Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 11/01/13
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
842 PM MDT THU OCT 31 2013
.UPDATE...HAVE SEEN WIND GUSTS IN AND NEAR THE FOOTHILLS OF
BOULDER AND JEFFERSON COUNTY IN THE 60-70 MPH RANGE DURING THE
PAST HOUR. EVENING MODEL RUNS OF THE RAP AND NAM SHOW THAT WINDS
MAY NOT PEAK UNTIL THE 06Z-08Z TIME FRAME...SO WILL ISSUE A HIGH
WIND WARNING FOR ZONES 35..36 AND 39. THE MAIN CORE OF THE UPPER
JET IS APPROACHING THE STATE FROM WYOMING AND WILL MOVE OUT OVER
THE NORTHEAST COLORADO PLAINS AFTER 12Z TOMORROW. IN THE MEANTIME
THERE WILL BE LOW VERTICAL SHEAR IN THE WIND PROFILE. THE ONSET OF
THE JET WILL ALSO BE SUBSIDENT...MAINTAINING AND POSSIBLY
STRENGTHENING THE AMPLIFIED MOUNTAIN WAVE THAT IS IN PLACE. WIND
GUSTS OF 70-80 MPH WILL BE POSSIBLE THROUGH 2 AM MDT.
RADAR CONTINUES TO INDICATE SNOW SHOWER ACTIVITY WEST OF THE
CONTINENTAL DIVIDE...SO WILL NOT MAKE ANY CHANGES TO THE
PRECIPITATION PART OF THE FORECAST. TEMPERATURE FORECASTS ALSO
LOOK GOOD FOR NOW.
&&
.AVIATION...GUSTY WEST WINDS WILL AFFECT PRIMARILY ROCKY MOUNTAIN
METRO AIRPORT. SOME GUSTS MAY REACH KDEN AT TIMES...BUT SHOULD NOT
HAVE TOO BIG AN IMPACT ON OPERATIONS. WINDS SHOULD DIMINISH
RAPIDLY AFTER 2 AM MDT.
&&
.PREV DISCUSSION... /ISSUED 344 PM MDT THU OCT 31 2013/
SHORT TERM...MOUNTAIN WAVE WEAKENING A BIT AS RIDGE TOP STABLE
LAYER SHOWING SIGNS OF DECREASING. 1500 METER PRESSURE GRADIENT
FROM GJT TO DEN HAS BEEN STEADILY DECREASING...CURRENTLY AT 9.23
MB FROM A MAX OF 10.11 MB AT 18Z. WINDS HAVE BEEN GRADUALLY
DECREASING IN RESPONSE TO THE WEAKENING GRADIENT...THOUGH STILL
GUSTY OVER THE MOUNTAINS AND IN AND NEAR FOOTHILLS. ALSO A BIT
GUSTY FAR EASTERN PLAINS. MOISTURE HAS BEEN GRADUALLY INCREASING
ACROSS MOUNTAINS...WITH FAVORABLE OROGRAPHICS HELPING TO GENERATE
SNOW SHOWERS ALONG THE CONTINENTAL DIVIDE AS WELL AS ACROSS
PORTIONS OF THE PARK AND GORE RANGES OF WESTERN GRAND AND WESTERN
JACKSON COUNTIES. FOR TONIGHT...FORECAST SOUNDINGS INDICATING A
WEAK INVERSION AT MOUNTAIN TOP WITH A SLIGHTLY UNSTABLE AIRMASS.
IN ADDITION...QG VERTICAL VELOCITY PROGS SHOW WEAK ASCENT AFTER
MIDNIGHT ASSOCIATED WITH A WEAK MID LEVEL WAVE MOVING INTO
WYOMING. THIS WILL LIMIT THE DOWNWARD MOTION AND LIMIT THE
STRONGER WINDS TO THE MOUNTAINS AND HIGHER FOOTHILLS. THE TREND
TOWARD DECREASING WINDS STILL LOOKS ON TRACK MOST AREAS THROUGH
THE EVENING. COMBINATION OF THE INCREASING MOISTURE AND WEAK
ASCENT OVER THE MOUNTAINS ENOUGH TO INCREASE POPS A BIT...MAINLY
WEST AND NORTH FACING SLOPES. ACCUMULATIONS TO BE LESS THAN 3
INCHES AND CONFINED TO THE NORTHWEST FACING SLOPES. SOME INCREASE
IN CLOUDS ACROSS THE PLAINS THROUGH THE EVENING. ON FRIDAY...
FAIRLY STRONG NORTHWEST FLOW ALOFT TO CONTINUE. CROSS SECTIONS
SHOW MOISTURE GRADUALLY DECREASING OVER THE MOUNTAINS THROUGH THE
MORNING AS AIRMASS BECOMES MORE SUBSIDENT. STILL ENOUGH MOISTURE
FOR A CHANCE OF SNOW DURING THE MORNING AS OROGRAPHICS CONTINUE.
MOISTURE DOES BECOMES SHALLOW DURING THE AFTERNOON WITH ONLY A
SLIGHT CHANCE OF SNOW. WINDS TO REMAIN GUSTY ACROSS THE MOUNTAINS
AND HIGHER FOOTHILLS AS CROSS MOUNTAIN FLOW INCREASES TO AROUND 30
KTS BY THE AFTERNOON. COMBINATION OF MIXING AND SUBSIDENCE WILL
ALLOW FOR THE GUSTY WINDS TO LOWER TO THE BASE OF THE FOOTHILLS
DURING THE MORNING...THEN ACROSS THE NORTHEAST PLAINS DURING THE
AFTERNOON. SOME GUSTS TO 45 MPH WILL BE POSSIBLE NORTH AND EAST OF
DENVER AS WELL AS NEAR THE FOOTHILLS. MODELS SUGGEST THE
DEVELOPMENT OF A WEAK ANTICYCLONE NEAR THE DENVER AREA BY THE
AFTERNOON WHICH COULD PRODUCE WEAKER WINDS. TEMPERATURE AND
THICKNESS PROGS SUGGEST TEMPERATURES TO BE IN THE LOWER TO MID 50S
ACROSS THE PLAINS WHICH IS IN LINE WITH GUIDANCE. DOWNSLOPE WINDS
MAY ADD A FEW DEGREES TO THE HIGHS...ESPECIALLY NEAR THE
FOOTHILLS.
LONG TERM...MEAN UPPER LEVEL RIDGE MAKES ITS WAY ACROSS COLORADO
THIS WEEKEND BRINGING DRIER AIR...NEAR TO SLIGHTLY ABOVE AVERAGE
TEMPERATURES AND LIGHTER WINDS TO THE FORECAST DOMAIN OF NORTH
CENTRAL AND NORTHEAST COLORADO. HIGHS BOTH SATURDAY AND SUNDAY WILL
BE IN THE UPPER 50S AND 60S ON THE PLAINS....MID 40S/LOWER 50S MTN
VALLEYS AND 30S AND 40S AT HIGHER ELEVATIONS.
FOR EARLY NEXT WEEK...THE MEDIUM RANGE MODEL COLLECTIVE CONTINUES TO
POINT TO A RATHER ABRUPT TURN TO COLDER TEMPERATURES MONDAY AND AN
INCREASING CHANCE OF RAIN/SNOW DURING THE DAY MONDAY THROUGH TUESDAY
NIGHT. A STRONG COLD FRONT IS STILL PROGGED TO SLIDE SOUTH OUT OF
WYOMING ACROSS NORTHEAST COLORADO EARLY MONDAY MORNING. MODELS HAVE
SHOWN THIS FOR THE PAST FEW DAYS. WHAT THE MODELS HAVEN`T BEEN ALL
TO CONSISTENT ABOUT IS THE TIMING AND AMPLITUDE OF THE UPPER TROUGH.
EARLIER MODEL RUNS SHOWED THE 500 MB TROUGH ARRIVING IN COLORADO ON
MONDAY. IT NOW APPEARS ITS ARRIVAL WILL BE DELAYED SOME. THE
CANADIAN MODEL SHOWS THE UPPER TROUGH DEEPENING FARTHER SOUTH OVER
ARIZONA/NEW MEXICO DURING THE MONDAY/TUESDAY TIME FRAME WHERE IT
ATTEMPTS TO CLOSE OFF OVER THE FOUR CORNERS AREA MIDDAY TUESDAY. THE
ECMWF INDICATES THE FORMATION OF A CLOSED LOW OVER CENTRAL UTAH
MONDAY NIGHT...AND FROM THERE IT WEAKENS THE UPPER TROUGH AS ITS
PASSES OVER COLORADO TUESDAY AFTERNOON/NIGHT. MEANWHILE THE GFS
MODEL SHOWS THE UPPER TROUGH DROPPING THROUGH UTAH INTO COLORADO BY
TUESDAY MORNING. THE GFS NO LONGER SHOWS IT CLOSING OFF OVER
COLORADO LIKE AN EARLIER ITERATION OF THE MODEL INDICATED. BOTH THE
GFS AND ECMWF SHOW ANTICYCLONIC/POST-FRONTAL UPSLOPE FLOW
STRENGTHENING/DEEPENING EAST OF THE MOUNTAINS THROUGH THE DAY MONDAY
INTO MONDAY NIGHT AS COLDER AIR CONTINUES TO FILTER DOWN FROM
WYOMING. BOTH MODELS ALSO SHOW PRECIP DEVELOPING IN THE HIGH COUNTRY
DURING THE DAY MONDAY...BUT NOT UNTIL NIGHTFALL IN THE FRONT RANGE
MTNS AND NEARBY PLAINS. AT PRESENT TIME QPF AMOUNTS ON THE LOW SIDE
IN BOTH AREAS. GFS TAKES THE LEAD ON PRECIP PRODUCTION...ESPLY ALONG
AND EAST OF THE CONTINENTAL DIVIDE MONDAY AFTERNOON-TUESDAY MORNING
WITH STRONGEST LEE SLOPE OROGRAPHICS AND QG LIFT WITH PASSING 700-
500 TROUGH. THE LATEST ECMWF...ON THE OTHER HAND...BRINGS EVERYTHING
TOGETHER FOR PRECIP PRODUCTION MONDAY NIGHT AND TUESDAY. THE
CANADIAN MODELS LOOKS ABOUT THE SAME. HOWEVER...THE CANADIAN LIFT A
CLOSED LOW ACROSS SERN COLORADO WHICH WOULD FAVOR MORE EAST SLOPE
PRECIP...BUT THIS SYSTEM DOES NOT LOOK AS WET ON THIS MODEL.
BOTTOMLINE...COLDER TEMPERATURES LOOK CERTAIN FOR MONDAY AND TUESDAY
BUT THE ODDS OF MEASURABLE PRECIP NOT AS CERTAIN. FOR NOW...WILL
CONTINUE TO NUDGE PRECIP CHANCES AND PRETTY MUCH HANG ONTO THE
SKY COVER...TEMPERATURES AND WINDS ALREADY IN THE FORECAST. FOR
WEDNESDAY...MODELS SHOW THE TROUGH MOVING OUT AND A FLAT UPPER
RIDGE MOVING OVER THE REGION. SHOULD SEE DRYING AREAWIDE BUT
TEMPERATURES WILL BE SLOW TO WARM.
AVIATION...NORTHWEST WINDS SHOWING SIGNS OF BECOMING A BIT MORE
WESTERLY AS GRADIENT WEAKENS A BIT. STILL SOME GUSTS AROUND 25 KTS
AT KDEN AND KAPA WITH GUSTS AROUND 35 KTS AT KBJC. GRADIENT TO
CONTINUE TO WEAKEN THROUGH THE EVENING...WITH DECREASING WINDS AT
KDEN AND KAPA WITH FLOW SHIFTING TO DRAINAGE. WESTERLY WINDS TO
PREVAIL AT KBJC WITH SOME GUSTS AROUND 25 KTS THOUGH COULD BE
ERRATIC AT TIMES WITH POTENTIAL FOR LLWS. ON FRIDAY...WINDS TO
BECOME NORTHWEST AROUND 16Z WITH SPEEDS INCREASING AT KDEN AND
KAPA WHILE REMAINING GUSTY AT KBJC. SOME GUSTS TO 30 KTS WILL BE
POSSIBLE DURING THE AFTERNOON. SLIGHT CHANCE FOR A WEAK
ANTICYCLONE DEVELOPING BY THE AFTERNOON WITH LIGHTER WINDS. VFR
TO PREVAIL WITH UNLIMITED CEILINGS.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...DANKERS
LONG TERM....99
AVIATION...RTG
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
318 PM MDT WED OCT 30 2013
.SHORT TERM...UPPER TROUGH MOVING INTO WESTERN COLORADO AT THIS
TIME WITH SOUTHWEST FLOW ALOFT OVER AREA. MOISTURE AND LIFT
INCREASING ACROSS MOUNTAINS...WITH SOME SHOWERS DEVELOPING ALONG
THE CONTINENTAL DIVIDE. RADAR ALSO INDICATING A BAND OF SHOWERS
ACROSS CENTRAL LARIMER COUNTY...LOOKS TO BE CSI INDUCED AS UPPER
JET NOW NOSING INTO THE MOUNTAINS. TROUGH TO MOVE ACROSS COLORADO
DURING THE EVENING WITH FLOW BECOMING NORTHWEST AROUND MIDNIGHT.
BEST LIFT TO OCCUR THIS EVENING WHEN FLOW IS WEST SOUTHWEST. BEST
OROGRAPHICS OCCUR AFTER MIDNIGHT BUT MID LEVEL ASCENT WEAKENS WITH
INCREASING MID LEVEL SUBSIDENCE. STILL A FAIRLY GOOD SHOT OF SNOW
FOR THE HIGH COUNTRY...THOUGH ACCUMULATIONS WILL BE ON THE LIGHT
SIDE. AMOUNTS OF 2 TO 4 INCHES WILL BE POSSIBLE BY THURSDAY
MORNING. FOOTHILL AREAS COULD ALSO SOME LIGHT ACCUMULATIONS THIS
EVENING AS THE BAND OF PRECIPITATION SHIFTS SOUTH AND EAST...
SHOULD BE LESS THAN 2 INCHES. ACROSS PLAINS...MID LEVEL ASCENT TO
INCREASE THIS EVENING AS TROUGH MOVES OVERHEAD. MODELS STILL
SHOWING BEST CHANCE FOR PRECIPITATION TO BE ACROSS THE PALMER
DIVIDE. PRIMARILY A RAIN/SNOW MIX AS TEMPERATURES TO BE ABOVE
FREEZING. WILL BE COLD ENOUGH FOR THE PRECIPITATION TO BE ALL SNOW
ALONG THE PALMER DIVIDE. LATEST RAP INDICATING THE POTENTIAL FOR
AROUND 2 INCHES IN AN AREA FROM EASTERN DOUGLAS COUNTY ACROSS
NORTHER ELBERT COUNTY. OVERNIGHT...NORTHWEST FLOW ALOFT INCREASES
BEHIND THE EXITING TROUGH. COULD SEE SOME GUSTS TO AROUND 35 MPH
ACROSS THE MOUNTAINS AND HIGHER FOOTHILLS TOWARDS DAYBREAK. ON
THURSDAY...FAIRLY STRONG AND SUBSIDENT NORTHWEST FLOW ALOFT WILL
BE OVER THE AREA. GOOD OROGRAPHICS AND ENOUGH MOISTURE TO GENERATE
SOME LIGHT SNOW...MAINLY NORTHWEST FACING SLOPES. WINDS TO
GRADUALLY INCREASE ACROSS THE MOUNTAINS AND FOOTHILLS ...WITH
POSSIBLE GUSTS TO 45 WINDS BY THE AFTERNOON. ACROSS PLAINS...
COMBINATION OF SUBSIDENCE...MIXING AND INCREASING NORTHWEST
SURFACE GRADIENT WILL CREATE GUSTY WINDS DURING THE AFTERNOON...
MAINLY NORTH AND EAST OF DENVER. SOME GUSTS COULD REACH 40 MPH
OVER THE NORTHEAST CORNER. THERE IS A SLIGHT CHANCE THAT A WEAK
ANTICYCLONE COULD DEVELOP IN THE DENVER AREA WHICH COULD PRODUCE
LIGHT NORTHEAST TO EAST WINDS IN THE DENVER AREA. TEMPERATURE AND
THICKNESS PROGS SUGGEST HIGHS WILL WARM INTO THE UPPER 50S. LATEST
GFS GUIDANCE SEEMS A BIT WARM WHILE THE NAM GUIDANCE APPEARS A BIT
COOL.
.LONG TERM...DEEP NORTHWESTERLY FLOW ON THE BACK SIDE OF EXITING
UPPER TROUGH EXPECTED TO PRODUCE GUSTY NORTHWESTERLY SURFACE WINDS
ON THE MTN RIDGES AND NORTHEAST PLAINS DURING THE DAY FRIDAY.
ACCORDING TO NAM...WRF AND GFS CROSS SECTION WIND PROFILES...
STRONGEST WINDS ON THE MTN RIDGE AND UP UP ALONG THE WYOMING/
NEBRASKA BORDER IN THE MORNING...AND ON THE PLAINS LATER IN THE DAY.
PEAK GUSTS IN THE 40-50 MPH HIGHER TERRAIN AND 30-40 MPH ON THE
PLAINS. SOUTHERN PORTIONS OF THE I-25 URBAN CORRIDOR AND WESTERN
VALLEYS WILL ESCAPE MUCH OF THIS WIND. STRONG/GUSTY WINDS DEVELOP
SOON AFTER PASSAGE OF QUICK MOVING SHORTWAVE TROUGH WHICH MODELS
SHOW SWINGING OVER THE WESTERN WYOMING. WEAK POSITIVE QG FORCING AND
SLIGHTLY UNSTABLE LAPSE RATES WITH COOLING ALOFT WILL COMBINE WITH
FAVORABLE OROGRAPHICS TO PRODUCE ANOTHER ROUND OF SNOW SHOWERS IN
THE NORTHERN MTNS THURSDAY NIGHT. NEW SNOW AMOUNTS EXPECTED TO STAY
ON THE LOW SIDE DUE THE RELATIVELY LIMITED MOISTURE. FRIDAY
TEMPERATURES ON THE PLAINS 1-2 DEG C WARMER THAN THE DAY BEFORE WITH
DOWNING FLOW OFF THE FRONT RANGE. TEMPERATURE IN THE HIGH COUNTRY AS
MUCH AS 3-4DEG C WARMER.
FRIDAY NIGHT THROUGH SUNDAY NIGHT...GRADIENT ALOFT SLACKENS AND SO
DO WIND SPEEDS WITH AN BROAD UPPER LEVEL RIDGE PROPAGATING EASTWARD
ACROSS THE ROCKY MOUNTAIN REGION. WARMEST TEMPERATURES ALOFT OVER
COLORADO SATURDAY NIGHT/SUNDAY TIME FRAME. SFC TEMPERATURES RESPOND
WITH A 1-2DEG C WARM UP FRIDAY-SUNDAY. ESSENTIALLY NO CHANCE OF
PRECIP FRIDAY NIGHT THROUGH SUNDAY AFTERNOON...EVEN IN THE HIGH
COUNTRY.
MONDAY-WEDNESDAY TIME FRAME...LONG WAVE PATTERN SHIFTS EASTWARD
ALLOWING THE NEXT UPPER WAVE TO SWING DOWN FROM THE PACIFIC
NORTHWEST. THIS OPEN WAVE DROPS INTO THE UPPER GREAT BASIN SUNDAY
NIGHT. FROM THERE MODELS GENERALLY AGREE IN MOVING THIS SYSTEM EAST-
SOUTHEASTWARD AT BIT OF A SLOWLY PACE THAN WHAT WAS INDICATED BY
EARLIER MODEL RUNS. ALSO LOOKS AS THOUGH THE TROUGH IS DIGGING A BIT
MORE AS IT PASSES OVER COLORADO DURING THE DAY MONDAY. MODELS SHOW A
COLD FRONT SLIDING SOUTH ALONG THE LEE SLOPE OF THE ROCKIES AND INTO
NERN COLORADO BY EARLY ON MONDAY. ASSUMING ALL THIS HAPPENS...SHOULD
SEE A STEADY FALL IN TEMPERATURES ON MONDAY AND A STEADY INCREASE IN
RAIN/SNOW SHOWER DEVELOPMENT IN THE HIGH COUNTRY. PRECIP SHOULD TURN
TO ALL SNOW IN THE HIGH COUNTRY BEFORE NIGHTFALL. ON THE
PLAINS...BASED ON CURRENT MODEL GUIDANCE...SHOWERY PRECIP WOULD
BEGIN LATE IN THE AFTERNOON...AND AS UPSLOPE FLOW STRENGTHENS/
DEEPENS WITH THE TROUGH PASSING OVERHEAD...PRECIP WOULD BECOME MORE
WIDESPREAD AND POSSIBLY BECOME ALL SNOW MONDAY NIGHT INTO TUESDAY.
REALLY TOO EARLY TO KNOW FOR CERTAIN IF ALL THIS WILL OCCUR. FOR NOW
WILL GENERALLY GO WITH 30-40 PCT POPS ON THE PLAINS AND MTN
VALLEYS...AND 40 60 PCT POPS AT HIGHER ELEVATIONS DURING THE TWO DAY
PERIOD. BEYOND TUESDAY...FORECAST LESS CERTAIN. ALL DEPENDS ON HOW
FAST TO THE UPPER TROUGH MOVES OUT. FOR NOW WILL TREND POPS DOWNWARD
AND BEGIN TO RAISE TEMPERATURES.
&&
.AVIATION...FINALLY VFR CONDITIONS. NORTHEAST WINDS PREVAILING AT
AREA AIRPORTS WITH SPEEDS AROUND 8 KTS. STILL A CHANCE OF SHOWERS
DEVELOPING BETWEEN 23Z AND 05Z AS UPPER TROUGH MOVES OVERHEAD.
CEILINGS OF AROUND 5000 FEET TO DEVELOP WITH OCCASIONAL CEILINGS
OF AROUND 2500-3000 FEET. BEST CHANCE FOR SHOWERS TO OCCUR AT APA.
THERE IS THE POTENTIAL FOR A MIX OF RAIN AND SNOW WHICH COULD
BRIEFLY CHANGE OVER TO ALL SNOW AFTER 01Z. AT THIS TIME
ACCUMULATIONS ARE NOT EXPECTED. THE THREAT OF PRECIPITATION WILL
END BY 06Z AND WINDS DECREASE AND DRAINAGE FLOW DEVELOPS. VFR
CONDITIONS TO THEN PREVAIL WITH UNLIMITED CEILINGS. THE WINDS
WILL SHIFT TO THE NORTHWEST AROUND 15Z WITH SPEEDS LESS THAN 8
KTS...THEN INCREASING TO AROUND 15 KTS AFTER 20Z. THERE IS A
SLIGHT CHANCE THAT A WEAK ANTICYCLONE WILL DEVELOP BY 18Z WHICH
COULD CREATE LIGHT NORTHEAST WINDS. AT THIS TIME WILL CONTINUE
WITH THE IDEA OF THE NORTHWEST WINDS.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...D-L
LONG TERM....BAKER
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1014 PM EDT THU OCT 31 2013
.SYNOPSIS...
A WARM FRONT CONTINUES TO LIFT NORTH THROUGH THE REGION TONIGHT.
TRAILING COLD FRONT WILL MOVE ACROSS THE AREA FRIDAY. SHOWERS
BECOME WIDESPREAD TONIGHT AND INTO FRIDAY MORNING AS MILDER AIR
MOVES IN. UNSEASONABLY WARM AND WINDY FRI. A FEW SHOWERS LINGER
ON SAT NEAR THE COAST...THEN COLDER AND BLUSTERY CONDITIONS ARRIVE
FOR SUNDAY INTO EARLY NEXT WEEK. HIGH PRESSURE BY THE MIDDLE OF
THE WEEK WILL ALLOW FOR MODERATING TEMPERATURES.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
10 PM UPDATE...
DECENT SHOT OF RAIN MOVING THROUGH SNE LATE THIS EVENING ASSOCD
WITH INITIAL STRENGTHENING OF LOW LEVEL JET. THIS RAIN WILL MOVE
ACROSS THE REGION THROUGH 04-06Z...WITH GREATEST CONCENTRATION IN
THE INTERIOR. MODELS ARE INDICATING A DRY SLOT MOVING UP FROM THE
OCEAN AHEAD OF THE MAIN BAND OF HEAVIER RAIN WITH THE COLD FRONT.
THIS DRY SLOT WILL BE MOST PRONOUNCED ACROSS E NEW ENG WHERE A DRY
PERIOD IS LIKELY LATE TONIGHT. THE HRRR ACTUALLY ENDS THE RAIN
FOR ALL SNE FOR A TIME BEFORE IT MOVES BACK IN FROM THE WEST
TOWARD DAYBREAK. WE KEPT HIGHER POPS ACROSS W ZONES THROUGH THE
NIGHT AS NOT CONFIDENT THE DRY SLOT WILL REACH AS FAR WEST AS THE
HRRR SUGGESTS...BUT WE ARE SHOWING DECREASING POPS IN EASTERN NEW
ENG 06-10Z.
MILDER AIR HAS OVERSPREAD ALL SNE AS TEMPS HAVE RISEN INTO THE
UPPER 50S TO LOWER 60S. TEMPS WILL SLOWLY RISE THROUGH THE NIGHT
INTO AND THROUGH THE 60S WITH PORTIONS OF SE MA AWAY FROM THE
OCEAN POSSIBLY REACHING 70 OVERNIGHT.
THESE MILDER TEMPS WILL HELP TO BRING DOWN SOME OF THE STRONGER
WINDS ALOFT WITH GUSTS POSSIBLY REACHING 40+ MPH BEFORE DAYBREAK
IN PORTIONS OF RI AND SE MA.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
*** STRONG TO PERHAPS DAMAGING WINDS FRIDAY ***
SYNOPTIC OVERVIEW...
ANOMALOUS EARLY SEASON BOMBOGENESIS OCCURRING THIS EVENING AND
OVERNIGHT ACROSS THE GREAT LAKES YIELDING A POWERFUL CYCLONE
MOVING THROUGH SOUTHERN ONTARIO AND QUEBEC FRI. MODELS IN VERY
GOOD AGREEMENT WITH A SUB 980 MB LOW TRAVERSING THIS REGION
TOMORROW...WHICH IS -4 STANDARD DEVIATIONS /STD/ FROM CLIMATOLOGY!
THIS RESULTS IN A STRENGTHENING/ANOMALOUS LOW LEVEL JET ACROSS
RI/EASTERN MA AND THE NEARBY COASTAL WATERS WITH GOOD MODEL
AGREEMENT ON 60-70 KT AT 925 MB FRI FROM 12Z-18Z! SPEEDS OF THIS
MAGNITUDE AT 925 MB ARE ABOUT +3 TO +4 STD FROM CLIMO. THUS
IMPRESSIVE SYSTEM THIS EARLY IN THE SEASON.
STRONG WIND THREAT...
ITS ALWAYS DIFFICULT TO PREDICT HOW MUCH WIND ALOFT WILL TRANSPORT
TO THE SURFACE IN THESE WARM ADVECTION EVENTS. HOWEVER GIVEN THE
ANOMALOUS JET AND PGRAD FROM THE SUB 980 MB LOW FAIRLY CONFIDENT
IN SSW WINDS 25-35 MPH WITH GUSTS UP TO 5O MPH ACROSS RI AND
EASTERN MA. IN ADDITION...SHALLOW BUT ROBUST UPDRAFTS/DOWNDRAFTS
ASSOCIATED WITH HEAVY SHOWERS FRI MORNING WILL ENHANCE THE
PROBABILITY OF STRONGER WINDS REACHING THE SURFACE. TYPICALLY IN
THESE SSW WIND EVENTS THE STRONGEST WINDS OCCUR JUST INLAND FROM
THE SOUTH COAST...AWAY FROM THE COOLER MARITIME AIRMASS. THUS
HIGHEST RISK FOR STRONG/DAMAGING WINDS WILL BE ACROSS RI AND
SOUTHEAST MA AWAY FROM THE IMMEDIATE SOUTH COAST. IN
ADDITION...THE THRESHOLD TO BRING DOWN BRANCHES AND SMALL LIMBS
ACROSS THIS AREA MAY BE LOWER GIVEN STILL FULLY LEAVED TREES.
THERE WILL BE A SECOND PULSE OF STRONG WINDS BEHIND THE COLD
FRONT DURING THE AFTERNOON AS CAA DEVELOPS AND STEEPENS LOW LEVEL
LAPSE RATES. STRONGEST WINDS WILL LIKELY OCCUR ACROSS NORTHERN MA
/POSSIBLY INTO GREATER BOSTON AREA/ INTO SOUTHWEST NH GIVEN
PROXIMITY OF STRONG LOW FARTHER TO THE NORTHWEST. LOWER
PROBABILITY OF G50 MPH FARTHER SOUTH INTO CT BUT CLOSE ENOUGH TO
WARRANT WIND ADVISORY.
RAINFALL...
STRONG JET DYNAMICS /WIND ANOMALIES +3 TO +4 STD/ COUPLED WITH
SUBTROPICAL MOISTURE /PWATS +3 STD/ YIELDS IMPRESSIVE 850 MB
MOISTURE FLUX. THIS WILL RESULT IN A PERIOD OF HEAVY SHOWERS FRI
MORNING AND INTO THE EARLY AFTERNOON FOR CAPE COD AND THE ISLANDS.
HOWEVER THE SPEED OF THIS SYSTEM AND LACK OF INSTABILITY /BOTH ALOFT
AND SURFACE BASED/ WILL LIMIT RAINFALL AMOUNTS. MOST LOCATIONS
SHOULD GET LESS THAN ONE INCH WITH A FEW AREAS ACROSS W ZONES
POSSIBLY EXCEEDING AN INCH. LOCALIZED MINOR URBAN AND POOR DRAINAGE
FLOODING IS POSSIBLE LATE TONIGHT INTO FRI MORNING AS THE HEAVIEST
RAIN MOVES THROUGH. THIS WILL LIKELY RESULT IN A SLOW MORNING
COMMUTE.
TEMPERATURES...
VERY WARM CONDITIONS FRI IN RESPONSE TO STRONG LOW LEVEL WARM AIR
ADVECTION. 925 MB TEMPS CLIMBING TO ABOUT +15C WHICH SHOULD SUPPORT
HIGHS IN THE U60S AND L70S! LOW PROBABILITY OF HIGHS NEARING THE
M70S IF COLD FRONT AND CLOUD SHIELD DEPART SOMEWHAT QUICKER THAN
GUIDANCE. STILL NOT RECORD BREAKING BUT QUITE ANOMALOUS.
FRI NIGHT...
DRYING TREND EXCEPT CAPE COD AND THE ISLANDS AS FRONT STALLS
OFFSHORE WITH CLOUDS AND PERHAPS SHOWERS LINGERING HERE. ELSEWHERE
DRY WEATHER PREVAILS. STILL MILD AS TRUE CAA HOLDS OFF UNTIL
SUNDAY.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
HIGHLIGHTS...
* LINGERING SHOWERS EAST SATURDAY
* BLUSTERY AND COLD SUNDAY AND MONDAY
* MODERATING TEMPS AND QUIET WEATHER MID WEEK
VERY GOOD AGREEMENT AMONGST THE MODELS...PARTICULARLY THROUGH EARLY
NEXT WEEK. AS PER USUAL...THERE IS A BIT OF DIVERGENCE AS WE MOVE
TOWARD A POTENTIAL STORM THE MIDDLE TO END OF NEXT WEEK. WE START
THIS WEEKEND OFF WITH SEASONABLE TEMPERATURES AND CLOUDS AND END THE
WEEKEND WITH TEMPS WELL BELOW NORMAL AND SUN. MONDAY STAYS COOL AND
THEN A MODERATING TREND AS HIGH PRESSURE STARTS TO MOVE OFFSHORE.
WEDNESDAY AND THURSDAY IS WHERE THE MOST UNCERTAINTY LIES AS AN
UPPER LEVEL TROUGH AND FRONTAL SYSTEM APPROACHES AND MOVES THROUGH
SOUTHERN NEW ENGLAND. THE 31/00Z ECMWF IS SLOWER THAN THE 31/12Z
GFS...KEEPING WEDNESDAY RELATIVELY PLEASANT AND THEN BRINGING THE
FRONTAL SYSTEM THROUGH LATE THURSDAY. THE GFS MOVES THE LOW
PRESSURE SYSTEM A BIT QUICKER WITH THE COLD FRONT COMING THROUGH
SOUTHERN NEW ENGLAND EARLY THURSDAY.
SATURDAY...SHOWERS LINGERING ON THE SOUTH COAST...CAPE...AND ISLANDS
WILL MOVE OFFSHORE DURING THE MORNING HOURS. THEN A FEW MORE
SCATTERED SHOWERS MAY MOVE THROUGH SOUTHERN NEW ENGLAND AHEAD OF A
SECONDARY FRONT. TEMPERATURES REMAIN NEAR NORMAL FOR THE BEGINNING
OF NOVEMBER AHEAD OF THE FRONT...DESPITE OVERCAST SKIES.
SUNDAY THROUGH TUESDAY...GUSTY WINDS EXPECTED WITH STRONG COLD AIR
ADVECTION SUNDAY BEHIND THE COLD FRONT AS AN UPPER LEVEL RIDGE
STARTS TO CREST OVER SOUTHERN NEW ENGLAND. DESPITE CLEAR
SKIES...SUNDAY AND MONDAY ARE LIKELY THE TWO COLDEST DAYS OF THE
FORECAST WITH TEMPERATURES WELL BELOW NORMAL AND A CHILLY BREEZE ON
TOP OF THAT. TEMPERATURES START TO MODERATE TUESDAY AS HIGH
PRESSURE STARTS TO PUSH OFFSHORE.
WEDNESDAY AND THURSDAY...AS STATED ABOVE THERE IS SOME UNCERTAINTY
AS TO HOW QUICKLY THE COLD FRONT WILL MOVE THROUGH THE REGION.
RIGHT NOW...LOOKING AT WEDNESDAY BEING RELATIVELY QUIET WITH WARMING
TEMPERATURES AND SUNNY SKIES THROUGH MUCH OF THE DAY. TEMPERATURES
MAY CONTINUE TO WARM THURSDAY DEPENDING ON THE TIMING OF THE COLD
FRONT. A PERIOD OF RAIN AND STRONG WINDS IS LIKELY TO ACCOMPANY
THIS FRONTAL SYSTEM BUT MUCH HAS YET TO BE RESOLVED WITH THE DETAILS
AND TIMING OF THE STORM.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
TONIGHT...A MIX OF CONDITIONS LOWER TO IFR AS STRATUS AND FOG
DEVELOP. SHOWERS MOVING THROUGH LATE THIS EVENING MAY TEMPORARILY
END IN E NEW ENG AFTER MIDNIGHT. LOCALLY HEAVY SHOWERS WILL BE
APPROACHING THE CT VALLEY TOWARD DAYBREAK. LLWS DEVELOPS 06Z-12Z
ACROSS RI AND EASTERN MA. STRONG SURFACE WINDS DEVELOP 08-10Z.
CONFIDENCE MODERATE TO HIGH.
FRI...IFR-MVFR IN HEAVY SHOWERS DURING THE MORNING IMPROVES TO
MVFR-VFR DURING THE AFTERNOON FROM WEST TO EAST. SHOWERS EXIT
DURING THIS TIME EXCEPT LINGER ALONG THE SOUTH COAST. STRONG SSW
WINDS GUSTING UP TO 45 KT RI AND EASTERN MA IN THE MORNING...THEN
SHIFTING TO WSW IN THE AFTERNOON WITH GUSTS 40-45 KT. MODERATE TO
HIGH CONFIDENCE.
FRI NIGHT...VFR EXCEPT MVFR SOUTH COAST INCLUDING CAPE COD AND
ISLANDS IN CHANCE OF SHOWERS. WINDS DIMINISH. MODERATE TO HIGH
CONFIDENCE.
KBOS TAF...HIGH CONFIDENCE IN TRENDS LOWER IN EXACT TIMING.
KBDL TAF...HIGH CONFIDENCE IN TRENDS LOWER IN EXACT TIMING.
OUTLOOK...SATURDAY THROUGH TUESDAY...
SATURDAY...MVFR/IFR CONDITIONS TO START WILL IMPROVE TO VFR FROM
WEST TO EAST.
SUNDAY...VFR. NNW WINDS COULD GUST TO 25 KTS.
MONDAY AND TUESDAY...VFR.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
TONIGHT...
SOUTH WINDS INCREASE AND REACH GALE FORCE TOWARD DAYBREAK. SEAS
WILL INCREASE SHARPLY ESPECIALLY SOUTH COASTAL WATERS. SHOWERS
BECOME WIDESPREAD AS THE NIGHT PROGRESSES.
FRIDAY...
SSW GALES BECOME WSW GALES DURING THE AFTERNOON. SCATTERED HEAVY
SHOWERS EXIT OFFSHORE DURING THE AFTERNOON...HOWEVER MAY LINGER
OVER SOUTHEAST WATERS.
FRIDAY NIGHT...
IMPROVING WEATHER WITH A DRYING TREND AND DIMINISHING WINDS. SEAS
WILL SLOWLY RELAX TOO. SHOWERS MAY LINGER OVER THE SOUTHEAST
WATERS.
SATURDAY AND SUNDAY...SMALL CRAFT ADVISORIES WILL LIKELY BE
NECESSARY FOR SEAS OVER 5 FEET AND NORTHWESTERLY WINDS GUSTING TO 30
KTS. VISIBILITIES MAY BE LIMITED IN INTERMITTENT SHOWERS.
MONDAY AND TUESDAY...WINDS AND SEAS DIMINISH AS HIGH PRESSURE MOVES
OVER SOUTHERN NEW ENGLAND AND OVER THE WATERS. LIGHT NORTHERLY
WINDS SHIFT TO THE EAST AND THEN SOUTH THROUGH THIS TIME PERIOD.
&&
.TIDES/COASTAL FLOODING...
COASTAL FLOODING CONCERNS ALONG THE SOUTH COAST ARE MINIMAL. NOT
MUCH OF A SURGE GIVEN SURFACE LOW AND PRESSURE FALLS ARE TRACKING
SO FAR NORTHWEST OF NEW ENGLAND. WILL HAVE MODEST TO LARGE WAVE
ACTION ON THE SOUTH COAST BUT TIDES WILL NOT BE HIGH ENOUGH TO
WARRANT ANY FLOODING. WORSE CASE SCENARIO WOULD BE SOME SPLASH
OVER.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WIND ADVISORY FROM 6 AM TO 6 PM EDT FRIDAY FOR CTZ002>004.
MA...WIND ADVISORY FROM 6 AM TO 6 PM EDT FRIDAY FOR MAZ002>024-026.
NH...WIND ADVISORY FROM 6 AM TO 6 PM EDT FRIDAY FOR NHZ011-012-015.
RI...WIND ADVISORY FROM 6 AM TO 6 PM EDT FRIDAY FOR RIZ001>008.
MARINE...GALE WARNING FROM 5 AM TO 6 PM EDT FRIDAY FOR ANZ230>237-250-
251-254>256.
&&
$$
SYNOPSIS...NOCERA/RLG
NEAR TERM...KJC
SHORT TERM...NOCERA
LONG TERM...RLG
AVIATION...KJC/NOCERA/RLG
MARINE...NOCERA/RLG
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS ALBANY NY
413 AM EDT WED OCT 30 2013
.SYNOPSIS...
A WEAK UPPER LEVEL DISTURBANCE WILL CROSS THE REGION INTO THIS
MORNING...BRINGING ISOLATED TO SCATTERED RAIN AND SNOW SHOWERS
MAINLY OVER THE HIGHER ELEVATIONS. A MORE SIGNIFICANT STORM SYSTEM
WILL IMPACT THE REGION LATE IN THE WEEK...AS A STRONG AREA OF LOW
PRESSURE TRACKS ACROSS SOUTHERN CANADA BRINGING WIDESPREAD RAIN AND
WIND TO THE AREA THURSDAY NIGHT INTO FRIDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 410 AM EDT...A WEAK UPPER LEVEL DISTURBANCE CONTINUES TO MOVE
ACROSS THE AREA EARLY THIS MORNING...BRINGING SOME LIGHT ISOLATED TO
SCATTERED SHOWERS. NEAR SURFACE TEMPERATURES ARE MARGINAL FOR
RAIN/SNOW...WITH THE BETTER CHANCE FOR ANY SNOW OVER THE HIGHER
TERRAIN. BASED ON LATEST RADAR TRENDS AND HRRR GUIDANCE WILL SHIFT
AREA OF MENTIONING CHANCE POPS A BIT FARTHER SOUTH...OVER THE
EASTERN CATSKILLS AND THE HIGHER TERRAIN OF WESTERN NEW ENGLAND.
STILL...QPF AMOUNTS WILL BE LIGHT WITH PERHAPS A DUSTING TO A FEW
TENTHS OF AN INCH OF SNOW MAINLY OVER 1000 FT ELEVATION.
THIS SYSTEM WILL MOVE EAST OF THE AREA BY AFTERNOON...LEAVING MOSTLY
CLOUDY SKIES FOR A TIME BEFORE SOME CLEARING DEVELOPS LATE IN THE
DAY. WITH SOME EXPECTED LATE DAY SUN...HIGH TEMPERATURES SHOULD END
UP AROUND 5 DEGREES WARMER THAN TUESDAY RANGING FROM THE MID TO
UPPER 40S IN THE HIGHER TERRAIN AND LOWER TO MID 50S IN THE VALLEYS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
TONIGHT SOME RIDGING ALOFT WILL TAKE PLACE...AS SURFACE HIGH
PRESSURE CONTINUES TO MOVE AWAY FROM THE EASTERN SEABOARD. A WARM
FRONT WILL APPROACH FROM THE OHIO VALLEY...RESULTING IN INCREASING
CLOUDS BY DAYBREAK THURSDAY. TEMPERATURES WILL BE MILDER THAN RECENT
NIGHTS.
HALLOWEEN LOOKS TO BE A CLOUDY AND SOMEWHAT WET DAY ACROSS THE
REGION...AS THE WARM FRONT PROGRESSES NORTHWARD INTO THE AREA AND
ISENTROPIC LIFT INCREASES ON THE 295K SURFACE. QPF LOOKS TO BE
RELATIVELY LIGHT...BUT THERE IS EXPECTED TO BE AN AREAL INCREASE IN
SHOWERS DURING THE AFTERNOON AND EVENING. WILL MENTION LIKELY TO
CATEGORICAL POPS BY EVENING FOR MUCH OF THE AREA...ALTHOUGH THE
SHOWER ACTIVITY COULD BE MORE INTERMITTENT FROM AROUND SOUTHERN
DUTCHESS COUNTY EASTWARD TO LITCHFIELD CT. IT WILL AT LEAST BE
MILD...ESPECIALLY COMPARED TO RECENT DAYS WITH TEMPS IN THE MID 50S
TO LOWER 60S EVEN INTO THE EVENING HOURS AS A SOUTHERLY BREEZE
INCREASES.
LATE THURSDAY NIGHT INTO FRIDAY MORNING...A POWERFUL LOW PRESSURE
SYSTEM WILL DEEPEN RAPIDLY OVER THE UPPER GREAT LAKES INTO SOUTHEAST
CANADA IN RESPONSE TO A STRONG UPPER LEVEL TROUGH LIFTING
NORTHEASTWARD ACROSS THE MIDWEST. MODEL GUIDANCE IN RELATIVELY GOOD
AGREEMENT WITH THE TRACK AND STRENGTH OF THIS SYSTEM...SHOWING A
970-975 MB SURFACE CYCLONE TRACKING NORTHEASTWARD INTO CENTRAL
QUEBEC ON FRIDAY...WITH A TRAILING OCCLUDED FRONT CROSSING OUR AREA
FRIDAY MORNING.
AS IS TYPICALLY SEEN WITH SUCH A STRONG STORM...THE WIND FIELD ALOFT
IS FORECAST TO BE QUITE INTENSE WITH A 60+ KT 850 MB SOUTH-SOUTHWEST
JET MOVING OVER OUR REGION. BASED ON CLIMO...THE PARENT STORM LOOKS
TO TRACK A BIT TOO FAR NORTH TO PRODUCE WIDESPREAD PROLONGED STRONG
WINDS ACROSS OUR AREA...HOWEVER THERE ARE SOME FAVORABLE FACTORS FOR
SOME AREAS POTENTIALLY EXPERIENCING STRONG WINDS. THE ENVIRONMENT
INITIALLY DOES NOT LOOK FAVORABLE FOR MIXING DURING THE OVERNIGHT
AND EARLY MORNING HOURS FRIDAY...HOWEVER SOME OF THE HIGHER
ELEVATIONS WITH SOUTH-SOUTHWEST FACING SLOPES MAY EXPERIENCE STRONG
WINDS. ALSO...THE REST OF THE AREA INCLUDING VALLEY LOCATIONS MAY
HAVE A TIME WINDOW FOR STRONGER WINDS MIXING DOWN FRIDAY MORNING
INTO THE AFTERNOON...AS FORECAST SOUNDINGS IN BUFKIT SHOWING GOOD
MOMENTUM TRANSFER ASSOCIATED WITH SHOWERS ALONG THE FRONT AND EVEN
POST-FRONTAL PASSAGE INTO FRIDAY AFTERNOON. WILL NOT ISSUE ANY
WATCHES FOR NOW...BUT WILL CONTINUE TO MENTION POTENTIAL IN THE HWO.
