TO THE MID-LEVEL CYCLONE. THE UPPER OHIO VALLEY IS IN A
DRY SLOT AHEAD OF THE LOW WITH PARTLY SUNNY SKIES THIS AFTERNOON
AHEAD OF MID-LEVEL CLOUDS APPROACHING WESTERN PENNSYLVANIA.
THIS EVENING...THE CLOSED LOW WILL SLOWLY SHIFT EASTWARD ACROSS
LAKE MICHIGAN WITH THE EASTERN EXTENT OF ITS ASSOCIATED MOISTURE
ROTATING INTO THE UPPER OHIO VALLEY. WEAK VORT ENERGY INITIALLY MAY
PROVIDE ENOUGH FORCING FOR A FEW SHOWERS IN EASTERN OHIO LATE THIS
AFTERNOON INTO THE EARLY EVENING ALTHOUGH DRY AIR BELOW 800MB (30F
TD DEPRESSION AT THE SURFACE) WILL LIMIT SHOWERS TO MOSTLY VIRGA
INITIALLY.
THE BETTER CHANCE FOR SHOWERS WILL BE WHEN THE 1000-800MB LAYER
MOISTENS AND STRONGER FORCING PIVOTS INTO OHIO LATER THIS
EVENING. 4KM NSSL WRF AND HRRR SIMULATED REFLECTIVITY SUPPORT A
SOLUTION WITH COVERAGE OF SHOWERS INCREASING FROM THE WEST THIS
EVENING. WITH THIS IN MIND...CHC POPS ARE FORECAST
EARLY...INCREASING TO LIKELY BY 00Z IN EASTERN OHIO. FURTHER EAST
IN WESTERN PA...NORTHERN WV...AND WESTERN MD...DRY SLOT WILL LIMIT
KEEP THE FORECAST DRY INTO THE EARLY EVENING.
TONIGHT...THE CLOSED LOW WILL MOVE ACROSS MICHIGAN...CENTERED OVER
WESTERN LAKE ERIE BY 12Z ON SATURDAY. THE BEST VORT ENERGY WITH
THE LOW ALONG WITH MOISTURE IN THE 1000-700MB LAYER ARE PROGGED TO
ROTATE INTO THE AREA OVERNIGHT. THIS WILL ALLOW FOR THE CHANCE OF
SHOWERS TO EXTEND EASTWARD INTO WESTERN PA AND CONTINUE ACROSS
THE AREA. 500MB HEIGHTS DECREASE WITH CAA ALLOWING FOR A COOL AND
CLOUDY NIGHT. LOWS ARE A MAV/MET BLEND...RANGING FROM THE UPPER
30S ACROSS THE EASTERN RIDGES TO THE LOWER 40S ACROSS THE LOWLANDS
ELSEWHERE.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
THERE IS GFS/NAM AGREEMENT THAT THE CLOSED LOW WILL SLOWLY MOVE INTO
THE EASTERN GREAT LAKES ON SATURDAY AND FINALLY PULL NORTHEAST OF
THE AREA ON SATURDAY NIGHT. 500MB VORT ENERGY SWINGING AROUND THE
LOW BETWEEN 12Z AND 00Z WILL MAKE SCATTERED SHOWERS POSSIBLE
THROUGH THE DAY...WITH SHOWERS MORE LIKELY NORTH OF PITTSBURGH.
FORCING WITH THE SYSTEM WILL PULL NORTHEAST OF THE AREA SAT
NIGHT...BRINGING SHOWERS TO AN END.
THE COOLEST AIR ALOFT (850MB TEMPS OF 0-1C) WILL CROSS
THE FORECAST AREA AROUND 18Z ON SATURDAY. DESPITE 1000-500MB
THICKNESSES DROPPING TO NEAR OR JUST BELOW 5400M NORTH OF
PITTSBURGH...THE TIMING OF THE COOLEST AIR ADVECTING ACROSS THE AREA
IN THE AFTERNOON ON SATURDAY ALONG WITH WARMER LOW-LEVEL THICKNESSES
AND THERMAL PROFILES OF MODEL SOUNDINGS THROUGH SATURDAY NIGHT
SHOULD KEEP PRECIP TYPE ALL RAIN (WET SNOWFLAKES MELTING BEFORE
REACHING THE SURFACE ACROSS THE RIDGES AND I-80 CORRIDOR). HIGHS ON
SATURDAY ARE A MAV/MET BLEND...WITH TEMPS STRUGGLING TO REACH THE MID
50S ACROSS MOST OF THE AREA. WITH THE HIGH CENTERED SOUTHWEST OF
THE AREA ON SAT NIGHT...MORE CLEARING AND RADIATIONAL COOLING WILL
OCCUR SOUTHWEST OF PITTSBURGH...WITH LOWS RANGING FROM THE UPPER
30S IN EASTERN OHIO TO THE LOWER 40S ACROSS MUCH OF WESTERN PA.
THERE IS REASONABLE OPERATIONAL MODEL AGREEMENT THAT A SURFACE HIGH
WILL BUILD INTO THE AREA FROM THE SOUTHWEST ON SUNDAY AND SLIDE
SLOWLY SOUTHEASTWARD INTO THE CAROLINAS ON MONDAY. THIS WILL ALLOW
FOR A DRY FORECAST THROUGH THIS PERIOD. TEMPERATURES WILL BE
MODERATING EACH DAY WITH WARM AIR ADVECTION AND THE LOW-LEVEL FLOW
BACKING FROM SOUTHWESTERLY TO SOUTHERLY TO START THE WEEK. HIGHS ON
SUNDAY WILL BE AROUND 5 DEGREES ABOVE NORMAL...WARMING TO AROUND 5
DEGREES ABOVE NORMAL WITH MORE ABUNDANT SUNSHINE ON MONDAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
THE MODELS GENERALLY AGREE THAT AN UPPER LEVEL RIDGE WILL BE IN
PLACE OVER MUCH OF THE CENTRAL-EASTERN HALF OF THE US FOR THE START
OF THE PERIOD. WHAT REMAINS A BIT MORE INCONSISTENT ARE THE TIMING
AND STRENGTH OF THE SYSTEMS THAT DEVELOP AND ATTEMPT TO BREAK DOWN
THE RIDGE LATER TUESDAY/WEDNESDAY AND THE TIMING OF THE EVENTUAL
COLD FRONT SUGGESTED BY BOTH THE GFS/ECMWF FOR FRIDAY.
THE GFS TENDS TO BE A BIT FASTER WITH THE WARM-FRONTAL SHOWERS
TUESDAY AFTERNOON/EVENING THAN THE ECMWF...WHICH HAS A STRONGER HIGH
PRESSURE RIDGE AND KEEPS MORE OF THE MOISTURE NORTH. AT THIS
POINT...WILL MAINTAIN A FORECAST CLOSE TO HPC VALUES FOR POPS. BOTH
MODELS AND ENSEMBLE MEANS/MOS GUIDANCE SUGGEST THAT TEMPERATURES
WILL REMAIN 10 DEGREES ABOVE NORMAL THROUGH MUCH OF THE PERIOD UNDER
THE UPPER LEVEL RIDGE AND SOUTHERLY FLOW.
&&
.AVIATION /22Z FRIDAY THROUGH WEDNESDAY/...
SKIES WILL CONTINUE TO REMAIN VFR THROUGH THE EVE ALTHOUGH LIGHT
RAIN WL GRADUALLY ENCROACH AND CLOUD DECKS LOWER. BASED OFF OF
THE UPSTREAM OBSERVATIONS AND MODEL GUIDANCE...MVFR CONDITIONS/ISOLD
IFR SHOULD GRADUALLY PREVAIL AFTR NIGHTFALL...ALTHOUGH THE SURFACE
WIND SHOULD REMAIN SUFFICIENTLY ELEVATED TO PRECLUDE FOG FORMATION.
WITH THE CROSSING OF THE UPPER TROUGH AXIS ON SATURDAY...MVFR
SHOULD BE ANTICIPATED GIVEN THE STRATOCU AND SHRA POTENTIAL WITH
THE LOW CONVECTIVE TEMPS.
.OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/...
ALTHOUGH THE UPPER LOW WL DEPART AND HIGH PRES WL BUILD ON SATURDAY
NIGHT...RESTRICTIONS IN STRATUS/FOG COULD CONTINUE INTO SUNDAY
MORNING GIVEN THE DAMP BOUNDARY LAYER. VFR CONDITIONS SHOULD
RETURN AFTR DAYBREAK SUNDAY AND REMAIN THROUGH AT LEAST TUESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
333 PM EDT FRI OCT 19 2012
.SYNOPSIS...
AN UPPER LOW WILL MOVE ACROSS THE GREAT LAKES TONIGHT INTO TOMORROW
AND BRING SHOWERS AND COOLER TEMPERATURES TO THE REGION. HIGH
PRESSURE WILL THEN BUILD IN FROM THE SOUTHWEST...ALLOWING FOR A
DRY SUNDAY AND MODERATING TEMPERATURES FOR EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
THE LATEST RAP ANALYSIS INDICATES A LARGE CLOSED LOW CENTERED
OVER LAKE MICHIGAN WITH ITS BROAD AND MOIST CYCLONIC FLOW EXTENDING
EASTWARD INTO THE OHIO VALLEY. WEAK 500MB VORT ENERGY IS LOCATED
ACROSS EASTERN OHIO WITH STRONGER SYNOPTIC FORCING WITH THE
SYSTEM FURTHER UPSTREAM IN ILLINOIS AIDING MORE WIDESPREAD PRECIP
IN INDIANA. AT THE SURFACE...THE LOW IS CENTERED IN A SIMILAR
LOCATION TO THE MID-LEVEL CYCLONE. THE UPPER OHIO VALLEY IS IN A
DRY SLOT AHEAD OF THE LOW WITH PARTLY SUNNY SKIES THIS AFTERNOON
AHEAD OF MID-LEVEL CLOUDS APPROACHING WESTERN PENNSYLVANIA.
THIS EVENING...THE CLOSED LOW WILL SLOWLY SHIFT EASTWARD ACROSS
LAKE MICHIGAN WITH THE EASTERN EXTENT OF ITS ASSOCIATED MOISTURE
ROTATING INTO THE UPPER OHIO VALLEY. WEAK VORT ENERGY INITIALLY MAY
PROVIDE ENOUGH FORCING FOR A FEW SHOWERS IN EASTERN OHIO LATE THIS
AFTERNOON INTO THE EARLY EVENING ALTHOUGH DRY AIR BELOW 800MB (30F
TD DEPRESSION AT THE SURFACE) WILL LIMIT SHOWERS TO MOSTLY VIRGA
INITIALLY.
THE BETTER CHANCE FOR SHOWERS WILL BE WHEN THE 1000-800MB LAYER
MOISTENS AND STRONGER FORCING PIVOTS INTO OHIO LATER THIS
EVENING. 4KM NSSL WRF AND HRRR SIMULATED REFLECTIVITY SUPPORT A
SOLUTION WITH COVERAGE OF SHOWERS INCREASING FROM THE WEST THIS
EVENING. WITH THIS IN MIND...CHC POPS ARE FORECAST
EARLY...INCREASING TO LIKELY BY 00Z IN EASTERN OHIO. FURTHER EAST
IN WESTERN PA...NORTHERN WV...AND WESTERN MD...DRY SLOT WILL LIMIT
KEEP THE FORECAST DRY INTO THE EARLY EVENING.