IN TERMS OF PRECIPITATION...WIDESPREAD RAIN IS EXPECTED FROM
THURSDAY NIGHT INTO FRIDAY MORNING. DUE TO THE STRONG
SOUTH-SOUTHWEST FLOW ALOFT...RAINFALL ENHANCEMENT IS LIKELY ACROSS
THE HIGHER TERRAIN OF THE SOUTHERN ADIRONDACKS...WHERE CLOSE TO TWO
INCHES MAY FALL. LESSER AMOUNTS ARE EXPECTED ELSEWHERE. FLOODING IS
NOT EXPECTED...SEE HYDRO SECTION FOR DETAILS. RAIN SHOULD TAPER OFF
TO SCATTERED SHOWERS FRIDAY AFTERNOON IN WAKE OF THE FRONTAL
PASSAGE. TEMPERATURES WILL LIKELY SPIKE EARLY FRIDAY
AFTERNOON...ONCE DEEPER MIXING OCCURS BEHIND THE OCCLUDED FRONT.
HIGHS IN THE UPPER 60S TO LOWER 70S ARE POSSIBLE FROM THE MOHAWK AND
UPPER HUDSON VALLEY SOUTH AND EAST...INCLUDING THE CAPITAL REGION.
THE WARMTH WILL BE ACCOMPANIED BY WINDY CONDITIONS THOUGH.
MAINLY DRY CONDITIONS ARE EXPECTED FRIDAY NIGHT AS THE STORM SYSTEM
LIFTS NORTHEASTWARD INTO THE CANADIAN MARITIMES. THERE COULD BE A
FEW LAKE ENHANCED SHOWERS OVER THE WESTERN ADIRONDACKS.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
THE MODEL GUIDANCE IS IN GENERAL AGREEMENT IN REGARDS TO THE
LONGWAVE PATTERN...TROUGH MOVES EASTWARD ACROSS THE EASTERN UNITED
STATES OVER THE WEEKEND AS SHORT WAVE ENERGY ROTATES THROUGH IT. AT
THE SURFACE...A WAVE OF LOW PRESSURE IS EXPECTED TO FORM ALONG A
COLD FRONTAL BOUNDARY MOVING OFF THE EAST IN RESPONSE TO A SHORT
WAVE ROTATING THROUGH THE BASE OF THE TROUGH...WHILE A SECONDARY
COLD FRONT MOVES ACROSS THE REGION WHICH WILL USHER IN A MUCH COLDER
AIRMASS. HEIGHTS WILL BEGIN TO RISE AS WE HEAD INTO NEXT WEEK AND
RIDGING BUILDS IN OVER THE EASTERN UNITED STATES AS TROUGH DIGS OVER
THE PLAINS. AT THE SURFACE...CANADIAN HIGH PRESSURE BUILDS IN
CRESTING OVER THE REGION MONDAY...THEN SHIFTING OFF THE NEW ENGLAND
COAST TUESDAY.
THE WEATHER WILL REMAIN UNSETTLED OVER THE WEEKEND WITH SOME RAIN
AND SNOW SHOWERS ESPECIALLY TO THE NORTH AND WEST OF THE CAPITAL
DISTRICT AND DOWNWIND FROM LAKE ONTARIO. DRY WEATHER IS EXPECTED
FOR THE START OF THE NEW WORK WEEK WITH RIDGING IN CONTROL AT THE
SURFACE AND ALOFT.
TEMPERATURES WILL COOL TOWARD SEASONABLE LEVELS SATURDAY. HOWEVER ON
SUNDAY...THE PRESSURE GRADIENT IS EXPECTED TO TIGHTEN UP RESULTING
IN BRISK AND GUSTY NORTHWESTERLY WINDS WHICH WILL USHER IN EVEN
COLDER AIR. HIGHS SUNDAY ARE ANTICIPATED TO BE BELOW NORMAL WITH
SUNDAY NIGHT LOOKING TO BE THE COLDEST NIGHT OF THE SEASON WITH
LOWS ACROSS THE FORECAST AREA DROPPING INTO THE 20S WITH TEENS
POSSIBLE ACROSS PORTIONS OF THE WESTERN ADIRONDACKS. THE LAST TIME
WE HAD WIDESPREAD TEMPERATURES THIS COLD WAS BACK IN EARLY APRIL.
TEMPERATURES SHOULD MODERATE CLOSE TO SEASONABLE LEVELS ON TUESDAY
AS THE HIGH SHIFTS OFFSHORE AND A SOUTHERLY FLOW DEVELOPS.
&&
.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD...06Z/THURSDAY. A
QUICK MOVING SHORT WAVE TROUGH WILL PASS OVER THE REGION THIS
MORNING AND MOVE OFF TO THE EAST THIS AFTERNOON. MOISTURE IS RATHER
LIMITED AND ONLY ISOLATED TO SCATTERED LIGHT RAIN/SNOW SHOWERS ARE
EXPECTED. OVERALL CHANCES ARE TOO LOW TO WARRANT MENTION OF SHOWERS
IN TAFS. THE THREAT FOR SHOWERS WILL END BY LATE MORNING AS THE
TROUGH PASSES OVERHEAD. CLOUDS COVER WILL DECREASE BY LATE AFTERNOON
INTO THE EVENING AS SOME RIDGING BUILDS IN.
CALM WINDS WILL EVENTUALLY BECOME SOUTHWEST AT KALB AND
KPOU...WESTERLY AT KPSF AND SOUTHERLY AT KGFL BY AFTERNOON. WINDS
WILL BE LIGHT AT LESS THAN 10 KNOTS AND ARE EXPECTED TO DIMINISH
DURING THE EVENING.
OUTLOOK...
THU NIGHT: HIGH OPERATIONAL IMPACT. BREEZY. DEFINITE RA.
FRI: HIGH OPERATIONAL IMPACT. WINDY. DEFINITE SHRA.
FRI NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
SAT-SAT NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
SUN: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
SUN NIGHT-MON: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.FIRE WEATHER...
A WEAK UPPER LEVEL DISTURBANCE WILL CROSS THE REGION INTO THIS
MORNING...BRINGING ISOLATED TO SCATTERED RAIN AND SNOW SHOWERS
MAINLY OVER THE HIGHER ELEVATIONS. A MORE SIGNIFICANT STORM SYSTEM
WILL IMPACT THE REGION LATE IN THE WEEK...AS A STRONG AREA OF LOW
PRESSURE TRACKS ACROSS SOUTHERN CANADA BRINGING WIDESPREAD RAIN AND
WIND TO THE AREA THURSDAY NIGHT INTO FRIDAY.
MINIMUM RELATIVE HUMIDITY VALUES WILL ONLY DROP TO AROUND 50 TO 60
PERCENT THIS AFTERNOON...THEN INCREASE TO NEAR 100 PERCENT TONIGHT.
RH VALUES WILL BE HIGH ON THURSDAY...WITH MINIMUM VALUES ONLY AROUND
65 TO 75 PERCENT.
WINDS TODAY WILL BE WESTERLY AROUND 5 TO 10 MPH...BECOMING SOUTH
LESS THAN 5 MPH TONIGHT. WINDS ON THURSDAY ARE EXPECTED TO BE
SOUTHERLY AROUND 10 TO 15 MPH.
&&
.HYDROLOGY...
NO HYDRO ISSUES ARE ANTICIPATED THROUGH THE PERIOD. OVERALL RIVER
AND STREAM LEVELS ARE NEAR TO SLIGHTLY BELOW NORMAL FOR LATE
OCTOBER.
ISOLATED TO SCATTERED LIGHT PRECIPITATION...LESS THAN ONE TENTH OF
AN INCH LIQUID EQUIVALENT...IS EXPECTED FROM A WEAK UPPER LEVEL
DISTURBANCE THIS MORNING.
A STRONGER SYSTEM LOOKS TO IMPACT THE REGION THURSDAY INTO
FRIDAY WITH WIDESPREAD RAINFALL EXPECTED. AS OF NOW...DUE TO THE
EXPECTED PROGRESSIVE NATURE OF THIS SYSTEM AND RECENT DRY ANTECEDENT
CONDITIONS...RAINFALL SHOULD NOT BE HEAVY ENOUGH TO CAUSE HYDRO
PROBLEMS. QPF AMOUNTS ARE EXPECTED TO RANGE FROM HALF AN INCH TO AN
INCH AND A HALF...WITH ISOLATED AMOUNTS NEAR TWO INCHES. THIS WILL
LIKELY CAUSE SOME WITHIN BANK RISES ON MAIN STEM RIVERS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...JPV
NEAR TERM...JPV
SHORT TERM...JPV
LONG TERM...IAA
AVIATION...IAA
FIRE WEATHER...JPV
HYDROLOGY...JPV
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
858 PM EDT THU OCT 31 2013
.PREV DISCUSSION... /ISSUED 320 PM EDT THU OCT 31 2013/
SHORT TERM /TONIGHT THROUGH FRIDAY/...
OBVIOUSLY THE MAIN QUESTION THROUGH THE SHORT TERM IS TIMING OF THE
FRONT AND PRECIP ASSOCIATED WITH IT. DEEP UPPER TROUGH OVER THE
CENTER OF THE COUNTRY IS BEGINNING TO LIFT OUT. STRONG SURFACE LOW
OVER THE GREAT LAKES WILL CONTINUE MOVING NORTHEAST...DRAGGING A
COLD FRONT THROUGH THE SOUTHEAST TONIGHT AND TOMORROW AS THE SURFACE
LOW OCCLUDES. MOST OF THE PRECIP WILL BE OUT OF THE AREA BY THE END
OF THE SHORT TERM WITH THE EXCEPTION OF EXTREME SOUTHEAST ZONES.
STRONG SOUTHERLY FLOW IS IN PLACE ACROSS THE SOUTHEAST AHEAD OF THE
FRONT AT AFD TIME...WITH SOME PATCHY RETURNS SHOWING UP HERE AND
THERE ON RADAR. IT IS DOUBTFUL THAT ANYTHING IS REACHING THE GROUND
FROM THESE WEAK ECHOES BUT THEIR EXISTENCE DOES LEND SOME CREDENCE
TO THE HRRR SOLUTION FOR THIS AFTERNOON AND EARLY EVENING. GUIDANCE
IS ALL REALLY COMING INTO AGREEMENT WITH THE PROGRESSION OF THE
FRONT AND IT LOOKS LIKE FOR THE MOST PART THE CWA WILL REMAIN
PRECIP-FREE UNTIL AFTER 00Z. MAY SEE SOME SPRINKLES NORTHWEST BUT
REALLY HAVE NOT STARTED INCREASING POPS UNTIL AFTER THAT POINT.
SHOULD ENCROACH UPON THE METRO AREA NEAR OR JUST AFTER MIDNIGHT...
AND TOWARDS CENTRAL GEORGIA /MACON AREA/ BY 12Z. SO TRICK-OR-
TREATING SHOULD BE IN GOOD SHAPE THIS EVENING.
ONTO SOME DETAILS...STARTING WITH QPF...NOT OVERLY CONCERNED ABOUT
OVERALL BASIN-AVERAGE VALUES WHICH GENERALLY REMAIN BELOW AN INCH
THROUGH THE EVENT. NAM IS A LITTLE MORE AGGRESSIVE WITH QPF VALUES
ESPECIALLY 12-18Z FRIDAY BUT IT SEEMS TO BE A BIT OF AN OUTLIER.
CANNOT RULE OUT SOME ISOLATED PRECIP ISSUES ESPECIALLY WITH ANY
OROGRAPHIC ENHANCEMENT IN THE NORTH GEORGIA MOUNTAINS...BUT THAT
WILL HAVE TO BE HANDLED ON A CASE-BY-CASE BASIS.
OTHER CONCERN IS SEVERE POTENTIAL. AS IS ALWAYS THE CASE...NAM IS
MORE UNSTABLE THAN OTHER GUIDANCE BUT THE GFS IS COMING IN WITH
SLIGHTLY HIGHER MUCAPE FRIDAY AFTERNOON THAN PREVIOUS RUNS WITH OVER
700 J/KG...NOT THAT DIFFERENT FROM THE NAM. EXPECT THAT ANY PRECIP
THIS EVENING AND THROUGH MOST OF THE OVERNIGHT PERIOD WILL REMAIN AS
SHOWERS...THOUGH DID BRING SLIGHT CHANCE THUNDER IN STARTING AT 06Z
NORTHWEST...BUT GENERALLY ONLY WHERE POPS ARE LIKELY OR HIGHER.
SWATH OF INSTABILITY WILL BE ACROSS THE METRO AREA BY AROUND
12Z...AND CENTRAL GEORGIA BY 18Z. SO OVERALL VERY...VERY LITTLE
INSTABILITY TO WORK WITH BUT WHEN CONTRASTED WITH THE VERY STRONG
SHEAR...WE CANNOT LET OUR GUARD DOWN. 0-1KM BULK SHEAR VALUES BY 06Z
TONIGHT ARE OVER 40KT IN NORTHWEST GEORGIA...WITH 60-70KT 0-6KM
SHEAR. 0-1KM SHEAR DROPS OFF THROUGH TIME TO GENERALLY BELOW 35KT BY
12Z FRIDAY...AND LESS THAN 30KT BY 18Z FRIDAY...BUT DEEP LAYER SHEAR
REMAINS QUITE STRONG AT OVER 60KT. SO WE HAVE A TREND OF INCREASING
INSTABILITY FROM 06-18Z FRIDAY AND DECREASING SHEAR. SOMEWHERE IN
THERE A PERFECT JUXTAPOSITION CANNOT BE RULED OUT. SPC HAS A SEE
TEXT FOR DAY2 ACROSS CENTRAL GEORGIA AND SREF GUIDANCE SEEMS TO
POINT TO FRIDAY LATE MORNING AND EARLY AFTERNOON BEING OF GREATER
CONCERN THAN OVERNIGHT TONIGHT. SHERB PARAMETER...WHICH WAS
CALIBRATED TO INDICATE A FAVORABLE ENVIRONMENT FOR HIGH SHEAR LOW
CAPE SEVERE WEATHER...IS MAXIMIZED LATE THIS EVENING IN NORTHWEST
GEORGIA WITH ANOTHER MAXIMUM JUST BEFORE 18Z TOMORROW /RIGHT BEFORE
FROPA/ AROUND THE METRO AREA.
OF COURSE...ALL THAT SAID /OR WRITTEN/...OVERALL CONCERN FOR SEVERE
IS NOT PARTICULARLY HIGH. IT JUST CANNOT BE RULED OUT.
USED A BLEND FOR TEMPERATURES BUT PULLED BACK ON BIAS ADJUSTMENT DUE
TO WIDESPREAD CLOUDS AND IMPENDING AIRMASS CHANGE.
TDP
LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
COLD FRONT EXPECTED TO EXIT THE SE CWA FRIDAY NIGHT WITH PRECIP
CHANCES DIMINISHING. UPPER TROUGH MOVES ACROSS THE AREA ON SATURDAY
WITH SOME MOISTURE ASSOCIATED OVER THE FAR NORTHERN COUNTIES. CAN
NOT RULE OUT SOME LIGHT SHOWERS OR SPRINKLES DURING THE DAY.
TEMPERATURES TRENDING TO BELOW NORMAL INTO EARLY NEXT WEEK.
BDL
PREVIOUS DISCUSSION...
MODELS IN GOOD AGREEMENT WITH CONTINUING TO PUSH THE COLD FRONT AND
ASSOCIATED MOISTURE OUT OF THE CWA BY SATURDAY MORNING LEAVING THE
LONG TERM DRY UNTIL THE MIDDLE OF NEXT WEEK. THE H5 TROUGH WILL EXIT
THE U.S. SATURDAY WITH A RIDGE BUILDING OVER THE EASTERN U.S. SUNDAY
THROUGH EARLY NEXT WEEK. SOME DIFFERENCES IN THE NEXT SYSTEM APPEAR
BETWEEN THE 00Z GFS AND THE 12Z ECMWF WITH THE ECMWF HOLDING ONTO
THE H5 HIGH OVER THE SOUTHEAST WHILE THE GFS WEAKENS THE HIGH AND
BRINGS A FAST MOVING TROUGH AND ASSOCIATED COLD FRONT INTO THE CWA
BY WEDNESDAY NIGHT AND THURSDAY. AT THIS TIME WILL MAINTAIN CHANCE
POPS BEGINNING WEDNESDAY.
17
&&
.AVIATION...
00Z UPDATE...
RAIN IS MOVING INTO NW GA WITH CEILINGS BEGINNING TO COME DOWN.
CEILINGS ARE STILL VFR BU THEY SHOULD BE DOWN INTO THE MVFR RANGE
BY 04Z-06Z. WINDS HAVE TURNED TO THE SW AND WILL TURN TO THE WEST
AND EVENTUALLY NW BY THE END OF THE TAF PERIOD. WIND SPEEDS IN THE
8-12KT RANGE AND EXPECTED TO STAY THERE THROUGH THE NIGHT WILL
ALSO SEE GUST TO 18KT THROUGH 12Z. WIND SPEEDS WILL DIMINISH SOME
AFTER THE FRONT MOVES THROUGH BY 16-18Z. VSBYS WILL STAY IN THE VFR
TO MVFR RANGE. MAY SEE SOME BRIEF PERIODS OF IFR VSBYS IN AND
AROUND ANY STRONGER CONVECTION.
//ATL CONFIDENCE...00Z UPDATE...
CONFIDENCE MEDIUM ON ALL ELEMENTS.
01
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 64 70 48 69 / 100 100 10 0
ATLANTA 63 71 50 67 / 100 100 10 0
BLAIRSVILLE 58 71 43 61 / 100 80 10 20
CARTERSVILLE 65 73 44 67 / 100 70 5 0
COLUMBUS 69 73 51 72 / 90 100 10 0
GAINESVILLE 62 72 49 67 / 100 100 10 10
MACON 67 74 49 74 / 60 100 20 0
ROME 63 72 43 66 / 100 40 5 0
PEACHTREE CITY 66 72 45 69 / 100 100 10 0
VIDALIA 66 78 58 76 / 30 90 80 0
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...01
LONG TERM....NLISTEMAA
AVIATION...01
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1009 PM CDT THU OCT 31 2013
.DISCUSSION...
815 PM CDT
RAIN CONTINUES TO WIND DOWN FROM WEST TO EAST ACROSS THE CWA THIS
EVENING. SOUTHEAST AREAS ARE STILL RECEIVING A GOOD COVERAGE OF
RAIN BUT THIS WILL BE ENDING THROUGH LATE EVENING AS DRIER AIR
SPREADS EAST. AN UPPER LEVEL TROUGH AXIS CONTINUES TO SWING
EASTWARD ACROSS THE MISSISSIPPI RIVER AND WILL CROSS THE AREA
THROUGH THE EVENING AS IT BECOMES NEGATIVELY TILTED. THE
ASSOCIATED DEFORMATION ZONE PRECIPITATION HAS BEEN DECREASING IN
COVERAGE ACROSS EASTERN IOWA AND EXPECT ONLY SPOTTY LIGHT RAIN OR
SPRINKLES TO AFFECT THE AREA ONCE THE MAIN BAND OF PRECIP EXITS. THE
ASSOCIATED SURFACE LOW CONTINUES TO STEADILY DEEPEN...LOSING ABOUT
A MILLIBAR PER HOUR AS IT BEGINS TO CONSOLIDATE ACROSS LOWER
MICHIGAN. THE RAPID DEEPENING THAT WILL TAKE PLACE AS THE UPPER
LOW CATCHES UP TO IT OVER THE NEXT SEVERAL HOURS WILL LIKELY
RESULT IN AT LEAST SOME MODEST INCREASE IN WINDS THROUGH THE
EVENING AS THE PRESSURE GRADIENT TIGHTENS BEHIND THE TROUGH AND
BEST PRESSURE RISES PASS BY THE AREA. GOING FORECAST IN GOOD SHAPE
AND HAVE ONLY REFINED THE DECREASING TREND IN POPS AND TWEAKED
HOURLY TEMPS THROUGH THE EVENING.
MDB
//PREV DISCUSSION...
310 PM CDT
THE FORECAST CHALLENGES THIS FINAL DAY OF OCTOBER WERE FOCUSED
EARLY ON WITH CONVECTIVE CHANCES...RAIN TIMING AND AMOUNTS...AND
WINDS THROUGH THIS EVE. OTHERWISE THE WEATHER LOOKS FAIRLY CALM
DURING THE FIRST WEEKEND OF NOV BEFORE THE NEXT PRONOUNCED MID-
LATITUDE SYSTEM POTENTIALLY DURING MIDWEEK.
SYNOPSIS...PROGRESSIVE AND VERY-WELL DEFINED UPPER WAVE ACROSS
CENTRAL MO THIS MID-AFTERNOON WILL ROTATE EAST OVER THE AREA THIS
EVENING...BRINGING A LARGE SCALE NEGATIVE TILT TO THE MIDWEST TROUGH
AS A WHOLE. DRY SLOT OF THE SYSTEM IS ENCROACHING IN ON THE AREA
WITH MODE OF RAIN ACTIVITY BECOMING MORE SHOWER-LIKE ACROSS
CENTRAL IL AND INTO THE SOUTHERN FORECAST AREA. CONSOLIDATING
SURFACE LOWS OVER THE CWA ARE A RESULT OF THE DEEP UPWARD
ASCENT...AND 5-7MB/3HR PRESSURE FALLS ARE CURRENTLY BEING OBSERVED
OVER MUCH OF THE AREA. THIS LOW WILL BE VERY NEAR A BOMB BY
DEFINITION THROUGH TONIGHT AS IT DEEPENS INTO LOWER MICHIGAN AND
TO 970-975MB JUST EAST OF LAKE HURON BY EARLY FRIDAY. THE SURFACE
COLD FRONT IS DRAPED ACROSS THE FAR WESTERN FORECAST AREA AS OF 3
PM AND THIS WILL INCH EASTWARD THIS EVE...WITH CONVECTIVE CHANCES
MAINLY AHEAD OF THIS WHERE OVERALL HIGHER MOISTURE
CONTENT/TRANSPORT REMAINS.
LATE THIS AFTERNOON AND TONIGHT...AS MID-LEVEL JET AND DRY SLOT
ROTATE OVERHEAD...THE SHOWER MODE SHOULD CONTINUE TO BECOME MORE
PREVALENT THROUGH LATE THIS AFTERNOON. THERE HAD BEEN A BAND OF
MORE ROBUST SHOWERS NEAR THE FRONT IN CENTRAL IL WITH 30-40 KT
WINDS JUST OFF THE SURFACE BUT THAT HAS DISSIPATED SINCE 230 PM.
IN ADDITION...MORE SHOWERS AND STORMS CONTINUE TO FIRE OVER
SOUTHERN IL...AND FURTHER SOUTH THAN THAT...ALL WHICH MAY BEGIN TO
LIMIT COVERAGE OF SHOWERS AND STORMS THAT DEVELOP THIS FAR NORTH
THROUGH THE NEXT SEVERAL HOURS. STILL EXPECT AT LEAST SCATTERED
DEVELOPMENT AHEAD OF THE FRONT AND ANY SHOWERS OR STORMS
IMMEDIATELY ON THE FRONT ITSELF WILL REMAIN THE MOST PROBABLE TO
HAVE AT LEAST A LIMITED GUSTY WIND POTENTIAL. WITH SCATTERING OF
CLOUDS LOOKING HIGHLY UNLIKELY TO MAKE IT TO THE SOUTHEAST
FORECAST AREA...THE POTENTIAL TO REALIZE LOW-LEVEL CAPE ALSO LOOKS
HIGHLY DIMINISHED. WHILE THE FRONT WILL END THE POTENTIAL FOR
THUNDER BY 7 PM...THERE WILL LINGER A COUPLE HOUR PERIOD BEHIND
THE FRONT INTO EARLY TO MID EVE WHERE SOME SCATTERED SHOWERS MAY
PERSIST AS THE UPPER LOW PASSES OVERHEAD.
AS THE PRESSURE RISES BEGIN TO BE SEEN ASSOCIATED WITH THE
DOWNWARD MOTION OF THE JET AND LOW-LEVEL COLD AIR ADVECTION...THE
ISALLOBARIC COUPLET WILL BECOME MORE AND MORE PRONOUNCED. WHILE
THERE IS LITTLE IN THE WAY OF WIND UPSTREAM TO OUR WEST AND
SOUTHWEST...EXPECT THAT HIGHER GUSTS WILL PRETTY MUCH DEVELOP
RIGHT OVER THE CWA...PARTICULARLY THE SOUTH AND EAST BY EARLY EVE.
LOOKING AT THE LATEST RAP AND NAM SOUNDINGS CONTINUE TO SUPPORT
TEMPORARY GUST POTENTIAL AROUND 40 MPH BETWEEN 6 AND 10 PM OR SO.
THE BEST CHANCES REMAIN SOUTH OF CHICAGO BUT CANNOT RULE OUT SOME
OF THE WIND POTENTIAL REACHING THAT FAR NORTH.
FRIDAY...NORTHWEST FLOW WILL DEVELOP OVER THE AREA INTO THE FIRST
HALF OF THIS WEEKEND...WITH A COUPLE UPPER SHORT WAVES DIVING OVER
THE AREA FRIDAY AFTERNOON AND MORE SO IN THE EVE. SATURATED LAYER
LOOKS SHALLOW AT FIRST BUT LATE IN THE AFTERNOON INTO THE
EVE...NAMELY OVER FAR NORTHERN AND NORTHEASTERN IL...IT LOOKS DEEP
ENOUGH TO SUPPORT SOME SHOWERS. SO MAINTAIN THE CHANCES WHICH
GENERALLY HAD A GOOD LOOKING ORIENTATION AND MAGNITUDE IN OUR
FORECAST. HIGHS WILL BE BACK DOWN INTO THE 50S...WITH A FEW UPPER
40S NEAR THE STATE LINE.
THIS WEEKEND...LITTLE IN THE WAY OF CHANGE TO THIS PART OF THE
FORECAST. SAT NIGHT SHOULD BE A COOL NIGHT WITH RIDGING
OVERHEAD...BUT ALL IN ALL ONLY ABOUT 5 DEGREE BELOW NORMAL.
MTF
LONG TERM...SUNDAY NIGHT THROUGH THURSDAY...
PRIMARY CONCERN IN THE EXTENDED PERIOD IS WHAT COULD POTENTIALLY BE
ANOTHER SIGNIFICANT RAIN EVENT FOR THE CWA LATER TUESDAY INTO
WEDNESDAY. THERE IS GOOD AGREEMENT AMONGST OPERATIONAL AND ENSEMBLE
GUIDANCE IN THE MID RANGE IN THE UPPER PATTERN TRANSITIONING TO
BROAD TROUGHING OVER WESTERN NOAM AND A RIDGE SETTING UP OVER THE
EASTERN THIRD OF THE CONUS...AND THIS STRENGTHENING TO ALMOST SUMMER
TIME HEIGHTS OFF THE SOUTHEAST COAST BY TUESDAY AND
WEDNESDAY...NEARING 590 DM. THIS WILL PUT OUR REGION INTO BROAD
SOUTHWEST FLOW ALOFT. AT THE SURFACE...HIGH PRESSURE OVER THE AREA
DURING THE WEEKEND WILL SLIDE EAST AND STRENGTHEN OVER THE NORTHEAST
TUESDAY AND WEDNESDAY...WHILE THE WESTERN TROUGH WILL SPUR INITIALLY
WEAK SURFACE CYCLOGENESIS OVER THE SOUTHERN AND CENTRAL PLAINS. THIS
LOW WILL STRENGTHEN AND THEN TRACK TOWARD THE NORTHERN LAKES ON
WEDNESDAY.
INCREASING WAA AND STEADY SOUTHEAST FLOW WILL RESULT IN A MILDER
NIGHT SUNDAY NIGHT...WITH TEMPERATURES WARMING TO 4 TO 5 DEGREES
ABOVE CLIMO ON MONDAY. RAIN CHANCES ARRIVE PRIMARILY OVER NORTHWEST
HALF OF CWA MONDAY NIGHT AS LOW LEVEL JET INCREASES MOISTURE
TRANSPORT WITH A WARM FRONT LIFTING NORTH. POPS WILL CONTINUE TO BE
FOCUSED NORTHWEST HALF ON TUESDAY...WITH THERMAL PROFILES POSSIBLY
SUPPORTIVE OF 60+ DEGREE READINGS IN THE SOUTHEAST HALF DEPENDING ON
CLOUD COVER. TUESDAY NIGHT INTO WEDNESDAY IS THE BIGGEST PERIOD OF
CONCERN AS LOW LEVEL JET WILL FURTHER INCREASE TO 40 TO POSSIBLY 50
KT...WITH TONGUE OF PWAT AROUND OR A BIT OVER 1.25 INCHES
TRANSPORTED OVER AREA...WHICH IS ALMOST 250% OF NORMAL FOR NOVEMBER.
EXPECTING TO SEE PERIODS OF RAIN WITH SHORTWAVES EMANATING FROM
TROUGH TO WEST LIKELY RIDING INTO AREA IN SOUTHWEST MID FLOW. STRONG
SURFACE SOUTHERLY FLOW WILL ALSO LIKELY RESULT IN LOW TEMPERATURES
AROUND OR ABOVE NORMAL HIGHS...AT LEAST INTO THE LOW 50S AND RISING
TEMPERATURES TOWARD DAYBREAK WEDNESDAY A NICE SPRINGBOARD FOR
POSSIBLY SEEING SOME 60 DEGREE READINGS AGAIN IN SOUTHEAST HALF OF
CWA. PRIOR TO COLD FRONT PASSAGE ON WEDNESDAY...SYNOPTIC PATTERN
APPEARS FAVORABLE FOR ANOTHER POSSIBLY 1 INCH PLUS RAIN EVENT.
DESPITE IT BEING SEVERAL DAYS OUT...FELT THERE WAS ENOUGH AGREEMENT
AND RUN TO RUN CONSISTENCY IN GUIDANCE TO MAINTAIN LIKELY POPS IN
TUES NIGHT THROUGH WEDNESDAY PERIOD.
MAIN UNCERTAINTY IS WITH HOW PROGRESSIVE TROUGH PASSAGE IS...AS
LATEST OPERATIONAL ECMWF TRENDED FASTER. GFS ENSEMBLES KEEP SOME LOW
POPS FOR EASTERN CWA INTO THURSDAY BUT IF TREND OF OPERATIONAL
MODELS TO HAVE SURFACE HIGH OVER AREA ON THURS COME TO
FRUITION...WILL LIKELY BE ABLE TO REMOVE MORNING POPS. 850 MB TEMPS
COOLING TO MID MINUS SINGLE DIGITS AND 925 MB AROUND 0C ON THURSDAY
SUPPORTS HIGHS A BIT BELOW NORMAL IN UPPER 40S.
CONFIDENCE IN SEEING RAIN TUESDAY INTO WEDNESDAY...MEDIUM-HIGH.
RC
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 03Z...
* MVFR CIGS THROUGH MUCH OF THE PERIOD WITH A SHORT PERIOD OF
IMPROVEMENT TO VFR TOMORROW AFTERNOON.
* GUSTY NNWLY WINDS BACKING TO WLY. GUSTS SUBSIDING FOR THE
OVERNIGHT HOURS.
KREIN
//DISCUSSION...UPDATED 00Z...
THE COLD FRONT HAS PUSHED THROUGH THE TERMINALS AND THE BULK OF
THE ASSOCIATED PCPN HAS MOVED OFF TO THE EAST. THERE MAY BE SOME
SCT SHRA FOR A FEW MORE HRS THIS EVENING...BUT SHOULD NOT BE A
PREVAILING CONDITION. WITH THE WARM..HUMID AIR PUSHING TO THE EAST
WITH THE COLD FRONT...COOLER AIR IS FILTERING IN ACROSS THE
REGION. THE IFR CIGS HAVE ENDED WITH THE LOSS OF THE WARM...HUMID
AIRMASS...BUT PERSISTENT COOL CYCLONIC FLOW ALOFT SHOULD KEEP MVFR
CIGS FOR MUCH OF THE REMAINDER OF THE PERIOD. SOME DIURNAL WARMING
TOMORROW AFTERNOON SHOULD ALLOW CIGS TO LIFT TO VFR FOR A BRIEF
PERIOD...BUT SHOULD THEN LOWER BACK TO MVFR AFTER SUNSET. WINDS
WILL WILL REMAIN GUSTY TO 20-25KT FOR A FEW HOURS FOLLOWING THE
FRONTAL PASSAGE WITH THE STRONGEST COLD ADVECTION...BUT SHOULD
THEN TAPER OFF FOR THE OVERNIGHT HOURS. ANOTHER MID LEVEL IMPULSE
DROPPING AROUND THE SWRN PERIPHERY OF THE MAIN UPPER LOW WILL
BRING ANOTHER SHOT OF REINFORCING COOLER AIR...BRINGING ANOTHER
CHANCE FOR SOME SCT SHRA AS WELL AS RENEWED GUSTINESS FOR THE LATE
AFTERNOON HOURS.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 03Z...
* MODERATE CONFIDENCE IN CIG TRENDS.
* MODERATE CONFIDENCE IN WIND TRENDS.
* MODERATE TO HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z...
SATURDAY...SLIGHT CHANCE OF SHOWERS EARLY...OTHERWISE VFR.
SUNDAY...VFR. WX NIL.
MONDAY...CHANCE OF SHOWERS LATE...OTHERWISE VFR.
TUESDAY...RAIN LIKELY. CHANCE MVFR CIGS/VIS.
WEDNESDAY...RAIN LIKELY EARLY THEN CHANCE OF SHOWERS. CHANCE
MVFR CIGS/VIS EARLY. VFR LIKELY LATE.
KREIN
&&
.MARINE...
209 PM CDT
DEVELOPING STORM SYSTEM THIS EVENING AS IT NEARS LAKE MICHIGAN. NO
CHANGES TO THE GOING HEADLINES OF GALES FOR THE ENTIRE LAKE AND
INDIANA NEARSHORE WATERS.
AN ELONGATED TROUGH OF LOW PRESSURE STRETCHED FROM CENTRAL WISCONSIN
SOUTH THROUGH SOUTHWEST ILLINOIS THIS AFTERNOON...AND IS FORECAST TO
CONSOLIDATE INTO A LOW OVER CENTRAL LAKE MICHIGAN EARLY THIS EVENING
AND RAPIDLY DEEPEN. AS THE LOW QUICKLY INTENSIFIES...THE PRESSURE
GRADIENT OVER THE LAKE WILL ALSO TIGHTEN. THIS WILL RESULT IN GALES
DEVELOPING WITH NEARLY 40-44KT ACROSS THE SOUTHERN HALF OF LAKE
MICHIGAN FROM THE WEST. TIMING CONTINUES TO BE AROUND MIDNIGHT. THE
STRONG LOW PRESSURE WILL CONTINUE TO DEEPEN AS IT SLIDES NORTHEAST
ACROSS NORTHEASTERN LAKE HURON INTO EASTERN ONTARIO AND WESTERN
QUEBEC FRI AFTN/EVE. THE GRADIENT WILL THEN QUICKLY DIMINISH LATE
FRI MORNING...WITH GALES ENDING BY MID-MORNING FRI.
WINDS WILL CONTINUE TO BE WESTERLY UNTIL THE UPPER LEVEL TROUGH
ARRIVES FRI EVE...THEN WINDS WILL TURN NORTHWESTERLY. A BROAD RIDGE
OF HIGH PRESSURE CONTINUES TO BE FORECAST TO SLIDE ACROSS THE
CENTRAL/SOUTHERN PLAINS. THIS WILL RESULT IN A PROLONGED PERIOD OF
NORTH/NORTHWEST WINDS FOR SAT. THE GRADIENT DOESN/T COMPLETELY GO
AWAY...WITH SPEEDS REMAINING ARND 10-20KT WITH GUSTS TO 25KT OVER
THE OPEN WATERS. THEN THIS HIGH PRESSURE SLIDES EAST AND STRETCHES
TO COVER LAKE MICHIGAN SAT NIGHT/SUN...WITH A PERIOD OF LIGHTER
WINDS. THE WEATHER REMAINS PROGRESSIVE AND THE HIGH PRESSURE WILL
PUSH EAST WITH WINDS SHIFTING TO SOUTHEASTERLY/SOUTHERLY FOR EARLY
NEXT WEEK.
FORECAST GUIDANCE IS BEGINNING TO POINT TOWARDS ANOTHER STRONG STORM
SYSTEM TO DEVELOP AND APPROACH THE GREAT LAKES REGION FOR THE MIDDLE
PART OF NEXT WEEK.
CONFIDENCE IN GALES TONIGHT/FRI MORNING...HIGH.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 9 AM FRIDAY.
GALE WARNING...INDIANA NEARSHORE WATERS UNTIL 4 AM FRIDAY.
SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 10 AM FRIDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
825 PM CDT THU OCT 31 2013
.DISCUSSION...
815 PM CDT
RAIN CONTINUES TO WIND DOWN FROM WEST TO EAST ACROSS THE CWA THIS
EVENING. SOUTHEAST AREAS ARE STILL RECEIVING A GOOD COVERAGE OF
RAIN BUT THIS WILL BE ENDING THROUGH LATE EVENING AS DRIER AIR
SPREADS EAST. AN UPPER LEVEL TROUGH AXIS CONTINUES TO SWING
EASTWARD ACROSS THE MISSISSIPPI RIVER AND WILL CROSS THE AREA
THROUGH THE EVENING AS IT BECOMES NEGATIVELY TILTED. THE
ASSOCIATED DEFORMATION ZONE PRECIPITATION HAS BEEN DECREASING IN
COVERAGE ACROSS EASTERN IOWA AND EXPECT ONLY SPOTTY LIGHT RAIN OR
SPRINKLES TO AFFECT THE AREA ONCE THE MAIN BAND OF PRECIP EXITS. THE
ASSOCIATED SURFACE LOW CONTINUES TO STEADILY DEEPEN...LOSING ABOUT
A MILLIBAR PER HOUR AS IT BEGINS TO CONSOLIDATE ACROSS LOWER
MICHIGAN. THE RAPID DEEPENING THAT WILL TAKE PLACE AS THE UPPER
LOW CATCHES UP TO IT OVER THE NEXT SEVERAL HOURS WILL LIKELY
RESULT IN AT LEAST SOME MODEST INCREASE IN WINDS THROUGH THE
EVENING AS THE PRESSURE GRADIENT TIGHTENS BEHIND THE TROUGH AND
BEST PRESSURE RISES PASS BY THE AREA. GOING FORECAST IN GOOD SHAPE
AND HAVE ONLY REFINED THE DECREASING TREND IN POPS AND TWEAKED
HOURLY TEMPS THROUGH THE EVENING.
MDB
&&
.PREV DISCUSSION...
310 PM CDT
THE FORECAST CHALLENGES THIS FINAL DAY OF OCTOBER WERE FOCUSED
EARLY ON WITH CONVECTIVE CHANCES...RAIN TIMING AND AMOUNTS...AND
WINDS THROUGH THIS EVE. OTHERWISE THE WEATHER LOOKS FAIRLY CALM
DURING THE FIRST WEEKEND OF NOV BEFORE THE NEXT PRONOUNCED MID-
LATITUDE SYSTEM POTENTIALLY DURING MIDWEEK.
SYNOPSIS...PROGRESSIVE AND VERY-WELL DEFINED UPPER WAVE ACROSS
CENTRAL MO THIS MID-AFTERNOON WILL ROTATE EAST OVER THE AREA THIS
EVENING...BRINGING A LARGE SCALE NEGATIVE TILT TO THE MIDWEST TROUGH
AS A WHOLE. DRY SLOT OF THE SYSTEM IS ENCROACHING IN ON THE AREA
WITH MODE OF RAIN ACTIVITY BECOMING MORE SHOWER-LIKE ACROSS
CENTRAL IL AND INTO THE SOUTHERN FORECAST AREA. CONSOLIDATING
SURFACE LOWS OVER THE CWA ARE A RESULT OF THE DEEP UPWARD
ASCENT...AND 5-7MB/3HR PRESSURE FALLS ARE CURRENTLY BEING OBSERVED
OVER MUCH OF THE AREA. THIS LOW WILL BE VERY NEAR A BOMB BY
DEFINITION THROUGH TONIGHT AS IT DEEPENS INTO LOWER MICHIGAN AND
TO 970-975MB JUST EAST OF LAKE HURON BY EARLY FRIDAY. THE SURFACE
COLD FRONT IS DRAPED ACROSS THE FAR WESTERN FORECAST AREA AS OF 3
PM AND THIS WILL INCH EASTWARD THIS EVE...WITH CONVECTIVE CHANCES
MAINLY AHEAD OF THIS WHERE OVERALL HIGHER MOISTURE
CONTENT/TRANSPORT REMAINS.
LATE THIS AFTERNOON AND TONIGHT...AS MID-LEVEL JET AND DRY SLOT
ROTATE OVERHEAD...THE SHOWER MODE SHOULD CONTINUE TO BECOME MORE
PREVALENT THROUGH LATE THIS AFTERNOON. THERE HAD BEEN A BAND OF
MORE ROBUST SHOWERS NEAR THE FRONT IN CENTRAL IL WITH 30-40 KT
WINDS JUST OFF THE SURFACE BUT THAT HAS DISSIPATED SINCE 230 PM.
IN ADDITION...MORE SHOWERS AND STORMS CONTINUE TO FIRE OVER
SOUTHERN IL...AND FURTHER SOUTH THAN THAT...ALL WHICH MAY BEGIN TO
LIMIT COVERAGE OF SHOWERS AND STORMS THAT DEVELOP THIS FAR NORTH
THROUGH THE NEXT SEVERAL HOURS. STILL EXPECT AT LEAST SCATTERED
DEVELOPMENT AHEAD OF THE FRONT AND ANY SHOWERS OR STORMS
IMMEDIATELY ON THE FRONT ITSELF WILL REMAIN THE MOST PROBABLE TO
HAVE AT LEAST A LIMITED GUSTY WIND POTENTIAL. WITH SCATTERING OF
CLOUDS LOOKING HIGHLY UNLIKELY TO MAKE IT TO THE SOUTHEAST
FORECAST AREA...THE POTENTIAL TO REALIZE LOW-LEVEL CAPE ALSO LOOKS
HIGHLY DIMINISHED. WHILE THE FRONT WILL END THE POTENTIAL FOR
THUNDER BY 7 PM...THERE WILL LINGER A COUPLE HOUR PERIOD BEHIND
THE FRONT INTO EARLY TO MID EVE WHERE SOME SCATTERED SHOWERS MAY
PERSIST AS THE UPPER LOW PASSES OVERHEAD.
AS THE PRESSURE RISES BEGIN TO BE SEEN ASSOCIATED WITH THE
DOWNWARD MOTION OF THE JET AND LOW-LEVEL COLD AIR ADVECTION...THE
ISALLOBARIC COUPLET WILL BECOME MORE AND MORE PRONOUNCED. WHILE
THERE IS LITTLE IN THE WAY OF WIND UPSTREAM TO OUR WEST AND
SOUTHWEST...EXPECT THAT HIGHER GUSTS WILL PRETTY MUCH DEVELOP
RIGHT OVER THE CWA...PARTICULARLY THE SOUTH AND EAST BY EARLY EVE.
LOOKING AT THE LATEST RAP AND NAM SOUNDINGS CONTINUE TO SUPPORT
TEMPORARY GUST POTENTIAL AROUND 40 MPH BETWEEN 6 AND 10 PM OR SO.
THE BEST CHANCES REMAIN SOUTH OF CHICAGO BUT CANNOT RULE OUT SOME
OF THE WIND POTENTIAL REACHING THAT FAR NORTH.
FRIDAY...NORTHWEST FLOW WILL DEVELOP OVER THE AREA INTO THE FIRST
HALF OF THIS WEEKEND...WITH A COUPLE UPPER SHORT WAVES DIVING OVER
THE AREA FRIDAY AFTERNOON AND MORE SO IN THE EVE. SATURATED LAYER
LOOKS SHALLOW AT FIRST BUT LATE IN THE AFTERNOON INTO THE
EVE...NAMELY OVER FAR NORTHERN AND NORTHEASTERN IL...IT LOOKS DEEP
ENOUGH TO SUPPORT SOME SHOWERS. SO MAINTAIN THE CHANCES WHICH
GENERALLY HAD A GOOD LOOKING ORIENTATION AND MAGNITUDE IN OUR
FORECAST. HIGHS WILL BE BACK DOWN INTO THE 50S...WITH A FEW UPPER
40S NEAR THE STATE LINE.
THIS WEEKEND...LITTLE IN THE WAY OF CHANGE TO THIS PART OF THE
FORECAST. SAT NIGHT SHOULD BE A COOL NIGHT WITH RIDGING
OVERHEAD...BUT ALL IN ALL ONLY ABOUT 5 DEGREE BELOW NORMAL.
MTF
LONG TERM...SUNDAY NIGHT THROUGH THURSDAY...
PRIMARY CONCERN IN THE EXTENDED PERIOD IS WHAT COULD POTENTIALLY BE
ANOTHER SIGNIFICANT RAIN EVENT FOR THE CWA LATER TUESDAY INTO
WEDNESDAY. THERE IS GOOD AGREEMENT AMONGST OPERATIONAL AND ENSEMBLE
GUIDANCE IN THE MID RANGE IN THE UPPER PATTERN TRANSITIONING TO
BROAD TROUGHING OVER WESTERN NOAM AND A RIDGE SETTING UP OVER THE
EASTERN THIRD OF THE CONUS...AND THIS STRENGTHENING TO ALMOST SUMMER
TIME HEIGHTS OFF THE SOUTHEAST COAST BY TUESDAY AND
WEDNESDAY...NEARING 590 DM. THIS WILL PUT OUR REGION INTO BROAD
SOUTHWEST FLOW ALOFT. AT THE SURFACE...HIGH PRESSURE OVER THE AREA
DURING THE WEEKEND WILL SLIDE EAST AND STRENGTHEN OVER THE NORTHEAST
TUESDAY AND WEDNESDAY...WHILE THE WESTERN TROUGH WILL SPUR INITIALLY
WEAK SURFACE CYCLOGENESIS OVER THE SOUTHERN AND CENTRAL PLAINS. THIS
LOW WILL STRENGTHEN AND THEN TRACK TOWARD THE NORTHERN LAKES ON
WEDNESDAY.
INCREASING WAA AND STEADY SOUTHEAST FLOW WILL RESULT IN A MILDER
NIGHT SUNDAY NIGHT...WITH TEMPERATURES WARMING TO 4 TO 5 DEGREES
ABOVE CLIMO ON MONDAY. RAIN CHANCES ARRIVE PRIMARILY OVER NORTHWEST
HALF OF CWA MONDAY NIGHT AS LOW LEVEL JET INCREASES MOISTURE
TRANSPORT WITH A WARM FRONT LIFTING NORTH. POPS WILL CONTINUE TO BE
FOCUSED NORTHWEST HALF ON TUESDAY...WITH THERMAL PROFILES POSSIBLY
SUPPORTIVE OF 60+ DEGREE READINGS IN THE SOUTHEAST HALF DEPENDING ON
CLOUD COVER. TUESDAY NIGHT INTO WEDNESDAY IS THE BIGGEST PERIOD OF
CONCERN AS LOW LEVEL JET WILL FURTHER INCREASE TO 40 TO POSSIBLY 50
KT...WITH TONGUE OF PWAT AROUND OR A BIT OVER 1.25 INCHES
TRANSPORTED OVER AREA...WHICH IS ALMOST 250% OF NORMAL FOR NOVEMBER.
EXPECTING TO SEE PERIODS OF RAIN WITH SHORTWAVES EMANATING FROM
TROUGH TO WEST LIKELY RIDING INTO AREA IN SOUTHWEST MID FLOW. STRONG
SURFACE SOUTHERLY FLOW WILL ALSO LIKELY RESULT IN LOW TEMPERATURES
AROUND OR ABOVE NORMAL HIGHS...AT LEAST INTO THE LOW 50S AND RISING
TEMPERATURES TOWARD DAYBREAK WEDNESDAY A NICE SPRINGBOARD FOR
POSSIBLY SEEING SOME 60 DEGREE READINGS AGAIN IN SOUTHEAST HALF OF
CWA. PRIOR TO COLD FRONT PASSAGE ON WEDNESDAY...SYNOPTIC PATTERN
APPEARS FAVORABLE FOR ANOTHER POSSIBLY 1 INCH PLUS RAIN EVENT.
DESPITE IT BEING SEVERAL DAYS OUT...FELT THERE WAS ENOUGH AGREEMENT
AND RUN TO RUN CONSISTENCY IN GUIDANCE TO MAINTAIN LIKELY POPS IN
TUES NIGHT THROUGH WEDNESDAY PERIOD.
MAIN UNCERTAINTY IS WITH HOW PROGRESSIVE TROUGH PASSAGE IS...AS
LATEST OPERATIONAL ECMWF TRENDED FASTER. GFS ENSEMBLES KEEP SOME LOW
POPS FOR EASTERN CWA INTO THURSDAY BUT IF TREND OF OPERATIONAL
MODELS TO HAVE SURFACE HIGH OVER AREA ON THURS COME TO
FRUITION...WILL LIKELY BE ABLE TO REMOVE MORNING POPS. 850 MB TEMPS
COOLING TO MID MINUS SINGLE DIGITS AND 925 MB AROUND 0C ON THURSDAY
SUPPORTS HIGHS A BIT BELOW NORMAL IN UPPER 40S.
CONFIDENCE IN SEEING RAIN TUESDAY INTO WEDNESDAY...MEDIUM-HIGH.
RC
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* MVFR CIGS THROUGH MUCH OF THE PERIOD WITH A SHORT PERIOD OF
IMPROVEMENT TO VFR TOMORROW AFTERNOON.
* GUSTY NNWLY WINDS BACKING TO WLY. GUSTS SUBSIDING FOR THE
OVERNIGHT HOURS.
KREIN
//DISCUSSION...UPDATED 00Z...
THE COLD FRONT HAS PUSHED THROUGH THE TERMINALS AND THE BULK OF
THE ASSOCIATED PCPN HAS MOVED OFF TO THE EAST. THERE MAY BE SOME
SCT SHRA FOR A FEW MORE HRS THIS EVENING...BUT SHOULD NOT BE A
PREVAILING CONDITION. WITH THE WARM..HUMID AIR PUSHING TO THE EAST
WITH THE COLD FRONT...COOLER AIR IS FILTERING IN ACROSS THE
REGION. THE IFR CIGS HAVE ENDED WITH THE LOSS OF THE WARM...HUMID
AIRMASS...BUT PERSISTENT COOL CYCLONIC FLOW ALOFT SHOULD KEEP MVFR
CIGS FOR MUCH OF THE REMAINDER OF THE PERIOD. SOME DIURNAL WARMING
TOMORROW AFTERNOON SHOULD ALLOW CIGS TO LIFT TO VFR FOR A BRIEF
PERIOD...BUT SHOULD THEN LOWER BACK TO MVFR AFTER SUNSET. WINDS
WILL WILL REMAIN GUSTY TO 20-25KT FOR A FEW HOURS FOLLOWING THE
FRONTAL PASSAGE WITH THE STRONGEST COLD ADVECTION...BUT SHOULD
THEN TAPER OFF FOR THE OVERNIGHT HOURS. ANOTHER MID LEVEL IMPULSE
DROPPING AROUND THE SWRN PERIPHERY OF THE MAIN UPPER LOW WILL
BRING ANOTHER SHOT OF REINFORCING COOLER AIR...BRINGING ANOTHER
CHANCE FOR SOME SCT SHRA AS WELL AS RENEWED GUSTINESS FOR THE LATE
AFTERNOON HOURS.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* MODERATE CONFIDENCE IN CIG TRENDS.
* MODERATE CONFIDENCE IN WIND TRENDS.
* MODERATE TO HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z...
SATURDAY...SLIGHT CHANCE OF SHOWERS EARLY...OTHERWISE VFR.
SUNDAY...VFR. WX NIL.
MONDAY...CHANCE OF SHOWERS LATE...OTHERWISE VFR.
TUESDAY...RAIN LIKELY. CHANCE MVFR CIGS/VIS.
WEDNESDAY...RAIN LIKELY EARLY THEN CHANCE OF SHOWERS. CHANCE
MVFR CIGS/VIS EARLY. VFR LIKELY LATE.
KREIN
&&
.MARINE...
209 PM CDT
DEVELOPING STORM SYSTEM THIS EVENING AS IT NEARS LAKE MICHIGAN. NO
CHANGES TO THE GOING HEADLINES OF GALES FOR THE ENTIRE LAKE AND
INDIANA NEARSHORE WATERS.
AN ELONGATED TROUGH OF LOW PRESSURE STRETCHED FROM CENTRAL WISCONSIN
SOUTH THROUGH SOUTHWEST ILLINOIS THIS AFTERNOON...AND IS FORECAST TO
CONSOLIDATE INTO A LOW OVER CENTRAL LAKE MICHIGAN EARLY THIS EVENING
AND RAPIDLY DEEPEN. AS THE LOW QUICKLY INTENSIFIES...THE PRESSURE
GRADIENT OVER THE LAKE WILL ALSO TIGHTEN. THIS WILL RESULT IN GALES
DEVELOPING WITH NEARLY 40-44KT ACROSS THE SOUTHERN HALF OF LAKE
MICHIGAN FROM THE WEST. TIMING CONTINUES TO BE AROUND MIDNIGHT. THE
STRONG LOW PRESSURE WILL CONTINUE TO DEEPEN AS IT SLIDES NORTHEAST
ACROSS NORTHEASTERN LAKE HURON INTO EASTERN ONTARIO AND WESTERN
QUEBEC FRI AFTN/EVE. THE GRADIENT WILL THEN QUICKLY DIMINISH LATE
FRI MORNING...WITH GALES ENDING BY MID-MORNING FRI.
WINDS WILL CONTINUE TO BE WESTERLY UNTIL THE UPPER LEVEL TROUGH
ARRIVES FRI EVE...THEN WINDS WILL TURN NORTHWESTERLY. A BROAD RIDGE
OF HIGH PRESSURE CONTINUES TO BE FORECAST TO SLIDE ACROSS THE
CENTRAL/SOUTHERN PLAINS. THIS WILL RESULT IN A PROLONGED PERIOD OF
NORTH/NORTHWEST WINDS FOR SAT. THE GRADIENT DOESN/T COMPLETELY GO
AWAY...WITH SPEEDS REMAINING ARND 10-20KT WITH GUSTS TO 25KT OVER
THE OPEN WATERS. THEN THIS HIGH PRESSURE SLIDES EAST AND STRETCHES
TO COVER LAKE MICHIGAN SAT NIGHT/SUN...WITH A PERIOD OF LIGHTER
WINDS. THE WEATHER REMAINS PROGRESSIVE AND THE HIGH PRESSURE WILL
PUSH EAST WITH WINDS SHIFTING TO SOUTHEASTERLY/SOUTHERLY FOR EARLY
NEXT WEEK.
FORECAST GUIDANCE IS BEGINNING TO POINT TOWARDS ANOTHER STRONG STORM
SYSTEM TO DEVELOP AND APPROACH THE GREAT LAKES REGION FOR THE MIDDLE
PART OF NEXT WEEK.
CONFIDENCE IN GALES TONIGHT/FRI MORNING...HIGH.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 9 PM THURSDAY.
GALE WARNING...INDIANA NEARSHORE WATERS UNTIL 4 AM FRIDAY.
GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 9 AM FRIDAY.
SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 10 AM FRIDAY.
&&
$$
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FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
653 PM CDT THU OCT 31 2013
.DISCUSSION...
310 PM CDT
THE FORECAST CHALLENGES THIS FINAL DAY OF OCTOBER WERE FOCUSED
EARLY ON WITH CONVECTIVE CHANCES...RAIN TIMING AND AMOUNTS...AND
WINDS THROUGH THIS EVE. OTHERWISE THE WEATHER LOOKS FAIRLY CALM
DURING THE FIRST WEEKEND OF NOV BEFORE THE NEXT PRONOUNCED MID-
LATITUDE SYSTEM POTENTIALLY DURING MIDWEEK.
SYNOPSIS...PROGRESSIVE AND VERY-WELL DEFINED UPPER WAVE ACROSS
CENTRAL MO THIS MID-AFTERNOON WILL ROTATE EAST OVER THE AREA THIS
EVENING...BRINGING A LARGE SCALE NEGATIVE TILT TO THE MIDWEST TROUGH
AS A WHOLE. DRY SLOT OF THE SYSTEM IS ENCROACHING IN ON THE AREA
WITH MODE OF RAIN ACTIVITY BECOMING MORE SHOWER-LIKE ACROSS
CENTRAL IL AND INTO THE SOUTHERN FORECAST AREA. CONSOLIDATING
SURFACE LOWS OVER THE CWA ARE A RESULT OF THE DEEP UPWARD
ASCENT...AND 5-7MB/3HR PRESSURE FALLS ARE CURRENTLY BEING OBSERVED
OVER MUCH OF THE AREA. THIS LOW WILL BE VERY NEAR A BOMB BY
DEFINITION THROUGH TONIGHT AS IT DEEPENS INTO LOWER MICHIGAN AND
TO 970-975MB JUST EAST OF LAKE HURON BY EARLY FRIDAY. THE SURFACE
COLD FRONT IS DRAPED ACROSS THE FAR WESTERN FORECAST AREA AS OF 3
PM AND THIS WILL INCH EASTWARD THIS EVE...WITH CONVECTIVE CHANCES
MAINLY AHEAD OF THIS WHERE OVERALL HIGHER MOISTURE
CONTENT/TRANSPORT REMAINS.
LATE THIS AFTERNOON AND TONIGHT...AS MID-LEVEL JET AND DRY SLOT
ROTATE OVERHEAD...THE SHOWER MODE SHOULD CONTINUE TO BECOME MORE
PREVALENT THROUGH LATE THIS AFTERNOON. THERE HAD BEEN A BAND OF
MORE ROBUST SHOWERS NEAR THE FRONT IN CENTRAL IL WITH 30-40 KT
WINDS JUST OFF THE SURFACE BUT THAT HAS DISSIPATED SINCE 230 PM.
IN ADDITION...MORE SHOWERS AND STORMS CONTINUE TO FIRE OVER
SOUTHERN IL...AND FURTHER SOUTH THAN THAT...ALL WHICH MAY BEGIN TO
LIMIT COVERAGE OF SHOWERS AND STORMS THAT DEVELOP THIS FAR NORTH
THROUGH THE NEXT SEVERAL HOURS. STILL EXPECT AT LEAST SCATTERED
DEVELOPMENT AHEAD OF THE FRONT AND ANY SHOWERS OR STORMS
IMMEDIATELY ON THE FRONT ITSELF WILL REMAIN THE MOST PROBABLE TO
HAVE AT LEAST A LIMITED GUSTY WIND POTENTIAL. WITH SCATTERING OF
CLOUDS LOOKING HIGHLY UNLIKELY TO MAKE IT TO THE SOUTHEAST
FORECAST AREA...THE POTENTIAL TO REALIZE LOW-LEVEL CAPE ALSO LOOKS
HIGHLY DIMINISHED. WHILE THE FRONT WILL END THE POTENTIAL FOR
THUNDER BY 7 PM...THERE WILL LINGER A COUPLE HOUR PERIOD BEHIND
THE FRONT INTO EARLY TO MID EVE WHERE SOME SCATTERED SHOWERS MAY
PERSIST AS THE UPPER LOW PASSES OVERHEAD.
AS THE PRESSURE RISES BEGIN TO BE SEEN ASSOCIATED WITH THE
DOWNWARD MOTION OF THE JET AND LOW-LEVEL COLD AIR ADVECTION...THE
ISALLOBARIC COUPLET WILL BECOME MORE AND MORE PRONOUNCED. WHILE
THERE IS LITTLE IN THE WAY OF WIND UPSTREAM TO OUR WEST AND
SOUTHWEST...EXPECT THAT HIGHER GUSTS WILL PRETTY MUCH DEVELOP
RIGHT OVER THE CWA...PARTICULARLY THE SOUTH AND EAST BY EARLY EVE.
LOOKING AT THE LATEST RAP AND NAM SOUNDINGS CONTINUE TO SUPPORT
TEMPORARY GUST POTENTIAL AROUND 40 MPH BETWEEN 6 AND 10 PM OR SO.
THE BEST CHANCES REMAIN SOUTH OF CHICAGO BUT CANNOT RULE OUT SOME
OF THE WIND POTENTIAL REACHING THAT FAR NORTH.
FRIDAY...NORTHWEST FLOW WILL DEVELOP OVER THE AREA INTO THE FIRST
HALF OF THIS WEEKEND...WITH A COUPLE UPPER SHORT WAVES DIVING OVER
THE AREA FRIDAY AFTERNOON AND MORE SO IN THE EVE. SATURATED LAYER
LOOKS SHALLOW AT FIRST BUT LATE IN THE AFTERNOON INTO THE
EVE...NAMELY OVER FAR NORTHERN AND NORTHEASTERN IL...IT LOOKS DEEP
ENOUGH TO SUPPORT SOME SHOWERS. SO MAINTAIN THE CHANCES WHICH
GENERALLY HAD A GOOD LOOKING ORIENTATION AND MAGNITUDE IN OUR
FORECAST. HIGHS WILL BE BACK DOWN INTO THE 50S...WITH A FEW UPPER
40S NEAR THE STATE LINE.
THIS WEEKEND...LITTLE IN THE WAY OF CHANGE TO THIS PART OF THE
FORECAST. SAT NIGHT SHOULD BE A COOL NIGHT WITH RIDGING
OVERHEAD...BUT ALL IN ALL ONLY ABOUT 5 DEGREE BELOW NORMAL.
MTF
LONG TERM...SUNDAY NIGHT THROUGH THURSDAY...
PRIMARY CONCERN IN THE EXTENDED PERIOD IS WHAT COULD POTENTIALLY BE
ANOTHER SIGNIFICANT RAIN EVENT FOR THE CWA LATER TUESDAY INTO
WEDNESDAY. THERE IS GOOD AGREEMENT AMONGST OPERATIONAL AND ENSEMBLE
GUIDANCE IN THE MID RANGE IN THE UPPER PATTERN TRANSITIONING TO
BROAD TROUGHING OVER WESTERN NOAM AND A RIDGE SETTING UP OVER THE
EASTERN THIRD OF THE CONUS...AND THIS STRENGTHENING TO ALMOST SUMMER
TIME HEIGHTS OFF THE SOUTHEAST COAST BY TUESDAY AND
WEDNESDAY...NEARING 590 DM. THIS WILL PUT OUR REGION INTO BROAD
SOUTHWEST FLOW ALOFT. AT THE SURFACE...HIGH PRESSURE OVER THE AREA
DURING THE WEEKEND WILL SLIDE EAST AND STRENGTHEN OVER THE NORTHEAST
TUESDAY AND WEDNESDAY...WHILE THE WESTERN TROUGH WILL SPUR INITIALLY
WEAK SURFACE CYCLOGENESIS OVER THE SOUTHERN AND CENTRAL PLAINS. THIS
LOW WILL STRENGTHEN AND THEN TRACK TOWARD THE NORTHERN LAKES ON
WEDNESDAY.
INCREASING WAA AND STEADY SOUTHEAST FLOW WILL RESULT IN A MILDER
NIGHT SUNDAY NIGHT...WITH TEMPERATURES WARMING TO 4 TO 5 DEGREES
ABOVE CLIMO ON MONDAY. RAIN CHANCES ARRIVE PRIMARILY OVER NORTHWEST
HALF OF CWA MONDAY NIGHT AS LOW LEVEL JET INCREASES MOISTURE
TRANSPORT WITH A WARM FRONT LIFTING NORTH. POPS WILL CONTINUE TO BE
FOCUSED NORTHWEST HALF ON TUESDAY...WITH THERMAL PROFILES POSSIBLY
SUPPORTIVE OF 60+ DEGREE READINGS IN THE SOUTHEAST HALF DEPENDING ON
CLOUD COVER. TUESDAY NIGHT INTO WEDNESDAY IS THE BIGGEST PERIOD OF
CONCERN AS LOW LEVEL JET WILL FURTHER INCREASE TO 40 TO POSSIBLY 50
KT...WITH TONGUE OF PWAT AROUND OR A BIT OVER 1.25 INCHES
TRANSPORTED OVER AREA...WHICH IS ALMOST 250% OF NORMAL FOR NOVEMBER.
EXPECTING TO SEE PERIODS OF RAIN WITH SHORTWAVES EMANATING FROM
TROUGH TO WEST LIKELY RIDING INTO AREA IN SOUTHWEST MID FLOW. STRONG
SURFACE SOUTHERLY FLOW WILL ALSO LIKELY RESULT IN LOW TEMPERATURES
AROUND OR ABOVE NORMAL HIGHS...AT LEAST INTO THE LOW 50S AND RISING
TEMPERATURES TOWARD DAYBREAK WEDNESDAY A NICE SPRINGBOARD FOR
POSSIBLY SEEING SOME 60 DEGREE READINGS AGAIN IN SOUTHEAST HALF OF
CWA. PRIOR TO COLD FRONT PASSAGE ON WEDNESDAY...SYNOPTIC PATTERN
APPEARS FAVORABLE FOR ANOTHER POSSIBLY 1 INCH PLUS RAIN EVENT.
DESPITE IT BEING SEVERAL DAYS OUT...FELT THERE WAS ENOUGH AGREEMENT
AND RUN TO RUN CONSISTENCY IN GUIDANCE TO MAINTAIN LIKELY POPS IN
TUES NIGHT THROUGH WEDNESDAY PERIOD.
MAIN UNCERTAINTY IS WITH HOW PROGRESSIVE TROUGH PASSAGE IS...AS
LATEST OPERATIONAL ECMWF TRENDED FASTER. GFS ENSEMBLES KEEP SOME LOW
POPS FOR EASTERN CWA INTO THURSDAY BUT IF TREND OF OPERATIONAL
MODELS TO HAVE SURFACE HIGH OVER AREA ON THURS COME TO
FRUITION...WILL LIKELY BE ABLE TO REMOVE MORNING POPS. 850 MB TEMPS
COOLING TO MID MINUS SINGLE DIGITS AND 925 MB AROUND 0C ON THURSDAY
SUPPORTS HIGHS A BIT BELOW NORMAL IN UPPER 40S.
CONFIDENCE IN SEEING RAIN TUESDAY INTO WEDNESDAY...MEDIUM-HIGH.
RC
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* MVFR CIGS THROUGH MUCH OF THE PERIOD WITH A SHORT PERIOD OF
IMPROVEMENT TO VFR TOMORROW AFTERNOON.
* GUSTY NNWLY WINDS BACKING TO WLY. GUSTS SUBSIDING FOR THE
OVERNIGHT HOURS.
KREIN
//DISCUSSION...UPDATED 00Z...
THE COLD FRONT HAS PUSHED THROUGH THE TERMINALS AND THE BULK OF
THE ASSOCIATED PCPN HAS MOVED OFF TO THE EAST. THERE MAY BE SOME
SCT SHRA FOR A FEW MORE HRS THIS EVENING...BUT SHOULD NOT BE A
PREVAILING CONDITION. WITH THE WARM..HUMID AIR PUSHING TO THE EAST
WITH THE COLD FRONT...COOLER AIR IS FILTERING IN ACROSS THE
REGION. THE IFR CIGS HAVE ENDED WITH THE LOSS OF THE WARM...HUMID
AIRMASS...BUT PERSISTENT COOL CYCLONIC FLOW ALOFT SHOULD KEEP MVFR
CIGS FOR MUCH OF THE REMAINDER OF THE PERIOD. SOME DIURNAL WARMING
TOMORROW AFTERNOON SHOULD ALLOW CIGS TO LIFT TO VFR FOR A BRIEF
PERIOD...BUT SHOULD THEN LOWER BACK TO MVFR AFTER SUNSET. WINDS
WILL WILL REMAIN GUSTY TO 20-25KT FOR A FEW HOURS FOLLOWING THE
FRONTAL PASSAGE WITH THE STRONGEST COLD ADVECTION...BUT SHOULD
THEN TAPER OFF FOR THE OVERNIGHT HOURS. ANOTHER MID LEVEL IMPULSE
DROPPING AROUND THE SWRN PERIPHERY OF THE MAIN UPPER LOW WILL
BRING ANOTHER SHOT OF REINFORCING COOLER AIR...BRINGING ANOTHER
CHANCE FOR SOME SCT SHRA AS WELL AS RENEWED GUSTINESS FOR THE LATE
AFTERNOON HOURS.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* MODERATE CONFIDENCE IN CIG TRENDS.
* MODERATE CONFIDENCE IN WIND TRENDS.
* MODERATE TO HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z...
SATURDAY...SLIGHT CHANCE OF SHOWERS EARLY...OTHERWISE VFR.
SUNDAY...VFR. WX NIL.
MONDAY...CHANCE OF SHOWERS LATE...OTHERWISE VFR.
TUESDAY...RAIN LIKELY. CHANCE MVFR CIGS/VIS.
WEDNESDAY...RAIN LIKELY EARLY THEN CHANCE OF SHOWERS. CHANCE
MVFR CIGS/VIS EARLY. VFR LIKELY LATE.
KREIN
&&
.MARINE...
209 PM CDT
DEVELOPING STORM SYSTEM THIS EVENING AS IT NEARS LAKE MICHIGAN. NO
CHANGES TO THE GOING HEADLINES OF GALES FOR THE ENTIRE LAKE AND
INDIANA NEARSHORE WATERS.
AN ELONGATED TROUGH OF LOW PRESSURE STRETCHED FROM CENTRAL WISCONSIN
SOUTH THROUGH SOUTHWEST ILLINOIS THIS AFTERNOON...AND IS FORECAST TO
CONSOLIDATE INTO A LOW OVER CENTRAL LAKE MICHIGAN EARLY THIS EVENING
AND RAPIDLY DEEPEN. AS THE LOW QUICKLY INTENSIFIES...THE PRESSURE
GRADIENT OVER THE LAKE WILL ALSO TIGHTEN. THIS WILL RESULT IN GALES
DEVELOPING WITH NEARLY 40-44KT ACROSS THE SOUTHERN HALF OF LAKE
MICHIGAN FROM THE WEST. TIMING CONTINUES TO BE AROUND MIDNIGHT. THE
STRONG LOW PRESSURE WILL CONTINUE TO DEEPEN AS IT SLIDES NORTHEAST
ACROSS NORTHEASTERN LAKE HURON INTO EASTERN ONTARIO AND WESTERN
QUEBEC FRI AFTN/EVE. THE GRADIENT WILL THEN QUICKLY DIMINISH LATE
FRI MORNING...WITH GALES ENDING BY MID-MORNING FRI.
WINDS WILL CONTINUE TO BE WESTERLY UNTIL THE UPPER LEVEL TROUGH
ARRIVES FRI EVE...THEN WINDS WILL TURN NORTHWESTERLY. A BROAD RIDGE
OF HIGH PRESSURE CONTINUES TO BE FORECAST TO SLIDE ACROSS THE
CENTRAL/SOUTHERN PLAINS. THIS WILL RESULT IN A PROLONGED PERIOD OF
NORTH/NORTHWEST WINDS FOR SAT. THE GRADIENT DOESN/T COMPLETELY GO
AWAY...WITH SPEEDS REMAINING ARND 10-20KT WITH GUSTS TO 25KT OVER
THE OPEN WATERS. THEN THIS HIGH PRESSURE SLIDES EAST AND STRETCHES
TO COVER LAKE MICHIGAN SAT NIGHT/SUN...WITH A PERIOD OF LIGHTER
WINDS. THE WEATHER REMAINS PROGRESSIVE AND THE HIGH PRESSURE WILL
PUSH EAST WITH WINDS SHIFTING TO SOUTHEASTERLY/SOUTHERLY FOR EARLY
NEXT WEEK.
FORECAST GUIDANCE IS BEGINNING TO POINT TOWARDS ANOTHER STRONG STORM
SYSTEM TO DEVELOP AND APPROACH THE GREAT LAKES REGION FOR THE MIDDLE
PART OF NEXT WEEK.
CONFIDENCE IN GALES TONIGHT/FRI MORNING...HIGH.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 9 PM THURSDAY.
GALE WARNING...INDIANA NEARSHORE WATERS UNTIL 4 AM FRIDAY.
GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 9 AM FRIDAY.
SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 10 AM FRIDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1254 PM CDT WED OCT 30 2013
.DISCUSSION...
547 AM CDT
UPDATE FOR DENSE FOG ADVISORY.
HAVE ISSUED A DENSE FOG ADVISORY FOR THE SOUTHWEST 2/3 OF THE CWA
THROUGH 16Z.
WHILE A FEW SPOTS HAVE DEVELOPED LOCALLY DENSE FOG ACROSS NORTHERN
IL EARLY THIS MORNING...HAVE BECOME CONCERNED ABOUT VISIBILITY
TRENDS ACROSS CENTRAL IL WHERE HIGH DEW POINT AIR CONTINUES TO
ADVECT NORTH INTO COOLER NOCTURNAL AIR MASS. SUSPECT VISIBILITY
WILL DETERIORATE FROM THE SOUTH OVER THE NEXT FEW HOURS...WITH
AREAS OF DENSE FOG DEVELOPING. HAVE KEPT IMMEDIATE LAKE SHORE AND
CHICAGO CENTER OUT OF ADVISORY...AS WELL AS MOST OF NORTHWEST
INDIANA AT THIS POINT DUE TO WARMER TEMPS ALONG LAKE/CITY AND
LOWER DEW POINTS UPSTREAM ACROSS NORTHWEST IN. CONFIDENCE IS A
LITTLE LOW ON HOW THIS WILL EVOLVE...THOUGH IT APPEARS FOG OF SOME
SUBSTANCE WILL BE AROUND FOR A GOOD PORTION OF THE MORNING HOURS.
RATZER
//PREV DISCUSSION...
354 AM CDT
MAIN FORECAST FOCUS REMAINS ON LARGE STORM SYSTEM THAT WILL TRACK
ACROSS THE REGION THROUGH THURSDAY NIGHT. RAINFALL AMOUNTS RANGING
FROM THREE QUARTERS OF AN INCH TO PERHAPS IN EXCESS OF 1.5 INCHES
ARE POSSIBLE WITH THIS SYSTEM...IN ADDITION TO TEMPERATURES IN THE
60S BEFORE THE COLD FRONT PUSHES THROUGH LATE THURSDAY.
RELATIVELY QUIET WEATHER IS IN PLACE ACROSS THE CWA EARLY THIS
MORNING...WITH ONLY SOME PATCHY FOG AND CLOUDY SKIES OF ANY NOTE.
SHOWERS WHICH HAD OCCURRED LAST EVENING HAD MOVED OFF TO THE
SOUTHEAST OF THE AREA...WITH A MID-LEVEL SHORT WAVE THAT TRAVERSED
THE REGION OVERNIGHT. AT THE SURFACE...WEAK LOW PRESSURE WAS OVER
THE MID-MISSOURI VALLEY NEAR OMAHA...WITH A WARM FRONT EXTENDING
ACROSS CENTRAL MISSOURI INTO CENTRAL ILLINOIS. RELATIVELY WEAK BUT
PERSISTENT WARM/MOIST ADVECTION WILL CONTINUE ATOP THE FRONTAL
ZONE THIS MORNING...WITH THE POTENTIAL FOR A FEW SHOWERS OR
SPRINKLES PARTICULARLY ACROSS THE SOUTHWESTERN PARTS OF THE CWA.
RAIN CHANCES WILL INCREASE THIS AFTERNOON FROM THE SOUTHWEST
HOWEVER...AS ANOTHER MID-LEVEL SHORT WAVE CURRENTLY OVER
KANSAS/NEBRASKA APPROACHES THE AREA. SOUTH LOW LEVEL FLOW WILL
INCREASE ACROSS THE BAROCLINIC ZONE TO OUR SOUTH...WITH ISENTROPIC
ASCENT AND MOISTURE TRANSPORT INCREASING BY LATE THIS AFTERNOON.
STRONGER HEIGHT FALLS DEVELOP TONIGHT THROUGH THURSDAY THEN...AS
LARGE WESTERN CONUS TROUGH BEGINS TO MOVE EASTWARD AND 145 KT UPPER
JET STREAK LIFTS OUT ACROSS THE MIDWEST. THIS INCREASE IN LARGE
SCALE FORCING WILL GENERATE MORE ORGANIZED RAIN AND A FEW
THUNDERSTORMS INTO THE REGION THIS EVENING...WITH PERIODS OF
RAIN/EMBEDDED THUNDER EXPECTED TO CONTINUE INTO THURSDAY. IN THE
PROCESS...THE SURFACE LOW PRESSURE IN THE PLAINS WILL LIFT NORTHEAST
INTO WISCONSIN THROUGH THURSDAY WITH THE SURFACE WARM FRONT LIFTING
NORTH ACROSS NORTHERN ILLINOIS AND NORTHWEST INDIANA TONIGHT. MILD
AND MOIST AIR WITH SFC DEW POINTS IN THE LOWER 60S AND AN AXIS OF
PRECIPITABLE WATER APPROACHING 1.50 INCHES WILL SURGE NORTH WITH THE
WARM SECTOR TONIGHT/THURSDAY...COMBINING WITH STRONG DYNAMICS TO
PRESENT THE POTENTIAL FOR SOME SUBSTANTIAL RAINFALL TOTALS. TEMPS
WILL RISE INTO THE 60S MOST AREAS TODAY...EXCEPT PERHAPS ALONG THE
NORTH SHORE WHERE SOUTHEAST WINDS WILL PROVIDE SOME LAKE COOLING.
TEMPS WILL NOT DIP TOO MUCH TONIGHT HOWEVER WITH THE WARM FRONT
MOVING NORTH...AND IN FACT WILL LIKELY RISE OVERNIGHT. WARM AIR
ALOFT COULD POTENTIALLY SUPPORT SOME UPPER 60S/NEAR 70 TEMPS
THURSDAY UNDER IDEAL CONDITIONS...BUT CONSIDERABLE CLOUDS AND RAIN
WILL LIKELY TEMPER READINGS SOMEWHAT WITH MID 60S EXPECTED.
THE COLD FRONT WILL MOVE INTO WESTERN IL THURSDAY MORNING...AND WILL
SLOWLY PROGRESS ACROSS THE CWA FROM THE WEST THROUGH THE DAY. A
STRONG SHORT WAVE CURRENTLY ROUNDING THE BASE OF THE WESTERN TROUGH
OVER SOUTHERN CALIFORNIA WILL APPROACH THE FORECAST AREA COINCIDENT
WITH THE FRONT THURSDAY/THURSDAY EVENING...MAINTAINING HIGH
PROBABILITY RAIN THREAT THROUGH THE DAY. STORM TOTAL RAINFALL
AMOUNTS FROM GUIDANCE RANGE FROM ABOUT 0.80 INCHES TO IN EXCESS OF
2.00 INCHES IN SOME SPOTS. RAIN SHOULD TAPER OFF FROM WEST TO EAST
THURSDAY EVENING BEHIND THE COLD FRONT.
BREEZY AND COOLER...BUT NOT COLD...WEATHER WILL SPREAD INTO THE AREA
FRIDAY BEHIND THE DEPARTING UPPER TROUGH/COLD FRONT. MODELS INDICATE
ANOTHER FAIRLY STRONG SHORT WAVE TROUGH WILL DIG FROM THE NORTHERN
PLAINS INTO THE REGION TOWARD EVENING...WITH 80 METER HEIGHT FALLS
AND A POCKET OF COLDER AIR ALOFT. MOST GUIDANCE MEMBERS SQUEEZE OUT
A LITTLE PRECIP WITH THE PASSAGE OF THIS WAVE FRIDAY NIGHT INTO
SATURDAY...BEFORE HIGH PRESSURE BUILDS INTO THE AREA SATURDAY NIGHT.
TEMPS FRIDAY ARE EXPECTED TO BE BACK IN THE MID-UPPER 50S...COOLING
TO THE UPPER 40S/AROUND 50 SATURDAY IN THE COLDER AIR BEHIND THE
SECONDARY COLD FRONT ASSOCIATED WITH THE SHORT WAVE. COLDEST
TEMPERATURES OF THE NEXT 7 DAYS APPEAR TO COME LATE SATURDAY
NIGHT...WITH THE SURFACE HIGH PRESSURE RIDGE ALLOWING FOR CLEARING
SKIES AND GOOD RADIATIONAL COOLING CONDITIONS. WILL LIKELY SEE TEMPS
INTO THE 20S IN THE OUTLYING TYPICALLY COOLER SPOTS EARLY SUNDAY
MORNING.
HIGH PRESSURE RIDGE THEN MOVES QUICKLY EASTWARD ON SUNDAY...WITH
LONGER RANGE MODEL RUNS DEPICTING ANOTHER DEEP LOW LIFTING NORTHEAST
ACROSS THE UPPER MIDWEST EARLY NEXT WEEK. THIS WILL ALLOW TEMPS TO
MODERATE...BUT WILL ALSO EVENTUALLY BRING ANOTHER CHANCE FOR SOME
RAIN MAINLY MONDAY NIGHT AND TUESDAY.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* IFR TO LIFR CIGS RETURNING BY THIS EVENING AND CONTINUING
THROUGH THE PERIOD.
* SHOWERS DEVELOPING BY THIS EVENING AND BECOMING
WIDESPREAD...WITH PERIODS OF RAIN CONTINUING FOR MUCH OF TONIGHT
AND THURSDAY.
* SMALL POSSIBILITY OF SOME EMBEDDED THUNDERSTORMS THIS EVENING.
KJB
//DISCUSSION...UPDATED 18Z...
THE WEATHER WILL BE MESSY ACROSS THE REGION THROUGH THE FORECAST
PERIOD AS A POTENT STORM SYSTEM IMPACTS THE CENTRAL CONUS.
CIGS HAVE REBOUNDED A BIT THIS AFTERNOON ALONG THE FAR NORTHEASTERN
FRINGE OF THE LOWER IFR CLOUDS. THIS AREA INCLUDES KORD...KMDW AND
KGYY AND EXTENDS EAST SOUTHEASTWARD ACROSS NORTHERN INDIANA.
HOWEVER...FARTHER WEST...THE VERY LOW CLOUDS AND VIS CONTINUES...AND
LIKELY WILL THROUGH THE DAY. WINDS WILL REMAIN SOUTHEASTERLY AROUND
OR JUST UNDER 10 KT.
A SURFACE WARM FRONT WILL LIFT NORTHWARD FROM CENTRAL AND SOUTHERN
ILLINOIS ACROSS ALL OF NORTHERN ILLINOIS BY MIDNIGHT AS THE PARENT
SURFACE LOW RAPIDLY DEVELOPS NORTHEASTWARD ACROSS THE UPPER
MISSISSIPPI RIVER VALLEY. AS THIS OCCURS...SHOWERS WILL BEGIN TO
OVERSPREAD THE AREA VERY LATE THIS AFTERNOON TO EARLY THIS
EVENING...ROUGHLY AFTER 23 UTC. CIGS AND VISIBILITIES WILL ALSO
LIKELY TANK INTO THE IFR TO LIFR CATEGORY AGAIN BY EARLY EVENING
WITH THE CONTINUED INCREASING LOW LEVEL MOISTURE...ESPECIALLY ACROSS
THE EASTERN TAF SITES THAT SEE IMPROVEMENT THIS AFTERNOON. THERE IS
STILL A SMALL THREAT OF A FEW EMBEDDED THUNDERSTORMS THIS
EVENING...BUT...CONFIDENCE IS NOT VERY HIGH AS LAPSE RATES APPEAR TO
BE MARGINAL FOR THUNDER. IN SPITE OF THIS...I HAVE OPTED TO LEAVE
THE MENTION OF THUNDER IN THE TAF AS A VCTS...SINCE THE PROB 30
GROUP NEEDED TO BE DROPPED WITHIN THE FIRST 9 HOURS OF THE NEW
TAF.
PERIODS OF RAIN...MODERATE TO HEAVY AT TIMES LOOKS TO SET UP LATER
TONIGHT AND THROUGH MUCH OF THE DAY ON THURSDAY. THIS WILL LIKELY
ALLOW FOR A CONTINUATION OF LOWER VIS AND IFR TO LIFR CIGS ACROSS
THE AREA. A COLD FRONT SHOULD PUSH ACROSS THE AREA VERY LATE IN THE
DAY...LIKELY AFTER 22 UTC THURSDAY AFTERNOON. WINDS WILL SWITCH MORE
WEST NORTHWESTERLY AND BECOME VERY GUSTY FOR A PERIOD THURSDAY
EVENING.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM CONFIDENCE WITH CEILING TRENDS INTO THIS AFTERNOON.
* MEDIUM TO HIGH CONFIDENCE WITH IFR TO LIFR CEILINGS TONIGHT AND
MUCH OF THURSDAY.
* MEDIUM TO HIGH CONFIDENCE WITH SHOWERS/TRENDS.
KJB
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT...CHANCE OF SHRA...OTHERWISE VFR.
FRIDAY...SLIGHT CHANCE OF SHRA LATE...OTHERWISE VFR.
SATURDAY...SLIGHT CHANCE OF SHRA...OTHERWISE VFR.
SUNDAY...VFR.
MONDAY...SLIGHT CHANCE OF SHRA LATE...OTHERWISE VFR.
TUESDAY...CHANCE OF SHRA...OTHERWISE VFR.
RODRIGUEZ
&&
.MARINE...
439 AM CDT
MAIN FORECAST CONCERNS ARE WITH UNCERTAINTIES REGARDING STRENGTH
AND PLACEMENT OF AN APPROACHING SYSTEM...WHICH IS RAISING ISSUES
WITH REGARDS TO STRENGTH OF WINDS THURSDAY INTO EARLY FRIDAY.
AS HIGH PRESSURE REMAINS SITUATED OVER THE ATLANTIC COAST...A
TROUGH OF LOW PRESSURE WILL LIFT NORTHEAST THROUGH THE CENTRAL
PLAINS AND UPPER MISSISSIPPI VALLEY TODAY INTO TONIGHT. ALTHOUGH
FOR TODAY...THE GRADIENT OVER THE LAKE REMAINS RATHER WEAK WITH
SOUTHEAST WINDS ONLY INCREASING SLIGHTLY TO THE 10 TO 20 KT RANGE
BY THIS AFTERNOON. WITH THE LOW APPROACHING AND WARM FRONT SURGING
NORTHWARD TONIGHT EXPECT WINDS TO BECOME MORE SOUTHERLY WHILE
INCREASING TO 30 KT. THIS LOW WILL CONTINUE DEEPENING AS IT MOVES
ACROSS THE CENTRAL GREAT LAKES REGION THURSDAY...WITH SPEEDS STILL
HOVERING AROUND 30 KT. A PERIOD OF GALES TO 35 KT ARE STILL NOT
OUT OF THE QUESTION ON THURSDAY BUT WITH THE WARMER AIR SURGING
NORTHWARD ACROSS THE LAKE...THINK ANY PREVAILING GALES WILL BE
SUPPRESSED WITH ONLY AN OCCASIONAL GALE FORCE GUST LIKELY. WINDS
ACROSS THE NEARSHORE WILL INCREASE TONIGHT AS WELL INTO THE 20-25
KT RANGE...WITH A BRIEF PERIOD OF TO 30 KT GUSTS POSSIBLE AS THIS
FRONT LIFTS NORTH OVERNIGHT. THIS LOW WILL CONTINUE NORTHEAST INTO
SOUTHEAST ONTARIO AND QUEBEC THURSDAY NIGHT INTO FRIDAY WITH A
BRIEF LULL IN THE WINDS BEFORE WEST WINDS TO 30 KT ARE LIKELY ONCE
AGAIN. ITS DURING THIS TIME WHEN MODEL GUIDANCE VARIES
SIGNIFICANTLY WITH REGARDS TO THIS LOW PRESSURE SYSTEM...WITH
CONFIDENCE AS TO THE STRENGTH OF THE WINDS LOW. ONCE AGAIN...HAVE
MAINTAINED 30 KT WINDS BUT WILL NEED TO MONITOR THIS PERIOD FOR
GALES POSSIBLY DEVELOPING ONCE AGAIN.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...DENSE FOG ADVISORY...NEARSHORE WATERS
UNTIL 10 PM WEDNESDAY.
SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...10 PM WEDNESDAY TO 10 AM FRIDAY.
&&
$$
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Area Forecast Discussion
National Weather Service Lincoln IL
1230 PM CDT Wed Oct 30 2013
.DISCUSSION...
ISSUED 1015 AM CDT Wed Oct 30 2013
Have let the dense fog advisory expire at 10 am. Still seeing some
areas of dense fog lingering, mainly across the eastern CWA, but
this will continue to lift over the next 30 to 60 minutes.
Focus in the near term is shifting to elevated convection moving
across northeast Missouri and about to cross into far western
Illinois. Main cluster of storms southwest of Quincy should bypass
our CWA, but showers/storms continue to develop further west
across Iowa and Missouri. These should become more surface based
with time. In addition, RAP and NAM models continue to show some
development across southern Illinois as the warm front lifts
northward toward our area. Latest visible satellite imagery
showing some decent thinning of the clouds in that area to help
make the air more unstable there.
Have done some timing adjustments of the rain chances for our area
today, but general trend is OK for now. Temperatures remain on
target to reach the lower 70s over the southern half of the CWA
later today, once the front arrives.
Geelhart
&&
.AVIATION...
ISSUED 1230 PM CDT Wed Oct 30 2013
Widespread IFR conditions will prevail over the next 24 hours with
ceilings typically around 500 feet or below. May see ceilings rise
temporarily this afternoon as a warm front moves up from the
south. Most of the earlier fog has lifted to around 3SM, but still
will see some limited low visibility of 1/4 to 1/2SM around
KPIA/KBMI for another couple hours.
Convection will remain a significant concern as well. Storms near
KUIN have been weakening recently as they move east, but more
widespread showers/storms in Iowa and Missouri will move in during
mid to late afternoon. Showers and periodic thunderstorms are then
likely the remainder of the forecast period, although thunder
potential will be more limited between 06-12Z. Late in the period,
a cold front will be moving in from the west, swinging winds to
the northwest. Areas near KCMI should stay southerly until 18Z,
with wind gusts of around 25 knots developing by late morning.
Geelhart
&&
.PREV DISCUSSION...
ISSUED 222 AM CDT Wed Oct 30 2013
Main forecast challenges continue to be rain chances over the next
couple of days, as well as, severe weather threat Thursday afternoon.
07z/2am surface analysis shows low pressure near Kansas City, with
stationary frontal boundary extending eastward across central
Missouri into far southern Illinois. A few showers are occurring
immediately along/north of the boundary, with an extensive area of
fog/drizzle extending much further north toward the I-80 corridor.
Aloft...deep upper low continues to spin over the Great Basin,
while ridging prevails downstream over the Plains into the Midwest.
SHORT TERM...Today through Friday
As western CONUS upper trough slowly tracks eastward, rising upper
heights ahead of the system will help give the stationary frontal
boundary a push northward today. High-res models are in good
agreement that the boundary will reach the northern KILX CWA by
around midday, then will lift into northern Illinois/southern
Wisconsin later this afternoon. Fog/drizzle will be ongoing
along/north of the front through the morning hours, but will
gradually dissipate and shift northward as the morning progresses.
Winds will initially be from the E/SE, but will veer to the south
during the afternoon, helping bring much warmer air into the
region. High temperatures will range from the middle 60s far north
around Lacon and Galesburg, to the lower 70s along/south of I-70.
In addition to the warmer conditions, showers and a few
thunderstorms will become more numerous ahead of the approaching
upper trough and associated cold front late in the day. As a
result, will carry likely to categorical POPs along/west of I-55
for mid to late afternoon, tapering down to just chance POPs
further east along the Indiana border.