TONIGHT...THE CLOSED LOW WILL MOVE ACROSS MICHIGAN...CENTERED OVER
WESTERN LAKE ERIE BY 12Z ON SATURDAY. THE BEST VORT ENERGY WITH
THE LOW ALONG WITH MOISTURE IN THE 1000-700MB LAYER ARE PROGGED TO
ROTATE INTO THE AREA OVERNIGHT. THIS WILL ALLOW FOR THE CHANCE OF
SHOWERS TO EXTEND EASTWARD INTO WESTERN PA AND CONTINUE ACROSS
THE AREA. 500MB HEIGHTS DECREASE WITH CAA ALLOWING FOR A COOL AND
CLOUDY NIGHT. LOWS ARE A MAV/MET BLEND...RANGING FROM THE UPPER
30S ACROSS THE EASTERN RIDGES TO THE LOWER 40S ACROSS THE LOWLANDS
ELSEWHERE.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
THERE IS GFS/NAM AGREEMENT THAT THE CLOSED LOW WILL SLOWLY MOVE INTO
THE EASTERN GREAT LAKES ON SATURDAY AND FINALLY PULL NORTHEAST OF
THE AREA ON SATURDAY NIGHT. 500MB VORT ENERGY SWINGING AROUND THE
LOW BETWEEN 12Z AND 00Z WILL MAKE SCATTERED SHOWERS POSSIBLE
THROUGH THE DAY...WITH SHOWERS MORE LIKELY NORTH OF PITTSBURGH.
FORCING WITH THE SYSTEM WILL PULL NORTHEAST OF THE AREA SAT
NIGHT...BRINGING SHOWERS TO AN END.
THE COOLEST AIR ALOFT (850MB TEMPS OF 0-1C) WILL CROSS
THE FORECAST AREA AROUND 18Z ON SATURDAY. DESPITE 1000-500MB
THICKNESSES DROPPING TO NEAR OR JUST BELOW 5400M NORTH OF
PITTSBURGH...THE TIMING OF THE COOLEST AIR ADVECTING ACROSS THE AREA
IN THE AFTERNOON ON SATURDAY ALONG WITH WARMER LOW-LEVEL THICKNESSES
AND THERMAL PROFILES OF MODEL SOUNDINGS THROUGH SATURDAY NIGHT
SHOULD KEEP PRECIP TYPE ALL RAIN (WET SNOWFLAKES MELTING BEFORE
REACHING THE SURFACE ACROSS THE RIDGES AND I-80 CORRIDOR). HIGHS ON
SATURDAY ARE A MAV/MET BLEND...WITH TEMPS STRUGGLING TO REACH THE MID
50S ACROSS MOST OF THE AREA. WITH THE HIGH CENTERED SOUTHWEST OF
THE AREA ON SAT NIGHT...MORE CLEARING AND RADIATIONAL COOLING WILL
OCCUR SOUTHWEST OF PITTSBURGH...WITH LOWS RANGING FROM THE UPPER
30S IN EASTERN OHIO TO THE LOWER 40S ACROSS MUCH OF WESTERN PA.
THERE IS REASONABLE OPERATIONAL MODEL AGREEMENT THAT A SURFACE HIGH
WILL BUILD INTO THE AREA FROM THE SOUTHWEST ON SUNDAY AND SLIDE
SLOWLY SOUTHEASTWARD INTO THE CAROLINAS ON MONDAY. THIS WILL ALLOW
FOR A DRY FORECAST THROUGH THIS PERIOD. TEMPERATURES WILL BE
MODERATING EACH DAY WITH WARM AIR ADVECTION AND THE LOW-LEVEL FLOW
BACKING FROM SOUTHWESTERLY TO SOUTHERLY TO START THE WEEK. HIGHS ON
SUNDAY WILL BE AROUND 5 DEGREES ABOVE NORMAL...WARMING TO AROUND 5
DEGREES ABOVE NORMAL WITH MORE ABUNDANT SUNSHINE ON MONDAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
THE MODELS GENERALLY AGREE THAT AN UPPER LEVEL RIDGE WILL BE IN
PLACE OVER MUCH OF THE CENTRAL-EASTERN HALF OF THE US FOR THE START
OF THE PERIOD. WHAT REMAINS A BIT MORE INCONSISTENT ARE THE TIMING
AND STRENGTH OF THE SYSTEMS THAT DEVELOP AND ATTEMPT TO BREAK DOWN
THE RIDGE LATER TUESDAY/WEDNESDAY AND THE TIMING OF THE EVENTUAL
COLD FRONT SUGGESTED BY BOTH THE GFS/ECMWF FOR FRIDAY.
THE GFS TENDS TO BE A BIT FASTER WITH THE WARM-FRONTAL SHOWERS
TUESDAY AFTERNOON/EVENING THAN THE ECMWF...WHICH HAS A STRONGER HIGH
PRESSURE RIDGE AND KEEPS MORE OF THE MOISTURE NORTH. AT THIS
POINT...WILL MAINTAIN A FORECAST CLOSE TO HPC VALUES FOR POPS. BOTH
MODELS AND ENSEMBLE MEANS/MOS GUIDANCE SUGGEST THAT TEMPERATURES
WILL REMAIN 10 DEGREES ABOVE NORMAL THROUGH MUCH OF THE PERIOD UNDER
THE UPPER LEVEL RIDGE AND SOUTHERLY FLOW.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
SKIES WILL CONTINUE TO REMAIN VFR THROUGH THE AFTERNOON AS MOST OF
THE REGION CONTINUES TO REMAIN IN THE DRY SLOT. MID-HIGH LEVEL
CLOUDS WHICH HAVE ALREADY REACHED WESTERN PA WILL CONTINUE TO
GRADUALLY SHIFT EASTWARD WITH THE SLOW PROGRESSION OF THE UPPER LOW.
AS A SHORTWAVE ROUNDS THE BASE OF THE TROUGH...ANOTHER AREA OF
SHOWERS AND LOWER CIGS WILL APPROACH FOR THE OVERNIGHT HOURS. BASED
OFF OF THE UPSTREAM OBSERVATIONS AND MODEL GUIDANCE...MVFR CIGS
SHOULD BE PREVALENT. HOWEVER...THE NAM AND SREF PROBABILITIES DO
SUGGEST A PERIOD OF IFR CIGS...ESPECIALLY IN THOSE LOCATIONS CLOSER
TO THE LOW AND NEAR THE RIDGES OF WV.
WITH THE UPPER LOW OVERHEAD SATURDAY...MVFR/VFR VARIABLE CIGS WILL
BE POSSIBLE FOR MOST OF THE DAY. FOR NOW...WILL TRY TO IMPROVE
CONDITIONS BACK TO MAINLY VFR FOR SATURDAY AFTERNOON BUT THAT MAY
NOT HAPPEN EVERYWHERE. SCATTERED SHOWER CHANCES SHOULD ALSO CONTINUE
THROUGH MOST OF THE DAY.
WINDS ARE EXPECTED TO REMAIN ELEVATED FOR MUCH OF THE OVERNIGHT
HOURS...LIMITING FOG POTENTIAL. GUSTS TO 20KTS COULD ONCE AGAIN BE
POSSIBLE SAT AFTERNOON.
.OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/...
AS THE UPPER LOW DEPARTS SATURDAY NIGHT AND HIGH PRESSURE BUILDS
OVERHEAD...RESTRICTIONS IN REMAINING STRATUS/FOG COULD CONTINUE
THROUGH SUNDAY MORNING. CONDITIONS SHOULD RETURN TO AND STAY VFR
THROUGH AT LEAST TUESDAY BEFORE THE NEXT SYSTEM APPROACHES MIDWEEK.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
SYNOPSIS...WOODRUM
NEAR TERM...WOODRUM
SHORT TERM...WOODRUM
LONG TERM...34
AVIATION...34
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
302 PM EDT FRI OCT 19 2012
.SYNOPSIS...
HIGH PRESSURE WILL BUILD ACROSS THE MID ATLANTIC FROM THE WEST
SATURDAY THROUGH MONDAY...THEN PERSIST OVER THE CAROLINAS THROUGH
THE REST OF THE WORK WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
CLOUD COVER HAS SCATTERED OUT FOR THE MOST PART WHICH HAS LED TO
SOME DESTABILIZATION OF THE BOUNDARY LAYER THIS AFTERNOON. A FEW
ISOLATED SHOWERS COULD DEVELOP MAINLY EAST OF THE BLUE RIDGE THE
REMAINDER OF THIS AFTERNOON INTO THE EARLY EVENING. LOCAL HRRR MODEL
DEPICTS THIS SCENARIO AND HAVE ADDED SLIGHT CHANCE POPS ACCORDINGLY.
DRIER AIRMASS WORKS IN OVERNIGHT WITH COOLER TEMPERATURES IN THE
UPPER 30S OVER THE HIGH TERRAIN AND UPPER 40S TO NEAR 50 OVER THE
METRO AREAS.
UPPER LOW WILL EJECT ACROSS THE GREAT LAKES TONIGHT AND SATURDAY.
WESTERLY WIND SHIFT EXPECTED DURING THE AFTERNOON ALONG WITH COOLER
HIGH TEMPERATURES IN THE UPPER 60S IN THE METRO AREAS TO THE 40S AND
50S OVER THE WESTERN HIGH TERRAIN. SCATTERED SHOWERS WILL BE
POSSIBLE OVER THE ALLEGHENY FRONT AT ANY TIME ON SATURDAY IN UPSLOPE
FLOW REGIME. WILL CONTINUE HIGHEST POPS THERE.
&&
.SHORT TERM /SATURDAY NIGHT/...
SATURDAY NIGHT...CLOSED LOW WILL CONTINUE TO EJECT NORTHEAST FROM
THE EASTERN GREAT LAKES. NWLY FLOW WILL CONTINUE TO BRING LIGHT
UPSLOPE PRECIP TO THE ALLEGHENY HIGHLANDS. THE SATURATED LAYER IS
QUITE SHALLOW...ABOUT 6 KFT MSL OVER THE PIERCE BUFR SOUNDING
LOCATION IN TUCKER COUNTY WV PER THE 12Z GFS. THEREFORE...THE PRECIP
WILL BE MORE DRIZZLE...ENDING AS VERY LIGHT SNOW /OR AS WE CALL IT
IN THE OFFICE...SNIZZLE/ ABOVE ABOUT 3500 FT.
EAST OF THE ALLEGHENY FRONT EXPECT CLEARING SKIES /WITH ONLY A FEW
WAVE CLOUDS OFF THE MOUNTAINS TO THE BLUE RIDGE/. MIN TEMPS MID TO
UPR 30S WEST OF THE BLUE RIDGE...LOW 40S IN THE PIEDMONT...MID TO
UPR 40S COASTAL PLAINS AND URBAN AREAS.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
SUNDAY WELL INTO NEXT WEEK...A DOMINATING RIDGE BUILDS IN THE WAKE
OF LOW MOVING UP THE ST LAWRENCE VALLEY. A 1022MB SFC HIGH WILL
BUILD ACROSS THE E-CNTRL CONUS...WITH WLY FLOW OVER THE MID
ATLANTIC...THROUGH MONDAY NIGHT. THE HIGH THEN STALLS OVER THE
SOUTHERN MID ATLANTIC/CAROLINAS FOR THE REST OF THE WORK WEEK
BRINGING QUITE TRANQUIL WEATHER TO THE LWX CWA. NEAR NORMAL
TEMPERATURES THROUGH MONDAY NIGHT...WARMING FOR TUESDAY AND ON.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
MVFR CIGS IN SPOTS TRANSITIONING TO VFR BY LATE THIS AFTERNOON.
ISOLATED LIGHT RAIN SHOWERS WILL BE POSSIBLE BUT ANY DIRECT IMPACT
TO THE TERMINALS IS LOW AND WILL LEAVE MENTION OUT OF THE TAF ATTM.