As upper wave/cold front get closer, increasing southerly flow
will bring copious amounts of moisture northward into the area
tonight into Thursday. 00z Oct 30 KILX upper air sounding already
showed precipitable water values of just over 1 inch and upstream
soundings at KSGF and forecast projections indicate values rising
to around 1.5 inches tonight/Thursday. Given rich moisture and
strong upper dynamics, will carry categorical POPs across the
board through Thursday.
Cold front will push into Illinois on Thursday, gradually exiting
into Indiana by evening. GFS shows a clean FROPA late Thursday
afternoon, while the NAM is hinting at a weak surface wave along
the boundary potentially slowing its eastward progression a bit.
If the NAM is correct, surface low will track from northeast
Oklahoma midday Thursday into southwest Indiana by evening. This
could allow a slightly more unstable airmass just off to the
southwest of Illinois to briefly spill into the SE KILX CWA during
the late afternoon and evening. If this occurs, this somewhat
enhanced instability in conjunction with impressive 0-6km wind
shear of 70 to 80kt could lead to strong to severe thunderstorms
along the advancing front. As a result, the latest Day 2 outlook
from SPC has placed areas along/south of I-70 in a slight risk for
severe. Given low CAPE/high shear environment, biggest threat
would likely be damaging wind gusts. Further north across the
remainder of the CWA, widespread clouds/precip will keep
instability parameters even weaker, so threat for strong storms is
lower. Since front may be delayed by surface wave, will hold onto
chance POPs through Thursday evening, before drying things out
after midnight.
LONG TERM...Saturday through Tuesday
Upper trough will dig into the Great Lakes behind the departing
front Friday into Saturday. Models continue to suggest clouds and
showers beneath this system will impact northern Illinois into
north-central Indiana, but will remain just N/NE of the KILX CWA.
Main story will be the cooler weather, with highs on Saturday only
making it into the lower to middle 50s. High pressure will build
into the region by early next week, resulting in cool/dry weather
for both Sunday and Monday. Models are still in disagreement with
regards to the next approaching system, with the GFS trying to
spread precip back into Illinois as early as Monday night. Given
sprawling surface high and dry airmass in place, think the slower
ECMWF is the way to go in the extended. As a result, will maintain
dry forecast Monday night followed by low chance POPs on Tuesday.
Best rain chances will likely hold off until Tuesday night into
Wednesday as cold front slowly pushes into the region.
Barnes
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1106 AM CDT WED OCT 30 2013
.DISCUSSION...
547 AM CDT
UPDATE FOR DENSE FOG ADVISORY.
HAVE ISSUED A DENSE FOG ADVISORY FOR THE SOUTHWEST 2/3 OF THE CWA
THROUGH 16Z.
WHILE A FEW SPOTS HAVE DEVELOPED LOCALLY DENSE FOG ACROSS NORTHERN
IL EARLY THIS MORNING...HAVE BECOME CONCERNED ABOUT VISIBILITY
TRENDS ACROSS CENTRAL IL WHERE HIGH DEW POINT AIR CONTINUES TO
ADVECT NORTH INTO COOLER NOCTURNAL AIR MASS. SUSPECT VISIBILITY
WILL DETERIORATE FROM THE SOUTH OVER THE NEXT FEW HOURS...WITH
AREAS OF DENSE FOG DEVELOPING. HAVE KEPT IMMEDIATE LAKE SHORE AND
CHICAGO CENTER OUT OF ADVISORY...AS WELL AS MOST OF NORTHWEST
INDIANA AT THIS POINT DUE TO WARMER TEMPS ALONG LAKE/CITY AND
LOWER DEW POINTS UPSTREAM ACROSS NORTHWEST IN. CONFIDENCE IS A
LITTLE LOW ON HOW THIS WILL EVOLVE...THOUGH IT APPEARS FOG OF SOME
SUBSTANCE WILL BE AROUND FOR A GOOD PORTION OF THE MORNING HOURS.
RATZER
//PREV DISCUSSION...
354 AM CDT
MAIN FORECAST FOCUS REMAINS ON LARGE STORM SYSTEM THAT WILL TRACK
ACROSS THE REGION THROUGH THURSDAY NIGHT. RAINFALL AMOUNTS RANGING
FROM THREE QUARTERS OF AN INCH TO PERHAPS IN EXCESS OF 1.5 INCHES
ARE POSSIBLE WITH THIS SYSTEM...IN ADDITION TO TEMPERATURES IN THE
60S BEFORE THE COLD FRONT PUSHES THROUGH LATE THURSDAY.
RELATIVELY QUIET WEATHER IS IN PLACE ACROSS THE CWA EARLY THIS
MORNING...WITH ONLY SOME PATCHY FOG AND CLOUDY SKIES OF ANY NOTE.
SHOWERS WHICH HAD OCCURRED LAST EVENING HAD MOVED OFF TO THE
SOUTHEAST OF THE AREA...WITH A MID-LEVEL SHORT WAVE THAT TRAVERSED
THE REGION OVERNIGHT. AT THE SURFACE...WEAK LOW PRESSURE WAS OVER
THE MID-MISSOURI VALLEY NEAR OMAHA...WITH A WARM FRONT EXTENDING
ACROSS CENTRAL MISSOURI INTO CENTRAL ILLINOIS. RELATIVELY WEAK BUT
PERSISTENT WARM/MOIST ADVECTION WILL CONTINUE ATOP THE FRONTAL
ZONE THIS MORNING...WITH THE POTENTIAL FOR A FEW SHOWERS OR
SPRINKLES PARTICULARLY ACROSS THE SOUTHWESTERN PARTS OF THE CWA.
RAIN CHANCES WILL INCREASE THIS AFTERNOON FROM THE SOUTHWEST
HOWEVER...AS ANOTHER MID-LEVEL SHORT WAVE CURRENTLY OVER
KANSAS/NEBRASKA APPROACHES THE AREA. SOUTH LOW LEVEL FLOW WILL
INCREASE ACROSS THE BAROCLINIC ZONE TO OUR SOUTH...WITH ISENTROPIC
ASCENT AND MOISTURE TRANSPORT INCREASING BY LATE THIS AFTERNOON.
STRONGER HEIGHT FALLS DEVELOP TONIGHT THROUGH THURSDAY THEN...AS
LARGE WESTERN CONUS TROUGH BEGINS TO MOVE EASTWARD AND 145 KT UPPER
JET STREAK LIFTS OUT ACROSS THE MIDWEST. THIS INCREASE IN LARGE
SCALE FORCING WILL GENERATE MORE ORGANIZED RAIN AND A FEW
THUNDERSTORMS INTO THE REGION THIS EVENING...WITH PERIODS OF
RAIN/EMBEDDED THUNDER EXPECTED TO CONTINUE INTO THURSDAY. IN THE
PROCESS...THE SURFACE LOW PRESSURE IN THE PLAINS WILL LIFT NORTHEAST
INTO WISCONSIN THROUGH THURSDAY WITH THE SURFACE WARM FRONT LIFTING
NORTH ACROSS NORTHERN ILLINOIS AND NORTHWEST INDIANA TONIGHT. MILD
AND MOIST AIR WITH SFC DEW POINTS IN THE LOWER 60S AND AN AXIS OF
PRECIPITABLE WATER APPROACHING 1.50 INCHES WILL SURGE NORTH WITH THE
WARM SECTOR TONIGHT/THURSDAY...COMBINING WITH STRONG DYNAMICS TO
PRESENT THE POTENTIAL FOR SOME SUBSTANTIAL RAINFALL TOTALS. TEMPS
WILL RISE INTO THE 60S MOST AREAS TODAY...EXCEPT PERHAPS ALONG THE
NORTH SHORE WHERE SOUTHEAST WINDS WILL PROVIDE SOME LAKE COOLING.
TEMPS WILL NOT DIP TOO MUCH TONIGHT HOWEVER WITH THE WARM FRONT
MOVING NORTH...AND IN FACT WILL LIKELY RISE OVERNIGHT. WARM AIR
ALOFT COULD POTENTIALLY SUPPORT SOME UPPER 60S/NEAR 70 TEMPS
THURSDAY UNDER IDEAL CONDITIONS...BUT CONSIDERABLE CLOUDS AND RAIN
WILL LIKELY TEMPER READINGS SOMEWHAT WITH MID 60S EXPECTED.
THE COLD FRONT WILL MOVE INTO WESTERN IL THURSDAY MORNING...AND WILL
SLOWLY PROGRESS ACROSS THE CWA FROM THE WEST THROUGH THE DAY. A
STRONG SHORT WAVE CURRENTLY ROUNDING THE BASE OF THE WESTERN TROUGH
OVER SOUTHERN CALIFORNIA WILL APPROACH THE FORECAST AREA COINCIDENT
WITH THE FRONT THURSDAY/THURSDAY EVENING...MAINTAINING HIGH
PROBABILITY RAIN THREAT THROUGH THE DAY. STORM TOTAL RAINFALL
AMOUNTS FROM GUIDANCE RANGE FROM ABOUT 0.80 INCHES TO IN EXCESS OF
2.00 INCHES IN SOME SPOTS. RAIN SHOULD TAPER OFF FROM WEST TO EAST
THURSDAY EVENING BEHIND THE COLD FRONT.
BREEZY AND COOLER...BUT NOT COLD...WEATHER WILL SPREAD INTO THE AREA
FRIDAY BEHIND THE DEPARTING UPPER TROUGH/COLD FRONT. MODELS INDICATE
ANOTHER FAIRLY STRONG SHORT WAVE TROUGH WILL DIG FROM THE NORTHERN
PLAINS INTO THE REGION TOWARD EVENING...WITH 80 METER HEIGHT FALLS
AND A POCKET OF COLDER AIR ALOFT. MOST GUIDANCE MEMBERS SQUEEZE OUT
A LITTLE PRECIP WITH THE PASSAGE OF THIS WAVE FRIDAY NIGHT INTO
SATURDAY...BEFORE HIGH PRESSURE BUILDS INTO THE AREA SATURDAY NIGHT.
TEMPS FRIDAY ARE EXPECTED TO BE BACK IN THE MID-UPPER 50S...COOLING
TO THE UPPER 40S/AROUND 50 SATURDAY IN THE COLDER AIR BEHIND THE
SECONDARY COLD FRONT ASSOCIATED WITH THE SHORT WAVE. COLDEST
TEMPERATURES OF THE NEXT 7 DAYS APPEAR TO COME LATE SATURDAY
NIGHT...WITH THE SURFACE HIGH PRESSURE RIDGE ALLOWING FOR CLEARING
SKIES AND GOOD RADIATIONAL COOLING CONDITIONS. WILL LIKELY SEE TEMPS
INTO THE 20S IN THE OUTLYING TYPICALLY COOLER SPOTS EARLY SUNDAY
MORNING.
HIGH PRESSURE RIDGE THEN MOVES QUICKLY EASTWARD ON SUNDAY...WITH
LONGER RANGE MODEL RUNS DEPICTING ANOTHER DEEP LOW LIFTING NORTHEAST
ACROSS THE UPPER MIDWEST EARLY NEXT WEEK. THIS WILL ALLOW TEMPS TO
MODERATE...BUT WILL ALSO EVENTUALLY BRING ANOTHER CHANCE FOR SOME
RAIN MAINLY MONDAY NIGHT AND TUESDAY.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* MVFR VIS CONTINUING.
* IFR CIGS LIKELY CONTINUING THROUGH THE DAY...WITH ONLY A SHORT
PERIOD OF IMPROVEMENT POSSIBLE THIS AFTERNOON.
* LIFR CEILINGS POSSIBLE TONIGHT.
* SCT SHOWERS POSSIBLE THIS AFTERNOON...MORE WIDESPREAD COVERAGE
EXPECTED EARLY THIS EVENING WITH POSSIBLE THUNDERSTORMS DURING
THIS TIME AS WELL.
RODRIGUEZ/KB
//DISCUSSION...UPDATED 12Z...
IFR AND LIFR CEILINGS HAVE MOVED OVER ALL OF THE TERMINALS EARLY
THIS MORNING WITH FOG AFFECTING THE TERMINALS AS WELL...AND WITH
RFD OBSERVING DENSE FOG. THE ARRIVAL OF THIS LOW STRATUS HAS
MARKED THE START OF AN EXTENDED PERIOD WITH EITHER IFR OR LOW END
MVFR CEILINGS IN PLACE. WITH A WARM FRONT WELL SOUTH OF THE
TERMINALS AND AN ABUNDANCE OF MOISTURE STREAMING NORTH OUT AHEAD
OF IT...SEE NO REASON WHY CONDITIONS WILL IMPROVE TOO MUCH. WILL
LIKELY SEE SOME SLIGHT IMPROVEMENT THROUGH MID DAY BUT WITH A
DEFINITE POSSIBILITY FOR SOME AREAS TO STAY LOCKED IN THESE IFR
CEILINGS. CONFIDENCE WAS LOW WITH REGARDS TO KEEPING IFR
THROUGHOUT THE DAY...SO ONCE AGAIN HAVE SOME SLIGHT IMPROVEMENT TO
LOW END MVFR WHILE FOG IMPROVES AS WELL TODAY. ALTHOUGH THIS
IMPROVEMENT WILL BE SHORT LIVED AS CONDITIONS DETERIORATE ONCE
AGAIN EARLY THIS EVENING WITH IFR CONDITIONS LIKELY. AFTER
POSSIBLE SCT LIGHT SHOWERS THIS AFTERNOON...MORE PREVAILING PRECIP
IS EXPECTED THIS EVENING. HAVE NOT INCLUDED LIFR CEILINGS TONIGHT
DUE TO THIS POSSIBLE PRECIP AND ESPECIALLY WITH A CHANCE FOR
PERIODIC THUNDERSTORMS...BUT LIFR CEILINGS ARE A DEFINITE
POSSIBILITY TONIGHT. LIGHT SOUTHEAST WINDS WILL PREVAIL WITH WINDS
APPROACHING 9-10 KT...BUT SHOULD STAY UNDER 10 KT TODAY. THEN
EXPECT WINDS TO INCREASE TONIGHT WHILE TURNING TO THE SOUTH WITH
WARM FROPA...WITH GUSTS AROUND 20KT. ITS POSSIBLE THAT WITH FROPA
OVERNIGHT...CONDITIONS BEHIND THE FRONT HELP CEILINGS/VIS IMPROVE.
ALTHOUGH WITH AN ABUNDANCE OF MOISTURE AND EXPECTED PRECIP ONCE
AGAIN EARLY THURSDAY MORNING...HAVE CONTINUED THE PESSIMISTIC
TRENDS AND KEPT IFR CEILINGS THROUGH THE END OF THE FORECAST
PERIOD.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* MEDIUM CONFIDENCE WITH CEILING TRENDS INTO THIS AFTERNOON.
* LOW MEDIUM CONFIDENCE WITH LIFR CEILINGS TONIGHT.
* MEDIUM CONFIDENCE WITH SHOWERS/TRENDS.
RODRIGUEZ/KB
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT...CHANCE OF SHRA...OTHERWISE VFR.
FRIDAY...SLIGHT CHANCE OF SHRA LATE...OTHERWISE VFR.
SATURDAY...SLIGHT CHANCE OF SHRA...OTHERWISE VFR.
SUNDAY...VFR.
MONDAY...SLIGHT CHANCE OF SHRA LATE...OTHERWISE VFR.
TUESDAY...CHANCE OF SHRA...OTHERWISE VFR.
RODRIGUEZ
&&
.MARINE...
439 AM CDT
MAIN FORECAST CONCERNS ARE WITH UNCERTAINTIES REGARDING STRENGTH
AND PLACEMENT OF AN APPROACHING SYSTEM...WHICH IS RAISING ISSUES
WITH REGARDS TO STRENGTH OF WINDS THURSDAY INTO EARLY FRIDAY.
AS HIGH PRESSURE REMAINS SITUATED OVER THE ATLANTIC COAST...A
TROUGH OF LOW PRESSURE WILL LIFT NORTHEAST THROUGH THE CENTRAL
PLAINS AND UPPER MISSISSIPPI VALLEY TODAY INTO TONIGHT. ALTHOUGH
FOR TODAY...THE GRADIENT OVER THE LAKE REMAINS RATHER WEAK WITH
SOUTHEAST WINDS ONLY INCREASING SLIGHTLY TO THE 10 TO 20 KT RANGE
BY THIS AFTERNOON. WITH THE LOW APPROACHING AND WARM FRONT SURGING
NORTHWARD TONIGHT EXPECT WINDS TO BECOME MORE SOUTHERLY WHILE
INCREASING TO 30 KT. THIS LOW WILL CONTINUE DEEPENING AS IT MOVES
ACROSS THE CENTRAL GREAT LAKES REGION THURSDAY...WITH SPEEDS STILL
HOVERING AROUND 30 KT. A PERIOD OF GALES TO 35 KT ARE STILL NOT
OUT OF THE QUESTION ON THURSDAY BUT WITH THE WARMER AIR SURGING
NORTHWARD ACROSS THE LAKE...THINK ANY PREVAILING GALES WILL BE
SUPPRESSED WITH ONLY AN OCCASIONAL GALE FORCE GUST LIKELY. WINDS
ACROSS THE NEARSHORE WILL INCREASE TONIGHT AS WELL INTO THE 20-25
KT RANGE...WITH A BRIEF PERIOD OF TO 30 KT GUSTS POSSIBLE AS THIS
FRONT LIFTS NORTH OVERNIGHT. THIS LOW WILL CONTINUE NORTHEAST INTO
SOUTHEAST ONTARIO AND QUEBEC THURSDAY NIGHT INTO FRIDAY WITH A
BRIEF LULL IN THE WINDS BEFORE WEST WINDS TO 30 KT ARE LIKELY ONCE
AGAIN. ITS DURING THIS TIME WHEN MODEL GUIDANCE VARIES
SIGNIFICANTLY WITH REGARDS TO THIS LOW PRESSURE SYSTEM...WITH
CONFIDENCE AS TO THE STRENGTH OF THE WINDS LOW. ONCE AGAIN...HAVE
MAINTAINED 30 KT WINDS BUT WILL NEED TO MONITOR THIS PERIOD FOR
GALES POSSIBLY DEVELOPING ONCE AGAIN.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...DENSE FOG ADVISORY...ILZ003-ILZ004-ILZ008-ILZ010-ILZ011-ILZ012-
ILZ019-ILZ020-ILZ021-ILZ022-ILZ023-ILZ032-ILZ033-ILZ039
UNTIL 11 AM WEDNESDAY.
IN...DENSE FOG ADVISORY...INZ019 UNTIL 11 AM WEDNESDAY.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...10 PM WEDNESDAY TO 10 AM FRIDAY.
&&
$$
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Area Forecast Discussion
National Weather Service Lincoln IL
1015 AM CDT Wed Oct 30 2013
.DISCUSSION...
ISSUED 1015 AM CDT Wed Oct 30 2013
Have let the dense fog advisory expire at 10 am. Still seeing some
areas of dense fog lingering, mainly across the eastern CWA, but
this will continue to lift over the next 30 to 60 minutes.
Focus in the near term is shifting to elevated convection moving
across northeast Missouri and about to cross into far western
Illinois. Main cluster of storms southwest of Quincy should bypass
our CWA, but showers/storms continue to develop further west
across Iowa and Missouri. These should become more surface based
with time. In addition, RAP and NAM models continue to show some
development across southern Illinois as the warm front lifts
northward toward our area. Latest visible satellite imagery
showing some decent thinning of the clouds in that area to help
make the air more unstable there.
Have done some timing adjustments of the rain chances for our area
today, but general trend is OK for now. Temperatures remain on
target to reach the lower 70s over the southern half of the CWA
later today, once the front arrives.
Geelhart
&&
.AVIATION...
ISSUED 630 AM CDT Wed Oct 30 2013
Main forecast challenge will be timing of improving vsbys acrs the
area this morning...and then coverage of rain and tsra this afternoon
and tonight. Widespread VLIFR conditions across the area early this
morning as a very moist air mass is being advected northward into
our area in advance of a warm front currently over southern Illinois.
This boundary will lift north this morning which should bring about
a gradual improvement in cigs and vsbys aftr 15z. We will then turn
our attention to a band of showers and thunderstorms which should
be pushing into our area in the 19z-22z time frame...with any
cig or vsby improvement seen late this morning into this afternoon
deteriorating once again after the rain starts. Once darkness sets
in early this evening...we look for LIFR and some VLIFR cigs to
prevail in rain and fog thru the remainder of the forecast period.
Right now it appears the fog will not be as thick as this morning.
Surface winds will be southeast at 5 to 10 kts this morning, and then
veer into a south direction this afternoon as the warm front lifts
north of our area with speeds in the 12 to 17 knot range.
Smith
&&
.PREV DISCUSSION...
ISSUED 222 AM CDT Wed Oct 30 2013
Main forecast challenges continue to be rain chances over the next
couple of days, as well as, severe weather threat Thursday afternoon.
07z/2am surface analysis shows low pressure near Kansas City, with
stationary frontal boundary extending eastward across central
Missouri into far southern Illinois. A few showers are occurring
immediately along/north of the boundary, with an extensive area of
fog/drizzle extending much further north toward the I-80 corridor.
Aloft...deep upper low continues to spin over the Great Basin,
while ridging prevails downstream over the Plains into the Midwest.
SHORT TERM...Today through Friday
As western CONUS upper trough slowly tracks eastward, rising upper
heights ahead of the system will help give the stationary frontal
boundary a push northward today. High-res models are in good
agreement that the boundary will reach the northern KILX CWA by
around midday, then will lift into northern Illinois/southern
Wisconsin later this afternoon. Fog/drizzle will be ongoing
along/north of the front through the morning hours, but will
gradually dissipate and shift northward as the morning progresses.
Winds will initially be from the E/SE, but will veer to the south
during the afternoon, helping bring much warmer air into the
region. High temperatures will range from the middle 60s far north
around Lacon and Galesburg, to the lower 70s along/south of I-70.
In addition to the warmer conditions, showers and a few
thunderstorms will become more numerous ahead of the approaching
upper trough and associated cold front late in the day. As a
result, will carry likely to categorical POPs along/west of I-55
for mid to late afternoon, tapering down to just chance POPs
further east along the Indiana border.
As upper wave/cold front get closer, increasing southerly flow
will bring copious amounts of moisture northward into the area
tonight into Thursday. 00z Oct 30 KILX upper air sounding already
showed precipitable water values of just over 1 inch and upstream
soundings at KSGF and forecast projections indicate values rising
to around 1.5 inches tonight/Thursday. Given rich moisture and
strong upper dynamics, will carry categorical POPs across the
board through Thursday.
Cold front will push into Illinois on Thursday, gradually exiting
into Indiana by evening. GFS shows a clean FROPA late Thursday
afternoon, while the NAM is hinting at a weak surface wave along
the boundary potentially slowing its eastward progression a bit.
If the NAM is correct, surface low will track from northeast
Oklahoma midday Thursday into southwest Indiana by evening. This
could allow a slightly more unstable airmass just off to the
southwest of Illinois to briefly spill into the SE KILX CWA during
the late afternoon and evening. If this occurs, this somewhat
enhanced instability in conjunction with impressive 0-6km wind
shear of 70 to 80kt could lead to strong to severe thunderstorms
along the advancing front. As a result, the latest Day 2 outlook
from SPC has placed areas along/south of I-70 in a slight risk for
severe. Given low CAPE/high shear environment, biggest threat
would likely be damaging wind gusts. Further north across the
remainder of the CWA, widespread clouds/precip will keep
instability parameters even weaker, so threat for strong storms is
lower. Since front may be delayed by surface wave, will hold onto
chance POPs through Thursday evening, before drying things out
after midnight.
LONG TERM...Saturday through Tuesday
Upper trough will dig into the Great Lakes behind the departing
front Friday into Saturday. Models continue to suggest clouds and
showers beneath this system will impact northern Illinois into
north-central Indiana, but will remain just N/NE of the KILX CWA.
Main story will be the cooler weather, with highs on Saturday only
making it into the lower to middle 50s. High pressure will build
into the region by early next week, resulting in cool/dry weather
for both Sunday and Monday. Models are still in disagreement with
regards to the next approaching system, with the GFS trying to
spread precip back into Illinois as early as Monday night. Given
sprawling surface high and dry airmass in place, think the slower
ECMWF is the way to go in the extended. As a result, will maintain
dry forecast Monday night followed by low chance POPs on Tuesday.
Best rain chances will likely hold off until Tuesday night into
Wednesday as cold front slowly pushes into the region.
Barnes
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
332 PM CDT WED OCT 30 2013
.SHORT TERM /TONIGHT/...
ISSUED AT 314 PM CDT WED OCT 30 2013
INTERESTING FORECAST TONIGHT WITH THE SURFACE LOW OVER NW MO AND A
TROUGH EXTENDING INTO CENTRAL IOWA LOCATED FROM ALGONA THROUGH
CRESTON. THE WARM FRONT ASSOCIATED WITH THIS LOW IS STILL IN
NORTHERN MO AND IS JUST STARTING TO INCH INTO FAR SOUTHERN/SW IA.
THE MODELS HAVE CAUGHT ON TO TRENDING DOWN WITH POPS/QPF...
ESPECIALLY ACROSS THE WEST. THE RAP ACTUALLY HAD THE BEST HANDLE ON
THINGS FOR TONIGHT. ALTHOUGH ALL MODELS WERE TRENDING LOWER WITH
POPS...NAM/GFS STILL LOOKED A BIT OVERDONE AND HIT QPF MORE THAN
WHAT I THINK WILL OCCUR. CONSEQUENTLY THE AREA FOR PRECIP THIS
EVENING WILL BE ALONG OUR FAR SOUTHERN AND EASTERN AREAS...NEAR THE
FRONTAL BOUNDARY WHERE SHOWERS AND ISOLATED TO SCATTERED STORMS ARE
STILL POSSIBLE. THE THUNDERSTORMS WILL STILL BE CAPABLE OF
PRODUCING MODERATE TO HEAVY RAINFALL THOUGH I THINK THE HEAVIEST
RAIN WILL OCCUR SE OF OUR FORECAST AREA.
I END POPS THIS EVENING FROM W/NW TO ABOUT THE I-35 CORRIDOR BY 12Z.
INSTABILITY AND FORCING SHIFTS EAST OVERNIGHT AS WELL SO THUNDER
CHANCES DIMINISH AFTER 06Z BUT STILL LINGER ACROSS THE FAR SOUTHEAST
BY 12Z. PATCHY FOG STILL A CONCERN AS SOUNDING SHOW SATURATED
SOUNDINGS ACROSS CENTRAL IOWA. FOR NOW I AM NOT CONSIDERING DENSE
FOG THOUGH LOWER LYING AREAS AND LOCATIONS THAT RECEIVED AN INCH OF
RAIN TODAY COULD SEE AT LEAST LOCALIZED DENSE FOG OVERNIGHT. I WILL
BRIEF THE EVENING SHIFT ON THE POSSIBILITY OF DENSE FOG LATER
TONIGHT.
.LONG TERM /THURSDAY THROUGH WEDNESDAY/...
ISSUED AT 314 PM CDT WED OCT 30 2013
MAIN CHALLENGE IN THE NEAR TERM WILL BE THE EXITING OF OVERNIGHT
PRECIPITATION INTO THURSDAY MORNING. THE BULK OF THE RAIN AND ANY
LEFTOVER ISO THUNDER WILL BE EXITING THE AREA BY EARLY AFTERNOON
WITH SOME LINGERING SHOWERS SOUTHEAST THROUGH 00Z. OTHERWISE
...EXPECTING SIGNIFICANT CLOUD COVER OVER MUCH OF THE SOUTHEAST
HALF THROUGH MIDDAY FOLLOWED BY PARTIAL CLEARING DURING THE
AFTERNOON. SUBSIDENCE SHOULD BE OFFSET BY SOME COLD AIR ADVECTION
WHICH WILL RESULT IN LINGERING CLOUDS FOR THE DAY. HIGHS WILL ONCE
AGAIN REACH THE UPPER 50S SOUTHEAST WITH NEAR 50 HIGHS FAR NORTH
WHERE COLD AIR WILL ARRIVE SOONER. A SECONDARY COLD FRONT/WEAK WAVE
WILL TRACK SOUTHEAST THURSDAY EVENING. THIS WILL CONTINUE CLOUD
COVER ACROSS THE AREA SO OVERNIGHT LOWS WILL BE HELD IN CHECK
COMPARED TO CLEARING. LIMITED WARM AIR ADVECTION IS EXPECTED ON
FRIDAY WITH CLOUDS...SO HIGHS WILL ONCE AGAIN STRUGGLE TO REACH THE
LOWER TO MID 50S FOR THE DAY. THE MODELS ARE CONTINUING TO PICK UP A
WAVE IN THE FLOW OVER THE NORTH PACIFIC/GULF OF ALASKA NOW...WHICH
WILL RACE EAST AND THEN DROP SOUTHEAST INTO THE AREA BY FRIDAY
AFTERNOON. THOUGH GENERALLY MOISTURE STARVED...THIS FEATURE SHOULD
AMPLIFY AS IT HOOKS UP WITH THE H500 TROUGH STILL LINGERING OVER THE
CENTRAL PLAINS. THE TIMING OF THE FEATURE SUGGESTS THAT SOME LIGHT
SHOWERS MAY OCCUR LATE FRIDAY AFTERNOON OR EARLY EVENING PRIOR TO
THE SYSTEM MOVING EAST. THE EURO/GEM ALSO SUGGEST A BRIEF SHOT OF
COLD AIR ADVECTION FRIDAY NIGHT WITH THIS FEATURE REINFORCING THE
COOL WEATHER INTO SATURDAY. BOTH THE GFS AND NAM ARE FASTER WITH
ARRIVAL/DEPARTURE AND ARE ALREADY WARMING UP THE COLUMN SATURDAY
AFTERNOON. FOR NOW...WILL LEAN TOWARD MED RANGE SOLUTIONS AND DELAY
ONSET OF WARM AIR UNTIL LATER SATURDAY AND SUNDAY. WITH A H500
TROUGH JUST OFF THE COAST OF BRITISH COLUMBIA EXPECTED TO DIG
ONSHORE AND DEEPEN OVER THE NORTHERN ROCKIES BY SUNDAY...A NICE
FETCH OF SOUTHERLY FLOW WILL DEVELOP ACROSS THE REGION FOR SUNDAY.
H850 TEMPS WILL QUICKLY TURN THE CORNER AND RISE TO 3C TO 6C BY LATE
DAY...COMBINED WITH MIXING TO 875MB MAXT SHOULD RISE TO THE MID TO
UPPER 50S SOUTH AND AND LOWER 50S SOUTH. ALONG WITH THE INCREASING
SOUTHERLY FLOW...MOISTURE WILL BE RETURNING BY LATE SUNDAY NIGHT
THROUGH TUESDAY AS A DEEP SUBTROPICAL CONNECTION SETS UP WITH THE
GULF/PACIFIC BEING CHANNELED NORTH INTO THE CENTRAL PLAINS AND OHIO
RIVER VALLEY. SOME QUESTION ABOUT THE EXACT POSITION...BUT OVERALL
ADDITIONAL RAINFALL...EVEN IF MODEST OVER THE AREA...WILL BE
WELCOMED TO ADD TO TODAYS RAIN EVENT. IT APPEARS THAT THERE WILL
BE SEVERAL WAVES APPROACHING THE AREA BY EARLY NEXT WEEK INTO
MIDWEEK KEEPING RAINFALL IN THE FORECAST THROUGH AT LEAST
WEDNESDAY. FOR NOW...MODESTLY COOLER AIR FOLLOWS THE SYSTEM SO
HIGHS SHOULD TRACK JUST SLIGHTLY BELOW NORMAL FOR THIS TIME OF THE
YEAR.
&&
.AVIATION...30/18Z
ISSUED AT 1245 PM CDT WED OCT 30 2013
AS THE RAINFALL IS MOVING THROUGH THE TAF LOCATIONS IT IS LIFTING
VISIBILITIES AND LIFTING THE DENSE FOG. EXPECT THIS TREND TO
CONTINUE AND AS SUCH IMPROVING VSBYS. HOWEVER...AS A SFC LOW LIFTS
OUT OF SE NEB AND PULLS A WARM FRONT NORTH ACROSS CENTRAL IOWA I
EXPECT AN ADDITIONAL ROUND OF STORMS AFT 20Z AND CIGS TO LOWER ONCE
AGAIN TO IFR CONDITIONS. BEST CHANCE OF STORMS REMAINS ACROSS THE
SOUTHERN TAF LOCATIONS WITH MODERATE RAINFALL POSSIBLE OVER ALL
LOCATIONS. CONDITIONS ARE NOT FORECAST TO IMPROVE UNTIL AFT 31/14Z
WHEN THE SYSTEM SHIFTS EAST.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...FAB
LONG TERM...REV
AVIATION...FAB
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
730 AM CDT WED OCT 30 2013
.UPDATE...
ISSUED AT 727 AM CDT WED OCT 30 2013
I HAVE EXTENDED THE FOG ADVISORY TO COVER THE ENTIRE CWA...AND NOW
HAVE IT GOING THROUGH 16Z. VISIBILITIES CONTINUE TO LOWER OVER THE
CENTRAL CWA...AND BY SEVERAL OBSERVATIONS...THIS IS DUE TO
CEILINGS LOWERING TO THE SURFACE COMBINED WITH NORMAL ADVECTION
FOG. THIS SHOULD BE RATHER LONG LASTING ONCE IT FORMS...AND MAY
LINGER UNTIL IT IS DISSIPATED BY RAIN TODAY. CONVECTION OVER
EASTERN KANSAS AND NEBRASKA/SOUTHWEST IOWA SHOULD ARRIVE INTO THE
CWA BY MID TO LATE MORNING IN THE WEST. THIS IS BEST HANDLED BY
THE HRRR MODEL...WHILE THE 06Z GFS AND 06Z NAM DO NOT HANDLE THIS
ACTIVITY WELL AT ALL SO FAR THIS MORNING.
ERVIN
UPDATE ISSUED AT 618 AM CDT WED OCT 30 2013
ISSUED A DENSE FOG ADVISORY A AT 520 AM...FOR SOUTHERN COUNTIES
DUE TO VISIBILITIES CRASHING TO LESS THAN 1/2 MILE IN ADVANCE OF
THE WARM FRONT. THIS CONTINUES THROUGH 10 AM...BUT MAY NEED TO BE
EXPANDED OVER THE ENTIRE CWA BORDERS SHOULD FOG CONTINUE TO
FORM...WHICH IS HAS IN NORTHEAST ILLINOIS. FOR THE MOMENT...AM
COVERING THIS POTENTIAL WITH AN SPS STATEMENT ON FOG...BUT WHEN
AND IF VISIBILITIES DROP RAPIDLY...WE WILL EXPAND SINCE
SYNOPTICALLY...IT IS SUPPORTED FOR FOG FORMATION THROUGH
ADVECTION.
ERVIN
&&
.SYNOPSIS...
ISSUED AT 331 AM CDT WED OCT 30 2013
LOW LEVEL MOISTURE ADVECTION IS WELL UNDERWAY OVER THE CWA AND THE
REST OF THE UPPER MIDWEST...NOTED BY WIDESPREAD LOW CLOUDS...AREAS
OF FOG AND DRIZZLE. AN ABSENCE OF MID LEVEL MOISTURE NORTH OVER THE
REGION THIS PAST EVENING AND EARLY OVERNIGHT HAS RESULTED IN AREAS
OF DRIZZLE OVER A WIDE AREA...AND THIS PROCESS CONTINUES. IN
ADDITION...AS MID LEVEL MOISTURE IS ADVECTING BACK INTO THE
REGION...IT APPEARS ELEVATED SHOWERS ARE GROWING IN NUMBER ONCE
AGAIN OVER CENTRAL AND SOUTHEAST IOWA...THESE ARE FORMING ON THE
NOSE OF 850MB MOISTURE TRANSPORT...AND SHOULD BE WITH THUS THROUGH
THE MORNING HOURS.
THE BROAD UPPER LOW TO THE WEST REMAINED CENTERED IN SOUTHERN NEVADA
THROUGH 00Z THIS PAST EVENING...AND IT REMAINS QUITE STRONG...BUT IS
NO LONGER CLOSED OFF FROM THE FLOW. IT WILL BE MOVING EAST AND
LIFTING OUT INTO THE PLAINS TODAY...RESULTING IN MOISTURE LADEN
STORM SYSTEM DEVELOPMENT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 331 AM CDT WED OCT 30 2013
TODAY WILL BE CLOUDY...DRIZZLY...FOGGY...AND EVENTUALLY RAINY DAY.
WHILE FORCING FOR LOW LEVEL PROCESSES OF FOG AND DRIZZLE WILL
CONTINUE THROUGH THE DAY...THE EVENTUAL DEEP SATURATION SHOULD LEAD
TO AN EVOLUTION TOWARDS WIDESPREAD RAIN FALL BY LATE AFTERNOON.
MODELS ARE QUITE VARIED ON THE PLACEMENT OF SHOWERS TODAY...BUT AT
THE MOMENT THEY APPEAR A BIT UNDERDONE ON SHOWER AND THUNDERSTORM
ACTIVITY IN NORTHERN KS AND CENTRAL IOWA...WHICH IS THE MOISTURE
TRANSPORT PLUME THAT IS LIT UP ON THE UKMET...GEM...AND ECMWF TODAY.
THE NAM AND GFS ARE EITHER TOO FAR SOUTH OR NORTH IT SEEMS...AND MAY
NOT BE USABLE IN THE SHORT TERM. I WILL RAMP UP POPS FROM CHANCE
SHOWERS THIS MORNING...TO WIDESPREAD SHOWERS AND EMBEDDED THUNDER BY
AFTERNOON. AT THE SAME TIME...I WILL CONTINUE THE FOG AND DRIZZLE
WHICH WILL BE REMOVED FROM THE FORECAST BY AFTERNOON...AS RAINFALL
SHOULD BE MORE DOMINANT BY THEN. THE MORNING POPS ARE THERE TO COVER
BOTH THE SCATTERED SHOWER THREAT...AND THE FACT THAT DRIZZLE
INTENSITIES MAY PICK UP TO MEASURABLE LEVELS...I.E. MODERATE/HEAVY
AT TIMES. FOG COULD BE DENSE THROUGH MID MORNING AS WELL...BUT WILL
NOT ISSUE AN ADVISORY UNTIL WE SEE WIDESPREAD DENSE FOG
DEVELOP...SINCE THE CURRENT SHOWER ACTIVITY MAY ACT TO BREAK UP THE
DENSITY PROCESSES IN THE SOUTHERN CWA.
TONIGHT...ONGOING FORCING AND RAIN SHOULD BE CENTERED THROUGH THE
CWA THROUGH AT LEAST THE EARLY MORNING HOURS BEFORE MODELS SHIFT THE
MOIST CONVEYOR. AS WITH THIS MORNING AND AFTERNOON...A POOL OF
MUCAPE IS AVAILABLE...AND WILL MAINTAIN EMBEDDED THUNDER IN THE
GRIDS.
QPF...THE MILLION DOLLAR QUESTION WITH WHETHER HEAVY RAIN IS
POSSIBLE. THE ANSWER CLEARLY IS YES. HOWEVER...THE MESOSCALE DETAILS
OF CONVECTION MAY MAKE IT LESS WIDESPREAD THAN THE MORE BULLISH
MODELS...AND OUR FORECAST WILL HAVE A TOUGH TIME SORTING THIS OUT
EXPLICITLY. AT THIS POINT...THROUGH 12Z THURSDAY...IT APPEARS AMOUNTS
AROUND 0.75 NORTHWEST WILL CLIMB TO AROUND 1.5 INCHES NEAR THE QUAD
CITIES...TO 1.7 INCHES IN THE SOUTH. SOME VARIATION OF A QUARTER
INCH OR MORE IS VERY LIKELY FROM THESE NUMBERS...BUT IN GENERAL...
IT IS NEARLY CERTAIN THAT THIS WILL BE MOST WIDESPREAD SIGNIFICANT
RAIN OUR CWA HAS SEEN SINCE EARLY/MID SUMMER. SHOULD THIS EVENT
UNFOLD AS SEEN BY OUR FORECAST...AND NEARLY EVERY MODEL FORECAST...A
DENT WILL BE MADE INTO THE ONGOING SEVERE DROUGHT.
ERVIN
.LONG TERM...(THURSDAY THROUGH NEXT TUESDAY)
ISSUED AT 331 AM CDT WED OCT 30 2013
THURSDAY...STILL SOME VARIANCES IN THE LATEST RUN MODELS IN HANDLING
SFC WAVE/OR WAVES DEVELOPMENT ALONG PASSING FRONTAL BOUNDARY AS UPPER
LONG WAVE TROF AXIS APPROACHES THE MS RVR VALLEY FROM THE WEST BY
LATE THU. BUT THE GENERAL IDEA BY A GENERAL BLEND/SREF TYPE OUTPUT
HAS THE BOUNDARY PUSHING EAST OF THE MS RVR FROM THE WEST BY LATE
THU MORNING AND THEN SLOWED BY SECONDARY WAVE GENESIS ON THE FRONT
ACRS CENTRAL MO WITH IT PROPAGATING ACRS CENTRAL IL BY MIDDAY/EARLY
AFTERNOON. THUS IT APPEARS AFTER PRE-FRONTAL RAIN SWATH WITH SOME
EMBEDDED THUNDER PUSHES EAST THU MORNING...SECONDARY DEF ZONE TYPE
PRECIP ZONE TO MOVE ACRS PORTIONS OF THE AREA WITH MEAN AXIS MORE
LIKELY MOVING ACRS THE SOUTHEASTERN THIRD OR SLIGHTLY MORE OF THE
DVN CWA FROM LATE MORNING AND MUCH OF THE AFTERNOON. TAKING INTO
ACCOUNT THIS ACCEPTED PLACEMENT...COLUMN SATURATION AND FORCING
SUGGEST ANOTHER 0.40 TO 0.80 OF RAINFALL ALONG AND EAST OF A LINE
FROM STERLING IL...TO JUST WEST OF MONMOUTH IL...AND TO KEOKUK IA BY
00Z FRI. PRECIP AMOUNTS MAY DROP OFF SHARPLY FROM THERE AS WESTERLY
TO NORTHWESTERLY POST-FRONTAL FLOW WITH DRIER AIR SURGES INTO THE
WESTERN CWA AS THE DAY PROGRESSES. DESPITE THE SATURATED BOUNDARY
LAYER...MILD TEMPS WITH HIGHS IN THE LOW TO MID 60S FRO MOST OF THE
CWA..ALTHOUGH THE FAR WEST AND NORTHWEST MAY BE HELD IN THE 50S BY
INCREASING POST-FRONTAL PROCESSES. THE MAIN CYCLONE DEEPENS ACRS
NORTHERN LOWER MI THU EVENING AND SOME LLVL WESTERLY ACCELERATION
OF INCOMING DRIER AIR AND FRONTAL PUSH TO THE EAST SHOULD BRING
ABOUT AN END TO THE PRECIP EAST OF THE MS RVR BY 10 PM CDT. BUT THIS
STILL SUBJECT TO SOME FINE TUNING DEPENDING ON HOW FAR WEST OR EAST
THE DEF ZONE REALLY DEVELOPS EARLIER IN THE DAY. LOWS BY FRI MORNING
IN THE UPPER 30S IN THE WESTERN CWA...AND IN THE LOWER 40S IN THE
EASTERN FCST AREA.
FRIDAY THROUGH SUNDAY...FRI AND SAT STILL APPEAR AS POST-SYSTEM COLD
AIR ADVECTION DAYS AND WRAP AROUND STRATOCU...KEEPING TEMPS IN THE
50S OR EVEN HELD DOWN IN THE 40S IN SOME LOCATIONS. EMBEDDED
NORTHWEST UPPER FLOW VORTS TO POSSIBLY WRING OUT SOME DRIZZLE OR
PATCHY LIGHT RAIN FRI NIGHT INTO SAT ESPECIALLY ACRS THE NORTHWESTERN
THIRD TO HALF OF THE DVN CWA. INCREASING SOUTHEASTERLY RETURN FLOW
LATE SUNDAY AHEAD OF THE NEXT DIGGING UPSTREAM TROF TO BRING ABOUT
SOME SFC TEMP MODERATION WITH VALUES RECOVERING BACK INTO AT LEAST
THE MID TO UPPER 50S ALONG AND SOUTH OF I80...LOWER 50S TO THE
NORTH.
NEXT MONDAY AND TUESDAY...LATEST RUN MEDIUM RANGE MODELS SHOWING
SIGNS OF MOISTURE RETURN AND LIGHT PRECIP BREAKING OUT IN
INCREASING WARM MOIST CONVEYOR TO LEE OF NEXT L/W TROF COMPLEX...BUT
HAVE DELAYED THE PROCESS TO LATE MONDAY NIGH OR MORE LIKELY TUE.
COULD SEE SOME MORE DELAY PRECIP ARRIVAL TIMING IN UPCOMING
MODEL RUNS...BUT ANOTHER POTENTIALLY SIGNIFICANT RAINFALL EVENT MAY
BE IN LINE FOR THE REGION EARLY TO MID NEXT WEEK. ..12..
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 618 AM CDT WED OCT 30 2013
A CHALLENGING AVIATION FORECAST WITH WIDESPREAD VERY POOR FLYING
WEATHER IS EXPECTED TODAY THROUGH THURSDAY AS A STORM SYSTEM BRING
EXTENDED PERIODS OF VERY LOW IFR AND IFR WEATHER TO THE REGION.
DENSE FOG...FOG...DRIZZLE...AND SHOWERS WILL DROP VISIBILITIES
BETWEEN 2 AND 1/4 MILE THROUGH THE PERIOD...WITH CIGS BETWEEN 200
FT AND 800 FT THROUGH THE PERIOD. EAST WINDS WILL CHANGE TO SOUTH
BY THIS EVENING. RAINFALL IS POSSIBLE THROUGH THE PERIOD...BUT IS
EXPECTED TO BE MODERATE AND CONTINUOUS FROM LATE AFTERNOON THROUGH
12Z THURSDAY IN ALL SITES. HEAVY RAIN IS POSSIBLE AT MLI AND BRL
TONIGHT. SOME THUNDER MAY ALSO OCCUR..BUT IS NOT INCLUDED AT THIS
TIME DUE TO UNCERTAINTY ON TIMING AND OCCURRENCE.
ERVIN
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...DENSE FOG ADVISORY UNTIL 11 AM CDT THIS MORNING FOR BENTON-
BUCHANAN-CEDAR-CLINTON-DELAWARE-DES MOINES-DUBUQUE-HENRY IA-
IOWA-JACKSON-JEFFERSON-JOHNSON-JONES-KEOKUK-LEE-LINN-LOUISA-
MUSCATINE-SCOTT-VAN BUREN-WASHINGTON.
IL...DENSE FOG ADVISORY UNTIL 11 AM CDT THIS MORNING FOR BUREAU-
CARROLL-HANCOCK-HENDERSON-HENRY IL-JO DAVIESS-MCDONOUGH-
MERCER-PUTNAM-ROCK ISLAND-STEPHENSON-WARREN-WHITESIDE.
MO...DENSE FOG ADVISORY UNTIL 11 AM CDT THIS MORNING FOR CLARK-
SCOTLAND.
&&
$$
UPDATE...ERVIN
SYNOPSIS...ERVIN
SHORT TERM...ERVIN
LONG TERM...12
AVIATION...ERVIN
AREA FORECAST DISCUSSION
NWS TOPEKA KS
400 AM CDT Wed Oct 30 2013
.SHORT TERM...(Today and Tonight)
Issued at 358 AM CDT WED OCT 30 2013
08Z water vapor imagery shows the closed low slowly moving east
towards the central Rockies. At the surface, an inverted trough has
bisected the forecast areas east to west with warm moist air across
east central KS and cooler air moving into north central KS. Fog
this morning has been a bigger problem along and north of the warm
front across central MO, but there has been some narrow band of
dense fog reported near the cold front in north central KS.
Today and Tonight continue to look wet as occasional pieces of
energy eject out of the base of the closed upper low through the day
today while the main upper level trough propagates east late tonight
bringing the strongest forcing so far across eastern KS. There
remains plenty of moisture along and east of the surface trough so
occasional showers and thunderstorms are anticipated. Given the
amount of moisture, rainfall is likely to be moderate or even heavy
at times and think an additional 1 to 2 inches of rainfall is likely
across east central and parts or northeast KS. Considered the need
for a flood watch. But with flash flood guidance for one hour around
1.7 inches or better and the lack of any response to yesterday`s
rainfall by the rivers, confidence in widespread flooding is not
high enough for a watch at this point. If heavy rainfall occurs
today and sets the stage for later tonight as the stronger forcing
lifts out, then a watch may be needed. The potential for severe
weather appears to be conditional on whether the low clouds break up
and allow for stronger destabilization of the boundary layer. While
we can`t rule out severe weather due to the strong deep layer shear,
cloud cover and the expected elevated nature of the storms could
minimize the severe weather potential. Any stronger storms may be
able to produce some hail or strong winds. Temps today could be
tricky because of the surface trough/front and where it ends up.
With the model consensus keeping the boundary somewhere in north
central KS, have lowered highs into the middle and upper 50s, but
expect a strong gradient in temps with highs around 70 or in the
lower 70s across eastern KS. However do not anticipate a strong
diurnal change due to overcast skies and occasional precip. The cold
front should begin to push southeast late tonight as the upper
trough moves across the state. Because of this trended lows across
north central KS down to around 40, and think east central KS could
still be in the upper 50s ahead of boundary.
Wolters
.LONG TERM...(Thursday through Tuesday)
Issued at 358 AM CDT WED OCT 30 2013
Models are in agreement that the arrival and passage of the
main...over northwest Oklahoma at 12z Thu...will be later than
previous runs with an east/northeast track as it ejects out into the
lower Mo valley through the day. This should result not only in a
slower end to precip chances across most of the cwa on Thursday than
earlier models runs...but also higher chances further north and west
through midday and afternoon. Will end precip chances by 1 pm
generally west of an Emporia to Hiawatha line and continue low pops
to the east through most of the afternoon. With veering winds and
drier air working eastward across the cwa below 5 kft through the
day...will only carry isolated thunder potential in the morning.
Still expect dry conditions across the entire cwa by late afternoon
with skies becoming mostly sunny west to east through the day. This
should help temps recover into the upper 50s northeast to lower 60s
south by mid afternoon.
Will continue to maintain a dry fcst Thursday night on through the
weekend as the cwa remains in weak ridging in between the eastern
and western CONUS troughs over the eastern and western CONUS. Highs
in the upper 50s and lower 60s still look on track for the weekend.
With clouds and shower chances increasing early next week with the
approach of the next upper trough...highs in the middle and upper
50s should be the rule.
&&
.AVIATION...(For the 06Z TAFs through 06Z Wednesday Night)
Issued at 131 AM CDT WED OCT 30 2013
The frontal boundary has moves through TOP and FOE shifting the
winds to the west and dropping the surface dewpoint. Because of
this CIGS have improved to MVFR and VSBY is P6SM. With the RAP and
HRRR showing a northwest wind persisting until about 12Z, have
amended the forecast to reflect the better VSBY. CIGS may try to
come back down, but think they will stay above 500 FT.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Wolters
LONG TERM...63
AVIATION...Wolters
AREA FORECAST DISCUSSION
NWS TOPEKA KS
131 AM CDT Wed Oct 30 2013
...AVIATION UPDATE...
.SHORT TERM...(This Evening through Wednesday)
Issued at 322 PM CDT TUE OCT 29 2013
Tonight through Wednesday ....
As of 20z, water vapor imagery showed the mid-level low still
stalled out and spinning over the Great Basin region, resulting in a
deep mid-level trough stretching southward west of the Rockies with
a weak, broad ridge extending across much of the central and eastern
U.S. With this mid-level pattern, a southwesterly flow has
persisted across the region resulting in substantial moisture
advection into the Southern and Central Plains. This deep moisture
has led to the region remaining blanketed under overcast skies all
through today with a few isolated light rain showers and periods of
drizzle. Surface low pressure has moved into central Kansas with the
stationary front stretching across central and east central Kansas.
Locations south of this boundary with southeasterly winds have been
able to have high temperatures creep into the middle 60s while
locations north of the boundary with winds generally out of the east
have remained fairly unchanged through the day in the upper 50s/low
60s.
Model soundings continue to show the mid levels of the atmosphere
drying out during the evening hours with saturation in the
low-levels still present. As a result, could continue to see periods
of drizzle developing through the evening hours. Overnight the low
and mid-level jet begins to ramp up over the region and
significantly increases by Wednesday morning with southwesterly
500MB winds reaching upwards of 55-65kts. This increasing jet will
bring additional moisture into the region, resaturating the moisture
profiles and supporting the development of additional precipitation
for Wednesday. With this increasing moisture and light winds in the
vicinity of the stationary boundary across northeast Kansas, will
likely see some areas of fog develop through the overnight hours
into Wednesday morning. As for low temperatures, these overcast
skies will limit the amount of cooling that can occur with
temperatures remaining fairly unchanged in the middle 50s to lower
60s.
For Wednesday, the focus is on the potential for any strong to
severe thunderstorms to develop as the mid-level trough finally
begins to progress eastward across the Rockies through the day.
Models show very substantial 0-6km bulk shear in place over the
region, increasing to upwards of 55-65kts by the afternoon.
Soundings show that most of the shear is unidirectional out of the
southwest, but there could be some slight veering of winds close to
the surface as winds may be more out of the south. The potential for
strong to severe thunderstorms to develop during the afternoon may be
highly dependent upon whether or not we can get any breaks in the
extensive cloud cover to enhance the daytime heating and instability
over the region. If temperatures are able to warm up into the low
70s we could see MU CAPE values reaching into the 1000-1500 J/kg
range. This instability combined with the sufficient wind shear
could support the development of some stronger storms possibly
organizing into more of a squall line, with the primary threats being
large hail and strong winds. An additional concern with this
activity will be the potential for some heavy rainfall. Several
locations received an inch or more of rain Monday night/early
Tuesday morning. Models have the next round of showers and
thunderstorms entering into the forecast area early Wednesday
morning with periods of scattered activity likely persisting through
the day. With the deep moisture in place, models have PWAT values
upwards of 1 to 1.5 inches by the afternoon hours. As a result, will
need to keep an eye out for any localized flooding that may occur
with the additional precipitation.
.LONG TERM...(Wednesday Night through Tuesday)
Issued at 322 PM CDT TUE OCT 29 2013
Wednesday Night through Thursday...An upper level trough across the
central and southern high plains will move east across Kansas
Wednesday night into Thursday morning. A squall line will most
likely be in progress along the front cold front. The primary hazard
during the early evening hours will be damaging winds as the 700MB
winds increase to 50 KTS ahead of the approaching H5 trough. Once
storms become elevated during the mid and late evening hours the
damaging winds threat should decrease. Some of the stronger updrafts
within the line may produce quarter size hail. The line of storms
will move Southeast of the CWA after midnight. Post frontal showers
and isolated thunderstorms will continue through the morning hours
of Thursday until the upper level trough shifts east of the CWA.
Isentropic down-glide on the back side of the departing H5 trough
will cause skies to clear from west to east across the CWA during
the afternoon hours of Thursday. Highs on Thursday will be in the
upper 50s to lower 60s.
Thursday Night through Sunday...Northwest flow aloft late this week
will transition to southwesterly flow aloft as another upper level
trough deepens across the western CONUS early next week. Expect dry
conditions with Highs in the upper 50s to lower 60s. Overnight lows
will be in the mid 30s to lower 40s.
Sunday Night through Tuesday...Southerly low-level flow will advect
deeper moisture northward across the plains. Isentropic lift along
with minor H5 troughs ejecting out into plains may provide a chance
for showers and perhaps some isolated thunderstorms. The best chance
for showers and thunderstorms will occur on Tuesday as the main
trough moves east into the southern and central plains and a
stronger cold front moves southeast across western KS. Highs will
continue in the upper 50s to lower 60s, due to cloud cover and
periods of rain and isolated thunderstorms.
&&
.AVIATION...(For the 06Z TAFs through 06Z Wednesday Night)
Issued at 131 AM CDT WED OCT 30 2013
The frontal boundary has moves through TOP and FOE shifting the
winds to the west and dropping the surface dewpoint. Because of
this CIGS have improved to MVFR and VSBY is P6SM. With the RAP and
HRRR showing a northwest wind persisting until about 12Z, have
amended the forecast to reflect the better VSBY. CIGS may try to
come back down, but think they will stay above 500 FT.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...Hennecke
LONG TERM...Gargan
AVIATION...Wolters
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1055 PM EDT THU OCT 31 2013
.UPDATE...
ISSUED AT 1055 PM EDT THU OCT 31 2013
DID ANOTHER UPDATE TO FINE TUNE THE MOVEMENT OF THE SQUALL LINE
THROUGH OUR AREA OVER THE NEXT SEVERAL HOURS. USED THIS LINE TO
HIGHLIGHT THE HIGHEST WINDS AND BEST THUNDER CHANCES. ALSO TWEAKED
THE T AND TD GRIDS TO REFLECT THE LATEST OBS AND TRENDS. UPDATES HAVE
BEEN SENT TO THE NDFD AND WEB SERVERS.
UPDATE ISSUED AT 810 PM EDT THU OCT 31 2013
23Z SFC ANALYSIS SHOWS A DEEP AREA OF LOW PRESSURE MOVING INTO THE
GREAT LAKES. A POWERFUL COLD FRONT ASSOCIATED WITH THIS IS SLICING
EAST THROUGH THE MIDWEST...NOW APPROACHING WESTERN KENTUCKY. AHEAD OF
THIS...THE WEAKER PATCHES OF SHOWERS ARE BREAKING UP...CLEARING THE
WAY FOR MORE BANDED CLUSTERS AND EVEN SOME LINEAR THUNDERSTORMS. IN
THIS ENVIRONMENT...HIGH SHEAR AND PASSING 850 MB JET AT 75+ KTS...
THESE HAVE THE DISTINCT POTENTIAL OF BRINGING DOWN DAMAGING WINDS
GUSTS AND A SMALL THREAT OF SHORT LIVED TORNADOES. THE MAIN QUESTION
IS HOW THESE STORMS EVOLVE TO OUR WEST AND MOVE THROUGH EAST KENTUCKY
LATER TONIGHT. THE LATEST HRRR SUGGESTS THAT A SQUALL LINE WILL MOVE
THROUGH JUST AHEAD OF THE FRONT WITH THE HEAVIEST RAINS AND WINDS
PASSING THROUGH EAST KENTUCKY FROM 04 TO 08Z. HAVE SET UP THE LATEST
GRIDS TO REFLECT THIS AND READJUSTED THE WIND/GUST GRIDS TO BETTER
FOCUS ON THIS POTENTIAL LINE. FOR TEMPERATURES AND DEWPOINTS...HAVE
ADJUSTED THEM TOWARD THE LATEST CONSSHORT EXPECTING THEM TO STAY UP
UNTIL THE MAIN BOUNDARY AND RAIN APPROACHES LATER THIS EVENING. HAVE
ALSO UPDATED THE NPW TO REFLECT THESE LATEST THOUGHTS WITH A ZFP AND
HWO UPDATE TO FOLLOW. GRIDS HAVE BEEN SENT TO THE NDFD AND WEB
SERVERS.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 349 PM EDT THU OCT 31 2013
DEEPENING AREA OF SURFACE LOW PRESSURE IS CURRENTLY LOCATED ACROSS
NORTHEASTERN WISCONSIN...WITH A TRAILING SURFACE COLD FRONT ALIGNED
SOUTH ALONG CENTRAL ILLINOIS AND THEN BACK ACROSS SOUTHWESTERN
MISSOURI. A STOUT PRESSURE GRADIENT SETTING UP BETWEEN THE LOW AND
HIGH PRESSURE LOCATED ACROSS THE NORTHERN ATLANTIC...HAS ALLOWED FOR
SUSTAINED SOUTHERLY WINDS OF 10 TO 20 MPH...WITH OCCASIONAL GUSTS
RANGING IN THE 30 TO 40 MILE PER HOUR RANGE.
THE MODELS ARE IN GOOD AGREEMENT THROUGH THE SHORT TERM...PLOWING THE
COLD FRONT THROUGH THE COMMONWEALTH TONIGHT...BRINGING WIDESPREAD
RAINS...STRONG WIND GUSTS...AND PERHAPS A FEW THUNDERSTORMS. THE
THREAT FOR SEVERE WEATHER LOOKS LOW GIVEN THE LACK OF
INSTABILITY...HOWEVER WITH SUCH STRONG WINDS AVAILABLE NOT FAR OFF
THE SURFACE...STILL EXPECT WIND GUSTS AROUND 40 MPH...ESPECIALLY
WITHIN ANY BETTER BANDS OF THE PRE-FRONTAL SHOWERS.
SHOWER ACTIVITY WILL COME TO AN END QUICKLY FROM WEST TO EAST AS THE
FRONT PULLS AWAY EARLY FRIDAY MORNING. SKIES WILL CLEAR OUT DURING
THE DAY ON FRIDAY...WITH HIGHS RETURNING TO THE MID 60S FOR MOST
LOCATIONS.
CLOUDS WILL THEN MOVE BACK IN LATE FRIDAY NIGHT...AS A TROUGH AXIS
APPROACHES FROM THE WEST...ALTHOUGH ANY PRECIPITATION CHANCES LOOK
TO HOLD OFF UNTIL SATURDAY. LOWS FRIDAY NIGHT WILL BE MUCH
COOLER THAN WE HAVE SEEN OVER THE PAST FEW DAYS...WITH LOW TO MID
40S EXPECTED.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 330 PM EDT THU OCT 31 2013
THE MODELS START OUT IN VERY GOOD AGREEMENT WITH A FAIRLY SHARP AND
STRONG UPPER TROUGH OVER WESTERN KENTUCKY. THIS TROUGH WILL HELL TO
GENERATE SOME SCATTERED SHOWERS ACROSS THE AREA IN THE COLD AIR
BEHIND THE FRONT. CONSIDERED THE POSSIBILITY OF AN ISOLATED
THUNDERSTORM...HOWEVER THE TQ INDEX...WAS A LITTLE TOO LOW TO
SUPPORT THUNDER. WOULD NOT BE TOO SURPRISED TO SEE SOME GRAUPEL WITH
THESE SHOWERS. AS THE TROUGH MOVES OFF TO THE EAST...HIGH PRESSURE
WILL BE BUILDING IN FROM THE WEST. THIS WILL USHER IN A DRY PERIOD
UNTIL THE LEADING EDGE OF THE NEXT FRONT MOVES INT THE AREA ON
WEDNESDAY EVENING. BY WEDNESDAY EVENING THE MODELS START TO DIFFER
SOME ON SPEED WITH THE ARRIVAL OF THE NEXT SYSTEM. THE FRONT WILL
MOST LIKELY TO MOVE THROUGH THE AREA ON THURSDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 820 PM EDT THU OCT 31 2013
EXPECT VFR CONDITIONS AND SOME VCSH TO CONTINUE THROUGH THE REST OF
THE EVENING ACROSS THE FORECAST AREA. AROUND MIDNIGHT...THOUGH...A
BETTER AND MORE ORGANIZED BAND OF SHOWERS...POSSIBLY INCLUDING A FEW
THUNDERSTORMS...IS EXPECTED TO PUSH INTO AND SLOWLY THROUGH EAST
KENTUCKY. THIS BAND WILL HAVE THE HIGHEST WINDS AND LOWEST VIS IN
HEAVIER RAIN WITH A VCTS AND CB INCLUDED IN THE TAFS. THE HEAVIEST
RAINS SHOULD END TOWARD 08Z FROM WEST TO EAST LEAVING BEHIND LIGHTER
WINDS AND MVFR CIGS. CONDITIONS WILL CONTINUE TO IMPROVE INTO FRIDAY
MORNING AS THE LOWER CLOUDS SUBSEQUENTLY BREAK UP AND WINDS SETTLE
FROM THE WEST. VFR CONDITIONS FOLLOW THROUGH THE REST OF THE AVIATION
PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 6 AM EDT FRIDAY FOR KYZ044-050>052-058>060-
068-069-079-080-083>088-104-106>120.
&&
$$
UPDATE...GREIF
SHORT TERM...GEOGERIAN
LONG TERM...JJ
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
820 PM EDT THU OCT 31 2013
.UPDATE...
ISSUED AT 810 PM EDT THU OCT 31 2013
23Z SFC ANALYSIS SHOWS A DEEP AREA OF LOW PRESSURE MOVING INTO THE
GREAT LAKES. A POWERFUL COLD FRONT ASSOCIATED WITH THIS IS SLICING
EAST THROUGH THE MIDWEST...NOW APPROACHING WESTERN KENTUCKY. AHEAD OF
THIS...THE WEAKER PATCHES OF SHOWERS ARE BREAKING UP...CLEARING THE
WAY FOR MORE BANDED CLUSTERS AND EVEN SOME LINEAR THUNDERSTORMS. IN
THIS ENVIRONMENT...HIGH SHEAR AND PASSING 850 MB JET AT 75+ KTS...
THESE HAVE THE DISTINCT POTENTIAL OF BRINGING DOWN DAMAGING WINDS
GUSTS AND A SMALL THREAT OF SHORT LIVED TORNADOES. THE MAIN QUESTION
IS HOW THESE STORMS EVOLVE TO OUR WEST AND MOVE THROUGH EAST KENTUCKY
LATER TONIGHT. THE LATEST HRRR SUGGESTS THAT A SQUALL LINE WILL MOVE
THROUGH JUST AHEAD OF THE FRONT WITH THE HEAVIEST RAINS AND WINDS
PASSING THROUGH EAST KENTUCKY FROM 04 TO 08Z. HAVE SET UP THE LATEST
GRIDS TO REFLECT THIS AND READJUSTED THE WIND/GUST GRIDS TO BETTER
FOCUS ON THIS POTENTIAL LINE. FOR TEMPERATURES AND DEWPOINTS...HAVE
ADJUSTED THEM TOWARD THE LATEST CONSSHORT EXPECTING THEM TO STAY UP
UNTIL THE MAIN BOUNDARY AND RAIN APPROACHES LATER THIS EVENING. HAVE
ALSO UPDATED THE NPW TO REFLECT THESE LATEST THOUGHTS WITH A ZFP AND
HWO UPDATE TO FOLLOW. GRIDS HAVE BEEN SENT TO THE NDFD AND WEB
SERVERS.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 349 PM EDT THU OCT 31 2013
DEEPENING AREA OF SURFACE LOW PRESSURE IS CURRENTLY LOCATED ACROSS
NORTHEASTERN WISCONSIN...WITH A TRAILING SURFACE COLD FRONT ALIGNED
SOUTH ALONG CENTRAL ILLINOIS AND THEN BACK ACROSS SOUTHWESTERN
MISSOURI. A STOUT PRESSURE GRADIENT SETTING UP BETWEEN THE LOW AND
HIGH PRESSURE LOCATED ACROSS THE NORTHERN ATLANTIC...HAS ALLOWED FOR
SUSTAINED SOUTHERLY WINDS OF 10 TO 20 MPH...WITH OCCASIONAL GUSTS
RANGING IN THE 30 TO 40 MILE PER HOUR RANGE.
THE MODELS ARE IN GOOD AGREEMENT THROUGH THE SHORT TERM...PLOWING THE
COLD FRONT THROUGH THE COMMONWEALTH TONIGHT...BRINGING WIDESPREAD
RAINS...STRONG WIND GUSTS...AND PERHAPS A FEW THUNDERSTORMS. THE
THREAT FOR SEVERE WEATHER LOOKS LOW GIVEN THE LACK OF
INSTABILITY...HOWEVER WITH SUCH STRONG WINDS AVAILABLE NOT FAR OFF
THE SURFACE...STILL EXPECT WIND GUSTS AROUND 40 MPH...ESPECIALLY
WITHIN ANY BETTER BANDS OF THE PRE-FRONTAL SHOWERS.
SHOWER ACTIVITY WILL COME TO AN END QUICKLY FROM WEST TO EAST AS THE
FRONT PULLS AWAY EARLY FRIDAY MORNING. SKIES WILL CLEAR OUT DURING
THE DAY ON FRIDAY...WITH HIGHS RETURNING TO THE MID 60S FOR MOST
LOCATIONS.
CLOUDS WILL THEN MOVE BACK IN LATE FRIDAY NIGHT...AS A TROUGH AXIS
APPROACHES FROM THE WEST...ALTHOUGH ANY PRECIPITATION CHANCES LOOK
TO HOLD OFF UNTIL SATURDAY. LOWS FRIDAY NIGHT WILL BE MUCH
COOLER THAN WE HAVE SEEN OVER THE PAST FEW DAYS...WITH LOW TO MID
40S EXPECTED.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 330 PM EDT THU OCT 31 2013
THE MODELS START OUT IN VERY GOOD AGREEMENT WITH A FAIRLY SHARP AND
STRONG UPPER TROUGH OVER WESTERN KENTUCKY. THIS TROUGH WILL HELL TO
GENERATE SOME SCATTERED SHOWERS ACROSS THE AREA IN THE COLD AIR
BEHIND THE FRONT. CONSIDERED THE POSSIBILITY OF AN ISOLATED
THUNDERSTORM...HOWEVER THE TQ INDEX...WAS A LITTLE TOO LOW TO
SUPPORT THUNDER. WOULD NOT BE TOO SURPRISED TO SEE SOME GRAUPEL WITH
THESE SHOWERS. AS THE TROUGH MOVES OFF TO THE EAST...HIGH PRESSURE
WILL BE BUILDING IN FROM THE WEST. THIS WILL USHER IN A DRY PERIOD
UNTIL THE LEADING EDGE OF THE NEXT FRONT MOVES INT THE AREA ON
WEDNESDAY EVENING. BY WEDNESDAY EVENING THE MODELS START TO DIFFER
SOME ON SPEED WITH THE ARRIVAL OF THE NEXT SYSTEM. THE FRONT WILL
MOST LIKELY TO MOVE THROUGH THE AREA ON THURSDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 820 PM EDT THU OCT 31 2013
EXPECT VFR CONDITIONS AND SOME VCSH TO CONTINUE THROUGH THE REST OF
THE EVENING ACROSS THE FORECAST AREA. AROUND MIDNIGHT...THOUGH...A
BETTER AND MORE ORGANIZED BAND OF SHOWERS...POSSIBLY INCLUDING A FEW
THUNDERSTORMS...IS EXPECTED TO PUSH INTO AND SLOWLY THROUGH EAST
KENTUCKY. THIS BAND WILL HAVE THE HIGHEST WINDS AND LOWEST VIS IN
HEAVIER RAIN WITH A VCTS AND CB INCLUDED IN THE TAFS. THE HEAVIEST
RAINS SHOULD END TOWARD 08Z FROM WEST TO EAST LEAVING BEHIND LIGHTER
WINDS AND MVFR CIGS. CONDITIONS WILL CONTINUE TO IMPROVE INTO FRIDAY
MORNING AS THE LOWER CLOUDS SUBSEQUENTLY BREAK UP AND WINDS SETTLE
FROM THE WEST. VFR CONDITIONS FOLLOW THROUGH THE REST OF THE AVIATION
PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 6 AM EDT FRIDAY FOR KYZ044-050>052-058>060-
068-069-079-080-083>088-104-106>120.
&&
$$
UPDATE...GREIF
SHORT TERM...GEOGERIAN
LONG TERM...JJ
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1021 AM EDT WED OCT 30 2013
.SYNOPSIS...
HIGH PRESSURE WILL BUILD OVER THE STATE TODAY AND TONIGHT THEN
MOVE EAST THURSDAY. STRONG LOW PRESSURE WILL TRACK NORTHWEST OF
THE REGION THURSDAY NIGHT THROUGH FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...
LATEST UA ANALYSIS SHOWS A WEAK SHORT WAVE TROF CROSSING THE
REGION THIS MORNING. AFTER A MOSTLY CLOUDY START...THE VISIBLE
SATELLITE IMAGERY IS STARING TO SHOW THE BACK EDGE OF THE THICKER
HIGH/MID CLOUD COVER STARTING TO MOVE EAST ACROSS NORTHWEST MAINE.
THIS CLEARING TREND SHOULD CONTINUE THIS AFTERNOON. THE 12Z KCAR
SOUNDING SHOULD A DEEP DRY LAYER FROM 600 MB TO 850 MB SO
THINKING IS ONCE WE LOSE THE HIGH/MID CLOUDS WE SHOULD A FAIR
AMOUNT OF SUNSHINE DEVELOPING DURING THIS AFTERNOON ESPECIALLY
NORTHERN AREAS. CURRENT TEMPERATURES STILL LOOK GOOD. ONLY MINOR
ADJUSTMENTS WERE MADE USING THE LATEST HRRR TO TWEAK CURRENT SKY
COVER. THE REST OF THE FORECAST STILL LOOKS ON TARGET.
HIGH PRESSURE CRESTING OVER THE AREA TONIGHT WILL THEN BRING A
MOSTLY CLEAR AND CALM NIGHT ALLOWING TEMPS TO DROP INTO THE 20S
AGAIN OVER THE NORTH AND NEAR FREEZING DOWNEAST. SOME WARM
ADVECTION HIGH CLOUDS MAY BEGIN TO STRAY INTO THE AREA LATE
TONIGHT AS THE HIGH SHIFTS EAST OF THE STATE.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
HIGH PRESSURE WILL MOVE EAST THURSDAY WHILE INTENSIFYING LOW
PRESSURE ACROSS THE GREAT LAKES BEGINS TO DRAW A WARM FRONT NORTH
TOWARD THE REGION. CLOUD COVER WILL INCREASE ACROSS THE REGION
THURSDAY...WITH INCREASING RAIN CHANCES DURING THE AFTERNOON. THE
STRONG LOW WILL TRACK NORTHWEST OF THE REGION THURSDAY NIGHT THROUGH
FRIDAY. A WARM FRONT WILL LIFT ACROSS THE REGION THURSDAY NIGHT
WITH A COLD/OCCLUDED FRONT STARTING TO CROSS THE REGION LATER
FRIDAY. AN AREA OF RAIN WILL CROSS THE REGION THURSDAY NIGHT INTO
FRIDAY...THEN TAPER TO SHOWERS FRIDAY AFTERNOON. MODELS INDICATE A
STRONG LOW LEVEL JET CROSSING THE REGION IN ADVANCE OF THE
COLD/OCCLUDED FRONT FRIDAY...WITH THE STRONGEST WINDS ALONG THE
DOWNEAST COAST. WIND GUSTS OF 30 TO 40 MPH ARE POSSIBLE ACROSS
NORTHERN AREAS FRIDAY...WITH GUSTS OF 40 TO 50 MPH DOWNEAST WITH
THE STRONGEST WINDS ALONG THE COAST. TEMPERATURES WILL BE AT
SLIGHTLY ABOVE NORMAL LEVELS THURSDAY...WITH RISING TEMPERATURES
THURSDAY NIGHT. TEMPERATURES WILL BE AT MUCH ABOVE NORMAL LEVELS
FRIDAY IN ADVANCE OF THE COLD/OCCLUDED FRONT.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
THE COLD/OCCLUDED FRONT WILL CROSS THE REGION FRIDAY NIGHT WITH
SHOWERS IN ADVANCE OF THE FRONT. SHOWERS WILL THEN END IN THE WAKE
OF THE FRONT ACROSS DOWNEAST AREAS...WHILE SHOWERS WRAPPING AROUND
THE LOW LINGER ACROSS NORTHERN AREAS. A WEAK LOW WILL BEGIN TO
APPROACH FROM THE WEST LATER SATURDAY. SKIES WILL REMAIN MOSTLY
CLOUDY ACROSS NORTHERN AREAS SATURDAY...WITH INCREASING CLOUDS
ACROSS THE REMAINDER OF THE FORECAST AREA. RAIN SHOWER CHANCES
WILL INCREASE ACROSS THE REGION SATURDAY AFTERNOON. THE WEAK LOW
WILL CROSS THE REGION SATURDAY NIGHT INTO SUNDAY...THOUGH HOW
QUICKLY THE LOW MOVES EAST REMAINS UNCERTAIN. EXPECT A CHANCE OF
RAIN/SNOW SHOWERS ACROSS NORTHERN AREAS SATURDAY NIGHT INTO
SUNDAY...WITH A CHANCE OF RAIN SHOWERS ACROSS CENTRAL/DOWNEAST
PORTIONS OF THE FORECAST AREA. HIGH PRESSURE WILL BUILD EAST
SUNDAY NIGHT WITH DECREASING CLOUDS. HIGH PRESSURE THEN CROSSES
THE REGION MONDAY AND BEGINS TO MOVE EAST TUESDAY. TEMPERATURES
WILL BE AT ABOVE NORMAL LEVELS SATURDAY...WITH NEAR NORMAL LEVEL
TEMPERATURES SUNDAY THROUGH TUESDAY.
&&
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
NEAR TERM: VFR CONDITIONS ARE EXPECTED ACROSS THE AREA TODAY AND
TONIGHT ALTHOUGH A FEW NORTHERN SPOTS MAY BRIEFLY GO TO MVFR TODAY
IN PATCHY STRATOCUMULUS CLOUDS.
SHORT TERM: VFR CONDITIONS ARE EXPECTED ACROSS THE REGION EARLY
THURSDAY...LOWERING TO MVFR LEVELS THURSDAY AFTERNOON. IFR/LIFR
CONDITIONS ARE EXPECTED ACROSS THE REGION THURSDAY NIGHT INTO
FRIDAY...INCREASING TO MVFR LEVELS DURING THE AFTERNOON. STRONG
GUSTY WINDS ARE EXPECTED ACROSS THE REGION FRIDAY INTO FRIDAY
EVENING...WITH LOW LEVEL WIND SHEAR ALSO A CONCERN. OCCASIONAL
MVFR CONDITIONS WILL LINGER ACROSS NORTHERN AREAS SATURDAY...WITH
GENERALLY VFR CONDITIONS DOWNEAST. MVFR/IFR CONDITIONS ARE
EXPECTED SATURDAY NIGHT INTO SUNDAY...WITH IMPROVING CONDITIONS
LATER SUNDAY.
&&
.MARINE...
NEAR TERM: WINDS AND SEAS ARE EXPECTED TO REMAIN BELOW SCA TODAY
AND TONIGHT.
SHORT TERM: WINDS WILL INCREASE ACROSS THE WATERS THURSDAY
AFTERNOON INTO FRIDAY. GALE FORCE WINDS ARE THEN EXPECTED ACROSS
THE WATERS FRIDAY INTO FRIDAY NIGHT. SMALL CRAFT ADVISORY
CONDITIONS ARE THEN EXPECTED LATER FRIDAY NIGHT THROUGH SUNDAY.
VISIBILITIES WILL BE REDUCED IN RAIN AND FOG THURSDAY AFTERNOON
INTO FRIDAY EVENING.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...BLOOMER/DUDA
SHORT TERM...NORCROSS
LONG TERM...NORCROSS
AVIATION...BLOOMER/DUDA/NORCROSS
MARINE...BLOOMER/DUDA/NORCROSS
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1239 AM EDT WED OCT 30 2013
.SYNOPSIS...
VERY WARM TEMPERATURES WILL PREVAIL UNTIL A COLD FRONTAL PASSAGE
EARLY ON FRIDAY.
&&
.NEAR TERM /THROUGH TODAY/...
WITH 1230AM UPDATE...SLIGHT CHANGES WERE MADE TO HOURLY
TEMPERATURE TRENDS...AS WELL AS DOWNGRADING CHANCE POPS TO SLIGHT
CHANCE POPS DURING THE MORNING HOURS ACROSS THE RIDGES. 00Z RUN OF
THE HRRR SHOWED THERE MAY NOT BE ANY POPS DURING THIS TIME
PERIOD...AND WILL FURTHER EVALUATE REST OF 00Z MODEL SUITE TO
DETERMINE IF ALL POPS CAN BE REMOVED. PREVIOUS DISCUSSION FOLLOWS.
A SHRTWV IN ZONAL FLOW ALOFT WL MAINTAIN UPR...AND MID LVL
CLDINESS ACRS MUCH OF THE UPR OH VALLEY REGION TNGT. DRY AIR IN
THE LLVL WL PRECLUDE MUCH OF A PCPN CHC...ALTHOUGH SLGT CHC NMBRS
WERE MAINTAINED FOR SOME AREAS S OF I 70 EARLY ON WED WHEN COOLING
WL HELP IMPROVE THE RH PROFILE TO THE N OF A WARM FRONT POISED OVR
ACRS CNTL APPALCHIA AND THE MID ATLANTIC.
OTHERWISE...DRY WEA IS TO BE MAINTAINED ON WEDNESDAY VIA A WEAK
BUBBLE OF HIGH PRES BLDG IN THE WAKE OF THAT DISTURBANCE. WARM NR
TERM TEMPS WERE FORECAST USING A BLEND OF MOS.
&&
.SHORT TERM /TONIGHT THROUGH FRIDAY/...
SOUTHERN BOUNDARY WILL SLOWLY MOVE NORTHWARD AS A WARM FRONT
LATER WEDNESDAY NIGHT INTO THURSDAY...WITH AN ASSOCIATED
SHORTWAVE. LIKELY POPS ACROSS AREAS NORTH OF PITTSBURGH WITH
CHANCE POPS ELSEWHERE ESPECIALLY AFTER MIDNIGHT INTO EARLY
THURSDAY. AS THE WARM FRONT SHIFTS NORTH SHOWERS WILL DIMINISH AS
THURSDAY PROGRESSES. IT WILL BECOME QUITE MILD BY THURSDAY
AFTERNOON WITH TEMPERATURES MORE THAN 10 DEGREES ABOVE AVERAGE.
BY THURSDAY NIGHT STORM SYSTEM WILL BE INTENSIFYING OVER THE
NORTHERN GREAT LAKES AS AN UPPER LEVEL TROUGH DIGS INTO THE
NORTHEASTERN STATES. A STRONG COLD FRONT WILL MOVE ACROSS THE
UPPER OHIO VALLEY THURSDAY NIGHT INTO EARLY FRIDAY MORNING WITH
CAT POPS FOR SHOWERS. TIMING OF THE FRONT WITH LACK OF
INSTABILITY LOOKS TO PRECLUDE THUNDERSTORM DEVELOPMENT SO MENTION
OF THUNDER HAS BEEN LEFT OUT.
SURFACE PRESSURE GRADIENT WILL BE TIGHTENING AHEAD OF AND WITH THE
COLD FRONT FOR WIND GUSTS TO REACH OVER 30 MPH THURSDAY NIGHT. AN
INVERSION ON FORECAST SOUNDINGS LOOKS TO KEEP STRONGER WINDS JUST
ALOFT FROM MIXING DOWN TO THE SURFACE. MILD TEMPERATURES THURSDAY
NIGHT INTO FRIDAY AS MUCH COLDER AIR WILL LAG WELL BEHIND THE
FRONT.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
AS A DEEPENING UPPER LEVEL TROUGH DIGS INTO NEW ENGLAND TWO SEPARATE
SHORTWAVES WITH REINFORCING COLD FRONTS WILL CROSS THE EASTERN
GREAT LAKES BRINGING TEMPERATURES BACK BELOW AVERAGE FOR THE
WEEKEND. AS THE COLD AIR COMES IN WITH A SHORTWAVE SATURDAY
SCATTERED SHOWERS EXPECTED AND A BIT OF FLOW OFF THE LAKES
SATURDAY NIGHT WILL BRING A RAIN AND SNOW MIX. SURFACE HIGH
PRESSURE WILL BRING QUIET AND COOL CONDITIONS LATER SUNDAY. THIS
RIDGE WILL SLOWLY MOVES EAST INTO TUESDAY WITH A GRADUAL WARMING
TREND.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
VFR CONDS ARE EXPD THRU WED AS MID AND HIGH LVL CLDS MOVE ACRS THE
RGN. SOME STRATOCU IS EXPD FOR ZZV AND MGW WED AS A WRMFNT BEGINS
TO PUSH N INTO THE TN/OH VLY RGN...ALTHOUGH CIGS SHOULD REMAIN
VFR.
.OUTLOOK.../WEDNESDAY NIGHT THROUGH SUNDAY/...
THE CHC FOR WDSPRD RSTRNS WL INCRS LT WED NGT AND THU AS A WRMFNT
LIFTS N. A STG CDFNT WL FOLLOW THU NGT INTO FRI MRNG WITH RSTRNS
AND LLVL WIND SHEAR LIKELY. RSTRNS WL REMAIN PSBL THRU SAT AS AN
UPR LVL TROF CROSSES THE GT LKS.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
752 PM EDT THU OCT 31 2013
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 336 PM EDT THU OCT 31 2013
STRONG LOW PRESSURE WILL WILL BRING RAIN THIS EVENING AND HIGH
WINDS AFTER MIDNIGHT. SCATTERED POWER OUTAGES ARE EXPECTED AS
WINDS GUST OVER 50 MPH AT TIMES. THE WEATHER WILL COME DOWN FRIDAY
MORNING BUT SCATTERED SHOWERS WILL CONTINUE INTO SATURDAY. FAIR
AND COOL WEATHER IS EXPECTED FOR SUNDAY.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 336 PM EDT THU OCT 31 2013
FORECAST ISSUES ARE FOR HIGH WIND LATE TONIGHT...AND THUNDER/RAIN
THIS EVENING.
WENT WITH A WIND ADVISORY FOR LATE TONIGHT AS THE LOW DEEPENS AND
COLD AIR ADVECTION BEGINS AFTER MIDNIGHT SOME STRONG WINDS COULD
MIX DOWN. BOTH THE NAM AND GFS SHOW 50 KNOTS OF WIND CLOSE TO OR
IN THE MIXING LAYER. THE 12Z EURO IS A BIT WEAKER AND FASTER WITH
THE SFC LOW. WENT WITH A HIGH WIND ADVISORY...ALTHOUGH THERE IS A
CHANCE OF SOME SPOTS GUSTING TO 50 KNOTS ACROSS THE EASTERN
FORECAST AREA AROUND 09Z.
BEFORE THEN...WILL BE WATCHING THE RADAR EVOLUTION OF THE PRECIP
CURRENTLY ACROSS CENTRAL ILLINOIS. DRY SLOT CURRENTLY OVER WESTERN
LOWER MICHIGAN...BUT STILL SEEING DRIZZLE AND SOLID CLOUD
COVER...SO LITTLE IN THE WAY OF SFC INSTABILITY EXPECTED LATE THIS
AFTERNOON/EVENING. A WEAK NCFR COULD STILL FORM AS HINTED AT BY A
FEW RUNS OF THE HRRR AND RADAR ACROSS CENTRAL ILLINOIS. THIS COULD
BRING A BRIEF BURST OF RAIN AND WIND THIS EVENING...OTHERWISE IT
SHOULD JUST BE A SOGGY AND MILD TIME FOR TRICK OT TREATING. THE
SYNOPTIC WIND THREAT ARRIVES LATER.
NO REAL IMPACTS EXPECTED AFTER FRIDAY MORNING. SOME SNOWFLAKES ARE
POSSIBLE SATURDAY EVENING AS 850 MB TEMPS FALL BLO MINUS 6C AND
LAKE EFFECT CONTINUES...BUT THESE SHOULD NOT AMOUNT TO MUCH.
.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 336 PM EDT THU OCT 31 2013
FAIR WEATHER WITH SEASONABLY COOL TEMPERATURES IS EXPECTED SUNDAY
WITH HIGH PRESSURE IN PLACE. STRONG SOUTHERLY RETURN FLOW WARM AIR
ADVECTION WILL DEVELOP EARLY TO MID NEXT WEEK AS THE RIDGE MOVES
EAST. WARM AIR ADVECTION SHOWERS MAY DEVELOP AS EARLY AS LATE MONDAY
NIGHT AND TUESDAY.
HOWEVER THE BETTER CHANCE FOR RAIN WILL HOLD OFF UNTIL WEDNESDAY
THROUGH THURSDAY AS THE NEXT LOW PRESSURE SYSTEM MOVES THROUGH THE
GREAT LAKES REGION. MAX TEMPS MONDAY THROUGH WEDNESDAY WILL REACH
THE 50S BEFORE COOLING TO THE 40S BEHIND THAT SYSTEM FOR LATE NEXT
WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 752 PM EDT THU OCT 31 2013
WIDESPREAD IFR CONDITIONS ARE IN PLACE ACROSS SOUTHWEST LOWER
MICHIGAN AT 00Z. THE CEILINGS SHOULD GRADUALLY LIFT THROUGH THE
COURSE OF THE EVENING AS LOW PRESSURE MOVES NORTHEAST ACROSS THE
REGION...PLOWING A COLD FRONT THROUGH THE TAF SITES. AS THE LOW
MOVES NORTHEAST...CEILINGS SHOULD LIFT ABOVE 1000FT BY 05Z-08Z.
MVFR CEILINGS SHOULD THEN PREVAIL ALL THE WAY THROUGH THE DAY ON
FRIDAY. SCATTERED SHOWERS AND FOG WILL LIMIT VISIBILITY INTO THE
3-5SM RANGE THIS EVENING AND OCCASIONALLY BELOW THAT.
OVERNIGHT...VSBYS SHOULD COME UP IN THE WINDY CONDITIONS BEHIND
THE COLD FRONT. ADDITIONAL SHOWERS WILL DEVELOP OFF THE LAKE ON
FRIDAY...ESPECIALLY AFTER 15Z OR SO. THESE SHOWERS WILL AFFECT
MOST OF THE TAF SITES.
THE COLD FRONT SHOULD SWEEP EAST THROUGH THE TAF SITES BETWEEN 02Z
AND 05Z. A BURST OF WIND IS EXPECTED ALONG THE FRONT AS WINDS
SHIFT SOUTHWEST. SOUTHWEST 15-30 KNOT WINDS WILL GUST IMMEDIATELY
BEHIND THE FRONT. OVERNIGHT...AFTER 06Z...ALL SITES SHOULD SEE A
STIFF WEST-SOUTHWEST WIND FROM AROUND 250-260 DEGREES AT 15 TO 30
KNOTS. A FEW HIGHER GUSTS CANNOT BE RULED OUT UP TOWARDS 35 KNOTS
OR SO.
&&
.MARINE...
ISSUED AT 336 PM EDT THU OCT 31 2013
NO CHANGES TO THE SMALL CRAFT ADVISORY OR GALE WARNING. WINDS
WILL DIMINISH ON FRIDAY MORNING AND THE GALE WARNING WILL BE
REPLACED WITH ANOTHER SMALL CRAFT ADVISORY AT THAT TIME.
&&
.HYDROLOGY...
ISSUED AT 336 PM EDT THU OCT 31 2013
SOME RAIN TOTALS OVER 3 INCHES IN VAN BUREN COUNTY AND EXPECT
ANOTHER HALF INCH TO INCH BEFORE THE HEAVY RAIN ENDS TONIGHT. WE
WILL CONTINUE TO SEE SHARP RISES ON SOME STREAMS AND CREEKS WITH
RISES ON MANY OF THE MAINSTEM RIVERS INTO EARLY NEXT WEEK. AFTER A
BREAK...ANOTHER ROUND OF RAIN IS EXPECTED BY WEDNESDAY OF NEXT
WEEK.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WIND ADVISORY FROM 2 AM TO 8 AM EDT FRIDAY FOR MIZ037>040-
043>046-050>052-056>059-064>067-071>074.