A WESTERLY WIND SHIFT WILL OCCUR ON SATURDAY WITH WIND SPEEDS
REACHING THE 10 TO 15 KTS THRESHOLD BY AFTERNOON.
HIGH PRESSURE BUILDS FROM THE WEST SATURDAY NIGHT THROUGH MONDAY
NIGHT WITH VFR AND LIGHT WLY FLOW. MORNING FOG CHANCES BEST MONDAY
AND TUESDAY NIGHTS UNDER HIGH PRESSURE THAT WILL SAG SOUTH TO THE
CAROLINAS THROUGH THE REST OF THE WORK WEEK.
&&
.MARINE...
OCCASIONAL SMALL CRAFT CONDITIONS STILL POSSIBLE THE
REMAINDER OF THIS AFTERNOON...ESPECIALLY OVER THE SOUTHERN
CHESAPEAKE BAY AND LOWER TIDAL POTOMAC RIVER. WINDS TO REMAIN
BELOW SCA LEVELS DURING SATURDAY MORNING AND AFTERNOON.
SMALL CRAFT ADVISORY FOR SATURDAY NIGHT FOR THE MD PART OF THE BAY
SOUTH OF POOLES ISLAND AND LOWER TIDAL POTOMAC AS NWLY FLOW
INCREASES...GUSTING AROUND 20 KT AS HIGH PRESSURE BUILDS. LIGHTER
WLY FLOW THEN SUNDAY INTO MONDAY AS HIGH PRESSURE CONTINUES TO
BUILD. TRANQUIL MONDAY NIGHT/TUESDAY WITH HIGH PRESSURE STALLING
OVER THE CAROLINAS THROUGH THE END OF THE WORK WEEK.
&&
.TIDES/COASTAL FLOODING...
SOUTHERLY FLOW AND CHANNELING EXPECTED THIS AFTERNOON AND EVENING
WITH ADDITIONAL POTENTIAL FOR MINOR FLOODING AT THE TIME OF HIGH
TIDE. NOT EXPECTING TIDE LEVELS OF LAST NIGHT. WESTERLY WIND SHIFT
SHOULD ALLEVIATE TIDAL CONCERNS BY SATURDAY NIGHT.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR
ANZ530>532-535-536-538>540-542.
SMALL CRAFT ADVISORY FROM MIDNIGHT SATURDAY NIGHT TO 8 AM EDT
SUNDAY FOR ANZ531>534-537-539>541-543.
SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR ANZ533-
534-537-541-543.
&&
$$
SYNOPSIS...BAJ
NEAR TERM...KRW
SHORT TERM...BAJ
LONG TERM...BAJ
AVIATION...BAJ/KRW
MARINE...BAJ/KRW
TIDES/COASTAL FLOODING...KRW
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1250 PM EDT FRI OCT 19 2012
.SYNOPSIS...
AN UPPER LOW WILL MOVE ACROSS THE GREAT LAKES TONIGHT INTO TOMORROW
AND BRING SHOWERS AND COOL WEATHER TO THE REGION. HIGH PRESSURE WILL
THEN BUILD IN FROM THE SOUTHWEST...BRINGING A DRY SUNDAY AND WARMER
TEMPERATURES FOR EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AN EARLY AFTERNOON UPDATE HAS BEEN ISSUED TO REMOVE MORNING FOG
WORDING AND TO LIMIT PRECIP CHANCES THIS AFTERNOON AND EARLY
EVENING TO PRIMARILY EASTERN OHIO.
THE LATEST RAP ANALYSIS INDICATES A LARGE CLOSED LOW CENTERED
OVER LAKE MICHIGAN WITH ITS BROAD AND MOIST CYCLONIC FLOW EXTENDING
EASTWARD INTO THE OHIO VALLEY. WEAK 500MB VORT ENERGY IS LOCATED
ACROSS EASTERN KENTUCKY WITH STRONGER SYNOPTIC FORCING WITH THE
SYSTEM FURTHER UPSTREAM IN INDIANA. AT THE SURFACE...THE LOW IS
CENTERED IN A SIMILAR LOCATION TO THE MID-LEVEL CYCLONE. THE UPPER
OHIO VALLEY IS IN A DRY SLOT AHEAD OF THE LOW WITH MOSTLY SUNNY
SKIES THIS AFTERNOON AHEAD OF MID-LEVEL CLOUDS ADVANCING INTO
EASTERN OHIO.
THIS AFTERNOON...THE CLOSED LOW WILL SLOWLY SHIFT EASTWARD ACROSS
LAKE MICHIGAN WITH THE EASTERN EXTENT OF ITS ASSOCIATED MOISTURE
ROTATING INTO THE UPPER OHIO VALLEY. WEAK VORT ENERGY FROM EASTERN
KENTUCKY MAY PROVIDE ENOUGH FORCING FOR A FEW SHOWERS IN EASTERN
OHIO LATE THIS AFTERNOON INTO THE EARLY EVENING, ALTHOUGH THE
BETTER CHANCE WILL BE WITH STRONGER FORCING PIVOTING INTO OHIO
LATER THIS EVENING. IN ADDITION...4KM NSSL WRF AND HRRR SIMULATED
REFLECTIVITY SUPPORT A SOLUTION WITH COVERAGE OF SHOWERS
INCREASING FROM THE WEST LATE TODAY. WITH THIS IN MIND, CHC POPS
ARE FORECAST EARLY, INCREASING TO LIKELY BY 00Z IN EASTERN OHIO.
FURTHER EAST IN WESTERN PA...NORTHERN WV...AND WESTERN MD...DRY
SLOT WILL LIMIT CLOUD COVERAGE TO SCATTERED DIURNAL CUMULUS AND
KEEP THE FORECAST DRY THROUGH THE AFTERNOON.
TEMPS THIS AFTERNOON ARE CLOSE TO LAMP GUIDANCE...WITH HIGHS RANGING
FROM THE LOWER 60S ACROSS THE EASTERN RIDGES AND IN EASTERN
OHIO...WHERE CLOUD COVERAGE WILL BE INCREASING...TO THE MID TO
UPPER 60S IN THE DRY SLOT IN WESTERN PA AND NORTHERN WV.
TONIGHT...THE CLOSED LOW WILL MOVE ACROSS MICHIGAN...CENTERED OVER
WESTERN LAKE ERIE BY 12Z ON SATURDAY. THUS...BEST VORT ENERGY WITH
THE LOW WITH MOISTURE IN THE 1000-700MB LAYER WILL ROTATE ACROSS
THE AREA. THIS WILL ALLOW FOR THE CHANCE OF SHOWERS TO EXTEND
EASTWARD INTO WESTERN PA AND CONTINUE ACROSS THE AREA OVERNIGHT.
500MB HEIGHTS DECREASE WITH CAA ALLOWING FOR A COOL AND CLOUDY
NIGHT. LOWS ARE A MAV/MET BLEND...RANGING FROM THE UPPER 30S
ACROSS THE EASTERN RIDGES TO THE LOWER 40S ACROSS THE LOWLANDS
ELSEWHERE.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
THE AFOREMENTIONED CLOSED LOW IS FORECAST TO ROLL ACROSS THE OHIO
VALLEY THROUGH THE WEEKEND ACCOMPANIED BY COOL TEMPERATURES AND
SHOWERS. BY SUNDAY...THE SYSTEM IS PROGGED OVER NEW ENGLAND
LEAVING A DRY...BUT COOL SUNDAY IN ITS WAKE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
THERE IS ECWMF/GFSE AGREEMENT THAT THE UPPER OHIO VALLEY WILL BE IN
A NORTHWESTERLY MID-LEVEL FLOW TO BEGIN THE PERIOD. A MID-LEVEL
RIDGE WILL THEN BUILD INTO THE AREA FOR MONDAY AND KEEP THE AREA
DRY.
UNCERTAINTY ENTERS THE FORECAST ON TUESDAY AS ALTHOUGH BOTH THE
GFS/ECMWF INDICATE A WEAK LOW PRESSURE SYSTEM MOVING ACROSS THE
GREAT LAKES REGION...THEY VARY ON HOW FAR SOUTH A FRONTAL BOUNDARY
AND ASSOCIATED PRECIPITATION WILL EXTEND. FORECAST LEANS CLOSEST TO
THE ECMWF...WITH CHANCE POPS NORTH OF THE PITTSBURGH METRO AND SCHC
POPS SOUTHWARD FOR TUESDAY AND WEDNESDAY. A SCHC OF SHOWERS
CONTINUES ON THURSDAY WITH UNCERTAINTY REMAINING IN A ZONAL FLOW.
IN ANTICIPATION THAT THE FRONTAL BOUNDARY WILL REMAIN NORTH OF THE
AREA EARLY THIS WEEK...TEMPERATURES THROUGHOUT THIS PERIOD ARE
FORECAST TO BE AROUND 10 DEGREES ABOVE NORMAL.
&&
.AVIATION /16Z FRIDAY THROUGH TUESDAY/...
SKIES SHOULD THEN REMAIN VFR FOR THE REST OF THE AFTERNOON AS WE
REMAIN IN THE DRY SLOT BETWEEN UPPER LOW TO THE WEST AND THE COLD
FRONT TO THE EAST. MID-LEVEL CLOUDS SHOULD BEGIN TO ENCROACH AS
THE DAY GOES ON BUT SHOWER CHANCES SHOULD BE LOW UNTIL AFTER
SUNSET.
WINDS SHOULD SHIFT FROM EASTERLY TO MORE SOUTHERLY TODAY. GUSTS TO
20KTS WILL BE POSSIBLE THROUGH THE AFTERNOON.
.OUTLOOK.../FRIDAY NIGHT THROUGH TUESDAY/...
A CLOSED LOW ACROSS THE GREAT LAKES WILL SWING SCATTERED SHOWERS AND
POSSIBLE RESTRICTIONS ACROSS THE AREA FRIDAY NIGHT INTO SATURDAY.
CEILING RESTRICTIONS WILL BE POSSIBLE SATURDAY NIGHT WITH VFR
CONDITIONS PREVAILING SUNDAY INTO MONDAY AS HIGH PRESSURE BUILDS IN.
THE NEXT CHANCE OF SHOWERS WILL RETURN ON TUESDAY AS A FRONTAL
SYSTEM APPROACHES FROM THE NORTHWEST.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
SYNOPSIS...WOODRUM
NEAR TERM...WOODRUM
AVIATION...34
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
152 PM EDT FRI OCT 19 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 449 AM EDT FRI OCT 19 2012
UPPER LOW REMAINS NEARBY THIS MORNING...CENTERED OVER WI/NORTHERN
IL. AT THE SFC...PRIMARY SFC LOW HAS NOW FOCUSED FARTHER SOUTH WITH
POSITION OVER NORTHWEST ILLINOIS. AN OCCLUDED FRONT IS ARCING FROM
THE LOW TO THE NORTH OF LK SUPERIOR WHILE COLD FRONT IS PLOWING
TOWARD ATLANTIC SEABOARD WITH SOME CONVECTION. RADAR LOOP OVER THE
WESTERN GREAT LAKES REGION SHOWS CONCENTRATED AREAS OF SHOWERS OVER
MINNESOTA...NORTHERN INDIANA...AND LIFTING NORTH ACROSS LK MICHIGAN.
OVER UPR MICHIGAN...ARE JUST SEEING A SMATTERING OF LGT SHOWERS OVER
CNTRL CWA THOUGH THE SHOWERS OVER LK MICHIGAN ARE POISED TO IMPACT
SCNTRL CWA EARLY THIS MORNING.