LM...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LMZ844>849.
GALE WARNING UNTIL 10 AM EDT FRIDAY FOR LMZ844>849.
&&
$$
SYNOPSIS...OSTUNO
SHORT TERM...OSTUNO
LONG TERM...LAURENS
AVIATION...DUKE
HYDROLOGY...OSTUNO
MARINE...OSTUNO
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
424 PM EDT WED OCT 30 2013
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 420 PM EDT WED OCT 30 2013
WV IMAGERY AND RAP ANALYSIS SHOWING A BROAD UPPER TROUGH OVER THE
ROCKIES AND A WEAK UPPER RIDGE SHIFTING EAST ACROSS THE AREA. AS
THIS UPPER RIDGE SHIFTS EAST LATE THIS AFTERNOON AND EARLY THIS
EVENING...AREA WILL COME UNDER INCREASING SOUTHWESTERLY FLOW FROM
THE UPPER TROUGH...PUSHING OUR PWAT VALUES FROM 0.75IN (WHICH IS
STILL 150 PERCENT OF NORMAL) TO OVER 1.0IN (OR 200-225 PERCENT OF
NORMAL) OVER THE EASTERN CWA TONIGHT. THAT SOUTHWESTERLY FLOW ALOFT
WILL ALSO LEAD TO BROAD WARM AIR ADVECTION THROUGH THE
NIGHT...ESPECIALLY OVER THE CENTRAL AND EASTERN CWA. AT THE
SURFACE...A LOW THAT HAS DEVELOPED NEAR THE TEXAS PANHANDLE WILL BE
THE MAIN CONCERN FOR THE WEATHER FOR TOMORROW AFTERNOON INTO
TOMORROW NIGHT AS IT MOVES INTO THE GREAT LAKES REGION. BUT BEFORE
THAT OCCURS...AN ELONGATED SURFACE TROUGH WILL STRETCH NORTHEAST
FROM THAT LOW AND ACROSS UPPER MICHIGAN AND LAKE SUPERIOR TONIGHT.
THAT SURFACE TROUGH WILL COMBINE WITH THE SEVERAL SHORTWAVES MOVING
NORTHEAST FROM THE CENTRAL PLAINS (AND PRODUCING THE AREAS OF
CONVECTION AROUND SOUTHEAST IOWA AND NORTHWEST ILLINOIS)...ALONG
WITH THE BROAD WARM AIR ADVECTION AND MOISTURE TRANSPORT TO PRODUCE
SCATTERED SHOWERS WEST AND NUMEROUS/WIDESPREAD SHOWERS EAST TONIGHT.
AN INITIAL BAND OF RAIN SHOWERS AND DRIZZLE HAS BEEN MOVING
EAST-NORTHEAST ACROSS UPPER MICHIGAN THIS AFTERNOON AND EXPECT THAT
TO CONTINUE OVER THE NEXT COUPLE OF HOURS. WITH THE WARM AIR
ADVECTION AND MOISTURE TRANSPORT BEING VERY BROAD AND
COVERING MUCH OF THE CWA...IT/S HARD TO PIN DOWN AREAS WHERE THE
SHOWERS WILL BE LOCATED AND WHEN THEY WILL OCCUR. FEEL THAT THE
COVERAGE WILL LIKELY BE SCATTERED IN NATURE THROUGH THE
EVENING...AND THEN RAMP UP (ESPECIALLY OVER THE CENTRAL/EASTERN
CWA) TOWARDS MIDNIGHT AND THROUGH THE OVERNIGHT HOURS...AS THE
SHORTWAVE ENERGY IN IOWA MOVES THROUGH THE AREA. SINCE THERE IS
PLENTY OF LOW LEVEL MOISTURE...DID ADD MENTION OF PATCHY/AREAS OF
DRIZZLE FOR LATE THIS AFTERNOON AND INTO THE EVENING HOURS UNTIL
THE MORE WIDESPREAD PRECIPITATION ARRIVES. HIGHER RESOLUTION MODELS
SEEM TO BE STRUGGLING WITH THIS BROAD WAA...BUT SEEM TO FOLLOW THAT
SIMILAR IDEA...ALTHOUGH A FEW SHOW THE COVERAGE TO BE LACKING. IF
THE SHOWERS DEVELOP AS EXPECTED...THERE COULD BE SOME RUMBLES OF
THUNDER OVERNIGHT AS THERE IS A LITTLE BIT OF MUCAPE TONIGHT (50-150
J/KG). IN ADDITION...850-700/500MB LAPSE RATES DO INCREASE TO
6.5C/KM...SO CAN/T COMPLETELY RULE OUT SOME RUMBLES OF THUNDER AS
THE SHOWERS MOVE THROUGH. IF CONFIDENCE WAS HIGHER ON SHOWER
LOCATION AND INTENSITY...WOULD ADD IN ISOLATED THUNDER AND WILL
PASS ALONG TO THE EVENING SHIFT ON A POSSIBLE ADDITION.
ONCE THE SHORTWAVE MOVE THROUGH...HAVE SHOWN A DRYING TREND TO THE
POPS OVER THE WEST THIRD LATE TONIGHT. WITH WINDS SHIFTING TO THE
WEST OR EVEN WEST-NORTHWEST...THINK THE UPSLOPE DIRECTION TO THE
WINDS WILL PRODUCE SOME LIGHT DRIZZLE.
HAVE CONTINUED THE MENTION OF FOG FOR TONIGHT...BUT SPREAD INTO
THIS AFTERNOON AND EXPANDED TO BE WIDESPREAD OVER THE CENTRAL
HIGHER TERRAIN. WITH THE ABUNDANT MOISTURE AROUND AND LOW CLOUDS
AND FOG ALREADY IN PLACE...THINK THAT IS REASONABLE. AFTER THE
SHOWERS MOVE THROUGH...COULD SEE VISIBILITIES FALL TOWARDS
1/4-1/2MI IN THE CENTRAL CWA AND DID ADD A MENTION OF PATCHY DENSE
FOG.
FOR THURSDAY...WITH THE SHORTWAVES AND DEEPER MOISTURE PULLING
NORTHEAST AND AWAY FROM THE CWA THURSDAY MORNING...SHOULD SEE A
DIMINISHING TREND IN THE PRECIP FROM WEST TO EAST. WITH DRIER AIR
MOVING IN ALOFT AND PLENTY OF LOW LEVEL MOISTURE...EXPECT IT TO BE
A DREARY DAY OVER MUCH OF UPPER MICHIGAN. LOW CLOUDS WILL CONTINUE
TO COVER THE AREA AND WILL CONTINUE AREAS/PATCHY FOG OVER THE
HIGHER TERRAIN LOCATIONS AND IN AREAS FAVORED BY LIGHT
WEST-NORTHWESTERLY FLOW OVER THE WEST. HAVE ALSO CONTINUED LIGHT
RAIN SHOWERS OR DRIZZLE FOR THAT PERIOD OVER THE WESTERN CWA.
HEADING INTO THE AFTERNOON...THE SHORTWAVE AND PV ANOMALY WILL
EJECT OUT FROM THE SOUTHERN PLAINS AND INTENSIFY THE LOW AS IT
PULLS NORTHEAST TOWARDS THE GREAT LAKES REGION. MODELS HAVE BEEN
VARIABLE ON THE TRACK OF THE LOW...WITH A CONSENSUS NOW SHOWING IT
LOCATED OVER CENTRAL LAKE MICHIGAN AT 00Z. BUT THEY HAVE BEEN
CONSISTENT ON IT RAPIDLY DEEPENING THURSDAY NIGHT AS IT MOVES
THROUGH THE GREAT LAKES. THIS TRACK GREATLY INFLUENCES THE
PRECIPITATION CHANCES OVER THE SOUTHEASTERN 1/3RD OF THE CWA AND
HAVE FOLLOWED A GENERAL CONSENSUS WITH POPS INCREASING IN THAT AREA
TOWARDS LATE AFTERNOON. OVER THE REST OF THE AREA...THE
CLOUDY/DRIZZLY CONDITIONS WILL CONTINUE.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 420 PM EDT WED OCT 30 2013
THE MAIN FOCUS THIS FORECAST PERIOD WILL BE THE DEVELOPING LOW
PRESSURE OVER THE CENTRAL PLAINS...FORECAST TO MOVE INTO UPPER
MICHIGAN THURSDAY-FRIDAY. MODELS ARE GENERALLY IN DISAGREEMENT AS TO
THE LOWS POSITION BY 00-6Z FRIDAY. ALTHOUGH THE DIFFERENCES ARE
SLIGHT...THE LOCATION OF HIGHEST QPF WILL SHIFT DEPENDING ON THE LOW
TRACK. IF THE NAM VERIFIES...PRECIPITATION AMOUNTS WILL DIFFER
GREATLY FROM WHAT IS IN THE FORECAST NOW.
GENERALLY...THE 12Z GFS WRAPS THE SFC LOW UP SOONER THAN THE 00Z
ECMWF/12Z NAM RUN. THE LOW TRACKS FROM NORTHERN LAKE MICHIGAN AT 00Z
TO NORTHERN LAKE HURON BY 06Z...DEEPENING FROM 989MB TO 982MB. THE
NAM ON THE OTHER HAND...HAS A 992MB LOW OVER SOUTHERN LAKE MICHIGAN
AT 00Z...WITH A TROUGH EXPANDING NORTHWARD ACROSS THE LAKE. BY
6Z...THIS LOW DEEPENS TO 982MB OVER SAGINAW BAY. AT 00Z...THE 00Z
ECMWF POSITIONS A CLOSED LOW OVER CENTRAL LAKE MICHIGAN...A SORT OF
COMPROMISE BETWEEN THE GFS/NAM...BUT THEN ALIGNS ITSELF MORE
FAVORABLY WITH THE GFS BY 6Z...WITH THE LOW OVER NORTHERN LAKE
HURON. THE 12Z REGIONAL GEM BASICALLY IS A COMPROMISE BETWEEN THE
ECMWF/NAM...SO THIS WAS THE PRIMARY MODEL USED TO CREATE THE
WINDS/POPS FOR THIS FORECAST. THE GFS TRACK SEEMS TO BE TOO FAR
NORTH...AND IT STARTS TRENDING SOUTHWARD IN THE 6Z TIME
FRAME...WHICH MAKES ME FEEL MORE CONFIDENT USING THE GEM SOLUTION.
EXPECT LL FGEN BAND ASSOCIATED WITH A TROWAL-LIKE FEATURE TO SET UP
ACROSS EASTERN UPPER MICHIGAN/NEAR THE LAKE MI SHORE FROM 00Z-06Z.
EXPECT PRECIPITATION CHANCES TO BE GREATEST ALONG THIS AXIS. HIGHER
QPF AMOUNTS WERE LIMITED TO THE LAKE MICHIGAN SHORELINE...AS THIS IS
WHERE THE MID-UPPER LEVEL SUPPORT IS MAXIMIZED. MOISTURE WITH THIS
SYSTEM IS ABUNDANT...AS PWATS RISE TO AROUND 200 PERCENT OF
NORMAL...WITH THE HIGHEST VALUES ACROSS THE CENTRAL AND EAST.
THANKFULLY...850MB TEMPS ARE AROUND 0-9C DURING THIS EVENT...SO NO
SNOW IS EXPECTED. OVERALL TEMPERATURES/THICKNESSES ACROSS THE CWA
REMAIN SUPPORTIVE OF A RAIN EVENT THROUGH 12Z FRIDAY.
ONCE WE GET CLOSER TO THE LATE FRIDAY MORNING-SATURDAY TIME
FRAME...850MB TEMPS BECOME COOLER...AROUND -3 TO -6 AT THE
WORST...AND MAINLY OUT WEST. A SECONDARY SHORTWAVE ALOFT MOVES
THROUGH FRIDAY NIGHT AS WELL...WHICH WILL SUPPORT RAIN/SNOW SHOWERS
INLAND FROM THE LAKES DURING THIS TIME. OVERALL...WITH
NORTH-NORTHWESTERLY WINDS AND A LINGERING UPPER LEVEL
TROUGH/CYCLONIC FLOW...EXPECT THE LAKE EFFECT RAIN/SNOW SHOWERS TO
REMAIN THROUGH 06-12Z SUN...THOUGH THEY WILL TAPER OFF WITH TIME AS
THE FLOW GRADUALLY BECOMES MORE ANTICYCLONIC AND MOISTURE DWINDLES.
THE WEAK SFC HIGH PRESSURE WILL FINALLY MOVE IN SUNDAY...BRINGING A
BREAK TO THE MORE ACTIVE WEATHER.
FOR THE EXTENDED TIME FRAME...LOW PRESSURE DEVELOPS ACROSS THE
CENTRAL AND NORTHERN PLAINS AND MOVES INTO ONTARIO. THE ECMWF PULLS
THIS SURFACE LOW FURTHEST NORTH OVER JAMES BAY...AND THE GFS KEEPS
IT OVER NORTHERN ONTARIO. EITHER WAY...UPPER MICHIGAN WILL BE IN THE
SOUTHERLY FLOW AHEAD OF THE LOW...AND 850MB TEMPS REMAIN ABOVE ZERO
FOR THE MOST PART. EXPECT MAINLY RAIN CHANCES AS A RESULT...THOUGH
OVERNIGHT/MORNING COOLER TEMPERATURES COULD RESULT IN A RAIN/SNOW
MIX FOR SOME AREAS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 141 PM EDT WED OCT 30 2013
WARM MOIST AIR STREAMING NORTHEAST ACROSS UPPER MICHIGAN THIS
AFTERNOON AND TONIGHT ALONG AN ELONGATED SURFACE TROUGH WILL LEAD
TO LOW CLOUDS AND FOG FOR MOST SITES THROUGH THE PERIOD. THE FIRST
3-6HRS OF THE FORECAST WILL BE THE MOST DIFFICULT...AS THERE ARE
POCKETS OF DRIER AIR NEAR THE KEWEENAW THAT WILL LEAD TO OCCASIONAL
RISING OF THE CEILINGS TO VFR CONDITIONS. OTHERWISE...THE WARM
MOIST AIR HAS BEEN INFLUENCING KIWD/KSAW THROUGH THE MORNING AND
CEILINGS HAVE BEEN LOWERING. EXPECT MVFR TO IFR CONDITIONS TO
CONTINUE AT BOTH SITES THIS AFTERNOON...WITH KSAW OCCASIONALLY
GOING TO LIFR CEILINGS WITH THE FAVORABLE FLOW. A FEW SHOWERS COULD
LEAD TO BRIEF FLUCTUATIONS IN THE CONDITIONS (DUE TO INCREASED
MIXING) BUT THE OVERALL IDEA SHOULD REMAIN.
THE CONDITIONS WILL DETERIORATE FURTHER TONIGHT AS MORE MOISTURE
MOVES INTO THE AREA ALONG WITH SCATTERED/NUMEROUS RAIN SHOWERS.
EXPECT THIS TO PRODUCE LIFR CEILINGS AT ALL SITES OVERNIGHT AND
CONTINUE INTO MUCH OF TOMORROW MORNING. ALTHOUGH THE RAIN WILL
DEPART FROM WEST TO EAST LATE TONIGHT INTO EARLY TOMORROW
MORNING...THE WINDS TURNING TO THE WEST/NORTHWEST WILL FAVOR DRIZZLE
FOR KCMX/KIWD AND THE UPSLOPE FLOW WILL KEEP CEILINGS LOW. AT
KSAW...THE WINDS WILL STAY OUT OF THE SOUTHWEST THROUGH MUCH OF THE
MORNING AND EXPECT FOG TO BE THE MAIN VISIBILITY REDUCER.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 420 PM EDT WED OCT 30 2013
A LOW PRESSURE SYSTEM DEVELOPING NEAR THE TEXAS PANHANDLE TODAY
WILL BE THE MAIN WEATHER MAKER FOR THE FORECAST PERIOD. THIS LOW
WILL SLIDE A TROUGH NORTHEAST INTO LAKE SUPERIOR TONIGHT AND WILL
LEAD TO WINDS INCREASING OUT OF THE SOUTH TO 20KTS OVER THE
EASTERN HALF OF THE LAKE. WINDS ARE THEN EXPECTED TO WEAKEN
THURSDAY MORNING AS THE LOW INTENSIFIES AND QUICKLY MOVES NORTHEAST
TO CENTRAL LAKE MICHIGAN BY THURSDAY EVENING. AS THE LOW FURTHER
INTENSIFIES AND MOVES ACROSS LAKE HURON ON THURSDAY NIGHT...EXPECT
NORTH-NORTHWESTERLY WINDS TO INCREASE THURSDAY NIGHT INTO FRIDAY
MORNING. THE STRENGTH OF THE WINDS WILL DEPEND ON THE EXACT TRACK OF
THE LOW...BUT THE CURRENT THINKING IS GUSTS UP TO 30KTS OVER THE FAR
SOUTHEASTERN PART OF LAKE SUPERIOR AND TO 20-25KTS ELSEWHERE. IF THE
LOW TRACKS A LITTLE FARTHER NORTH...COULD SEE SOME GALES OVER THE
SOUTHEAST PART OF THE LAKE.
THE LOW WILL CONTINUE NORTHEAST FRIDAY NIGHT AND SATURDAY...BUT
WILL LEAVE A SURFACE TROUGH OVER THE UPPER GREAT LAKES REGION
THROUGH SATURDAY EVENING. WINDS DURING THIS PERIOD SHOULD STAY
BELOW 20KTS. WEAK HIGH PRESSURE WILL BUILD IN FOR SUNDAY AND LEAD TO
WINDS FALLING BELOW 15KTS BEFORE SOUTHERLY FLOW INCREASES AHEAD OF A
LOW MOVING NORTHEAST THROUGH ONTARIO ON MONDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...MCD
AVIATION...SRF
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
142 PM EDT WED OCT 30 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 435 AM EDT WED OCT 30 2013
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A NW FLOW ALF OVER
THE UPR GRT LKS BTWN TROF OVER ERN CANADA AND A RDG IN THE PLAINS
DOWNSTREAM OF CUTOFF LO OVER THE WRN CONUS. AREA OF -SN/-RA OVER UPR
MI RELATED TO ISENTROPIC ASCENT ON THE 290-295K SFCS /ABOUT H85-7/
ON WRN FLANK OF HI PRES RETREATING THRU THE NE CONUS IS TENDING TO
DIMINISH W-E EARLY THIS MRNG WITH ARRIVAL OF UPR CNVGC/DEEP LYR
QVECTOR DVGC ASSOCIATED WITH SLOWLY APRCHG UPR RDG AXIS FM THE
PLAINS. MORE PCPN...MAINLY ISOLD -SHRA...IS LINGERING OVER NW WI
CLOSER TO MOISTER AIR SHOWN ON THE 00Z MPX RAOB AND S OF A
PRONOUNCED DRY LYR BTWN H8-85 DEPICTED ON THE 00Z INL RAOB. THERE IS
ANOTHER AREA OF LO PRES IN THE SCENTRAL PLAINS ASSOCIATED WITH THE
WRN TROF.
MAIN FCST CONCERNS IN THE SHORT TERM ARE LINGERING POPS THIS MRNG
ASSOCIATED WITH 290-295K ISENTROPIC ASCENT AND THEN SURGE OF MORE
PCPN LATER TNGT TIED TO LO PRES NOW TAKING SHAPE IN THE SCENTRAL
PLAINS.
TODAY...PERSISTENT BUT WEAKENING ISENTROPIC ASCENT ON THE 290-295K
SFCS IN CONJUNCTION WITH MOIST AIR SHOWN ON THE 00Z MPX RAOB WL
SUPPORT SOME ISOLD -SHRA EARLY THIS MRNG MAINLY OVER THE SRN TIER.
BUT UNDER THE INCRSG LARGER SCALE QVECTOR DVGC/UPR CNVGC RELATED TO
DNVA AHEAD OF THE RDG...THIS PCPN SHOULD FADE THIS MRNG. AS THE LLVL
SLY FLOW STRENGTHENS THIS AFTN AHEAD OF THE DVLPG LO TO THE SW...THE
ARRIVAL OF MOISTER AIR WITH PWAT APRCHG 1 INCH TOWARD 00Z WL SUPPORT
A RETURN OF CHC POPS AGAIN OVER THE W. ABSENCE OF ANY OTHER DYNAMIC
FORCING WITH JUST WEAK DEEP LYR QVECTOR CVNGC UNDER UPR CNVGC SHOULD
LIMIT THE COVERAGE/PCPN AMNTS. DESPITE CLDY SKIES...THE STEADY LLVL
WAD WL BRING A WARMER DAY TO THE CWA...WITH HI TEMPS LATER REACHING
WELL INTO THE 40S AND EVEN INTO THE 50S OVER THE SRN TIER. SO ANY
PCPN WL BE IN THE FORM OF RA.
TNGT...AS UPR JET CORE STREAKS NEWD OUT OF ROCKIES TROF MOVING OUT
INTO THE PLAINS...MODELS INDICATE AREA OF UPR DVGC IN THE EXIT
REGION OF THIS JET WL STREAK NEWD THRU THE UPR LKS LATE TNGT. IN
CONCERT WITH PERSISTENT WARM/MOIST ADVECTION THAT LIFTS PWAT OVER AN
INCH /OVER 200 PCT OF NORMAL/...GOING FCST SHOWING CATEGORICAL POPS
ARRIVING FM THE SW LOOKS ON TRACK. BEST CHC FOR THE HEAVIER RA WL BE
OVER THE CENTRAL AND E...WHERE THE PWAT IS FCST HIER. THERE SHOULD
BE LTL IF ANY TEMP DROP TNGT...IN FACT TEMPS MAY RISE SLOWLY. TENDED
TOWARD THE HI END OF GUIDANCE FOR MIN TEMPS. WITH THE ARRIVAL OF THE
MOISTER AIR...EXPECT AREAS OF FOG AS WELL...ESPECIALLY OVER THE
CENTRAL WITH AN UPSLOPE SSE WIND.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 435 AM EDT WED OCT 30 2013
UPPER TROUGH OVER THE WESTERN CONUS HEADS ACROSS THE GREAT LAKES AND
EASTERN CONUS TO END THE WEEK. TROUGH IS RE-ENFORCED OVER THESE AREAS
INTO THE WEEKEND AS STRONG JET ENERGY IN NORTHERN BRANCH DIGS FROM
WESTERN CANADA INTO THE GREAT LAKES. BY LATER IN THE WEEKEND...150+
KT JET LIFTS ACROSS THE CANADAIAN MARITIMES USHERING THE TROUGH
ACROSS THE NORTH ATLANTIC. UPSTREAM...ANOTHER ROUND OF TROUGHING
DEVELOPS OVER THE WESTERN CONUS BY EARLY NEXT WEEK. TROUGH SLIDES
ACROSS MIDDLE CONUS BY END OF THE LONG TERM.
MAIN AREA OF LOW PRESSURE WHICH GETS GOING TODAY OVER THE PLAINS...
DEEPENS TO A SUB 985MB LOW ON THURSDAY NIGHT AND FRIDAY AS IT EXITS
THE UPPER GREAT LAKES TOWARD QUEBEC. GIVEN STRENGTH OF DIVERGENCE
ALOFT ON NOSE OF 130+ KT JET CORE ARRIVING FROM THE PLAINS...PREFER
DEEPER AND A FARTHER NORTH SFC LOW FOR DAYTIME ON THURSDAY...SIMILAR
TO ECMWF AND LOCAL REGIONAL-WRF. GEM-NH LOOKS SIMILAR AS WELL...AT
LEAST UNTIL MIDDAY THURSDAY. EXPECT SWATH OF RAIN TO SWEEP MAINLY OUT
OF NORTHERN CWA ON THURSDAY MORNING...LEAVING A LULL IN SHOWERS UNTIL
AT LEAST MID-LATE AFTN. FORECAST GETS RATHER TRICKY BY THIS POINT.
UNCERTAINTY COMES IN AS PRIMARY SOUTHERN STREAM WAVE LIFTS TOWARD THE
GREAT LAKES ALONG WITH SECONDARY JET STREAK. LIKELY WILL SEE INTIAL
SFC LOW FADE AWAY AS BETTER LARGE SCALE SUPPORT REGROUPS VCNTY OF LK
MICHIGAN. LIKE THE UKMET /GEM-NH IDEA WITH A SFC LOW DEEPENING TO
LESS THAN 990MB VCNTY OF CNTRL LK MICHIGAN BY 00Z FRIDAY. ECMWF IS ON
THIS TRACK NOW AS WELL...SHIFTING AWAY FM A WEAKER LOW VCNTY OF
EASTERN LK SUPERIOR. NAM SEEMS TOO FAR SOUTH BUT ON THE FLIP SIDE THE
GFS IS PROBABLY TOO FAR NORTHWEST AND TOO DEEP...PERHAPS SUFFERING FM
CONVECTIVE FEEDBACK. MSLP CENTER MORE IMPORTANT FOR THE WIND FCST
WHICH WILL BE A MESS UNTIL LATER TONIGHT OR ON THURSDAY WHEN EXACT
TRACK OF SFC LOW IS APPARENT. PRIMARY IMPACT ON WEATHER IS THE NON
NAM IDEA OPENS DOOR FOR FARTHER WEST JET STREAK/DIVERGENCE AND ALSO
SFC-H85 TEMP/MOISTURE ADVECTION. HIGHEST POPS LATER THURSDAY AFTN AND
EVENING ROUGHLY FOR THE EAST HALF OF CWA. STILL COULD BE SOME TSRA AS
WELL AS EASTERN CWA IS ON EDGE OF STEEPER H7-H5 LAPSE RATES AND ON
NOSE OF H5-H3 DRY SLOT POKING IN FM SOUTH WHICH WOULD STEEPEN THE
LAPSE RATES.
AS A SIDE NOTE...THURSDAY WILL LIKELY BE FIRST DAY WITH ABOVE NORMAL
DAILY TEMPS SINCE THE 12TH OF OCTOBER. TEMPS THAT START TO SLOWLY
RISE TONIGHT CONTINUE TO PUSH WELL INTO THE 50S ON THURSDAY FROM JUST
ADVECTION ALONE AS SKIES WILL STAY CLOUDY AND MIXING WILL BE MINIMAL.
HIGHER DWPNTS AND SATURATED LOW-LEVELS WITH LIGHT WINDS POINT TO FOG
LASTING THROUGH MUCH OF THE DAY...ESPECIALLY IN THE HIGHER TERRAIN OF
CNTRL UPR MICHIGAN. WINDS BECOMING WESTERLY LATE DAY SHOULD BEGIN TO
SCOUR OUT THE FOG...THOUGH IT MAY TAKE UNTIL LATER THURSDAY EVENING
ONCE STRONGER NW WINDS ARRIVE TO GET RID OF IT COMPLETELY.
DEEPENING SFC LOW PULLS AWAY FM UPR LAKES LATER THURSDAY NIGHT INTO
FRIDAY MORNING. MSLP DOWN BLO 980MB AT THIS POINT. CURRENT FORECAST
HAS NW WINDS ALONG LK SUPERIOR GUSTING OVER 30 MPH. IF LOW TRENDS
ANY FARTHER WEST...WOULD LIKELY BE A PERIOD OF ADVY LEVEL WINDS NEAR
LK SUPERIOR. DESPITE SUCH A DEEP LOW...COLD AIR ARRIVAL FOR FRIDAY
MORNING LAGGING MORE THAN PREVIOUS MODELS HAVE INDICATED. 1000-850MB
THICKNESSES STAYING ABOVE 1300M AND H85 TEMPS STAYING WARMER THAN
-4C INDICATE A MIX OF RAIN AND SNOW IN THE WEST WITH RAIN OVR THE
CNTRL AND EAST. GFS FORECAST SOUNDINGS AND EXPECTED SFC TEMPS IN THE
UPR 30S TO AROUND 40 DEGREES ALSO SUPPORT IDEA OF MORE RAIN THAN
SNOW FOR MOST OF CWA. A BIT MORE COOLING FOR FRIDAY NIGHT WITH H85
TEMPS -4C TO -6C. THIS IS ALSO THE TIME WHEN STRONGER SHORTWAVE
COMES THROUGH IN WNW FLOW ALOFT. IF IT WAS COLDER WOULD BE MORE
CONCERNED ABOUT A FEW INCHES OF SNOW OVER THE HIGHER TERRAIN OF THE
WEST DUE TO LAKE ENHANCEMENT. AS IT STANDS NOW...ONLY LOOKING AT
DELTA T/S 12-14C WITH ONLY MARGINALLY CYCLONIC LOW-LEVEL FLOW. SFC
TEMPS STILL MARGINALLY COLD TOO WITH READINGS EXPECTED IN THE LOW TO
MID 30S AT THE TIME THE STRONGEST LARGER SCALE LIFT IS OCCURRING.
SLIGHTLY BETTER CHANCE AT SEEING SOME ACCUMULATION WOULD BE LATE AT
NIGHT INTO SATURDAY MORNING...BUT LARGER SCALE FORCING IS NOT AS
SUPPORTATIVE BY THAT TIME. GENERALLY...SEEMS THAT THE MARGINALLY COLD
AIRMASS IS GOING TO PUT CRIMP IN EXTENT OF SNOW FROM THE LAKE
ENHANCEMENT.
TROUGHING/COOLER AIR STICKS AROUND UNTIL SUNDAY WHEN HEIGHTS BEGIN
TO RISE. ONSHORE FLOW NEAR LK SUPERIOR FIRST FM THE NORTHWEST AND
THEN EVENTUALLY FM THE NORTH ALONG WITH SUFFICIENT OVER-WATER
INSTABILITY /DELTA T/S OVER 15C/ WILL KEEP LK EFFECT GOING. ANY LK
EFFECT WILL BE HELD IN CHECK THOUGH AS FLOW BECOMING MORE
ANTICYLONIC LEADS TO LOWER INVERSION HEIGHTS...LESS
CONVERGENCE...AND MARGINAL MOISTURE BLO INVERSION. ANY LINGERING LK
EFFECT WILL FINALLY CUT OUT OF PICTURE BY SUNDAY NIGHT AS LARGER
SCALE WARM AIR ADVECTION OCCURS.
ON TO THE FAR REACHES OF THE LONG TERM. INDICATIONS ARE STILL
THERE THAT FLOW ALOFT BECOMES SW EARLY NEXT WEEK. GFS SHOWING
COLD FRONTAL PASSAGE LATER MONDAY INTO MONDAY NIGHT. ECMWF SLOWER
YET...NOT BRINGING FRONT THROUGH REGION UNTIL TUESDAY OR TUESDAY
NIGHT. ECMWF SHOWS MUCH WETTER SCENARIO AS IT HAS ANOTHER LOW
PRESSURE WAVE RIDING UP ALONG THE FRONT. SOME CONSISTENCY FM EACH
OF THESE MODELS...SO A CONSENSUS WILL HOLD FOR NOW. CRITICAL
THICKNESSES INDICATE RAIN OR SNOW OR A MIX OF BOTH FOR PYTPE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 141 PM EDT WED OCT 30 2013
WARM MOIST AIR STREAMING NORTHEAST ACROSS UPPER MICHIGAN THIS
AFTERNOON AND TONIGHT ALONG AN ELONGATED SURFACE TROUGH WILL LEAD
TO LOW CLOUDS AND FOG FOR MOST SITES THROUGH THE PERIOD. THE FIRST
3-6HRS OF THE FORECAST WILL BE THE MOST DIFFICULT...AS THERE ARE
POCKETS OF DRIER AIR NEAR THE KEWEENAW THAT WILL LEAD TO OCCASIONAL
RISING OF THE CEILINGS TO VFR CONDITIONS. OTHERWISE...THE WARM
MOIST AIR HAS BEEN INFLUENCING KIWD/KSAW THROUGH THE MORNING AND
CEILINGS HAVE BEEN LOWERING. EXPECT MVFR TO IFR CONDITIONS TO
CONTINUE AT BOTH SITES THIS AFTERNOON...WITH KSAW OCCASIONALLY
GOING TO LIFR CEILINGS WITH THE FAVORABLE FLOW. A FEW SHOWERS COULD
LEAD TO BRIEF FLUCTUATIONS IN THE CONDITIONS (DUE TO INCREASED
MIXING) BUT THE OVERALL IDEA SHOULD REMAIN.
THE CONDITIONS WILL DETERIORATE FURTHER TONIGHT AS MORE MOISTURE
MOVES INTO THE AREA ALONG WITH SCATTERED/NUMEROUS RAIN SHOWERS.
EXPECT THIS TO PRODUCE LIFR CEILINGS AT ALL SITES OVERNIGHT AND
CONTINUE INTO MUCH OF TOMORROW MORNING. ALTHOUGH THE RAIN WILL
DEPART FROM WEST TO EAST LATE TONIGHT INTO EARLY TOMORROW
MORNING...THE WINDS TURNING TO THE WEST/NORTHWEST WILL FAVOR DRIZZLE
FOR KCMX/KIWD AND THE UPSLOPE FLOW WILL KEEP CEILINGS LOW. AT
KSAW...THE WINDS WILL STAY OUT OF THE SOUTHWEST THROUGH MUCH OF THE
MORNING AND EXPECT FOG TO BE THE MAIN VISIBILITY REDUCER.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 435 AM EDT WED OCT 30 2013
LIGHT WINDS LESS THAN 20 KTS INTO THU AS A HIGH PRESSURE RIDGE OVER
THE AREA SLOWLY MOVES TOWARD THE EAST COAST. LOW PRESSURE DEVELOPING
OVER THE PLAINS TODAY WILL LIFT TOWARD THE UPPER GREAT LAKES ON
THURSDAY THEN DEEPEN AS IT MOVES INTO QUEBEC ON FRIDAY. STRONGEST
WINDS WITH THE SYSTEM WILL BE THURSDAY NIGHT INTO FRIDAY MORNING
OVER THE EAST HALF OF LAKE SUPERIOR. IF THE MSLP PATTERN REMAINS AS
FORECAST...ONLY WOULD BE A MINIMAL CHANCE OF SEEING GALES DURING
THIS TIME. IF THE LOW SHIFTS TO THE WEST...EVEN JUST SLIGHLY...THE
CHANCE OF GALES WILL INCREASE DUE TO A TIGHTER PRESSURE
GRADIENT...ESPECIALLY OVER EASTERN LK SUPERIOR. NW WINDS STAY UP TO
25 KTS INTO SATURDAY THEN DIMINISH BY SUNDAY MORNING WITH ARRIVAL OF
HIGH PRESSURE RIDGE. BREAK IN STRONGER WINDS ONLY BRIEF THOUGH WITH
SE WINDS UP TO 30 KTS BY MONDAY AS A STRONG LOW PRESSURE SYSTEM
MOVES ACROSS SOUTH CENTRAL CANADA.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...JLA
AVIATION...SRF
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
727 AM EDT WED OCT 30 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 435 AM EDT WED OCT 30 2013
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A NW FLOW ALF OVER
THE UPR GRT LKS BTWN TROF OVER ERN CANADA AND A RDG IN THE PLAINS
DOWNSTREAM OF CUTOFF LO OVER THE WRN CONUS. AREA OF -SN/-RA OVER UPR
MI RELATED TO ISENTROPIC ASCENT ON THE 290-295K SFCS /ABOUT H85-7/
ON WRN FLANK OF HI PRES RETREATING THRU THE NE CONUS IS TENDING TO
DIMINISH W-E EARLY THIS MRNG WITH ARRIVAL OF UPR CNVGC/DEEP LYR
QVECTOR DVGC ASSOCIATED WITH SLOWLY APRCHG UPR RDG AXIS FM THE
PLAINS. MORE PCPN...MAINLY ISOLD -SHRA...IS LINGERING OVER NW WI
CLOSER TO MOISTER AIR SHOWN ON THE 00Z MPX RAOB AND S OF A
PRONOUNCED DRY LYR BTWN H8-85 DEPICTED ON THE 00Z INL RAOB. THERE IS
ANOTHER AREA OF LO PRES IN THE SCENTRAL PLAINS ASSOCIATED WITH THE
WRN TROF.
MAIN FCST CONCERNS IN THE SHORT TERM ARE LINGERING POPS THIS MRNG
ASSOCIATED WITH 290-295K ISENTROPIC ASCENT AND THEN SURGE OF MORE
PCPN LATER TNGT TIED TO LO PRES NOW TAKING SHAPE IN THE SCENTRAL
PLAINS.
TODAY...PERSISTENT BUT WEAKENING ISENTROPIC ASCENT ON THE 290-295K
SFCS IN CONJUNCTION WITH MOIST AIR SHOWN ON THE 00Z MPX RAOB WL
SUPPORT SOME ISOLD -SHRA EARLY THIS MRNG MAINLY OVER THE SRN TIER.
BUT UNDER THE INCRSG LARGER SCALE QVECTOR DVGC/UPR CNVGC RELATED TO
DNVA AHEAD OF THE RDG...THIS PCPN SHOULD FADE THIS MRNG. AS THE LLVL
SLY FLOW STRENGTHENS THIS AFTN AHEAD OF THE DVLPG LO TO THE SW...THE
ARRIVAL OF MOISTER AIR WITH PWAT APRCHG 1 INCH TOWARD 00Z WL SUPPORT
A RETURN OF CHC POPS AGAIN OVER THE W. ABSENCE OF ANY OTHER DYNAMIC
FORCING WITH JUST WEAK DEEP LYR QVECTOR CVNGC UNDER UPR CNVGC SHOULD
LIMIT THE COVERAGE/PCPN AMNTS. DESPITE CLDY SKIES...THE STEADY LLVL
WAD WL BRING A WARMER DAY TO THE CWA...WITH HI TEMPS LATER REACHING
WELL INTO THE 40S AND EVEN INTO THE 50S OVER THE SRN TIER. SO ANY
PCPN WL BE IN THE FORM OF RA.
TNGT...AS UPR JET CORE STREAKS NEWD OUT OF ROCKIES TROF MOVING OUT
INTO THE PLAINS...MODELS INDICATE AREA OF UPR DVGC IN THE EXIT
REGION OF THIS JET WL STREAK NEWD THRU THE UPR LKS LATE TNGT. IN
CONCERT WITH PERSISTENT WARM/MOIST ADVECTION THAT LIFTS PWAT OVER AN
INCH /OVER 200 PCT OF NORMAL/...GOING FCST SHOWING CATEGORICAL POPS
ARRIVING FM THE SW LOOKS ON TRACK. BEST CHC FOR THE HEAVIER RA WL BE
OVER THE CENTRAL AND E...WHERE THE PWAT IS FCST HIER. THERE SHOULD
BE LTL IF ANY TEMP DROP TNGT...IN FACT TEMPS MAY RISE SLOWLY. TENDED
TOWARD THE HI END OF GUIDANCE FOR MIN TEMPS. WITH THE ARRIVAL OF THE
MOISTER AIR...EXPECT AREAS OF FOG AS WELL...ESPECIALLY OVER THE
CENTRAL WITH AN UPSLOPE SSE WIND.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 435 AM EDT WED OCT 30 2013
UPPER TROUGH OVER THE WESTERN CONUS HEADS ACROSS THE GREAT LAKES AND
EASTERN CONUS TO END THE WEEK. TROUGH IS RE-ENFORCED OVER THESE AREAS
INTO THE WEEKEND AS STRONG JET ENERGY IN NORTHERN BRANCH DIGS FROM
WESTERN CANADA INTO THE GREAT LAKES. BY LATER IN THE WEEKEND...150+
KT JET LIFTS ACROSS THE CANADAIAN MARITIMES USHERING THE TROUGH
ACROSS THE NORTH ATLANTIC. UPSTREAM...ANOTHER ROUND OF TROUGHING
DEVELOPS OVER THE WESTERN CONUS BY EARLY NEXT WEEK. TROUGH SLIDES
ACROSS MIDDLE CONUS BY END OF THE LONG TERM.
MAIN AREA OF LOW PRESSURE WHICH GETS GOING TODAY OVER THE PLAINS...
DEEPENS TO A SUB 985MB LOW ON THURSDAY NIGHT AND FRIDAY AS IT EXITS
THE UPPER GREAT LAKES TOWARD QUEBEC. GIVEN STRENGTH OF DIVERGENCE
ALOFT ON NOSE OF 130+ KT JET CORE ARRIVING FROM THE PLAINS...PREFER
DEEPER AND A FARTHER NORTH SFC LOW FOR DAYTIME ON THURSDAY...SIMILAR
TO ECMWF AND LOCAL REGIONAL-WRF. GEM-NH LOOKS SIMILAR AS WELL...AT
LEAST UNTIL MIDDAY THURSDAY. EXPECT SWATH OF RAIN TO SWEEP MAINLY OUT
OF NORTHERN CWA ON THURSDAY MORNING...LEAVING A LULL IN SHOWERS UNTIL
AT LEAST MID-LATE AFTN. FORECAST GETS RATHER TRICKY BY THIS POINT.
UNCERTAINTY COMES IN AS PRIMARY SOUTHERN STREAM WAVE LIFTS TOWARD THE
GREAT LAKES ALONG WITH SECONDARY JET STREAK. LIKELY WILL SEE INTIAL
SFC LOW FADE AWAY AS BETTER LARGE SCALE SUPPORT REGROUPS VCNTY OF LK
MICHIGAN. LIKE THE UKMET /GEM-NH IDEA WITH A SFC LOW DEEPENING TO
LESS THAN 990MB VCNTY OF CNTRL LK MICHIGAN BY 00Z FRIDAY. ECMWF IS ON
THIS TRACK NOW AS WELL...SHIFTING AWAY FM A WEAKER LOW VCNTY OF
EASTERN LK SUPERIOR. NAM SEEMS TOO FAR SOUTH BUT ON THE FLIP SIDE THE
GFS IS PROBABLY TOO FAR NORTHWEST AND TOO DEEP...PERHAPS SUFFERING FM
CONVECTIVE FEEDBACK. MSLP CENTER MORE IMPORTANT FOR THE WIND FCST
WHICH WILL BE A MESS UNTIL LATER TONIGHT OR ON THURSDAY WHEN EXACT
TRACK OF SFC LOW IS APPARENT. PRIMARY IMPACT ON WEATHER IS THE NON
NAM IDEA OPENS DOOR FOR FARTHER WEST JET STREAK/DIVERGENCE AND ALSO
SFC-H85 TEMP/MOISTURE ADVECTION. HIGHEST POPS LATER THURSDAY AFTN AND
EVENING ROUGHLY FOR THE EAST HALF OF CWA. STILL COULD BE SOME TSRA AS
WELL AS EASTERN CWA IS ON EDGE OF STEEPER H7-H5 LAPSE RATES AND ON
NOSE OF H5-H3 DRY SLOT POKING IN FM SOUTH WHICH WOULD STEEPEN THE
LAPSE RATES.
AS A SIDE NOTE...THURSDAY WILL LIKELY BE FIRST DAY WITH ABOVE NORMAL
DAILY TEMPS SINCE THE 12TH OF OCTOBER. TEMPS THAT START TO SLOWLY
RISE TONIGHT CONTINUE TO PUSH WELL INTO THE 50S ON THURSDAY FROM JUST
ADVECTION ALONE AS SKIES WILL STAY CLOUDY AND MIXING WILL BE MINIMAL.
HIGHER DWPNTS AND SATURATED LOW-LEVELS WITH LIGHT WINDS POINT TO FOG
LASTING THROUGH MUCH OF THE DAY...ESPECIALLY IN THE HIGHER TERRAIN OF
CNTRL UPR MICHIGAN. WINDS BECOMING WESTERLY LATE DAY SHOULD BEGIN TO
SCOUR OUT THE FOG...THOUGH IT MAY TAKE UNTIL LATER THURSDAY EVENING
ONCE STRONGER NW WINDS ARRIVE TO GET RID OF IT COMPLETELY.
DEEPENING SFC LOW PULLS AWAY FM UPR LAKES LATER THURSDAY NIGHT INTO
FRIDAY MORNING. MSLP DOWN BLO 980MB AT THIS POINT. CURRENT FORECAST
HAS NW WINDS ALONG LK SUPERIOR GUSTING OVER 30 MPH. IF LOW TRENDS
ANY FARTHER WEST...WOULD LIKELY BE A PERIOD OF ADVY LEVEL WINDS NEAR
LK SUPERIOR. DESPITE SUCH A DEEP LOW...COLD AIR ARRIVAL FOR FRIDAY
MORNING LAGGING MORE THAN PREVIOUS MODELS HAVE INDICATED. 1000-850MB
THICKNESSES STAYING ABOVE 1300M AND H85 TEMPS STAYING WARMER THAN
-4C INDICATE A MIX OF RAIN AND SNOW IN THE WEST WITH RAIN OVR THE
CNTRL AND EAST. GFS FORECAST SOUNDINGS AND EXPECTED SFC TEMPS IN THE
UPR 30S TO AROUND 40 DEGREES ALSO SUPPORT IDEA OF MORE RAIN THAN
SNOW FOR MOST OF CWA. A BIT MORE COOLING FOR FRIDAY NIGHT WITH H85
TEMPS -4C TO -6C. THIS IS ALSO THE TIME WHEN STRONGER SHORTWAVE
COMES THROUGH IN WNW FLOW ALOFT. IF IT WAS COLDER WOULD BE MORE
CONCERNED ABOUT A FEW INCHES OF SNOW OVER THE HIGHER TERRAIN OF THE
WEST DUE TO LAKE ENHANCEMENT. AS IT STANDS NOW...ONLY LOOKING AT
DELTA T/S 12-14C WITH ONLY MARGINALLY CYCLONIC LOW-LEVEL FLOW. SFC
TEMPS STILL MARGINALLY COLD TOO WITH READINGS EXPECTED IN THE LOW TO
MID 30S AT THE TIME THE STRONGEST LARGER SCALE LIFT IS OCCURRING.
SLIGHTLY BETTER CHANCE AT SEEING SOME ACCUMULATION WOULD BE LATE AT
NIGHT INTO SATURDAY MORNING...BUT LARGER SCALE FORCING IS NOT AS
SUPPORTATIVE BY THAT TIME. GENERALLY...SEEMS THAT THE MARGINALLY COLD
AIRMASS IS GOING TO PUT CRIMP IN EXTENT OF SNOW FROM THE LAKE
ENHANCEMENT.
TROUGHING/COOLER AIR STICKS AROUND UNTIL SUNDAY WHEN HEIGHTS BEGIN
TO RISE. ONSHORE FLOW NEAR LK SUPERIOR FIRST FM THE NORTHWEST AND
THEN EVENTUALLY FM THE NORTH ALONG WITH SUFFICIENT OVER-WATER
INSTABILITY /DELTA T/S OVER 15C/ WILL KEEP LK EFFECT GOING. ANY LK
EFFECT WILL BE HELD IN CHECK THOUGH AS FLOW BECOMING MORE
ANTICYLONIC LEADS TO LOWER INVERSION HEIGHTS...LESS
CONVERGENCE...AND MARGINAL MOISTURE BLO INVERSION. ANY LINGERING LK
EFFECT WILL FINALLY CUT OUT OF PICTURE BY SUNDAY NIGHT AS LARGER
SCALE WARM AIR ADVECTION OCCURS.
ON TO THE FAR REACHES OF THE LONG TERM. INDICATIONS ARE STILL
THERE THAT FLOW ALOFT BECOMES SW EARLY NEXT WEEK. GFS SHOWING
COLD FRONTAL PASSAGE LATER MONDAY INTO MONDAY NIGHT. ECMWF SLOWER
YET...NOT BRINGING FRONT THROUGH REGION UNTIL TUESDAY OR TUESDAY
NIGHT. ECMWF SHOWS MUCH WETTER SCENARIO AS IT HAS ANOTHER LOW
PRESSURE WAVE RIDING UP ALONG THE FRONT. SOME CONSISTENCY FM EACH
OF THESE MODELS...SO A CONSENSUS WILL HOLD FOR NOW. CRITICAL
THICKNESSES INDICATE RAIN OR SNOW OR A MIX OF BOTH FOR PYTPE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 726 AM EDT WED OCT 30 2013
CHALLENING AVIATION FCST IN THE SHORT TERM WITH OBSVD CONDITIONS
VARYING FM IFR TO VFR. BUT WITH PREVAILING S WIND...EXPECT MOISTER
AIR TO THE S...WHERE IFR CONDITIONS ARE COMMON...TO OVERSPREAD UPR
MI AND DROP CIGS AT THE TAF SITES TO MVFR. CONDITIONS WL DETERIORATE
FURTHER TO IFR TNGT WITH A SURGE OF EVEN MOISTER AIR AND SOME -SHRA.
BEST CHC FOR LIFR CONDITIONS WL BE AT SAW...WHICH WL BE CLOSER TO
THE SURGE OF MOISTER AIR AND EXPERIENCE AN UPSLOPE S WIND.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 435 AM EDT WED OCT 30 2013
LIGHT WINDS LESS THAN 20 KTS INTO THU AS A HIGH PRESSURE RIDGE OVER
THE AREA SLOWLY MOVES TOWARD THE EAST COAST. LOW PRESSURE DEVELOPING
OVER THE PLAINS TODAY WILL LIFT TOWARD THE UPPER GREAT LAKES ON
THURSDAY THEN DEEPEN AS IT MOVES INTO QUEBEC ON FRIDAY. STRONGEST
WINDS WITH THE SYSTEM WILL BE THURSDAY NIGHT INTO FRIDAY MORNING
OVER THE EAST HALF OF LAKE SUPERIOR. IF THE MSLP PATTERN REMAINS AS
FORECAST...ONLY WOULD BE A MINIMAL CHANCE OF SEEING GALES DURING
THIS TIME. IF THE LOW SHIFTS TO THE WEST...EVEN JUST SLIGHLY...THE
CHANCE OF GALES WILL INCREASE DUE TO A TIGHTER PRESSURE
GRADIENT...ESPECIALLY OVER EASTERN LK SUPERIOR. NW WINDS STAY UP TO
25 KTS INTO SATURDAY THEN DIMINISH BY SUNDAY MORNING WITH ARRIVAL OF
HIGH PRESSURE RIDGE. BREAK IN STRONGER WINDS ONLY BRIEF THOUGH WITH
SE WINDS UP TO 30 KTS BY MONDAY AS A STRONG LOW PRESSURE SYSTEM
MOVES ACROSS SOUTH CENTRAL CANADA.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...JLA
AVIATION...KC
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
447 AM EDT WED OCT 30 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 435 AM EDT WED OCT 30 2013
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A NW FLOW ALF OVER
THE UPR GRT LKS BTWN TROF OVER ERN CANADA AND A RDG IN THE PLAINS
DOWNSTREAM OF CUTOFF LO OVER THE WRN CONUS. AREA OF -SN/-RA OVER UPR
MI RELATED TO ISENTROPIC ASCENT ON THE 290-295K SFCS /ABOUT H85-7/
ON WRN FLANK OF HI PRES RETREATING THRU THE NE CONUS IS TENDING TO
DIMINISH W-E EARLY THIS MRNG WITH ARRIVAL OF UPR CNVGC/DEEP LYR
QVECTOR DVGC ASSOCIATED WITH SLOWLY APRCHG UPR RDG AXIS FM THE
PLAINS. MORE PCPN...MAINLY ISOLD -SHRA...IS LINGERING OVER NW WI
CLOSER TO MOISTER AIR SHOWN ON THE 00Z MPX RAOB AND S OF A
PRONOUNCED DRY LYR BTWN H8-85 DEPICTED ON THE 00Z INL RAOB. THERE IS
ANOTHER AREA OF LO PRES IN THE SCENTRAL PLAINS ASSOCIATED WITH THE
WRN TROF.
MAIN FCST CONCERNS IN THE SHORT TERM ARE LINGERING POPS THIS MRNG
ASSOCIATED WITH 290-295K ISENTROPIC ASCENT AND THEN SURGE OF MORE
PCPN LATER TNGT TIED TO LO PRES NOW TAKING SHAPE IN THE SCENTRAL
PLAINS.
TODAY...PERSISTENT BUT WEAKENING ISENTROPIC ASCENT ON THE 290-295K
SFCS IN CONJUNCTION WITH MOIST AIR SHOWN ON THE 00Z MPX RAOB WL
SUPPORT SOME ISOLD -SHRA EARLY THIS MRNG MAINLY OVER THE SRN TIER.
BUT UNDER THE INCRSG LARGER SCALE QVECTOR DVGC/UPR CNVGC RELATED TO
DNVA AHEAD OF THE RDG...THIS PCPN SHOULD FADE THIS MRNG. AS THE LLVL
SLY FLOW STRENGTHENS THIS AFTN AHEAD OF THE DVLPG LO TO THE SW...THE
ARRIVAL OF MOISTER AIR WITH PWAT APRCHG 1 INCH TOWARD 00Z WL SUPPORT
A RETURN OF CHC POPS AGAIN OVER THE W. ABSENCE OF ANY OTHER DYNAMIC
FORCING WITH JUST WEAK DEEP LYR QVECTOR CVNGC UNDER UPR CNVGC SHOULD
LIMIT THE COVERAGE/PCPN AMNTS. DESPITE CLDY SKIES...THE STEADY LLVL
WAD WL BRING A WARMER DAY TO THE CWA...WITH HI TEMPS LATER REACHING
WELL INTO THE 40S AND EVEN INTO THE 50S OVER THE SRN TIER. SO ANY
PCPN WL BE IN THE FORM OF RA.
TNGT...AS UPR JET CORE STREAKS NEWD OUT OF ROCKIES TROF MOVING OUT
INTO THE PLAINS...MODELS INDICATE AREA OF UPR DVGC IN THE EXIT
REGION OF THIS JET WL STREAK NEWD THRU THE UPR LKS LATE TNGT. IN
CONCERT WITH PERSISTENT WARM/MOIST ADVECTION THAT LIFTS PWAT OVER AN
INCH /OVER 200 PCT OF NORMAL/...GOING FCST SHOWING CATEGORICAL POPS
ARRIVING FM THE SW LOOKS ON TRACK. BEST CHC FOR THE HEAVIER RA WL BE
OVER THE CENTRAL AND E...WHERE THE PWAT IS FCST HIER. THERE SHOULD
BE LTL IF ANY TEMP DROP TNGT...IN FACT TEMPS MAY RISE SLOWLY. TENDED
TOWARD THE HI END OF GUIDANCE FOR MIN TEMPS. WITH THE ARRIVAL OF THE
MOISTER AIR...EXPECT AREAS OF FOG AS WELL...ESPECIALLY OVER THE
CENTRAL WITH AN UPSLOPE SSE WIND.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 435 AM EDT WED OCT 30 2013
UPPER TROUGH OVER THE WESTERN CONUS HEADS ACROSS THE GREAT LAKES AND
EASTERN CONUS TO END THE WEEK. TROUGH IS RE-ENFORCED OVER THESE AREAS
INTO THE WEEKEND AS STRONG JET ENERGY IN NORTHERN BRANCH DIGS FROM
WESTERN CANADA INTO THE GREAT LAKES. BY LATER IN THE WEEKEND...150+
KT JET LIFTS ACROSS THE CANADAIAN MARITIMES USHERING THE TROUGH
ACROSS THE NORTH ATLANTIC. UPSTREAM...ANOTHER ROUND OF TROUGHING
DEVELOPS OVER THE WESTERN CONUS BY EARLY NEXT WEEK. TROUGH SLIDES
ACROSS MIDDLE CONUS BY END OF THE LONG TERM.
MAIN AREA OF LOW PRESSURE WHICH GETS GOING TODAY OVER THE PLAINS...
DEEPENS TO A SUB 985MB LOW ON THURSDAY NIGHT AND FRIDAY AS IT EXITS
THE UPPER GREAT LAKES TOWARD QUEBEC. GIVEN STRENGTH OF DIVERGENCE
ALOFT ON NOSE OF 130+ KT JET CORE ARRIVING FROM THE PLAINS...PREFER
DEEPER AND A FARTHER NORTH SFC LOW FOR DAYTIME ON THURSDAY...SIMILAR
TO ECMWF AND LOCAL REGIONAL-WRF. GEM-NH LOOKS SIMILAR AS WELL...AT
LEAST UNTIL MIDDAY THURSDAY. EXPECT SWATH OF RAIN TO SWEEP MAINLY OUT
OF NORTHERN CWA ON THURSDAY MORNING...LEAVING A LULL IN SHOWERS UNTIL
AT LEAST MID-LATE AFTN. FORECAST GETS RATHER TRICKY BY THIS POINT.
UNCERTAINTY COMES IN AS PRIMARY SOUTHERN STREAM WAVE LIFTS TOWARD THE
GREAT LAKES ALONG WITH SECONDARY JET STREAK. LIKELY WILL SEE INTIAL
SFC LOW FADE AWAY AS BETTER LARGE SCALE SUPPORT REGROUPS VCNTY OF LK
MICHIGAN. LIKE THE UKMET /GEM-NH IDEA WITH A SFC LOW DEEPENING TO
LESS THAN 990MB VCNTY OF CNTRL LK MICHIGAN BY 00Z FRIDAY. ECMWF IS ON
THIS TRACK NOW AS WELL...SHIFTING AWAY FM A WEAKER LOW VCNTY OF
EASTERN LK SUPERIOR. NAM SEEMS TOO FAR SOUTH BUT ON THE FLIP SIDE THE
GFS IS PROBABLY TOO FAR NORTHWEST AND TOO DEEP...PERHAPS SUFFERING FM
CONVECTIVE FEEDBACK. MSLP CENTER MORE IMPORTANT FOR THE WIND FCST
WHICH WILL BE A MESS UNTIL LATER TONIGHT OR ON THURSDAY WHEN EXACT
TRACK OF SFC LOW IS APPARENT. PRIMARY IMPACT ON WEATHER IS THE NON
NAM IDEA OPENS DOOR FOR FARTHER WEST JET STREAK/DIVERGENCE AND ALSO
SFC-H85 TEMP/MOISTURE ADVECTION. HIGHEST POPS LATER THURSDAY AFTN AND
EVENING ROUGHLY FOR THE EAST HALF OF CWA. STILL COULD BE SOME TSRA AS
WELL AS EASTERN CWA IS ON EDGE OF STEEPER H7-H5 LAPSE RATES AND ON
NOSE OF H5-H3 DRY SLOT POKING IN FM SOUTH WHICH WOULD STEEPEN THE
LAPSE RATES.
AS A SIDE NOTE...THURSDAY WILL LIKELY BE FIRST DAY WITH ABOVE NORMAL
DAILY TEMPS SINCE THE 12TH OF OCTOBER. TEMPS THAT START TO SLOWLY
RISE TONIGHT CONTINUE TO PUSH WELL INTO THE 50S ON THURSDAY FROM JUST
ADVECTION ALONE AS SKIES WILL STAY CLOUDY AND MIXING WILL BE MINIMAL.
HIGHER DWPNTS AND SATURATED LOW-LEVELS WITH LIGHT WINDS POINT TO FOG
LASTING THROUGH MUCH OF THE DAY...ESPECIALLY IN THE HIGHER TERRAIN OF
CNTRL UPR MICHIGAN. WINDS BECOMING WESTERLY LATE DAY SHOULD BEGIN TO
SCOUR OUT THE FOG...THOUGH IT MAY TAKE UNTIL LATER THURSDAY EVENING
ONCE STRONGER NW WINDS ARRIVE TO GET RID OF IT COMPLETELY.
DEEPENING SFC LOW PULLS AWAY FM UPR LAKES LATER THURSDAY NIGHT INTO
FRIDAY MORNING. MSLP DOWN BLO 980MB AT THIS POINT. CURRENT FORECAST
HAS NW WINDS ALONG LK SUPERIOR GUSTING OVER 30 MPH. IF LOW TRENDS
ANY FARTHER WEST...WOULD LIKELY BE A PERIOD OF ADVY LEVEL WINDS NEAR
LK SUPERIOR. DESPITE SUCH A DEEP LOW...COLD AIR ARRIVAL FOR FRIDAY
MORNING LAGGING MORE THAN PREVIOUS MODELS HAVE INDICATED. 1000-850MB
THICKNESSES STAYING ABOVE 1300M AND H85 TEMPS STAYING WARMER THAN
-4C INDICATE A MIX OF RAIN AND SNOW IN THE WEST WITH RAIN OVR THE
CNTRL AND EAST. GFS FORECAST SOUNDINGS AND EXPECTED SFC TEMPS IN THE
UPR 30S TO AROUND 40 DEGREES ALSO SUPPORT IDEA OF MORE RAIN THAN
SNOW FOR MOST OF CWA. A BIT MORE COOLING FOR FRIDAY NIGHT WITH H85
TEMPS -4C TO -6C. THIS IS ALSO THE TIME WHEN STRONGER SHORTWAVE
COMES THROUGH IN WNW FLOW ALOFT. IF IT WAS COLDER WOULD BE MORE
CONCERNED ABOUT A FEW INCHES OF SNOW OVER THE HIGHER TERRAIN OF THE
WEST DUE TO LAKE ENHANCEMENT. AS IT STANDS NOW...ONLY LOOKING AT
DELTA T/S 12-14C WITH ONLY MARGINALLY CYCLONIC LOW-LEVEL FLOW. SFC
TEMPS STILL MARGINALLY COLD TOO WITH READINGS EXPECTED IN THE LOW TO
MID 30S AT THE TIME THE STRONGEST LARGER SCALE LIFT IS OCCURRING.
SLIGHTLY BETTER CHANCE AT SEEING SOME ACCUMULATION WOULD BE LATE AT
NIGHT INTO SATURDAY MORNING...BUT LARGER SCALE FORCING IS NOT AS
SUPPORTATIVE BY THAT TIME. GENERALLY...SEEMS THAT THE MARGINALLY COLD
AIRMASS IS GOING TO PUT CRIMP IN EXTENT OF SNOW FROM THE LAKE
ENHANCEMENT.
TROUGHING/COOLER AIR STICKS AROUND UNTIL SUNDAY WHEN HEIGHTS BEGIN
TO RISE. ONSHORE FLOW NEAR LK SUPERIOR FIRST FM THE NORTHWEST AND
THEN EVENTUALLY FM THE NORTH ALONG WITH SUFFICIENT OVER-WATER
INSTABILITY /DELTA T/S OVER 15C/ WILL KEEP LK EFFECT GOING. ANY LK
EFFECT WILL BE HELD IN CHECK THOUGH AS FLOW BECOMING MORE
ANTICYLONIC LEADS TO LOWER INVERSION HEIGHTS...LESS
CONVERGENCE...AND MARGINAL MOISTURE BLO INVERSION. ANY LINGERING LK
EFFECT WILL FINALLY CUT OUT OF PICTURE BY SUNDAY NIGHT AS LARGER
SCALE WARM AIR ADVECTION OCCURS.
ON TO THE FAR REACHES OF THE LONG TERM. INDICATIONS ARE STILL
THERE THAT FLOW ALOFT BECOMES SW EARLY NEXT WEEK. GFS SHOWING
COLD FRONTAL PASSAGE LATER MONDAY INTO MONDAY NIGHT. ECMWF SLOWER
YET...NOT BRINGING FRONT THROUGH REGION UNTIL TUESDAY OR TUESDAY
NIGHT. ECMWF SHOWS MUCH WETTER SCENARIO AS IT HAS ANOTHER LOW
PRESSURE WAVE RIDING UP ALONG THE FRONT. SOME CONSISTENCY FM EACH
OF THESE MODELS...SO A CONSENSUS WILL HOLD FOR NOW. CRITICAL
THICKNESSES INDICATE RAIN OR SNOW OR A MIX OF BOTH FOR PYTPE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 131 AM EDT WED OCT 30 2013
EXPECT PREVAILING MVFR CONDITIONS AT THE TAF SITES THROUGH THIS
FCST PERIOD UNDER A MOIST SOUTHERLY FLOW. SOME LIGHT RAIN IS
POSSIBLE WED EVENING...WHICH COULD LOWER CIGS DOWN TO IFR...
ESPECIALLY AT SAW.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 435 AM EDT WED OCT 30 2013
LIGHT WINDS LESS THAN 20 KTS INTO THU AS A HIGH PRESSURE RIDGE OVER
THE AREA SLOWLY MOVES TOWARD THE EAST COAST. LOW PRESSURE DEVELOPING
OVER THE PLAINS TODAY WILL LIFT TOWARD THE UPPER GREAT LAKES ON
THURSDAY THEN DEEPEN AS IT MOVES INTO QUEBEC ON FRIDAY. STRONGEST
WINDS WITH THE SYSTEM WILL BE THURSDAY NIGHT INTO FRIDAY MORNING
OVER THE EAST HALF OF LAKE SUPERIOR. IF THE MSLP PATTERN REMAINS AS
FORECAST...ONLY WOULD BE A MINIMAL CHANCE OF SEEING GALES DURING
THIS TIME. IF THE LOW SHIFTS TO THE WEST...EVEN JUST SLIGHLY...THE
CHANCE OF GALES WILL INCREASE DUE TO A TIGHTER PRESSURE
GRADIENT...ESPECIALLY OVER EASTERN LK SUPERIOR. NW WINDS STAY UP TO
25 KTS INTO SATURDAY THEN DIMINISH BY SUNDAY MORNING WITH ARRIVAL OF
HIGH PRESSURE RIDGE. BREAK IN STRONGER WINDS ONLY BRIEF THOUGH WITH
SE WINDS UP TO 30 KTS BY MONDAY AS A STRONG LOW PRESSURE SYSTEM
MOVES ACROSS SOUTH CENTRAL CANADA.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...JLA
AVIATION...KC
MARINE...JLA
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
718 PM CDT THU OCT 31 2013
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 358 PM CDT THU OCT 31 2013
LARGE AREA OF 120-150 DM 12-HR HEIGHT FALLS AT 500 MB ACROSS IA/MO
THIS AFTERNOON JUST OUT OUT AHEAD OF THE TROUGH TRANSVERSING THE
CENTRAL PLAINS. THIS IS AN IMPRESSIVE SYSTEM THAT WILL DEVELOP A
NEGATIVE TILT AND EVEN LARGER HEIGHT FALLS BETWEEN 06-12Z. THE
ASSOCIATED SURFACE LOW HAS DEEPENED FROM 1000 MB AT 12Z TO 992 MB
THIS AFTERNOON AND THE 850 MB JET IS BETWEEN 70-80 KTS OUT ACROSS
THE OHIO VALLEY. THE GEFS STANDARDIZED ANOMALIES FOR WIND MAGNITUDE
ARE BETWEEN +4 AND +7 STANDARD DEVIATIONS BETWEEN 1000-850 MB.
STRONG THUNDERSTORMS...HEAVY RAIN...HIGH WINDS WILL BE THE RESULT
ACROSS THE EASTERN CONUS. CLOSER TO HOME...A TROUGH WILL HANG BACK
TO THE WEST FROM THE DEEPENING SURFACE CYCLONE...WHICH COULD PROMOTE
THE GENERATION OF LIGHT RAIN SHOWERS ACROSS THE EASTERN FORECAST
AREA. THIS ALSO SUGGESTS THAT THE CLOUDS COULD TAKE THEIR SWEET TIME
GETTING OUT OF THE FORECAST AREA...AND WE WILL LIKELY REMAIN CLOUDY
TO CLOSE OUT THE WORK WEEK. THERE COULD BE A FEW BREAKS LATE
TOMORROW AFTERNOON.
IN TERMS OF TEMPERATURES...THE CLOUDS/FOG/LIGHT RAIN HAS KEPT US
FROM OUR NORMAL DIURNAL FLUCTUATIONS OVER THE PAST DAY OR TWO...AND
WE SHOULD SEE ONLY MINOR CHANGES IN TEMPERATURE THROUGH TOMORROW
NIGHT. ONLY SLIGHT COOLING IS EXPECTED TONIGHT AND SLIGHT WARMING
EXPECTED TOMORROW. IT WILL BE A COOL AND CLOUDY BUT DRY TRICK OR
TREAT NIGHT WITH TEMPS IN THE LOWER 40S. HOWEVER...THERE WILL BE A
WESTERLY BREEZE TO MAKE IT FEEL A BIT COOLER.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 358 PM CDT THU OCT 31 2013
SOME LIGHT SHOWERS WILL LINGER ACROSS THE FA FRIDAY NIGHT AS A
WEAK AREA OF LOW PRESSURE EXITS THE REGION TO THE SOUTHEAST.
SATURDAY WILL BE DRY WITH DECREASING CLOUDINESS FROM SOUTHWEST TO
NORTHEAST. HIGH PRESSURE PASSES BY SATURDAY NIGHT WITH A QUICK
DROP IN TEMPERATURES. FAVORED LOWER LOWS BASED ON THE LIGHT WINDS
AND A MAINLY CLEAR SKY. SUNDAY PRESENTS TWO CONCERNS. THE FIRST IS
THE WIND AND THE SECOND IS THE HIGH TEMPERATURE. THE SURFACE
PRESSURE GRADIENT TIGHTENS QUICKLY SUNDAY MORNING ON THE BACKSIDE
OF THE HIGH WITH 20 TO 25 KNOT WINDS LIKELY BY LATE MORNING ACROSS
WEST CENTRAL THROUGH SOUTH CENTRAL MN. MID LEVEL MOMENTUM
TRANSFER FROM BOTH THE NAM AND GFS BUFKIT DATA ARE IN THE MIDDLE 30
KNOT RANGE. THEREFORE A WINDY DAY REMAINS IN THE FORECAST ACROSS
THE AFOREMENTIONED AREAS WITH BREEZY CONDITIONS TO THE EAST. MIX
DOWN FROM AROUND 850 MB FROM THE GFS STILL POINTS TO MIDDLE 50S
FOR HIGHS ACROSS WEST CENTRAL AND SOUTHWEST MN WITH UPPER 40S TO
LOWER 50S TO THE EAST. THESE NUMBERS ARE REAL CLOSE TO THE ECMX
MOS AND WERE INCORPORATED INTO THE FORECAST.
A WET PERIOD FROM MONDAY INTO WEDNESDAY IS STILL ANTICIPATED AS A
LARGE TROUGH ALOFT MOVES INTO THE SOUTHWESTERN UNITED STATES LATE
THIS WEEKEND AND THEN EJECTS NORTHEAST. SEVERAL NORTHERN STREAM
SHORT WAVES STAY AHEAD AND OUT OF PHASE OF THE SOUTHERN STREAM
FEATURE FROM MONDAY INTO TUESDAY. HOWEVER... A THIRD SHORT WAVE IS
SHOWN BY BOTH THE GFS AND ECMWF TO BECOME MORE ALIGNED WITH THE
SOUTHERN STREAM BY WEDNESDAY MORNING OVER THE CENTER OF THE
COUNTRY. BY THAT TIME... WE ARE NEARING THE BACK EDGE OF THE
PRECIPITATION PATTERN WITH A PERIOD OF SNOW BECOMING MORE LIKELY.
THINGS WILL CERTAINLY CHANGE WITH THE TIMING ON THIS SYSTEM AS THE
DAYS PROGRESS... BUT THIS PHASING WOULD ALLOW ENOUGH COLD AIR INTO
THE FA TO SUPPORT SNOW LATE TUESDAY NIGHT/EARLY WEDNESDAY MORNING
ACROSS CENTRAL AND SOUTHERN MINNESOTA... WHICH IS REFLECTED IN THE
HOURLY WEATHER GRIDS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 718 PM CDT THU OCT 31 2013
IFR CEILINGS HAVE EXITED NWRN MN BUT STILL AFFECT AREAS SUCH AS
ALEXANDRIA... WILLMAR AND GLENCOE...NORTHERN METRO AND EAU CLAIRE.
WESTERN EDGE WAS CREEPING EASTWARD WITH W OR WNW SURFACE FLOW...BUT AM
CONCERNED THAT IN ANOTHER FEW HOURS...MORE NWLY FLOW WILL TAKE
HOLD PER LATEST RAP AND UPSTREAM OBS. THERE ARE SOME INDICATORS
THAT CYCLONIC FLOW WILL THEN PERSIST WELL INTO FRIDAY. ALL THIS
MEANS THAT EARLIER IDEA OF SCATTERING OUT LATE TONIGHT MAY BE IN
JEOPARDY. HAVE KEPT MVFR CEILINGS OVERNIGHT AT ALL BUT KRWF. ANY
AREAS THAT DO GO SCATTERED LATE TONIGHT MAY WELL FILL IN AGAIN
WITH 2500-3500 AGL MID MORNING FRIDAY. CONFIDENCE IS ABOUT
AVERAGE. FINALLY...SOME VSBYS IN NWRN WISC DOWN TO 2 MILES OR SO
BUT WITH WNW OR NW WINDS..THIS SHOULD PRECLUDE VSBY GOING DOWN TO
LIFR.
KMSP...
KEPT THE TIMING AT 09Z FOR GOING ABOVE 1700 FEET...BUT CONFIDENCE
IS BELOW AVERAGE DUE TO IFR CEILINGS CURRENTLY JUST WEST AND
NORTH OF THE METRO. HAVE KEPT 09Z FOR NOW BUT WILL NOT BE
SURPRISED IF IT TAKES TIL 15Z BEFORE GOING ABOVE 1700. COULD ALSO
BE SOME SPRINKLES ON THE AIRFIELD TOMORROW AFTERNOON AND THIS MAY
NEED TO BE ADDED. 3500 FEET AGL MAY ALSO BE A BIT TOO OPTIMISTIC
TOMORROW MIDDAY AS WELL.
/OUTLOOK FOR KMSP/
FRI NIGHT...MVFR CIGS POSSIBLE. WINDS W 10G20 KT.
SAT...VFR. WINDS NW 10-15 KT.
SUN...VFR. WINDS SE 10-20 KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...CLF
LONG TERM...RAH
AVIATION...TDK
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
400 PM CDT WED OCT 30 2013
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 400 PM CDT WED OCT 30 2013
DREARY FALL WEATHER WILL CONTINUE TONIGHT AND EARLY THURSDAY
MORNING UNTIL A SURFACE LOW AND COLD FRONT SLIDE EAST OF THE
FORECAST AREA. SEVERAL AREAS OF DRIZZLE AND WIDESPREAD FOG HAVE
PERSISTED FOR MOST OF THE DAY. MSLP HAS FALLEN 5-7 MB IN FAR SOUTH
CENTRAL MN IN THE VICINITY OF THE DRY SLOT SHOWING UP ON
SATELLITE. THIS HAS INCREASED THE BL WINDS AND HELPED MIX OUT SOME
OF THE DENSE FOG OBSERVED EARLIER IN THE DAY. HOWEVER...ACROSS
MOST OF CENTRAL MN AND WEST CENTRAL WI...THE FOG HAS ACTUALLY
THICKENED IN MANY LOCATIONS. THESE SAME AREAS WILL HOLD ONTO LIGHT
ENE WINDS THROUGH AT LEAST 06Z /NEAR CALM AT TIMES/. THIS WILL
KEEP THE LOW FOG AND STRATUS IN PLACE. BETWEEN 09-12Z...THE FLOW
WILL INCREASE OUT OF THE W-NW AND ADVECT COOLER/BUT DRIER 925-850
MB AIR INTO MN. THIS SHOULD DO THE TRICK OF BRINGING AN END TO THE
PRECIP. LOCAL WRF SIMULATIONS AND THE PAST COUPLE HRRR RUNS
SUPPORT THIS SCENARIO AS WELL. WE REDUCED POPS/QPF TONIGHT ACROSS
MOST OF THE FORECAST AREA TO ACCOUNT FOR THE SOUTH-EAST TREND IN
THE 12-18Z GUIDANCE. FAR EASTERN PORTIONS OF THE FORECAST AREA
/SUCH AS ALBERT LEA TO EAU CLAIRE/ SHOULD BE RIGHT ALONG OR JUST
NORTH OF THE LOW TRACK AND COULD STILL SEE 0.10-0.25" BETWEEN
03-09Z TONIGHT. OTHERWISE...MUCH MORE THAN TRACE AMOUNTS MIGHT BE
DIFFICULT TO ACCUMULATE ACROSS THE REST OF THE FORECAST AREA. THE
TWIN CITIES METRO COULD STILL PICK UP A FEW HUNDREDTHS TONIGHT.
TOMORROW WILL BE COOL BEHIND THE COLD FRONT WITH LINGERING STRATO
CU...BUT THE WINDS WILL REMAIN ALMOST DUE WESTERLY AND THERE MAY
BE A FEW BREAKS IN THE CLOUDS DURING THE AFTERNOON.
NONETHELESS...MID TO UPPER 40S ARE EXPECTED FOR HIGHS...WHICH IS
JUST A FEW DEGREES BELOW NORMAL.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 400 PM CDT WED OCT 30 2013
NOTHING TOO SCARY WEATHER WISE ACROSS THE REGION THURSDAY EVENING
OTHER THAN A FEW SHOWERS OVER WEST CENTRAL WISCONSIN IN THE WAKE
OF A LOW PRESSURE SYSTEM. A SHORT WAVE AND WEAK LOW PRESSURE
SYSTEM REMAIN ON TRACK TO DROP SOUTHEAST ACROSS THE REGION FRIDAY
AND FRIDAY NIGHT. HIGH CHANCE POPS REMAIN IN PLACE ACROSS THE FA.
WOULD HAVE GONE TO LIKELY AT THIS POINT ACROSS EASTERN MN AND WEST
CENTRAL WI... BASED ON THE NAM AND GFS SOLUTIONS. HOWEVER... THE
GEM AND ECMWF ARE NOT AS ENTHUSIASTIC WITH A MUCH LIGHTER AND
PATCHY PRECIPITATION PATTERN.
HIGH PRESSURE WILL FOLLOW THIS SYSTEM FROM SATURDAY INTO SUNDAY.
SUNDAY LOOKS TO BE THE BEST OF THE TWO DAYS FOR SUNSHINE BUT IT BECOME
QUITE BREEZY/WINDY ACROSS THE FA... ESPECIALLY FROM WEST CENTRAL
INTO SOUTH CENTRAL MN... WHERE SW WINDS NEAR 25 MPH GUSTING TO 35 MPH
ARE LIKELY. THE WIND IS THE RESULT OF A STRENGTHENING PRESSURE
GRADIENT BETWEEN HIGH PRESSURE OVER THE GREAT LAKES AND DEVELOPING
LOW PRESSURE OVER THE WESTERN HIGH PLAINS. THERE COULD BE A PRETTY
GOOD RUN ON THE HIGH TEMPERATURES FOR THE DAY ACROSS SOUTHWEST MN
AS ALONG AS THE DEVELOPING SOUTHERLY LOW LEVEL WAA PATTERN DOES
NOT SLOW MUCH. PUSHED HIGHS UP INTO THE MIDDLE 50S FOR THE SW CWA BASED
ON H85 MIX DOWN FROM THE ECMWF.
AN UNSETTLED WEATHER PATTERN WILL DOMINATE THE REGION FOR MUCH OF
NEXT WEEK AS YET ANOTHER LARGE STORM SYSTEM PUSHES INTO THE
ROCKIES BY MONDAY. THIS SYSTEM FEATURES BOTH NORTHERN AND SOUTHERN
STREAM ENERGY ALOFT. GFS/ECMWF SOLUTIONS HAVE BEEN MEANDERING
AROUND THE PAST FEW DAYS ON HOW THIS SYSTEM MOVES THROUGH OUR
AREA FROM MONDAY NIGHT INTO THURSDAY. THE GFS HAS BEEN TRYING TO
PHASE THE TWO STREAMS OVER THE CENTER OF THE COUNTRY BY WEDNESDAY
WITH SURFACE LOW PRESSURE TRACKING NORTHEAST FROM THE CENTRAL
PLAINS TO THE GREAT LAKES. THE ECMWF HAS KEPT SEPARATION BETWEEN THE
STREAMS. THE ECMWF HAS BECOME QUITE EXTREME TODAY CUTTING OFF AN
UPPER LOW NEAR NORTHERN MEXICO BY MID WEEK. OVERALL... A SLOWER
OUTCOME WILL LIKELY RESULT OVER WHAT THE GFS INDICATES AND PERHAPS
CLOSER TO THE ECMWF. HENCE... A RATHER WET PERIOD IS LIKELY NEXT
WEEK. THE THREAT FOR SNOW IS MINIMAL AS LONG AS THE NORTHERN AND
SOUTHERN STREAMS KEEP THEIR DISTANCE LIKE THE ECMWF INDICATES.
MORE PHASING LIKE THE GFS WOULD PREFER COULD LEAD TO TROUBLE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1246 PM CDT WED OCT 30 2013
WIDESPREAD IFR OR LIFR WILL CONTINUE THROUGH THE REMAINDER OF THE
AFTERNOON AND THROUGH THE EARLY OVERNIGHT HOURS. MOST TAFS SITES
HAVE BEEN STEADY WITH 1-3 SM VIS AND 200-500 FT CEILINGS. WHILE
SLIGHT IMPROVEMENT IS POSSIBLE LATE THIS AFTERNOON...THE AVIATION
IMPACTS DUE TO LOW CEILINGS AND VISIBILITY SHOULD LARGELY REMAIN
UNCHANGED UNTIL THURSDAY MORNING ONCE THE WINDS TURN MORE WESTERLY
AND THE RAIN/DRIZZLE/FOG MOVES OUT.
KMSP...
WE HAVE KEPT THE AIRPORT ABOVE 1/2SM FOR THE SURFACE VIS AND
200FT FOR THE CEILINGS TODAY AND TONIGHT. THERE SHOULD BE LITTLE
IMPROVEMENT OVER THE NEXT 12-18 HOURS...BUT IT ALSO APPEARS
UNLIKELY THAT MSP WILL SEE CONDITIONS BELOW 200 FT OR 1/2SM OR
LESS. EXPECT IMPROVEMENT TOMORROW MORNING WITH LIGHT WESTERLY
WINDS.
/OUTLOOK FOR KMSP/
THU NIGHT...MVFR...THEN VFR WITH CLEARING. WINDS NW 10-15 KT.
FRI...MVFR CIGS POSSIBLE WITH CHC -SHRA. WINDS W 15G25 KT.
SAT...VFR. WINDS NW 10-15 KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...CLF
LONG TERM...RAH
AVIATION...CLF
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
551 AM CDT WED OCT 30 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 326 AM CDT WED OCT 30 2013
UPPER LEVEL RIDGE IS SLOWLY WORKING EAST...ALLOWING MORE SOUTHWEST
FLOW TO DRAW IN MORE MOISTURE AND PERHAPS SOME WEAK SHORT WAVES
DURING THE DAY TODAY. STRATUS AND FOG EXPECTED MUCH OF THE PERIOD AS
UPPER LOW APPROACHES TODAY. MEAGER ISENTROPIC LIFT INDICATED AGAIN
...WITH MAIN FOCUS TRANSITIONING MORE EAST DURING THE AFTERNOON
AHEAD OF THE INCOMING TROUGH. THIS SHOULD ENHANCE LIFT AND INDEED
BY 00Z.31 MORE LIFT IS CONCENTRATED ALONG LEADING EDGE OF LAYERED
FRONTOGENESIS INTO CENTRAL MN ALONG SURFACE TROUGH. WILL LIKELY SEE
SOME THREAT OF ISOLATED THUNDER INTO SOUTHERN MN INTO THE EVENING AS
SYSTEM LIFTS NORTHEAST. THE GFS IS STILL INDICATING MIXED LAYER
MOST UNSTABLE CAPE TO AROUND 500 J/KG MOVING THROUGH SOUTHEAST MN
LATE AFTERNOON/EVENING ALONG WITH SOME ELEVATED CAPE. THE UPPER
TROUGH/LAYERED FRONTOGENESIS FOCUSES MORE INTO FAR EASTERN AREAS
AFTER 06Z.31 WILL MENTION CATEGORICAL POPS AS THIS MOVES ACROSS
SOUTHEAST AREAS INTO WESTERN WISCONSIN OVERNIGHT. NON DIURNAL
TEMPERATURE TRENDS INDICATED FOR THE EASTERN AREA AS SURFACE LOW
LIFTS OVER THE SOUTHEAST CWA DURING THE NIGHT.
QPF APPEARS TO BE ON THE DOWNWARD TRENDS AS WELL...AS BETTER
MOISTURE TRANSPORT IS ADVECTED MORE TO THE SOUTHEAST OF THE
AREA...IN AREA OF POSSIBLE HEAVIER CONVECTION INTO TONIGHT.
LOOKS LIKE A GENERAL ONE QUARTER TO ONE HALF INCH TYPE EVENT...WITH
PERHAPS A THREE QUARTER AMOUNT INTO WESTERN WISCONSIN.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 326 AM CDT WED OCT 30 2013
A SECONDARY SURFACE LOW WILL DEVELOP ACROSS NORTHERN OKLAHOMA AND
EASTERN KANSAS WEDNESDAY NIGHT AND TRACK NORTHEAST OVER THE GREAT
LAKES BY THURSDAY NIGHT. THE TROUGH WILL REMAIN POSITIVELY TILTED
THROUGH EARLY THURSDAY...BEFORE TWO VORT MAXES MERGE OVER THE MID
MISSOURI VALLEY AND CAUSE THE TROUGH TO BECOME NEGATIVELY TILTED
THURSDAY NIGHT. AS THE TROUGH MAKES ITS TRANSITION THE SURFACE LOW
WILL BOMB OUT...MOST EXTREME EXAMPLE BEING A 20 MB DEEPENING ON
THE GFS IN ONLY 12 HOURS. ALTHOUGH IMPRESSIVE AS THIS IS...IT
WON/T HAVE TOO MUCH OF AN IMPACT ON OUR WEATHER. IN FACT...MID
LEVEL DRY AIR WILL SURGE IN THURSDAY WITH ONLY THE LOWER 6-7 KFT
REMAINING SOMEWHAT MOIST ACROSS THE EAST. THUS...RAIN CHANCES ARE
NOT LOOKING GOOD AND A FURTHER DOWNWARD TREND OF POPS MAY BE NEEDED
IN THE NEXT FORECAST.
THAT TROUGH WILL LIFT NORTHEAST WITH ANOTHER EMBEDDED SHORT WAVE IN
THE NORTHWEST FLOW DIGGING IN LATE THURSDAY NIGHT AND FRIDAY. A
PRETTY POTENT VORT...DEEPER MOISTURE...AND STEEP LOW LEVEL LAPSE
RATES SHOULD BE ENOUGH TO GET SCATTERED SHOWERS DEVELOPING IN THE
LATE MORNING AND AFTERNOON. DESPITE THICKNESSES AROUND 534 DM...
THE STEEP LOW LEVEL LAPSE RATES WILL ALLOW TEMPERATURES TO CLIMB
INTO THE MID/UPPER 40S KEEPING P-TYPE ALL RAIN. WET BULB TEMPS
ALSO APPEAR UNFAVORABLE/TOO WARM FOR SLEET.
UPPER RIDGING BUILDS INTO THE MISSISSIPPI VALLEY SATURDAY...SUNDAY...
AND MONDAY. MILDER TEMPERATURES AND GENERALLY DRY CONDITIONS ARE
EXPECTED ASIDE FROM MONDAY WHERE A FEW SHOWERS ARE POSSIBLE AS A
DIGGING WESTERN TROUGH APPROACHES.
THE EVOLUTION OF THAT TROUGH TOWARD THE MIDDLE OF NEXT WEEK BRINGS
THE BIGGEST QUESTION MARK FOR THE LONG TERM. MODEL SOLUTIONS ARE
QUITE UNSTABLE WITH EACH RUN. GFS IS LESS AGGRESSIVE WITH THE
DIGGING TROUGH COMPARED TO THE GEM AND ECMWF AND THUS TOO
PROGRESSIVE...WHICH IS TO BE EXPECTED WITH THAT MODEL. THE LATTER
SET OF MODELS KEEP THE TROUGH POSITIVE WITH A MORE SOUTHERLY
SURFACE LOW TRACK...BUT THAT CAN EASILY CHANGE WITH A MORE ROBUST
SYSTEM OVER THE MIDWEST ON DAYS 6/7 AS SOME SOLUTIONS HAVE SHOWN
IN THE PAST COUPLE DAYS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 530 AM CDT WED OCT 30 2013
LIGHT RAIN/DRIZZLE REMAINS OVER CENTRAL PORTION OF THE AREA...WITH
LOWEST CEILINGS HERE AND TO THE WEST...CLOSER TO THE INVERTED
TROUGH OVER EASTERN SOUTH DAKOTA TRAILING SOUTH TO SURFACE LOW.
DEEPER MOISTURE AND SOUTHWEST FLOW ALOFT...WILL CONTINUE THE
THREAT OF DRIZZLE AND LIGHT RAIN DURING THE DAY...WITH CONTINUED
IFR CONDITIONS...POSSIBLE LIFR EARLY. THE LATEST HRRR LIFTS ANOTHER
BAND OF -RA OVER THE AREA THROUGH MIDDAY...WITH PERHAPS A BREAK
LATER INTO THE AFTERNOON OVER EAST. INVERTED TROUGH AND SURFACE
LOW MOVES OVER THE SOUTHEAST PORTION OF THE AREA THROUGH 12Z. WILL
SEE LOWER CONDITIONS TO THE EAST...AND MAY LIFT A BIT OUT WEST AS
THE TROUGH EXITS TO THE EAST AND WINDS ESTABLISH MORE OF A
NORTHWEST DIRECTION. WILL STILL MAINTAIN IFR THROUGH THIS TAF PERIOD.
KMSP...CONTINUE IFR CONDITIONS THROUGH MUCH OF THE MORNING. MAY
SEE A BRIEF BUMP INTO LOWER END MVFR INTO THE AFTERNOON BEFORE THE
MORE STEADY/HEAVIER RAIN AFFECTS THE AREA INTO THE LATE AFTERNOON
AND EVENING. SOME CONVECTIVE POTENTIAL INTO THE EVENING...BUT
BELIEVE ANYTHING SIGNIFICANT WILL REMAIN SOUTHEAST OF THE AREA,
STILL LOOKS LIKE THE MORE STEADY PCPN WILL BE IN THE 00Z-06Z
PERIOD. THE INVERTED TROUGH MOVES THROUGH WITH IFR CONDITIONS
HOLDING UNTIL AT LEAST MIDMORNING THURSDAY AS NORTHWEST WINDS
INCREASE THEN.
/OUTLOOK FOR KMSP/
THU...MVFR/IFR CIGS WITH -RA ENDING IN MRNG. WINDS NW 10-15 KT.
FRI...MVFR CIGS POSSIBLE WITH CHC -SHRA. WINDS W 15G25 KT.
SAT...VFR. WINDS NW 10-15 KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...DWE
LONG TERM...BORGHOFF
AVIATION...DWE
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
820 PM CDT Thu Oct 31 2013
.UPDATE:
Issued at 813 PM CDT Thu Oct 31 2013
Grids and products have been updated to reflect the slightly
quicker exit of precipitation. After the rain ends across
southwest IL, no further precipitation is expected for the rest of
the night across the LSX CWA.
Kanofsky
&&
.SHORT TERM: (Through Tonight)
Issued at 221 PM CDT Thu Oct 31 2013
Focus for tonight will be pops as the upper trof moves thru the
area.
Upper trof just starting to enter far nwrn MO with dry slot
spreading over much of the area. Vort max rounding the base of the
trof now will help eject the trof ewd along with the precip. Have
trended pops this eve twd the 4km local WRF and the HRRR which are
in fairly good agreement along with much of the other guidance as
well. These solns suggest a line of TSRA across far ern portions of
the CWA with some stratiform precip behind that, but exiting the
area quickly. The CWA shud be dry by 03z if not before.