SFC LOW MOVES FROM NORTHERN ILLINOIS TO VCNTY LK HURON THIS EVENING.
WV LOOP AND RUC ANALYSIS INDICATE SHORTWAVES TO THE SOUTH OF UPR
MICHIGAN ON FRONT EDGE OF UPPER LOW ARE LIFTING NORTH THIS MORNING.
PRIMARY SHORTWAVE OVER INDIANA LIFTS ACROSS LOWER MICHIGAN TODAY AS
UPPER LOW SLOWLY MOVES EAST. RUC/GEM-REGIONAL HAVE DECENT HANDLE ON
LOCATION OF CURRENT SHOWERS AND BOTH SHOW MAIN AREA OF SHOWERS
STAYING OVER LOWER MICHIGAN THROUGH THE DAY. HOWEVER...AS THE
SHORTWAVE LIFTS NORTH...H85 WINDS BACK FROM SOUTHERLY TO MORE
EASTERLY...ALLOWING INCREASE IN H85 MOISTURE TRANSPORT ACROSS
CENTRAL AND EASTERN ZONES. COMBINATION OF THE ADDITIONAL MOISTURE
AND WEAK LIFT ON PERIFERY OF STRONGER SHORTWAVES LIFTING ACROSS
LOWER MICHIGAN SHOULD LEAD TO INCREASING COVERAGE OF SHOWERS FOR THE
EAST HALF OF CWA. SCATTERED WORDING WORKS FOR MOST AREAS TODAY. ONLY
EXCEPTION IS OVER THE KEWEENAW WHERE CHANCES STAY A BIT LOWER AS
THEY ARE FARTHER DISPLACED FROM THE FORCING. JUST A SLIGHT RISE IN
925MB TEMPS THROUGH THE DAY AS LOW-LEVEL WINDS BECOME MORE NORTH OF
EAST BY LATE DAY. EXPECT HIGHS TO REACH UPR 40S NORTH CENTRAL AND
INTO THE 50S ELSEWHERE. WHATEVER WEAK LIFT IS LEFT EVADES IN THE
EVENING...LEAVING 925-850MB MOISTURE BUT NOT MUCH FORCING. CUT OUT
POPS TOWARD MIDNIGHT FOR ALL AREAS. WEAKLY CYCLONIC NORTHEAST
LOW-LEVEL WINDS COULD KEEP BKN CLOUDS IN MOST OF THE NIGHT OVER
UPSLOPE AREAS OF WESTERN AND NORTH CENTRAL CWA. MIN TEMPS JUST
SLIGHTLY COOLER THAN TONIGHT...UPR 30S TO MID 40S.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 449 AM EDT FRI OCT 19 2012
NAM SHOWS A CLOSED 500 MB LOW OVER SE LOWER MICHIGAN IN AN EMBEDDED
DEEP TROUGH OVER THE EASTERN U.S. WITH A TROUGH OVER SW CANADA AND A
BROAD RIDGE OVER THE SOUTHERN ROCKIES INTO THE PLAINS ON SAT. THE
NAM BUILDS THE RIDGE INTO THE UPPER GREAT LAKES SAT NIGHT THROUGH
SUN NIGHT. WITH THE RIDGE IN THE AREA...LOOKS TO STAY DRY THIS
PERIOD AS THE CLOSED 500 MB LOW PULLS OFF TO THE EAST AND TAKES ITS
RAIN WITH IT AND WE WAIT FOR SYSTEMS TO EJECT OUT OF THE BROAD 500
MB TROUGH THAT WILL SET UP TO THE WEST. OVERALL...DID NOT MAKE TOO
MANY CHANGES TO THE GOING FORECAST FOR TEMPERATURES OR WEATHER.
IN THE EXTENDED...GFS AND ECMWF SHOW A 500 MB RIDGE OVER THE ERN
U.S. WITH A BROAD 500 MB TROUGH OVER THE WESTERN U.S. 12Z MON. UPPER
AIR FLOW STAYS OUT SW-NE THROUGH WED WITH LITTLE MOVEMENT TO THE
RIDGE OR THE TROUGH. ECMWF SHOWS A SHORTWAVE TROUGH EJECTING INTO
THE UPPER GREAT LAKES 12Z THU WHILE THE GFS IS SLOWER WITH IT. LOOKS
TO BE WARM AND WET THROUGH THE PERIOD WITH A CHANCE OF RAIN EACH
DAY. TEMPERATURES WILL CONTINUE TO BE ABOVE NORMAL. GETS KIND OF
TRICKY LATER ON FOR WINDS IN THE EXTENDED...ESPECIALLY THURSDAY AS
THE GFS AND ECMWF ARE 180 DEGREES OPPOSITE FOR WIND DIRECTIONS...BUT
ARE STRONG ON THE WINDS. KEPT PERSISTENCE FORECAST IN FOR NOW.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 152 PM EDT FRI OCT 19 2012
CMX LOOKS TO STAY VFR OR NEAR MVFR THROUGH THE REST OF THE
PERIOD...WITH SOME POTENTIAL FOR A RETURN TO MVFR CIGS TONIGHT AS
MORE LOW LEVEL MOISTURE AND SOME SHOWERS MOVE INTO THE KEWEENAW.
SAW SHOULD SEE MOSTLY MVFR CONDITIONS INTO TONIGHT AS MOISTURE
PUSHES THROUGH...WITH GRADUALLY IMPROVING CONDITIONS EXPECTED
THROUGH THE PERIOD.
TRICKIEST CONDITIONS AT IWD TONIGHT AS NOCTURNAL COOLING TONIGHT
BRINGS THE INVERSION DOWN...TRAPPING MOISTURE IN THE VERY LOW LEVELS.
ALSO...LIGHT UPSLOPE N WINDS WILL HELP LOWER CIGS/VIS TONIGHT. MANY
OF THE HIGHER RES MODELS (NAM/WRF/HRRR) INDICATE VERY LOW VIS/CIG
TONIGHT OVER MUCH OF WRN UPPER MI...AND THE SREF SHOWS 100 PERCENT
PROBABILITY OF VIS LESS THAN 1 MILE AND CIG LESS THAN 500 FEET. EVEN
SO...DID NOT WANT TO JUMP COMPLETELY ON BOARD WITH THE LOWER
GUIDANCE JUST YET SINCE PREVIOUS FORECAST DID NOT INCLUDE CONDITIONS
NEARLY THAT LOW. WENT WITH LOW END IFR BUT DID TAKE CONDITIONS BELOW
ALTERNATE LANDING MINS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 449 AM EDT FRI OCT 19 2012
SE WINDS TO 25 KTS TO START THE DAY THEN WINDS DIMINISH TO LESS THAN
20 KTS LATER TONIGHT INTO SATURDAY. COULD SEE NW WINDS REACH 25 KTS
SATURDAY OVER EASTERN PORTIONS OF LK SUPERIOR AS HIGH PRESSURE
BUILDS TOWARD SLOWLY EXITING LOW PRESSURE OVER QUEBEC...LEADING TO
TEMPORARY TIGHTER PRESSURE GRADIENT. EXPECT WINDS TO DIMINISH ON
SATURDAY NIGHT ONCE THE RIDGE MOVES OVERHEAD. WINDS WILL REMAIN AT
20 KTS OR LESS THROUGH EARLY NEXT WEEK WITH WEAK PRESSURE GRADIENT
IN PLACE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...07
AVIATION...TITUS
MARINE...JLA
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
105 PM CDT FRI OCT 19 2012
.UPDATE...
ISSUED AT 1036 AM CDT FRI OCT 19 2012
SHORTWAVES ROTATING AROUND A DEEP UPPER LOW WILL BRING SCT SHRA
AND DRIZZLE TO PARTS OF THE AREA THROUGH THE AFTERNOON. ONE OF THE
CHALLENGES WITH MONITORING SHORT TERM WX TRENDS TODAY IS THAT THE
LOWEST ELEVATION ANGLE OF THE RADAR BEAM IS OVERSHOOTING MOST OF
THE PCPN BEYOND APPROXIMATELY 40 NMI. FOR EXAMPLE...LIGHT RAIN OR
DRIZZLE WAS LOWERING VSBYS TO AROUND 4 MI AT KUIN BETWEEN 14-15Z
HOWEVER THE 0.5 DEGREE ELEVATION SCANS DEPICTED NO PCPN ANYWHERE
NEAR KUIN. THERE MAY BE SOME BRIEF PDS OF CLEARING AND A FEW
GLIMPSES OF SUNSHINE DUE TO SUBSIDENCE ALOFT HOWEVER CLOUDS ARE
EXPECTED TO BUILD BACK IN FAIRLY QUICKLY.
KANOFSKY
&&
.SHORT TERM...
ISSUED AT 320 AM CDT FRI OCT 19 2012
(TODAY AND TONIGHT)
THE EXPANSIVE UPPER LOW CURRENTLY CENTERED IN WISCONSIN CONTINUES
TO MEANDER EASTWARD. A NUMBER OF WEAK IMPULSES PINWHEELING AROUND
THE VORTEX HAVE BEEN PRODUCING AREAS OF RAIN/SHOWERS. THE VAST
MAJORITY OF THE ACTIVITY THUS FAR WITHIN THE LSX CWA HAS BEEN
LOCATED ALONG AND NORTH OF I-70...AND HAS BEEN LIGHT AND NON-
MEASURABLE. REGIONAL RADARS SUGGEST THAT THE COVERAGE UPSTREAM HAS
BEGUN TO DIMINISH SOME. THE LATEST FORECASTS OF THE HRRR AND
DETERMINISTIC MODELS CONTINUE THIS TREND THOUGH THE MORNING AND
INTO THE AFTERNOON AS THE SYSTEM MOVES SLOWLY EASTWARD. STRATUS...GUSTY
WEST WINDS...AND POCKETS OF PRECIPITATION WILL MAKE FOR A COOL DAY
WITH WELL BELOW AVERAGE TEMPERATURES. THE UPPER LOW AND ATTENDANT
UPPER TROF WILL CONTINUE EASTWARD TONIGHT AND THE NWP MODEL SUITE
IS WELL CLUSTERED SHOWING THE UPPER LOW INVOF SRN MI WITH THE
UPPER TROF AXIS INTO THE TX PANHANDLE BY 12Z SAT. LOW LEVEL RH
PROGS SHOW THAT CLOUDS WILL PERSIST TONIGHT AND THIS SHOULD HELP
OVERNIGHT TEMPERATURES IN THE LOW-MID 40S.
GLASS
&&
.LONG TERM...
ISSUED AT 320 AM CDT FRI OCT 19 2012
(SATURDAY THROUGH SUNDAY)
THE UPPER AIR PATTERN WILL UNDERGO A CHANGE DURING THE PERIOD AS
THE UPPER LOW/TROF LIFT NEWD...WITH THE TROF SHIFTING INTO THE
WESTERN ATLANTIC BY SUNDAY EVENING. HEIGHTS ALOFT WILL RISE SOME
90 TO 120 M IN RESPONSE TO THE PROGRESSION...WITH A WEAK UPPER
RIDGE SHIFTING THROUGH THE MS VALLEY ON SUNDAY. SATURDAY WILL BE A
DAY OF TRANSITION AS CLOUDS ERODE AND A WEAK SURFACE RIDGE SLIDES
ACROSS THE CWA RESULTING IN MODERATING TEMPERATURES. A BIG WARM-UP
IS ON TAP SUNDAY IN RESPONSE TO THE HEIGHT RISES ALOFT AND GOOD
LOW LEVEL WAA.
(SUNDAY NIGHT THROUGH THURSDAY)
ABOVE AVERAGE TEMPERATURES AND A PERIOD OF POTENTIALLY STORMY
WEATHER ARE ON TAP FOR THE UPCOMING WEEK. SWLY UPPER FLOW WILL
DOMINATE THROUGH THE MS VALLEY WITH A DEEP BROAD UPPER TROF
CENTERED JUST OFF THE WEST COAST THROUGH AT LEAST MID WEEK. A 30+
KT SWLY LLJ WILL RAMP UP ON SUNDAY NIGHT AND THIS WILL RESULT IN
STRONG MOISTURE TRANSPORT AND CONVERGENCE BACK INTO THE AREA. THIS
MOISTENING COMBINED WITH THE EASTWARD ADVECTION OF STEEPER MID
LEVEL LAPSE RATES/THE EML WILL RESULT IN ELEVATED INSTABILITY WITH
POTENTIAL FOR ELEVATED SHOWERS AND THUNDERSTORMS IN THE WAA
REGIME SUNDAY NIGHT INTO MONDAY MORNING. AN IMPULSE LIFTING NEWD OUT OF
THE SRN PLAINS AND ACROSS THE AREA MONDAY AFTERNOON AND NIGHT IN
THE SW FLOW ALOFT WILL MAINTAIN THE THREAT OF SHOWERS AND
THUNDERSTORMS.
GLASS
&&
.AVIATION...
ISSUED AT 1231 PM CDT FRI OCT 19 2012
THE PRIMARY FCST ISSUES FOR THE 18Z TAFS ARE CIG TRENDS AND PCPN
CHCS. EXTENSIVE MVFR-VFR CLOUD DECK WILL REMAIN OVER THE TAF SITES
THROUGH MOST OF THE 24HR TAF PD UNTIL THE DEEP LOW PRESSURE SYSTEM
OVER THE GREAT LAKES MOVES AWAY FROM THE REGION. ANY HOLES THAT
DVLP WILL QUICKLY FILL IN WITH DVLPG STRATOCU DUE TO SFC HEATING
AND COLD AIR ALOFT. CIGS ARE EXPECTED TO RISE TO VFR BY TOMORROW
MORNING WITH CLRG SKIES FROM WEST TO EAST BEYOND THE END OF THE
VALID TAF PD. SCT SHRA/DZ ARE EXPECTED THROUGH THE AFTERNOON AND
INTO THE EVENING HOURS AS SEVERAL DISTURBANCES ROTATE AROUND THE
UPPER LOW.
SPECIFICS FOR KSTL...SCT SHRA/DZ EXPECTED TO CONTINUE THROUGH THE
AFTERNOON AND INTO THE EVENING AS SEVERAL DISTURBANCES ROTATE
AROUND A DEEP LOW PRESSURE SYSTEM. THERE MIGHT BE SOME PDS OF VFR
CIGS THIS AFTN BUT THE OVERALL TREND IS FOR MVFR CIGS TO PERSIST
THROUGH MOST OF THE NIGHT. CIGS WILL IMPROVE AND BEGIN TO CLEAR
OUT TOMORROW ONCE THE LOW PRESSURE SYSTEM MOVES AWAY FROM THE
REGION.
KANOFSKY
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
305 PM EDT FRI OCT 19 2012
.SYNOPSIS...
A FRONT WILL SLOWLY PASS THROUGH THE AREA TODAY WITH WIDESPREAD
SHOWERS EXPECTED IN CENTRAL NEW YORK, EAST OF I81 AND OVER
NORTHEAST PENNSYLVANIA. ISOLATED THUNDERSTORMS WILL ALSO OCCUR IN
THE ABOVE MENTIONED AREA. LOW PRESSURE MOVING SLOWLY EASTWARD
THROUGH THE GREAT LAKES WILL KEEP UNSETTLED WEATHER IN OUR AREA
FOR MUCH OF THE WEEKEND. SHOWERS FROM THE LOW WILL BE SCATTERED
OVER THE REGION INTO SUNDAY...ALONG WITH GRADUALLY COOLER AIR.
&&
.NEAR TERM /THROUGH TONIGHT/...
12 PM UPDATE...SFC WAVE ALONG BOUNDARY CURRENTLY OVER THE WYOMING
VALLEY WITH ACTIVITY NOW CONTINUING TO LIFT NORTHEAST AS EXPECTED.
FOR THIS AFTERNOON MOST WIDESPREAD SHOWERS WILL BE CONFINED TO THE
WESTERN CATSKILLS AND POCONOS. LOWERED MAX TEMPS SLIGHTLY BASED ON
CURRENT OBS, NO OTHER CHANGES.
945 AM UPDATE...LOCAL RADARS SHOW SHOWERS ACROSS CENTRAL NY
MAINLY EAST OF I81 AND NORTHEAST PA. OCCLUDED FRONT STRETCHED FROM
THE SYR AREA SOUTH ACROSS BGM INTO THE WYOMING VALLEY. SFC WAVE
ALONG BOUNDARY OVER SE PA WILL ACT TO SLOW THE PROGRESS OF THIS
FRONT THROUGH EARLY AFTERNOON ALONG WITH KEEPING ACTIVITY IN SAME
LOCATION UNTIL EASTWARD PROGRESS COMMENCES AGAIN. WEAK INSTABILITY
ALONG WITH FRONTAL LIFT WILL KEEP THE THREAT FOR THUNDERSTORMS
ALONG AND EAST OF BOUNDARY THROUGH THIS AFTERNOON. HIGH PWATS
INDICATE ANY STRONGER RETURNS ON RADAR WILL BE ASSOCIATED WITH
HEAVY DOWNPOURS AND THIS IS CONFIRMED BY OBSERVATIONS.
PREVIOUS DISC...
FNT DEAD CNTR OVER THE FCST AREA ATTM WITH A BRIEF AREA OF RW+
AND AN ISLTD LGTNG STRIKES OVER NE PA. LATEST HRRR AND NAM RUNS
ARE QUITE PROGRESSIVE WITH THE FNT PUSHING IT AND THE HEAVIEST
RAIN EAST OF THE FCST AREA BY 12Z...DESPITE THE DVLPG SFC LOW OVER
THE MID ATLANTIC STATES. DEEP MOISTURE AHD OF THE FNT WITH A GULF
CONNECTION AND PWATS NEAR 180% OF NRML FOR THIS TIME OF YEAR.
AREAS AHD OF THE FNT WILL CONT TO SEE HEAVY RAIN WITH THE GOOD
FRCG OF THE FNT.
HRRR AND NAM SHOWS SOME PCPN BEING TOSSED BACK BHD THE FNT LTR
THIS MRNG AS THE LOW MVES NEWRD...SO WILL KEEP HIER POPS OVER THE
ERN ZONES THRU MUCH OF THE DAY DESPITE THE ERWRD MVMT OF THE
BNDRY.
SINCE THE LATEST MODEL FCSTS KEEP THE FNT PROGRESSIVE THRU THE
FCST AREA...HEAVY RAINS SHD NOT BE A PRBLM...WITH STORM TTLS WELL
BLO FFG AND HEADWATERS GUID. WILL KEEP A LOW CHANCE OF THUNDER IN
THE EAST AND SOUTH WITH THE INSTABILITY ALOFT WITH THE FNT...AND
THE ADDED LIFT OF THE APRCHG WV.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY/...
LOW PLODS SLOWLY EAST AS IT GRADUALLY FILLS. DRY SLOT BHD THE FNT
TODAY IS QUICKLY REPLACED WITH THE DEEP MOISTURE ASSOCIATED WITH
THE UPR LOW. VERTICALLY STACKED LOW IS POSITIONED NEAR BUF BY 00Z
SUN. THIS WILL KEEP INSTABILITY AND MOISTURE OVER THE AREA...ALONG
WITH A GRADUAL COOLING AS THE COLD CORE APRCHS. DOES NOT APPEAR TO
BE ENUF INSTABILITY FOR TRWS ATTM...ALTHOUGH AN ISLTD WEAK STORM
CANNOT BE RULED OUT SAT AFTN...ESP WITH ANY HTG.
BY SUN...PROGRESSIVE LOW IS NORTH OF THE ST LAWRENCE VLY AND
SOMEWHAT DRIER AIR IS MVG BACK IN FROM THE OH VLY. ENUF LEFTIOVER
MOISTURE MAY ALLOW FOR A FEW SCT SHWRS OVER THE NRN ZONES...ESP
OVER THE HIER TERRAIN. ANY PCPN WILL BE LGT.
&&
.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
2 PM UPDATE...
MODELS IN GOOD AGREEMENT. ABOVE NORMAL TEMPERATURES THROUGHOUT
WITH TWO PERIODS OF SHOWERS...ONE EARLY AND ONE LATE. THE FIRST
WILL BE WITH A WARM FRONT MONDAY NIGHT AND TUESDAY. MOST OF THIS
RAINFALL WILL BE IN UPSTATE NY WITH LESSER AMOUNTS IN PA. THIS
FRONT WILL HAVE LITTLE FORCING WITH THE ASSOCIATED LOW IN THE
PLAINS. AS THE UPPER LEVEL TROF ON THE WEST COAST MOVES EAST A
RIDGE OF HIGH PRESSURE WILL MOVE INTO OUR REGION FOR WHAT SHOULD
BE A DRY PERIOD WED TO THU. A COLD OR OCCLUDED FRONT WILL MOVE
THROUGH FRIDAY WITH SHOWERS. THIS WILL BE AHEAD OF THE UPPER LEVEL
TROF.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
130 AM UPDATE...
SHOWERS HAVE BECOME ISOLATED WITH A BACK EDGE OF RME BGM AND
TOWANDA PA. THESE WILL KEEP MOVING EAST TO END AT RME BGM AVP
AROUND 21Z. IFR CIGS ONLY LEFT AT KBGM WITH MVFR AT REST. SYR AND
RME HAVE BEEN BOUNCING BETWEEN MVFR AND VFR. REST OF SITES WILL
HAVE CIGS RISE TO VFR BETWEEN 22Z TO 03Z AT KBGM.
LATE TONIGHT WILL BE TRICKY AND CONFIDENCE IS LOW. SOME GUIDANCE
SUGGESTS THAT THE CLEAR SKIES IN WRN NY AND WRN PA WILL MAKE IT
HERE. THIS CLEARING WILL ALLOW THE TEMPERATURES TO FALL AND MAYBE
FORM FOG. TRICKY PART IS BACK EDGE OF CURRENT CLOUDS IS SLOWING
WHILE NEXT BATCH OF CLOUDS WITH UPPER LEVEL CLOSED LOW CONTINUES
TO ADVANCE EAST. IN ADDITION DEWPOINT TEMPERATURES WILL CONTINUE
TO FALL. VFR CIGS SATURDAY.
WINDS LIGHT AND VARIABLE THROUGH TONIGHT. SW WINDS AT AROUND 8 KTS
STARTING 14Z SAT.
OUTLOOK...
SAT AFTN AND NGT...MVFR RESTRICTIONS EXPECTED IN OCNL -SHRA.
SUN TO TUE...MAINLY VFR.
TUE NGT AND WED...MVFR IN SHOWERS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DGM/RRM
NEAR TERM...DGM/RRM
SHORT TERM...DGM
LONG TERM...TAC
AVIATION...TAC
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1217 PM EDT FRI OCT 19 2012
.SYNOPSIS...
A FRONT WILL SLOWLY PASS THROUGH THE AREA TODAY WITH WIDESPREAD
SHOWERS EXPECTED IN CENTRAL NEW YORK, EAST OF I81 AND OVER
NORTHEAST PENNSYLVANIA. ISOLATED THUNDERSTORMS WILL ALSO OCCUR IN
THE ABOVE MENTIONED AREA. LOW PRESSURE MOVING SLOWLY EASTWARD
THROUGH THE GREAT LAKES WILL KEEP UNSETTLED WEATHER IN OUR AREA
FOR MUCH OF THE WEEKEND. SHOWERS FROM THE LOW WILL BE SCATTERED
OVER THE REGION INTO SUNDAY...ALONG WITH GRADUALLY COOLER AIR.
&&
.NEAR TERM /THROUGH TONIGHT/...
12 PM UPDATE...SFC WAVE ALONG BOUNDARY CURRENTLY OVER THE WYOMING
VALLEY WITH ACTIVITY NOW CONTINUING TO LIFT NORTHEAST AS EXPECTED.
FOR THIS AFTERNOON MOST WIDESPREAD SHOWERS WILL BE CONFINED TO THE
WESTERN CATSKILLS AND POCONOS. LOWERED MAX TEMPS SLIGHTLY BASED ON
CURRENT OBS, NO OTHER CHANGES.
945 AM UPDATE...LOCAL RADARS SHOW SHOWERS ACROSS CENTRAL NY
MAINLY EAST OF I81 AND NORTHEAST PA. OCCLUDED FRONT STRETCHED FROM
THE SYR AREA SOUTH ACROSS BGM INTO THE WYOMING VALLEY. SFC WAVE
ALONG BOUNDARY OVER SE PA WILL ACT TO SLOW THE PROGRESS OF THIS
FRONT THROUGH EARLY AFTERNOON ALONG WITH KEEPING ACTIVITY IN SAME
LOCATION UNTIL EASTWARD PROGRESS COMMENCES AGAIN. WEAK INSTABILITY
ALONG WITH FRONTAL LIFT WILL KEEP THE THREAT FOR THUNDERSTORMS
ALONG AND EAST OF BOUNDARY THROUGH THIS AFTERNOON. HIGH PWATS
INDICATE ANY STRONGER RETURNS ON RADAR WILL BE ASSOCIATED WITH
HEAVY DOWNPOURS AND THIS IS CONFIRMED BY OBSERVATIONS.
PREVIOUS DISC...
FNT DEAD CNTR OVER THE FCST AREA ATTM WITH A BRIEF AREA OF RW+
AND AN ISLTD LGTNG STRIKES OVER NE PA. LATEST HRRR AND NAM RUNS
ARE QUITE PROGRESSIVE WITH THE FNT PUSHING IT AND THE HEAVIEST
RAIN EAST OF THE FCST AREA BY 12Z...DESPITE THE DVLPG SFC LOW OVER
THE MID ATLANTIC STATES. DEEP MOISTURE AHD OF THE FNT WITH A GULF
CONNECTION AND PWATS NEAR 180% OF NRML FOR THIS TIME OF YEAR.
AREAS AHD OF THE FNT WILL CONT TO SEE HEAVY RAIN WITH THE GOOD
FRCG OF THE FNT.
HRRR AND NAM SHOWS SOME PCPN BEING TOSSED BACK BHD THE FNT LTR
THIS MRNG AS THE LOW MVES NEWRD...SO WILL KEEP HIER POPS OVER THE
ERN ZONES THRU MUCH OF THE DAY DESPITE THE ERWRD MVMT OF THE
BNDRY.
SINCE THE LATEST MODEL FCSTS KEEP THE FNT PROGRESSIVE THRU THE
FCST AREA...HEAVY RAINS SHD NOT BE A PRBLM...WITH STORM TTLS WELL
BLO FFG AND HEADWATERS GUID. WILL KEEP A LOW CHANCE OF THUNDER IN
THE EAST AND SOUTH WITH THE INSTABILITY ALOFT WITH THE FNT...AND
THE ADDED LIFT OF THE APRCHG WV.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
LOW PLODS SLOWLY EAST AS IT GRADUALLY FILLS. DRY SLOT BHD THE FNT
TODAY IS QUICKLY REPLACED WITH THE DEEP MOISTURE ASSOCIATED WITH
THE UPR LOW. VERTICALLY STACKED LOW IS POSITIONED NEAR BUF BY 00Z
SUN. THIS WILL KEEP INSTABILITY AND MOISTURE OVER THE AREA...ALONG
WITH A GRADUAL COOLING AS THE COLD CORE APRCHS. DOES NOT APPEAR TO
BE ENUF INSTABILITY FOR TRWS ATTM...ALTHOUGH AN ISLTD WEAK STORM
CANNOT BE RULED OUT SAT AFTN...ESP WITH ANY HTG.
BY SUN...PROGRESSIVE LOW IS NORTH OF THE ST LAWRENCE VLY AND
SOMEWHAT DRIER AIR IS MVG BACK IN FROM THE OH VLY. ENUF LEFTIOVER
MOISTURE MAY ALLOW FOR A FEW SCT SHWRS OVER THE NRN ZONES...ESP
OVER THE HIER TERRAIN. ANY PCPN WILL BE LGT.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
DURING THE EXTENDED PERIOD MEDIUM RANGE MODELS ARE IN AGREEMENT
THAT THE UPPER LEVEL TROF OVER THE NORTHEAST WILL BE REPLACED BY
RISING HEIGHTS AND DEVELOPMENT OF AN UPPER LEVEL RIDGE. AT THE
SURFACE THINGS ARE A BIT MORE TRICKY WITH LOW PRES MOVING THROUGH
THE UPPER GREAT LAKES WITH POSSIBLE FROPA TUESDAY NIGHT. GENERALLY
FOLLOWED HPC GUIDANCE.
SUNDAY EVENING WILL INCLUDE SLIGHT CHC POPS FAR NRN CWA ON BACK
SIDE OF UPPER LEVEL TROF THEN DRY. DRY WEATHER IS EXPECTED
MONDAY THROUGH MUCH OF MONDAY NIGHT THEN CHC/SLIGHT CHC POPS
TUESDAY THROUGH WEDNESDAY DUE TO PASSING COLD FRONT AND NORTHWEST
FLOW BEHIND BOUNDARY. DRY WEATHER WILL RETURN WED NIGHT/THURSDAY
AS SFC HIGH BUILDS DOWN FROM CANADA. TEMPS WILL BE 5-10 DEGREES
ABOVE NORMAL.
&&
.AVIATION /16Z FRIDAY THROUGH TUESDAY/...
730 AM UPDATE...
THE FIRST MAIN AREA OF RAIN SHOWERS IS EXITING THE REGION TO THE
EAST OF THE TERMINALS. KAVP HAS A THUNDERSTORM NOW THAT MAY LAST
AN HOUR BEFORE A BREAK. SCATTERED SHOWER ACTIVITY IN THE FINGER
LAKES AND CENTRAL SOUTHERN TIER OF NY WILL EXPAND AND FILL IN AS
IT MOVES SLOWLY NORTHEAST. SHOWERS WILL CONTINUE TODAY,
ESPECIALLY PRIOR TO NOON.
SKY COVER IS ERRATIC IN THE INTERIM. BEFORE THE SHOWERS COME IN
BGMA ND SYR BOUNCING BETWEEN IFR AND VFR. WITH THE SHOWERS CIGS
BETWEEN MVFR AND VFR. CIGS AS LOW AS 1500 FT.
MODELS SUGGEST A TEMPORARY DRYING OF THE ATMOSPHERE BETWEEN 20Z
AND 00Z, SO THE CURRENT TERMINAL FORECASTS SCATTER OUT THE MVFR
CLOUD COVER PRIOR TO SUNSET.
OUTLOOK...
SAT...MVFR RESTRICTIONS EXPECTED IN OCNL -SHRA.
SUN AND MON...MAINLY VFR.
TUE...BECOMING MVFR WITH SHOWERS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DGM/RRM
NEAR TERM...DGM/RRM
SHORT TERM...DGM
LONG TERM...RRM
AVIATION...DJP/TAC
AREA FORECAST DISCUSSION
NWS RALEIGH NC
230 PM EDT FRI OCT 19 2012
.SYNOPSIS...
A COLD FRONT OVER THE COASTAL PLAIN WILL PUSH OFFSHORE TONIGHT. HIGH
PRESSURE WILL THEN BUILD SLOWLY INTO THE CAROLINAS AND SOUTHERN
VIRGINIA BEHIND THE FRONT AND LINGER OVER THE REGION THROUGH EARLY
NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY NIGHT/...
AS OF 220 PM FRIDAY...
THE COLD FRONT EXTENDING SOUTH FROM THE OCCLUDED LOW OVER THE GREAT
LAKES HAS BEEN MOVING VERY SLOWLY ACROSS THE CWA TODAY...STRUGGLING
TO GET PAST US HWY 1 THROUGH NOON. HOWEVER...DEWPOINTS ARE FINALLY
BEGINNING TO MIX OUT MORE EFFICIENTLY BEHIND THE FRONT...AND THE
SHARP DEWPOINT/INSTABILITY GRADIENT IS SHIFTING EAST INTO THE
COASTAL PLAIN. DRIER AIR ALOFT NOTED IN WATER VAPOR IMAGERY IS
LIMITING CUMULUS DEVELOPMENT TO A NARROW STRIP ALONG A REGION
CONFLUENCE FROM LEXINGTON TO ROXBORO. HRRR RUNS HAVE BEEN SHOWING A
FEW ISOLATED SHOWERS OVER THE NORTHERN PIEDMONT AFTER 20Z...BUT THIS
SEEMS OVERDONE GIVEN THE AMOUNT OF DRY AIR ALOFT.
OTHERWISE...SOUTHWESTERLY WIND GUSTS ARE STARTING TO
DEVELOP...MOSTLY IN THE TEENS THUS FAR...BUT A FEW MAY REACH 20-25KT
BEFORE SUNSET.
TONIGHT...
A SHORTWAVE IN THE BASE OF THE UPPER TROUGH WILL SWING ACROSS
GA/SC...WITH CONTINUED DRY CONDITIONS AND MOSTLY CLEAR SKIES ACROSS
CENTRAL NC. A LIGHT WESTERLY WIND MAY LIMIT FULL RADIATIONAL
COOLING...MID TO UPPER 40S WEST TO EAST.
SATURDAY AND SATURDAY NIGHT...
BROAD CYCLONIC UPPER LEVEL FLOW WILL CONTINUE OVER THE AREA AS THE
GREAT LAKES UPPER LOW BEGINS TO OPEN UP AND LIFT NORTHEAST. A
SPEED MAX DIVING THROUGH THE BACK SIDE OF THE UPPER TROUGH WILL
SHARPEN THE TROUGH AXIS AS IT CROSSES THE AREA SATURDAY EVENING.
THE ADDED DPVA MAY BE ENOUGH TO HELP ENHANCE SOME LATE AFTERNOON
CLOUD COVER AS RH CROSS SECTIONS SHOW A LAYER OF MOISTURE AT THE TOP
OF THE BOUNDARY LAYER (5-8KT FT). WITH WEAK THERMAL ADVECTION/FLOW
AHEAD OF THE TROUGH AXIS...WILL USE 1000-850MB THICKNESSES FOR
HIGHS...YIELDING UPPER 60S TO LOWER 70S.
ONCE THE TROUGH AXIS MOVES EAST...NORTHWESTERLY FLOW WILL DEVELOP
ALOFT SATURDAY NIGHT. THIS TYPE OF PATTERN SUGGESTS THE POTENTIAL
FOR OROGRAPHIC CIRRUS...ALTHOUGH THE NAM/GFS SHOW THE BEST UPPER
LEVEL MOISTURE DIVING JUST SOUTH OF THE APPALACHIANS. WITHOUT
CIRRUS...THE ARRIVAL OF BETTER LOW LEVEL COLD ADVECTION BEHIND THE
TROUGH AXIS SHOULD LEAD TO LOWS IN THE LOW TO MID 40S.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 230 PM FRIDAY...
CLOSED UPPER LOW AND ASSOCIATED UPPER TROUGH OVER THE EASTERN US
WILL LIFT NORTHEASTWARD INTO SOUTHEASTERN CANADA DURING THE DAY ON
SUNDAY...WITH STRONG SYNOPTIC SCALE SUBSIDENCE SETTLING OVER THE
REGION IN IT WAKE AS THE UPSTREAM RIDGE OVER THE CENTRAL US
SHIFTS EASTWARD INTO THE AREA. THIS WILL RESULT IN CONTINUED DRY
CONDITIONS WITH A RAPID WARM-UP/MODERATION FROM BELOW NORMAL
DAYTIME TEMPERATURES IN THE MID TO UPPER 60S ON SUNDAY TO
ABOVE NORMAL READINGS IN THE LOWER TO MID 70S BY MONDAY. STRONG
RADIATIONAL COOLING AND A DRY AIRMASS IN PLACE WILL STILL ALLOW FOR
CHILLY MORNING LOWS BOTH MORNINGS. LOWS IN THE LOWER TO MID 40S.
&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 230 PM FRIDAY...
BROAD SUBTROPICAL RIDGING WILL ENVELOP THE SOUTHEASTERN/EASTERN US
THROUGH THE UPCOMING WORK WEEK...DOWNSTREAM OF THE WESTERN/CENTRAL US
TROUGH. WHILE THERE ARE SOME GROSS DIFFERENCES WITH HOW NWP MODELS
HANDLE THE EVOLUTION OF THE WESTERN US TROUGH AND ASSOCIATED REX
BLOCK...CENTRAL NC LOOKS TO BE WELL UNDER THE INFLUENCE OF THE
SUBTROPICAL RIDGE TO CLOSE THE WORK WEEK...KEEPING SHORTWAVE
DISTURBANCES AT ARMS LENGTH...TRACKING NORTHEAST THROUGH THE
PLAINS...THROUGH THE THE GREAT LAKES AND THEN INTO SOUTHEASTERN
CANADA.
THIS WILL RESULT IN WARM AND QUITE WEATHER CONDITIONS("INDIAN
SUMMER")THROUGH THE WEEK. DAYTIME HIGHS WELL IN THE MID TO UPPER 70S.
LOWS IN THE UPPER 40S TO LOWER 50S.
&&
.AVIATION /18Z FRIDAY THROUGH TUESDAY/...
AS OF 125 PM FRIDAY...
WHILE THE SURFACE COLD FRONT...CURRENTLY LOCATED BETWEEN KRDU AND
KRWI...IS ONLY SLOWLY MOVING TO THE EAST...MUCH DRIER AIR ALOFT HAS
BROUGHT PRECIP TO AN END. VFR CONDITIONS HAVE DEVELOPED ACROSS ALL
OF CENTRAL NC AND ARE EXPECTED TO PREVAIL THROUGH THE TAF PERIOD.
THE ONLY AVIATION CONCERN WILL BE THE POTENTIAL FOR 20-25KT
SOUTHWESTERLY WIND GUSTS THIS AFTERNOON. THESE GUSTS WILL BE MOST
PREVALENT OVER THE WESTERN PIEDMONT (KINT/KGSO).
HIGH PRESSURE WILL BUILD INTO THE AREA THROUGH THE WEEKEND. OTHER
THAN PERIODIC HIGH CLOUDS AND SCATTERED CU ON SATURDAY
AFTERNOON...SKIES WILL BE PREDOMINATELY CLEAR WITH LIGHT WESTERLY
WINDS SATURDAY BECOMING MORE VARIABLE SUNDAY INTO EARLY NEXT WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BLS
NEAR TERM...BLS
SHORT TERM...CBL
LONG TERM...CBL
AVIATION...BLS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
220 PM EDT FRI OCT 19 2012
.SYNOPSIS...
A COLD FRONT OVER THE COASTAL PLAIN WILL PUSH OFFSHORE TONIGHT. HIGH
PRESSURE WILL THEN BUILD SLOWLY INTO THE CAROLINAS AND SOUTHERN
VIRGINIA BEHIND THE FRONT AND LINGER OVER THE REGION THROUGH EARLY
NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY NIGHT/...
AS OF 220 PM FRIDAY...
THE COLD FRONT EXTENDING SOUTH FROM THE OCCLUDED LOW OVER THE GREAT
LAKES HAS BEEN MOVING VERY SLOWLY ACROSS THE CWA TODAY...STRUGGLING
TO GET PAST US HWY 1 THROUGH NOON. HOWEVER...DEWPOINTS ARE FINALLY
BEGINNING TO MIX OUT MORE EFFICIENTLY BEHIND THE FRONT...AND THE
SHARP DEWPOINT/INSTABILITY GRADIENT IS SHIFTING EAST INTO THE
COASTAL PLAIN. DRIER AIR ALOFT NOTED IN WATER VAPOR IMAGERY IS
LIMITING CUMULUS DEVELOPMENT TO A NARROW STRIP ALONG A REGION
CONFLUENCE FROM LEXINGTON TO ROXBORO. HRRR RUNS HAVE BEEN SHOWING A
FEW ISOLATED SHOWERS OVER THE NORTHERN PIEDMONT AFTER 20Z...BUT THIS
SEEMS OVERDONE GIVEN THE AMOUNT OF DRY AIR ALOFT.
OTHERWISE...SOUTHWESTERLY WIND GUSTS ARE STARTING TO
DEVELOP...MOSTLY IN THE TEENS THUS FAR...BUT A FEW MAY REACH 20-25KT
BEFORE SUNSET.
TONIGHT...
A SHORTWAVE IN THE BASE OF THE UPPER TROUGH WILL SWING ACROSS
GA/SC...WITH CONTINUED DRY CONDITIONS AND MOSTLY CLEAR SKIES ACROSS
CENTRAL NC. A LIGHT WESTERLY WIND MAY LIMIT FULL RADIATIONAL
COOLING...MID TO UPPER 40S WEST TO EAST.
SATURDAY AND SATURDAY NIGHT...
BROAD CYCLONIC UPPER LEVEL FLOW WILL CONTINUE OVER THE AREA AS THE
GREAT LAKES UPPER LOW BEGINS TO OPEN UP AND LIFT NORTHEAST. A
SPEED MAX DIVING THROUGH THE BACK SIDE OF THE UPPER TROUGH WILL
SHARPEN THE TROUGH AXIS AS IT CROSSES THE AREA SATURDAY EVENING.
THE ADDED DPVA MAY BE ENOUGH TO HELP ENHANCE SOME LATE AFTERNOON
CLOUD COVER AS RH CROSS SECTIONS SHOW A LAYER OF MOISTURE AT THE TOP
OF THE BOUNDARY LAYER (5-8KT FT). WITH WEAK THERMAL ADVECTION/FLOW
AHEAD OF THE TROUGH AXIS...WILL USE 1000-850MB THICKNESSES FOR
HIGHS...YIELDING UPPER 60S TO LOWER 70S.
ONCE THE TROUGH AXIS MOVES EAST...NORTHWESTERLY FLOW WILL DEVELOP
ALOFT SATURDAY NIGHT. THIS TYPE OF PATTERN SUGGESTS THE POTENTIAL
FOR OROGRAPHIC CIRRUS...ALTHOUGH THE NAM/GFS SHOW THE BEST UPPER
LEVEL MOISTURE DIVING JUST SOUTH OF THE APPALACHIANS. WITHOUT
CIRRUS...THE ARRIVAL OF BETTER LOW LEVEL COLD ADVECTION BEHIND THE
TROUGH AXIS SHOULD LEAD TO LOWS IN THE LOW TO MID 40S.
&&
.SHORT TERM / /...
AS OF 318 AM FRIDAY...
TO BE UPDATE SHORTLY...
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 220 AM FRIDAY...
SURFACE HIGH PRESSURE WILL SETTLE OVER THE REGION THROUGH EARLY TO
MID NEXT WEEK WHILE MID/UPPER LEVEL RIDGING IS EXPECTED TO BUILD
OVER THE AREA AS THE CURRENT DEEP EAST COAST TROUGH LIFTS OFF TO THE
NORTH-NORTHEAST. THIS WILL KEEP THE MAIN STORM TRACK TO THE NORTH OF
OUR REGION... ALLOWING FOR DRY CONDITIONS AND MODERATING
TEMPERATURES. THIS WILL YIELD HIGHS GENERALLY IN THE 70S... WITH
TEMPS IN THE MID TO UPPER 70S TO EVEN AROUND 80 DEGREE BY MIDWEEK.
HOWEVER... OVERNIGHT LOWS ARE STILL EXPECTED TO PLUMMET INTO THE 40S
TO AROUND 50 EACH NIGHT THANKS TO GOOD RADIATIONAL COOLING
CONDITIONS AND LOW DEWPOINTS (AS LOW LEVEL MOISTURE WILL BE SLOW TO
RETURN TO THE AREA).
&&
.AVIATION /18Z FRIDAY THROUGH TUESDAY/...
AS OF 125 PM FRIDAY...
WHILE THE SURFACE COLD FRONT...CURRENTLY LOCATED BETWEEN KRDU AND
KRWI...IS ONLY SLOWLY MOVING TO THE EAST...MUCH DRIER AIR ALOFT HAS
BROUGHT PRECIP TO AN END. VFR CONDITIONS HAVE DEVELOPED ACROSS ALL
OF CENTRAL NC AND ARE EXPECTED TO PREVAIL THROUGH THE TAF PERIOD.
THE ONLY AVIATION CONCERN WILL BE THE POTENTIAL FOR 20-25KT
SOUTHWESTERLY WIND GUSTS THIS AFTERNOON. THESE GUSTS WILL BE MOST
PREVALENT OVER THE WESTERN PIEDMONT (KINT/KGSO).
HIGH PRESSURE WILL BUILD INTO THE AREA THROUGH THE WEEKEND. OTHER
THAN PERIODIC HIGH CLOUDS AND SCATTERED CU ON SATURDAY
AFTERNOON...SKIES WILL BE PREDOMINATELY CLEAR WITH LIGHT WESTERLY
WINDS SATURDAY BECOMING MORE VARIABLE SUNDAY INTO EARLY NEXT WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BLS
NEAR TERM...BLS
SHORT TERM...WSS
LONG TERM...BSD
AVIATION...BLS
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
103 PM EDT FRI OCT 19 2012
.SYNOPSIS...
UPPER LEVEL LOW PRESSURE NEAR CHICAGO WILL SLOWLY MOVE EAST ACROSS
THE AREA THROUGH SATURDAY NIGHT. HIGH PRESSURE WILL THEN BUILD
NORTHEAST INTO THE REGION SUNDAY THEN SETTLE NEAR THE CAROLINA COAST
FOR MONDAY AND TUESDAY. A COLD FRONT WILL DROP SOUTHEAST AND STALL
OVER THE AREA FOR TUESDAY NIGHT AND WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
FEW CHANGES FOR 930 UPDATE. SLOWED DOWN TIMING OF RAIN SLIGHTLY AS
RAINFALL THAT IS REACHING THE GROUND ONLY A HUNDREDTH OR TWO PER
HOUR. WILL TAKE A LITTLE TIME TO SATURATE THE ATTM. SINCE SLOWED
PRECIP ALSO BUMPED UP TEMPS A DEGREE OR TWO.
DOING 630 AM UPDATE EARLY. HAVE ADDED EARLY MORNING MENTION OF
PATCHY FOG FOR THE YNG TO GKJ AREA. ALSO HAVE ADDED CHC OF SPRINKLES
TO CENTRAL PART OF AREA WHERE BAND OF CLOUDS CURRENTLY PRESENT AND
THEN PROG THIS EAST DURING THE REST OF THE MORNING. HRRR HAS BEEN
HINTING AT SPRINKLES FOR THIS AREA AND LATEST RADAR PIX STARTING TO
SHOW SOME INCREASE IN RETURNS.
THE MODELS ARE IN FAIRLY GOOD AGREEMENT IN MOVING THE UPPER LOW NEAR
CHICAGO SLOWLY EAST TODAY. RAIN AND SHRA POOLED UNDER THE UPPER LOW
WILL GET AN EASTWARD PUSH TODAY AS SHORTWAVE ENERGY AND A SURFACE
TROUGH ROTATE AROUND THE UPPER LOW. THE WESTERN PART OF THE CWA
LOOKS CATEGORICAL FOR MEASURABLE PRECIP WITH THE CENTRAL PART LIKELY
AND MAYBE JUST A CHANCE FOR THE EAST AS THE BETTER ENERGY DOES NOT
GET THERE UNTIL TONIGHT. PRECIP AMOUNTS WILL GENERALLY BE LIGHT WITH
MOST PLACES SEEING AROUND A TENTH OF AN INCH OR LESS WEST AND A FEW
HUNDREDTHS OR LESS EAST.
THE WARMER TEMPS SHOULD BE IN THE EAST WHERE CLOUDS WILL TAKE LONGER
TO FILL IN TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
PER THE PREVIOUS DISCUSSION...THE UPPER AND SURFACE FORCING WILL
WORK EAST ACROSS THE CWA TONIGHT AND SATURDAY WITH A FAIRLY
WIDESPREAD COOL RAIN. EVEN THOUGH THE COLDEST PART OF THE AIRMASS
WILL BE OVER THE AREA BY DAYBREAK SAT...THE EXTENSIVE CLOUD COVER
SHOULD KEEP TEMPS IN A 40 TO 45 DEGREE RANGE. HOWEVER...ON SAT THESE
SAME CLOUDS WILL HOLD HIGH TEMPS TO ONLY 50 TO 55 FOR MOST PLACES.
AS THE TROUGH MOVES EAST OF THE AREA SAT NIGHT...DRIER AIR WILL
START TO SPREAD IN FROM THE WEST. THE RAIN THREAT WILL SHIFT INTO
JUST THE SNOWBELT BY LATE SAT NIGHT THEN TAPER OFF IN THE SNOWBELT
SUNDAY AS THE PUSH OF DRIER AIR CONTINUES AND LAKE EFFECT CONDITIONS
LESSEN.
HIGH PRESSURE RIDGED NORTH INTO THE AREA SHOULD PROVIDE DRY WEATHER
FOR SUN NIGHT AND MON. TEMPS WILL MODERATE WITH THE ADDED SUNSHINE
AND WARM ADVECTION. MONDAY NIGHT IS MORE QUESTIONABLE AS THE MODELS
INDICATE A BACKDOOR COLD FRONT SAGGING INTO OR NEAR THE AREA. CHANCE
POPS...MAINLY NEAR LAKE ERIE STILL SEEMS REASONABLE.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
ONLY MINOR CHANGES TO THE LONG TERM THIS MORNING. A NEARLY
STATIONARY BOUNDARY WILL BE JUST NORTH OF THE AREA TUESDAY AND
WEDNESDAY. THIS WILL KEEP PLENTY OF CLOUDS AND A THREAT FOR SHOWERS
GOING EACH PERIOD FROM TUESDAY THROUGH WEDNESDAY NIGHT. THE
BOUNDARY IS FORECAST TO MOVE SLIGHTLY NORTH ON THURSDAY SO WILL PULL
THE MENTION OF PRECIP OUT OF THE FORECAST. A COLD FRONT WILL BEGIN
TO APPROACH FROM THE WEST AT THE VERY END OF THE PERIOD. THE AREA
WILL REMAIN IN THE WARM SECTOR THE ENTIRE PERIOD SO EXPECT HIGHS TO
BE MAINLY IN THE LOWER 70S ALL THREE DAYS.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
UPPER LEVEL LOW PRESSURE WILL REMAIN OVER THE CENTRAL GREAT LAKES
THROUGH SATURDAY. A PIECE OF JET ENERGY ROTATING AROUND THE LOW
WILL GENERATE AN AREA OF SHOWERS THAT WILL SPREAD ACROSS THE
REGION FROM SOUTHWEST TO NORTHEAST LATE THIS AFTERNOON INTO THE
EVENING. BELIEVE THE LIGHT RAIN WILL REACH NW OHIO AROUND
21Z...CENTRAL AREAS NEAR KCLE AROUND 23Z AND KERI AROUND 03Z.
CEILINGS WILL BEGIN TO LOWER WITH THE LIGHT RAIN AND MAY FALL TO
MVFR LEVELS NEAR OR AFTER MIDNIGHT. HOWEVER A FEW LOCATIONS MAY
DIP TO MVFR CONDITIONS WITH THE HEAVIER SHOWERS EARLIER IN THE
EVENING. THE MVFR CEILINGS SHOULD PERSIST INTO SATURDAY AFTERNOON.
AS WINDS SHIFT AROUND TO THE SOUTHWEST AND WEST ON SATURDAY THERE
SHOULD BE A FEW GUSTS. THESE GUSTS SHOULD REMAIN AROUND 20 KNOTS.
.OUTLOOK...NON VFR CONTINUING NE OHIO AND NW PA INTO SATURDAY
NIGHT. NON VFR POSSIBLE TUESDAY INTO TUESDAY NIGHT IN SHOWERS.
&&
.MARINE...
LOW PRESSURE REMAINS OVER EASTERN IA THIS MORNING. THIS LOW IS
FORECAST TO GRADUALLY WEAKEN AND TO PASS TO THE NORTH OF THE LAKE
TONIGHT. S FLOW WILL BECOME SW TODAY AND TONIGHT. SPEEDS WILL
INCREASE LATE TONIGHT AND SATURDAY MORNING AND MAY NEED A SMALL
CRAFT FOR THE EASTERN TWO THIRDS OF THE LAKE. A TROUGH FROM THE LOW
WILL CROSS THE LAKE ON SATURDAY AND THIS WILL CAUSE THE FLOW TO
BECOME WEST. HIGH PRESSURE WILL TRY TO BUILD IN FROM THE SOUTH ON
SUNDAY WITH THE RIDGE AXIS JUST EAST OF THE LAKE ON MONDAY WHICH WILL
CAUSE THE FLOW TO AGAIN BECOME S TO SW. A WARM FRONT IS EXPECTED TO
DEVELOP TO THE NORTH OF THE LAKE ON MONDAY NIGHT AND SOME WARM AIR
ADVECTION SHOWERS COULD OCCUR BY EARLY TUESDAY. THE LAKE WILL
REMAIN IN THE WARM SECTOR FOR THE REMAINDER OF THE PERIOD. AS A
RESULT SW FLOW AT UNDER 15 KNOTS WILL CONTINUE.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...ADAMS
NEAR TERM...ADAMS/DJB
SHORT TERM...ADAMS
LONG TERM...KUBINA
AVIATION...MULLEN
MARINE...KUBINA
AREA FORECAST DISCUSSION...UPDATED
NWS NASHVILLE TN
601 PM CDT FRI OCT 19 2012
.UPDATE...
CURRENT SFC OBS AND CONSENSUS SHORT RANGE MODEL GUIDANCE...INCLUDING THE
LATEST HIGH RESOLUTION RAPID REFRESH...SHOWING CLDY SKIES ACROSS THE MID
STATE CONTINUING THRU AT LEAST THE MID EVENING HRS...WITH SOME DECREASE
IN CLOUDINESS POSSIBLE LATE EVENING AND OVERNIGHT. HRRR MOST AGGRESSIVE IN
ERODING CLOUD COVERAGE AS COMPARED TO SREF AND RUC 13KM. ACCORDINGLY...
HAVE UPDATED THE SUITE OF FORECAST PRODUCTS TO REFLECT CLDY SKIES THRU
THE EVENING HRS...WITH PTCLDY SKIES OVERNIGHT. ALSO MADE SOME MINOR CHANGES
TO CLOUD COVERAGE ON SAT FOR A TRANSITION TO PTSUNNY SKIES ACROSS THE ENTIRE
MID STATE DURING THIS TIME PERIOD.
&&
.PREV DISCUSSION.../ISSUED 149 PM CDT FRI OCT 19 2012/
SHORT TERM...LOW LEVEL WRAP-AROUND CLOUDS CONTINUED TO SINK
SOUTHWARD ACROSS THE MID STATE EARLY THIS AFTERNOON. TEMPERATURES
ACROSS THE EXTREME NORTH, WHERE SKIES HAVE BEEN OVC MUCH OF THE
DAY, STALLED OUT IN THE UPPER 50S TO AROUND 60, WHILE SUNNY
SOUTHERN AREAS SAW TEMPS PUSH TO AROUND 70 BY 1 PM. THE LIGHT
RAIN AND SPRINKLES HAVE, SO FAR, REMAINED MOSTLY NORTH OF THE
BORDER (UP ACROSS KY).
BELIEVE LOW LEVEL MOISTURE WILL CONTINUE TO ROTATE AROUND BASE OF
GREAT LAKES AND OHIO VALLEY TROUGH THROUGH SATURDAY, PROVIDING
VARIABLE CLOUDINESS ACROSS OUR NORTHERN COUNTIES. THIS WILL
PRODUCE A TEMP GRADIENT MUCH LIKE TODAY`S, WITH HIGHS TOMORROW
RANGING FROM THE UPPER 50S AND LOWER 60S NORTH AND PLATEAU, TO
AROUND 70 OVER THE SOUTH.
CLOUDS FINALLY DISSIPATE BY SATURDAY NIGHT AND AN UPPER LEVEL
RIDGE BUILDS IN ACROSS THE TENNESSEE VALLEY FOR SUNDAY AND MONDAY.
A WEAKENING SHORTWAVE IS FORECAST TO MOVE OUT OF THE MID-
MISSISSIPPI VALLEY ACROSS THE OHIO RIVER VALLEY ON TUESDAY.
HOWEVER, MAINLY JUST HIGH CLOUDS ARE EXPECTED TO SWEEP ACROSS THE
MID STATE AND KEEP OUR DRY WEATHER IN PLACE.
RIDGE BUILDS BACK IN AFTER WEAK SHORTWAVE PASSES TO OUR NORTHWEST
ON TUESDAY AND, ASIDE FROM SOME HIGH CLOUDS STREAMING IN ON
SOUTHWEST FLOW, DRY WEATHER PERSISTS AT LEAST INTO THE MIDDLE OF
NEXT WEEK.
LONG TERM...LATEST GFS SWEEPS A COLD FRONT ACROSS OUR AREA LATE
NEXT WEEK, ALONG WITH A CHANCE FOR SHOWERS AND THUNDERSTORMS.
HOWEVER, PREVIOUS ECMWF KEPT TENNESSEE VALLEY MORE UNDER THE
INFLUENCE OF HIGH PRESSURE AND DRY WEATHER INTO LATE NEXT WEEK.
UNLESS NEW ECMWF COMES IN WITH A MORE SOLID TREND TOWARD THE GFS,
WILL PROBABLY KEEP A DRY FORECAST RUNNING THROUGH THE EXTENDED PERIOD.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
31