With clouds clearing out of the area tonight, have trended twd the
cooler guidance. That said, do not anticipate temps dropping too
much tonight with mixing persisting thru the night and with no
substantial cooler or drier air advecting into the region.
Tilly
.LONG TERM: (Friday through Next Thursday)
Issued at 321 PM CDT Thu Oct 31 2013
Period begins with focus on temps thru the weekend.
With ample clouds expected across much of the area on Fri and with
the sfc ridge building into the area on Sat, have trended twd the
cooler guidance thru the weekend. Warm up shud begin on Sun as the
sfc ridge starts to retreat and as the thermal ridge starts moving
nwd into the area.
For the extd, focus turns to pops late Mon thru Wed. Mdls have
come into better agreement with trof timing and phasing. Have
lowered pops on Mon and on Thurs with better agreement among mdls.
Increased pops between these times where mdls were in better
agreement regarding precip. Some uncertainty still remains and
will continue to adjust as needed.
Tilly
&&
.AVIATION: (For the 00z TAFs through 00z Friday Evening)
Issued at 622 PM CDT Thu Oct 31 2013
The cold front has passed through all the TAF sites and stretched
across south central IL into southeast MO at 23z. In the wake of
the front, the back edge of more continuous rainfall was located
right through metro St. Louis with a large area of MVFR cigs
extending back into central MO and a narrow band of IFR conditions
just west of the St. Louis area. The rain and lower cigs will push
east this evening, with clearing at KUIN and KCOU within the next
hour or so and by 02-03z in St. Louis. Mostly clear skies/VFR then
expected the remainder of the night with some diurnal cu and gusty
west northwest winds on Friday.
Specifics for KSTL:
Rain will push to the east and become very light within the next
hour. MVFR conditions should dominate through 02z with a period
of IFR conditions possible through 01z or so. Clearing and VFR expected
by 03z then diurnal cu and gusty west northwest winds on Friday.
Glass
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
633 PM CDT Thu Oct 31 2013
.SHORT TERM: (Through Tonight)
Issued at 221 PM CDT Thu Oct 31 2013
Focus for tonight will be pops as the upper trof moves thru the
area.
Upper trof just starting to enter far nwrn MO with dry slot
spreading over much of the area. Vort max rounding the base of the
trof now will help eject the trof ewd along with the precip. Have
trended pops this eve twd the 4km local WRF and the HRRR which are
in fairly good agreement along with much of the other guidance as
well. These solns suggest a line of TSRA across far ern portions of
the CWA with some stratiform precip behind that, but exiting the
area quickly. The CWA shud be dry by 03z if not before.
With clouds clearing out of the area tonight, have trended twd the
cooler guidance. That said, do not anticipate temps dropping too
much tonight with mixing persisting thru the night and with no
substantial cooler or drier air advecting into the region.
Tilly
.LONG TERM: (Friday through Next Thursday)
Issued at 321 PM CDT Thu Oct 31 2013
Period begins with focus on temps thru the weekend.
With ample clouds expected across much of the area on Fri and with
the sfc ridge building into the area on Sat, have trended twd the
cooler guidance thru the weekend. Warm up shud begin on Sun as the
sfc ridge starts to retreat and as the thermal ridge starts moving
nwd into the area.
For the extd, focus turns to pops late Mon thru Wed. Mdls have
come into better agreement with trof timing and phasing. Have
lowered pops on Mon and on Thurs with better agreement among mdls.
Increased pops between these times where mdls were in better
agreement regarding precip. Some uncertainty still remains and
will continue to adjust as needed.
Tilly
&&
.AVIATION: (For the 00z TAFs through 00z Friday Evening)
Issued at 622 PM CDT Thu Oct 31 2013
The cold front has passed through all the TAF sites and stretched
across south central IL into southeast MO at 23z. In the wake of
the front, the back edge of more continuous rainfall was located
right through metro St. Louis with a large area of MVFR cigs
extending back into central MO and a narrow band of IFR conditions
just west of the St. Louis area. The rain and lower cigs will push
east this evening, with clearing at KUIN and KCOU within the next
hour or so and by 02-03z in St. Louis. Mostly clear skies/VFR then
expected the remainder of the night with some diurnal cu and gusty
west northwest winds on Friday.
Specifics for KSTL:
Rain will push to the east and become very light within the next
hour. MVFR conditions should dominate through 02z with a period
of IFR conditions possible through 01z or so. Clearing and VFR expected
by 03z then diurnal cu and gusty west northwest winds on Friday.
Glass
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
231 PM CDT Wed Oct 30 2013
.SHORT TERM...(This Evening through Thursday Afternoon)
Issued at 230 PM CDT WED OCT 30 2013
19Z surface analysis and visible satellite imagery depict a sharp
cold front extending from extreme NW MO to just west of Topeka to
just west of Wichita. This boundary has become nearly stationary
this afternoon, slowed by upstream pressure falls and increasing
southerly warm sector flow that has more than offset the anemic
post-frontal wind fields. The elevated mixed layer present in the
12Z KTOP sounding has been eliminating by a surge of mid-high level
subtropical moisture that overspread the area between 17-18Z per
water vapor imagery, and has resulted in widespread showers and
thunderstorms. This activity should continue to progress steadily
eastward over the next few hours, with the activity in the warm
sector diminishing and being maintained north of the warm front
across nrn MO.
Further west, satellite imagery has shown some thinning/partial clearing
along and ahead of the immediate frontal zone over eastern KS into
Kansas City. Enough insolation is expected to boost temperatures into
the lower 70s, coupled with dewpoints now in the mid 60s in the pre-
frontal moist axis. Although frontal convergence is presently weak
owing to light/calm winds on the cool side of the boundary, a short-
wave impulse over wrn KS is expected to lift across Kansas during
the late afternoon and early evening hours. Large scale ascent
associated with this feature should be sufficient for thunderstorms
to quickly develop along the frontal zone around 21-22Z. Increasing
destabilization in this region should yield SBCAPE upwards of 1500
J/kg co-located beneath an impressive mid-upper level wind field
(65-70 knots at 500mb and 120 knots at 250mb) that will shift toward
the KS/MO border by 00Z. The HRRR model, which has done extremely
well to this point, clearly shows the low level response to the upper
wave, with an increasing low level wind field this evening over ern
KS and far wrn MO, with low level SRH values increasing to between
200-300 m^2/s^s. Certainly the large scale environment would be
supportive of both supercells and smaller scale bowing segments
within a QLCS type of system. And although the warm front has become
rather diffuse from recent widespread convection, and convectively
induced boundary could also aid in the available boundary layer
vorticity. Bottom line is that we may see a period between roughly 22
and 02Z where the tornado potential becomes non-zero over the
southwest quadrant of the CWA.
In addition to the severe threat late this afternoon and early this
evening, moderate to heavy precipitation will likely train ahead of
the slow moving boundary through much of the overnight hours (and
into the day tomorrow). The deep subtropical moisture plume, with
direct connections to both the Gulf and the remnants of Hurricane
Raymond in the EPAC, have contributed to GPS measured precipitable
water column around 1.60" which is nearing the maximum values ever
recorded on this date. An intensifying low level jet this evening
and overnight will maximize rainfall efficiency by focusing moisture
transport and ascent along the frontal zone. Given that 1-2.5" of
rain has already fallen over the past 48 hours across portions of
the area, have gone ahead and issued a flash flood watch for areas
along and southeast of a St. Joseph to Trenton line, effective from
now through 18Z tomorrow.
Temperature wise, very warm and humid conditions will persist
through the warm sector overnight. Basically kept readings in the
mid 60s along and south of the MO river, with only a gradual drop
off through the 50s further north given the initial lack of cold
advection.
.LONG TERM...(Thursday Evening through Wednesday)
Issued at 230 PM CDT WED OCT 30 2013
Rain is expected to continue through the majority of the daytime
hours of Thursday as models have trended deeper and more developed
with upper energy rotating around the base of the larger trough.
Despite the surface front sinking into the southeastern third of
Missouri Thursday morning, the track of the upper wave would support
a large deformation rain band to form and spread across the CWA
through the day. Rain should finally taper off late Thursday
afternoon, leaving damp and cool conditions for Halloween evening.
Friday-Sunday: A secondary upper trough will pass through the region
on Friday ushering in slightly cooler air for Saturday. However,
mid-level ridging will quickly move eastward for the second half of
the weekend, and model guidance indicates a quick return of
southerly flow by Sunday morning. Strong warm advection should push
temperatures back into the lower 60s.
Sunday night - Wednesday: Stratus should stream northward Sunday
night, insulating the area from any extreme temperature drop. With
the next upper trough diving into the Four Corners region Monday
night, rain chances will begin to increase substantially by Tuesday
through Wednesday and have bumped up PoPs both days.
&&
.AVIATION...(For the 18Z TAFS through 18Z Thursday Afternoon)
Issued at 1242 PM CDT WED OCT 30 2013
Convection is becoming more widespread this afternoon across the
area. There may be a brief lull in activity after this first wave
moves through, but expect additional storms to quickly expand in
coverage after 21Z as a front pushes into northeast KS and northwest
MO. Right now frontal passage is timed into Kansas City around 06Z.
As far as flight conditions, there will be some occasional
improvement into MVFR this afternoon before the front and associated
thunderstorms move in this evening. After that prolonged IFR
conditions are expected into tomorrow morning.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...FLASH FLOOD WATCH through Thursday afternoon FOR KSZ025-057-060-
103>105.
MO...FLASH FLOOD WATCH through Thursday afternoon FOR MOZ007-008-
013>017-020>025-028>033-037>040-043>046-053-054.
&&
$$
SHORT TERM...Bookbinder
LONG TERM...Dux
AVIATION...Hawblitzel
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1242 PM CDT Wed Oct 30 2013
.SHORT TERM...(Today through Thursday)
Issued at 241 AM CDT WED OCT 30 2013
Several forecast challenges exist over the next 30 hours, primarily
ongoing dense fog, precipitation amounts and timing, and the
potential for severe weather.
As of this morning, a surface warm front was slowly moving
northward, currently situated just north of I-70. To the north of
this boundary, areas of dense fog continue to persist with
visibilities a half mile or less and very low ceilings. To the south,
conditions steadily improve with southward extent with a seasonably
warm and humid air mass advecting into the area. The pattern and
short-term model guidance supports areas of dense fog along and north
of the boundary through 14Z. Will continue to carry dense fog
advisory and remove counties from south to north as conditions
improve largely tied to the warm frontal position.
Attention turns to large upper trough beginning to emerge into the
Plains states. At the surface, a cold front currently located from
Omaha to Wichita will remain nearly stationary throughout the day in
response to pressure falls to the west. The forecast area will find
itself within the warm sector, with dew points steadily increasing
into the lower to middle 60s. As the nose of a 100kt upper jet
approaches the region, widespread convection is expected to develop
along the boundary and warm sector as strong large scale ascent
occurs. Convective-resolving models support synoptic scenario with
convection initially developing over eastern Kansas by mid morning
and spreading northeastward/additional development over the forecast
area. Extensive cloud cover should preclude strong boundary layer
destabilization. However, model guidance has been progressively
higher with regards to elevated instability in advance of said
mid-morning convection. Current RAP MU CAPE analysis has 500-1000
J/kg over much of the CWA. Expect similar or slightly higher MU CAPE
values to proceed initial convection. With 1-6km bulk shear values of
50kts expected, ample support for organized storms will exist. The
biggest question is whether sufficient instability will remain
available for initial activity. The highest probability for robust
convection will be across the west/southwest quarter of the CWA,
generally KC Metro and south/west, where an initial round of strong
to severe weather may be possible between 8am to 1pm. The primary
threat would be hail to quarter-size and possibility any wind gust
that can reach the surface through the near-surface stable layer.
As the upper trough begins to move further into the Plains this
afternoon and evening, the surface cold front will begin to shift
eastward into far northwestern Missouri during the late afternoon
hours. Additional showers and thunderstorms are expected as this
occurs with large scale ascent still in place and surface forcing
increases. While wind shear will be supportive of organized
convection, degree of instability is much more in question. At this
time, do not expect much severe weather unless better atmospheric
recovery can take place following earlier anticipated convection.
The highest probability for a few stronger storms should be tied to
near the boundary over the far western CWA, with a decreasing
probability with eastward extent. Regardless, widespread showers and
thunderstorms are expected over much of the area from the evening
into Thursday morning. Will continue post-frontal precipitation
chances into Thursday afternoon as the base of the trough passes
through the forecast area, prior to upper downglide. With modest
lapse rates, could still see some embedded thunder in this activity
as well.
As for additional precipitation totals now through Thursday
afternoon, another 1-2 inches of rainfall will be possible. As
mentioned above, a very moist air mass remains in place for this time
of year. Precipitable water values between 1.25-1.5 inches is
roughly two standard deviations above PW climatology, suggesting
robust convection will be efficient rainfall producers. With the
relatively quick storm speed and flash flood rainfall guidance, the
overall threat from flash flooding should be low outside of urban
centers. Will monitor river levels and subsequent response as the
event progresses.
.LONG TERM...(Thursday night through Tuesday)
Issued at 241 AM CDT WED OCT 30 2013
Northwest flow aloft will gradually transition to ridging across the
central CONUS this weekend, allowing for near to slightly above
normal temperatures by Sunday and dry, quiet conditions across the
region through early next week. The primary focus in the long range
forecast period will be a deepening trough over the western U.S.
early next week, which could move into the region by Tuesday.
Precipitation with this system should again spread over a fairly
long period of time with a surface boundary stretching up into the
region on Monday, warm-sector precipitation on Monday night into
Tuesday morning, and frontal precipitation possibly stretching into
early Wednesday. Currently, the most likely time frame for rainfall
will be on Tuesday night, but changes in timing are likely as the
system draws closer.
&&
.AVIATION...(For the 18Z TAFS through 18Z Thursday Afternoon)
Issued at 1242 PM CDT WED OCT 30 2013
Convection is becoming more widespread this afternoon across the
area. There may be a brief lull in activity after this first wave
moves through, but expect additional storms to quickly expand in
coverage after 21Z as a front pushes into northeast KS and northwest
MO. Right now frontal passage is timed into Kansas City around 06Z.
As far as flight conditions, there will be some occasional
improvement into MVFR this afternoon before the front and associated
thunderstorms move in this evening. After that prolonged IFR
conditions are expected into tomorrow morning.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
SHORT TERM...Blair
LONG TERM...Laflin
AVIATION...Hawblitzel
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1138 AM CDT Wed Oct 30 2013
.MESOSCALE DISCUSSION...
Issued at 1120 AM CDT WED OCT 30 2013
Radar trends over the past few hours have indicated increasing
coverage of thunderstorm activity across eastern Kansas and Western
Missouri. This is occurring along the leading edge of a 30 to 40 knot
low level jet, which is currently nosing into northern Missouri.
Objective analysis from 12z RAOBS indicates a very moist low level
air mass, characterized by 12 to 15 C dew points at 850 mb. This
moist air mass, along with decent surface heating should act keep the
low to mid levels of the atmosphere unstable. At the surface a fairly
potent warm front was objectively analyzed running wet to east just
north of Interstate 70. This warm should continue to gradually slide
north through the day, perhaps reaching Highway 36. The most
impressive storm on radar just departed the KSTJ area, and is
continuing to the east around 40 mph. This storm is located north of
the warm front, and is likely caused by the aforementioned low level
jet lifting the moist parcels above the LFC. With the storm currently
located north of the warm front, the tornado threat is low, and the
wind threat is marginal. However, should the storm continue east, or
perhaps slightly south of east it could become surface based. 0-1 SRH
is currently around 150 J/kg in the vicinity of the warm front, so if
the storm does interact with the warm frontal boundary, or somehow
slide south of the boundary, the tornado and wind threat could
increase.
Given the general orientation of the warm front from
northwest to southeast the eastward progression of the storm should
keep it north of the boundary. With the storm being firmly on the
cool air side of the boundary the main threat is hail, ranging from
quarter to golf ball sized. With the storm existing in a marginally
unstable atmosphere, characterized by 1000 to 1500 J/kg of MU CAPE
updraft strength will be fairly marginal. However, with 40 to 50
knots of deep layer and effective shear the updraft portion of the
storm could be enhanced by the better deep layer shear. The most
recent reports from the warned storm in NW Missouri have been
quarters, but given radar trends with mid level Vr ranging from 30 to
40 knots a few golf ball sized hail reports cannot be ruled out.
Showery activity is expected to increase in coverage this afternoon
as the deeper moisture continues to stream in within the strong low
level jet. The severe weather threat will remain marginal throughout
the day, but widespread moderate to heavy rain this afternoon and
this evening should occur, with amounts ranging from 1 to 3 inches
through the evening to overnight hours.
&&
.SHORT TERM...(Today through Thursday)
Issued at 241 AM CDT WED OCT 30 2013
Several forecast challenges exist over the next 30 hours, primarily
ongoing dense fog, precipitation amounts and timing, and the
potential for severe weather.
As of this morning, a surface warm front was slowly moving
northward, currently situated just north of I-70. To the north of
this boundary, areas of dense fog continue to persist with
visibilities a half mile or less and very low ceilings. To the south,
conditions steadily improve with southward extent with a seasonably
warm and humid air mass advecting into the area. The pattern and
short-term model guidance supports areas of dense fog along and north
of the boundary through 14Z. Will continue to carry dense fog
advisory and remove counties from south to north as conditions
improve largely tied to the warm frontal position.
Attention turns to large upper trough beginning to emerge into the
Plains states. At the surface, a cold front currently located from
Omaha to Wichita will remain nearly stationary throughout the day in
response to pressure falls to the west. The forecast area will find
itself within the warm sector, with dew points steadily increasing
into the lower to middle 60s. As the nose of a 100kt upper jet
approaches the region, widespread convection is expected to develop
along the boundary and warm sector as strong large scale ascent
occurs. Convective-resolving models support synoptic scenario with
convection initially developing over eastern Kansas by mid morning
and spreading northeastward/additional development over the forecast
area. Extensive cloud cover should preclude strong boundary layer
destabilization. However, model guidance has been progressively
higher with regards to elevated instability in advance of said
mid-morning convection. Current RAP MU CAPE analysis has 500-1000
J/kg over much of the CWA. Expect similar or slightly higher MU CAPE
values to proceed initial convection. With 1-6km bulk shear values of
50kts expected, ample support for organized storms will exist. The
biggest question is whether sufficient instability will remain
available for initial activity. The highest probability for robust
convection will be across the west/southwest quarter of the CWA,
generally KC Metro and south/west, where an initial round of strong
to severe weather may be possible between 8am to 1pm. The primary
threat would be hail to quarter-size and possibility any wind gust
that can reach the surface through the near-surface stable layer.
As the upper trough begins to move further into the Plains this
afternoon and evening, the surface cold front will begin to shift
eastward into far northwestern Missouri during the late afternoon
hours. Additional showers and thunderstorms are expected as this
occurs with large scale ascent still in place and surface forcing
increases. While wind shear will be supportive of organized
convection, degree of instability is much more in question. At this
time, do not expect much severe weather unless better atmospheric
recovery can take place following earlier anticipated convection.
The highest probability for a few stronger storms should be tied to
near the boundary over the far western CWA, with a decreasing
probability with eastward extent. Regardless, widespread showers and
thunderstorms are expected over much of the area from the evening
into Thursday morning. Will continue post-frontal precipitation
chances into Thursday afternoon as the base of the trough passes
through the forecast area, prior to upper downglide. With modest
lapse rates, could still see some embedded thunder in this activity
as well.
As for additional precipitation totals now through Thursday
afternoon, another 1-2 inches of rainfall will be possible. As
mentioned above, a very moist air mass remains in place for this time
of year. Precipitable water values between 1.25-1.5 inches is
roughly two standard deviations above PW climatology, suggesting
robust convection will be efficient rainfall producers. With the
relatively quick storm speed and flash flood rainfall guidance, the
overall threat from flash flooding should be low outside of urban
centers. Will monitor river levels and subsequent response as the
event progresses.
.LONG TERM...(Thursday night through Tuesday)
Issued at 241 AM CDT WED OCT 30 2013
Northwest flow aloft will gradually transition to ridging across the
central CONUS this weekend, allowing for near to slightly above
normal temperatures by Sunday and dry, quiet conditions across the
region through early next week. The primary focus in the long range
forecast period will be a deepening trough over the western U.S.
early next week, which could move into the region by Tuesday.
Precipitation with this system should again spread over a fairly
long period of time with a surface boundary stretching up into the
region on Monday, warm-sector precipitation on Monday night into
Tuesday morning, and frontal precipitation possibly stretching into
early Wednesday. Currently, the most likely time frame for rainfall
will be on Tuesday night, but changes in timing are likely as the
system draws closer.
&&
.AVIATION...(For the 12Z TAFS through 12Z Thursday Morning)
UPDATE...
Issued at 1154 AM CDT WED OCT 30 2013
Storms are currently bypassing the KC area to the north
and south, and currently do not expect areas in between to fill in
until at least early this afternoon, possibly later. Therefore sent
an amendment keeping thunder out of the MCI terminals until 18Z at
the earliest. Best chances for widespread thunder around KC look to
be a few hours either side of 00Z. Meanwhile strong storm heading for
STJ may be capable of strong winds.
Previous Discussion...
Issued at 627 AM CDT WED OCT 30 2013
IFR stratus and light fog will continue across much of the region
this morning, except in far northern and northeast portions of the
region where dense fog and LIFR ceilings may continue for another
2-3 hours. Scattered showers and thunderstorms this morning will
become widespread this afternoon through tonight, impacting much of
the region especially after 18z. Ceilings are likely to remain IFR
or very low-end MVFR through the remainder of the forecast period,
even as precipitation begins to clear out from northwest to southeast
Thursday morning.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
MESOSCALE...Leighton
SHORT TERM...Blair
LONG TERM...Laflin
AVIATION...Hawblitzel
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1055 AM CDT Wed Oct 30 2013
.SHORT TERM...(Today through Thursday)
Issued at 241 AM CDT WED OCT 30 2013
Several forecast challenges exist over the next 30 hours, primarily
ongoing dense fog, precipitation amounts and timing, and the
potential for severe weather.
As of this morning, a surface warm front was slowly moving
northward, currently situated just north of I-70. To the north of
this boundary, areas of dense fog continue to persist with
visibilities a half mile or less and very low ceilings. To the south,
conditions steadily improve with southward extent with a seasonably
warm and humid airmass advecting into the area. The pattern and
short-term model guidance supports areas of dense fog along and north
of the boundary through 14Z. Will continue to carry dense fog
advisory and remove counties from south to north as conditions
improve largely tied to the warm frontal position.
Attention turns to large upper trough beginning to emerge into the
Plains states. At the surface, a cold front currently located from
Omaha to Wichita will remain nearly stationary throughout the day in
response to pressure falls to the west. The forecast area will find
itself within the warm sector, with dewpoints steadily increasing
into the lower to middle 60s. As the nose of a 100kt upper jet
approaches the region, widespread convection is expected to develop
along the boundary and warm sector as strong large scale ascent
occurs. Convective-resolving models support synoptic scenario with
convection initially developing over eastern Kansas by mid morning
and spreading northeastward/additional development over the forecast
area. Extensive cloud cover should preclude strong boundary layer
destabilization. However, model guidance has been progressively
higher with regards to elevated instability in advance of said
mid-morning convection. Current RAP MUCAPE analysis has 500-1000
J/kg over much of the CWA. Expect similar or slightly higher MUCAPE
values to proceed initial convection. With 1-6km bulk shear values of
50kts expected, ample support for organized storms will exist. The
biggest question is whether sufficient instability will remain
available for initial activity. The highest probability for robust
convection will be across the west/southwest quarter of the CWA,
generally KC Metro and south/west, where an initial round of strong
to severe weather may be possible between 8am to 1pm. The primary
threat would be hail to quarter-size and possibility any wind gust
that can reach the surface through the near-surface stable layer.
As the upper trough begins to move further into the Plains this
afternoon and evening, the surface cold front will begin to shift
eastward into far northwestern Missouri during the late afternoon
hours. Additional showers and thunderstorms are expected as this
occurs with large scale ascent still in place and surface forcing
increases. While wind shear will be supportive of organized
convection, degree of instability is much more in question. At this
time, do not expect much severe weather unless better atmospheric
recovery can take place following earlier anticipated convection.
The highest probability for a few stronger storms should be tied to
near the boundary over the far western CWA, with a decreasing
probability with eastward extent. Regardless, widespread showers and
thunderstorms are expected over much of the area from the evening
into Thursday morning. Will continue post-frontal precipitation
chances into Thursday afternoon as the base of the trough passes
through the forecast area, prior to upper downglide. With modest
lapse rates, could still see some embedded thunder in this activity
as well.
As for additional precipitation totals now through Thursday
afternoon, another 1-2 inches of rainfall will be possible. As
mentioned above, a very moist airmass remains in place for this time
of year. Precipitable water values between 1.25-1.5 inches is
roughly two standard deviations above PW climatology, suggesting
robust convection will be efficient rainfall producers. With the
relatively quick storm speed and flash flood rainfall guidance, the
overall threat from flash flooding should be low outside of urban
centers. Will monitor river levels and subsequent response as the
event progresses.
.LONG TERM...(Thursday night through Tuesday)
Issued at 241 AM CDT WED OCT 30 2013
Northwest flow aloft will gradually transition to ridging across the
central CONUS this weekend, allowing for near to slightly above
normal temperatures by Sunday and dry, quiet conditions across the
region through early next week. The primary focus in the long range
forecast period will be a deepening trough over the western U.S.
early next week, which could move into the region by Tuesday.
Precipitation with this system should again spread over a fairly
long period of time with a surface boundary stretching up into the
region on Monday, warm-sector precipitation on Monday night into
Tuesday morning, and frontal precipitation possibly stretching into
early Wednesday. Currently, the most likely timeframe for rainfall
will be on Tuesday night, but changes in timing are likely as the
system draws closer.
&&
.AVIATION...(For the 12Z TAFS through 12Z Thursday Morning)
UPDATE...
Issued at 1154 AM CDT WED OCT 30 2013
Storms are currently bypassing the KC area to the north
and south, and currently do not expect areas in between to fill in
until at least early this afternoon, possibly later. Therefore sent
an amendment keeping thunder out of the MCI terminals until 18Z at
the earliest. Best chances for widespread thunder around KC look to
be a few hours either side of 00Z. Meanwhile strong storm heading for
STJ may be capable of strong winds.
Previous Discussion...
Issued at 627 AM CDT WED OCT 30 2013
IFR stratus and light fog will continue across much of the region
this morning, except in far northern and northeast portions of the
region where dense fog and LIFR ceilings may continue for another
2-3 hours. Scattered showers and thunderstorms this morning will
become widespread this afternoon through tonight, impacting much of
the region especially after 18z. Ceilings are likely to remain IFR
or very low-end MVFR through the remainder of the forecast period,
even as precipitation begins to clear out from northwest to southeast
Thursday morning.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
SHORT TERM...Blair
LONG TERM...Laflin
AVIATION...Hawblitzel
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
627 AM CDT Wed Oct 30 2013
.SHORT TERM...(Today through Thursday)
Issued at 241 AM CDT WED OCT 30 2013
Several forecast challenges exist over the next 30 hours, primarily
ongoing dense fog, precipitation amounts and timing, and the
potential for severe weather.
As of this morning, a surface warm front was slowly moving
northward, currently situated just north of I-70. To the north of
this boundary, areas of dense fog continue to persist with
visibilities a half mile or less and very low ceilings. To the south,
conditions steadily improve with southward extent with a seasonably
warm and humid airmass advecting into the area. The pattern and
short-term model guidance supports areas of dense fog along and north
of the boundary through 14Z. Will continue to carry dense fog
advisory and remove counties from south to north as conditions
improve largely tied to the warm frontal position.
Attention turns to large upper trough beginning to emerge into the
Plains states. At the surface, a cold front currently located from
Omaha to Wichita will remain nearly stationary throughout the day in
response to pressure falls to the west. The forecast area will find
itself within the warm sector, with dewpoints steadily increasing
into the lower to middle 60s. As the nose of a 100kt upper jet
approaches the region, widespread convection is expected to develop
along the boundary and warm sector as strong large scale ascent
occurs. Convective-resolving models support synoptic scenario with
convection initially developing over eastern Kansas by mid morning
and spreading northeastward/additional development over the forecast
area. Extensive cloud cover should preclude strong boundary layer
destabilization. However, model guidance has been progressively
higher with regards to elevated instability in advance of said
mid-morning convection. Current RAP MUCAPE analysis has 500-1000
J/kg over much of the CWA. Expect similar or slightly higher MUCAPE
values to proceed initial convection. With 1-6km bulk shear values of
50kts expected, ample support for organized storms will exist. The
biggest question is whether sufficient instability will remain
available for initial activity. The highest probability for robust
convection will be across the west/southwest quarter of the CWA,
generally KC Metro and south/west, where an initial round of strong
to severe weather may be possible between 8am to 1pm. The primary
threat would be hail to quarter-size and possibility any wind gust
that can reach the surface through the near-surface stable layer.
As the upper trough begins to move further into the Plains this
afternoon and evening, the surface cold front will begin to shift
eastward into far northwestern Missouri during the late afternoon
hours. Additional showers and thunderstorms are expected as this
occurs with large scale ascent still in place and surface forcing
increases. While wind shear will be supportive of organized
convection, degree of instability is much more in question. At this
time, do not expect much severe weather unless better atmospheric
recovery can take place following earlier anticipated convection.
The highest probability for a few stronger storms should be tied to
near the boundary over the far western CWA, with a decreasing
probability with eastward extent. Regardless, widespread showers and
thunderstorms are expected over much of the area from the evening
into Thursday morning. Will continue post-frontal precipitation
chances into Thursday afternoon as the base of the trough passes
through the forecast area, prior to upper downglide. With modest
lapse rates, could still see some embedded thunder in this activity
as well.
As for additional precipitation totals now through Thursday
afternoon, another 1-2 inches of rainfall will be possible. As
mentioned above, a very moist airmass remains in place for this time
of year. Precipitable water values between 1.25-1.5 inches is
roughly two standard deviations above PW climatology, suggesting
robust convection will be efficient rainfall producers. With the
relatively quick storm speed and flash flood rainfall guidance, the
overall threat from flash flooding should be low outside of urban
centers. Will monitor river levels and subsequent response as the
event progresses.
.LONG TERM...(Thursday night through Tuesday)
Issued at 241 AM CDT WED OCT 30 2013
Northwest flow aloft will gradually transition to ridging across the
central CONUS this weekend, allowing for near to slightly above
normal temperatures by Sunday and dry, quiet conditions across the
region through early next week. The primary focus in the long range
forecast period will be a deepening trough over the western U.S.
early next week, which could move into the region by Tuesday.
Precipitation with this system should again spread over a fairly
long period of time with a surface boundary stretching up into the
region on Monday, warm-sector precipitation on Monday night into
Tuesday morning, and frontal precipitation possibly stretching into
early Wednesday. Currently, the most likely timeframe for rainfall
will be on Tuesday night, but changes in timing are likely as the
system draws closer.
&&
.AVIATION...(For the 12Z TAFS through 12Z Thursday Morning)
Issued at 627 AM CDT WED OCT 30 2013
IFR stratus and light fog will continue across much of the region
this morning, except in far northern and northeast portions of the
region where dense fog and LIFR ceilings may continue for another
2-3 hours. Scattered showers and thunderstorms this morning will
become widespread this afternoon through tonight, impacting much of
the region especially after 18z. Ceilings are likely to remain IFR
or very low-end MVFR through the remainder of the forecast period,
even as precipitation begins to clear out from northwest to southeast
Thursday morning.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...DENSE FOG ADVISORY until 9 AM CDT this morning FOR KSZ025-102-
103.
MO...DENSE FOG ADVISORY until 9 AM CDT this morning FOR MOZ001>008-
011>017-020>025-028>032.
&&
$$
SHORT TERM...Blair
LONG TERM...Laflin
AVIATION...Laflin
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
251 AM CDT Wed Oct 30 2013
.SHORT TERM...(Today through Thursday)
Issued at 241 AM CDT WED OCT 30 2013
Several forecast challenges exist over the next 30 hours, primarily
ongoing dense fog, precipitation amounts and timing, and the
potential for severe weather.
As of this morning, a surface warm front was slowly moving
northward, currently situated just north of I-70. To the north of
this boundary, areas of dense fog continue to persist with
visibilities a half mile or less and very low ceilings. To the south,
conditions steadily improve with southward extent with a seasonably
warm and humid airmass advecting into the area. The pattern and
short-term model guidance supports areas of dense fog along and north
of the boundary through 14Z. Will continue to carry dense fog
advisory and remove counties from south to north as conditions
improve largely tied to the warm frontal position.
Attention turns to large upper trough beginning to emerge into the
Plains states. At the surface, a cold front currently located from
Omaha to Wichita will remain nearly stationary throughout the day in
response to pressure falls to the west. The forecast area will find
itself within the warm sector, with dewpoints steadily increasing
into the lower to middle 60s. As the nose of a 100kt upper jet
approaches the region, widespread convection is expected to develop
along the boundary and warm sector as strong large scale ascent
occurs. Convective-resolving models support synoptic scenario with
convection initially developing over eastern Kansas by mid morning
and spreading northeastward/additional development over the forecast
area. Extensive cloud cover should preclude strong boundary layer
destabilization. However, model guidance has been progressively
higher with regards to elevated instability in advance of said
mid-morning convection. Current RAP MUCAPE analysis has 500-1000
J/kg over much of the CWA. Expect similar or slightly higher MUCAPE
values to proceed initial convection. With 1-6km bulk shear values of
50kts expected, ample support for organized storms will exist. The
biggest question is whether sufficient instability will remain
available for initial activity. The highest probability for robust
convection will be across the west/southwest quarter of the CWA,
generally KC Metro and south/west, where an initial round of strong
to severe weather may be possible between 8am to 1pm. The primary
threat would be hail to quarter-size and possibility any wind gust
that can reach the surface through the near-surface stable layer.
As the upper trough begins to move further into the Plains this
afternoon and evening, the surface cold front will begin to shift
eastward into far northwestern Missouri during the late afternoon
hours. Additional showers and thunderstorms are expected as this
occurs with large scale ascent still in place and surface forcing
increases. While wind shear will be supportive of organized
convection, degree of instability is much more in question. At this
time, do not expect much severe weather unless better atmospheric
recovery can take place following earlier anticipated convection.
The highest probability for a few stronger storms should be tied to
near the boundary over the far western CWA, with a decreasing
probability with eastward extent. Regardless, widespread showers and
thunderstorms are expected over much of the area from the evening
into Thursday morning. Will continue post-frontal precipitation
chances into Thursday afternoon as the base of the trough passes
through the forecast area, prior to upper downglide. With modest
lapse rates, could still see some embedded thunder in this activity
as well.
As for additional precipitation totals now through Thursday
afternoon, another 1-2 inches of rainfall will be possible. As
mentioned above, a very moist airmass remains in place for this time
of year. Precipitable water values between 1.25-1.5 inches is
roughly two standard deviations above PW climatology, suggesting
robust convection will be efficient rainfall producers. With the
relatively quick storm speed and flash flood rainfall guidance, the
overall threat from flash flooding should be low outside of urban
centers. Will monitor river levels and subsequent response as the
event progresses.
.LONG TERM...(Thursday night through Tuesday)
Issued at 241 AM CDT WED OCT 30 2013
Northwest flow aloft will gradually transition to ridging across the
central CONUS this weekend, allowing for near to slightly above
normal temperatures by Sunday and dry, quiet conditions across the
region through early next week. The primary focus in the long range
forecast period will be a deepening trough over the western U.S.
early next week, which could move into the region by Tuesday.
Precipitation with this system should again spread over a fairly
long period of time with a surface boundary stretching up into the
region on Monday, warm-sector precipitation on Monday night into
Tuesday morning, and frontal precipitation possibly stretching into
early Wednesday. Currently, the most likely timeframe for rainfall
will be on Tuesday night, but changes in timing are likely as the
system draws closer.
&&
.AVIATION...(For the 06Z TAFS through 06Z Wednesday Night)
Issued at 1153 PM CDT TUE OCT 29 2013
A warm front will remain stalled across northern Missouri through
the morning hours, likely keeping the LIFR low ceilings and
visibilities in place at STJ through mid-morning. Expectations are
that showers will begin to replace the drizzle and fog through the
later half of the morning hours with widespread thunderstorms in the
afternoon hours. Conditions might improve above the IFR category
currently forecast for the afternoon hours with the thunderstorms,
but given abundant moisture and lift ahead of the cold front that
will push through late Wednesday night, confidence is not high enough
to improve conditions.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...DENSE FOG ADVISORY until 9 AM CDT this morning FOR KSZ025-
102>104.
MO...DENSE FOG ADVISORY until 9 AM CDT this morning FOR MOZ001>008-
011>017-020>024-028>031.
&&
$$
SHORT TERM...Blair
LONG TERM...Laflin
AVIATION...Cutter
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1247 PM CDT WED OCT 30 2013
.UPDATE...
ISSUED AT 955 AM CDT WED OCT 30 2013
UPDATE TO THE FORECAST TO EXPIRE THE NORTHWEST NEBRASKA WINTER
WEATHER ADVISORY. TEMPERATURES ACROSS THE REGION /SAVE KVTN WHERE
THE CURRENT TEMP IS 0C/ HAVE RISEN ABOVE 0C AND PRECIPITATION IS
CURRENTLY HAVING DIFFICULTLY OVERCOMING DRY LAYERS IN THE LOWER
AND MID LEVELS. OTHERWISE THE FORECAST IS ON TRACK WITH NO OTHER
UPDATES NEEDED AT THIS TIME.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 331 AM CDT WED OCT 30 2013
A 700MB WARM FRONT...CURRENTLY ACROSS NORTHEAST COLORADO WILL
LIFT THROUGH THE PANHANDLE AND WRN NEB THIS MORNING TRIGGERING
RAIN AND FREEZING RAIN. THE WARM AIR ADVECTION IS QUITE
STRONG...NEAR 50 KT FROM 850MB TO 700MB ON THE KGLD RADAR AND
AROUND 40 KT ON THE KFTG RADAR. THIS SHOULD KEEP TEMPERATURES
ABOVE FREEZING 850MB TO 700MB AS INDICATED BY THE RAP MODEL. SFC
OBS ACROSS WRN NEB SUGGEST JUST SHERIDAN AND CHERRY COUNTIES COULD
GET FREEZING RAIN WHILE AREAS TO THE SOUTH UNDERGO WEAK SCOURING.
THIS ELEVATED WARM FRONT SHOULD ALSO TRIGGER SCATTERED SHOWERS
FARTHER EAST THIS MORNING...FROM KIML NORTHEAST THROUGH KVTN AND THE
NAM TSTM PROBABILITY SUGGESTS SOME POTENTIAL FOR AN ISOLATED TSTM
EAST OF HIGHWAY 83. NOTE THE KGLD VWP IS FILLING UP WITH RETURNS
SUGGESTING MOISTURE IS ON THE INCREASE. THE MODELS CAPTURE THIS BUT
SHOW QUITE A SPREAD IN RAIN COVERAGE. SINCE THE RADAR REFLECTIVITY
PRODUCT IS FILLING UP ACROSS WRN THIS MORNING CONFIDENCE IS GOOD
THAT SOME RAIN WILL SPREAD THROUGH THE WRN HALF OF THE FCST AREA.
FARTHER EAST...ECHOS HAVE YET TO DEVELOP. THE SREF IS VERY GENEROUS
WITH THE RAINFALL COVERAGE WHILE THE RAP IS QUITE DRY SHOWING LITTLE
IN THE WAY OF QPF. A FULL MULTIMODEL BLEND WAS USED FOR POPS AND QPF
BUT STILL PRODUCES 1/10 OR AN INCH OR LESS RAINFALL THROUGHOUT THE
FCST AREA. EITHER WAY THE DISTURBANCE SHOULD LIFT THROUGH THE FCST
AREA THIS MORNING AND EXIT THE AREA BY LATE THIS AFTERNOON.
THE NEXT FEATURE IS THE HEAVILY ADVERTISED "CLEARING" FORECAST BY
ALL MODELS ACROSS WRN NEB THIS AFTERNOON. THERE IS VERY LITTLE SFC
FORCING TODAY AS WEAK HIGH PRESSURE AND TRAPPED MOISTURE WILL REMAIN
FROM THE FRONT RANGE EAST THROUGH THE FCST AREA. THE WPC KEEPS A
STATIONARY FRONT PINNED AGAINST THE FRONT RANGE TODAY AND TONIGHT
AND LIFTS THAT FRONT EAST OF THE FCST AREA THURSDAY MORNING ONCE THE
SFC LOW EJECTS NORTHEAST INTO THE UPPER MIDWEST.
THE FCST WILL ALLOW FOR SOME CLEARING WEST OF HIGHWAY 83 THIS
AFTERNOON BUT KEEPS SKIES CLOUDY THROUGHOUT THE DAY EAST OF HIGHWAY
83 WHICH IS VERY CLOSE TO THE RAP MODEL. FOR TONIGHT...THERE IS NO
CHOICE BUT TO BLEND A MULTIMODEL SOLN FOR CLEARING SKIES WITH ONE
CAVEAT. THE NAM12 VISIBILITY PRODUCT AND MODEL SOUNDINGS SHOW A FOG
BANK SPREADING SOUTH INTO THE FCST AREA AFTER MIDNIGHT. THE FOG
SHOULD SPREAD TO NEAR NEBRASKA HIGHWAY 2 BUT NO FURTHER SOUTH. GIVEN
THE PROPENSITY FOR THE NAM TO USE FORECAST SNOWFALL TO GENERATE
SPURIOUS BOUNDARY LAYER MOISTURE THE CONFIDENCE IN FOG DEVELOPMENT
IS LOW. FOR NOW WILL JUST MENTION PATCHY FOG ACROSS THE NORTH.
OTHERWISE THE FORECAST CALLS FOR LIGHT WINDS TODAY AND TONIGHT WITH
HIGHS IN THE 40S TO AROUND 50 AND LOWS TONIGHT IN THE UPPER 20S TO
LOWER 30S. THE FCST HIGHS TODAY ARE COOLER THAN THE GUIDANCE WHILE
TONIGHTS LOWS ARE SLIGHTLY WARMER TO ACCOMMODATE COLD AIR DAMMING
AND TRAPPED MOISTURE.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 331 AM CDT WED OCT 30 2013
THIS PERIOD BEGINS WITH THE UPPER LEVEL SYSTEM NOW OVER THE
INTER-MOUNTAIN WEST TO FINALLY BE MOVING THROUGH THE PLAINS. BY 00Z
FRIDAY...MODELS ARE IN GOOD AGREEMENT THAT THE TROUGH AXIS WILL BE
EAST OF THE AREA AND MOVING INTO THE MISSISSIPPI RIVER VALLEY. THIS
WILL LEAD THE REGION INTO NORTHWEST FLOW WITH THE NEXT SHORTWAVE
TROUGH LOOKING TO MOVE OUT OF ALBERTA AND INTO MONTANA THURSDAY
NIGHT. MEANWHILE...THE RIDGE WILL BE PLACED OVER THE WEST
COAST...WITH TROPICAL STORM RAYMOND WEST OF BAJA CALIFORNIA
WEAKENING...WHILE ONLY MOVING MINIMALLY.
THURSDAY HAS A DECENT SET-UP FOR SOME WINDY CONDITIONS AS AN UPPER
LEVEL VORTICITY MAXIMUM MOVES ACROSS NEBRASKA...WHILE ALSO
CONCURRENTLY EXPECTING GOOD COLD AIR ADVECTION AND SUBSIDENCE IN THE
SFC TO 500MB LAYER. PRESSURE GRADIENT ISN/T REAL TIGHT SO SHOULD BE MORE
OF A SITUATION WITH WINDS MIXING DOWN RATHER THAN STRONG GRADIENT
WINDS. SOUNDINGS ARE SHOWING PRETTY STEEP LAPSE RATES IN THE MIXED
LAYER WHICH TOPS OUT AROUND 800MB ACROSS MUCH OF THE FORECAST
AREA...A BIT HIGHER ACROSS THE WESTERN ARES. MAX WINDS IN THE MIXED
LAYER ARE 30-35KT SO EXPECT GUSTS FROM TIME TO TIME UP TO 35 MPH.
ALTHOUGH GOOD SUNSHINE IS EXPECTED...WILL STILL HAVE NEAR TO BELOW
NORMAL TEMPERATURES FOR MUCH OF THE AREA DUE TO THE COLDER AIR
MOVING IN BEHIND THE SYSTEM AS 850MB TEMPERATURES GENERALLY STAY IN
THE 0C TO 5C RANGE.
THE NEXT SHORTWAVE PUSHES OUT OF CANADA AND INTO THE CENTRAL PLAINS
ON FRIDAY WHICH WILL BRING SIMILAR CONDITIONS TO THURSDAY. THE
SURFACE PRESSURE GRADIENT IS SLIGHTLY TIGHTER THAN ON THURSDAY...AND
WHILE THERE ISN/T AS STRONG OF A MID LEVEL VORTICITY MAX MOVING
ACROSS THE AREA...SUBSIDENCE AND COLD AIR ADVECTION BELOW 500MB
REMAINS STRONG AND WINDS ABOVE THE SURFACE ARE A BIT STRONGER AS
850MB WINDS ARE LOOKING TO BE 30KTS TO 40KTS. SO AGAIN EXPECTING A
BREEZY DAY WITH GUSTS UP TO 35 MPH TO 40 MPH AT TIMES. ALSO...WITH A
REINFORCING SHOT OF COLDER AIR COMING SOUTHWARD BEHIND THIS
SYSTEM...AGAIN LOOKING FOR NEAR TO BELOW NORMAL TEMPERATURES FOR
FRIDAY. A FEW OF THE MODELS ARE DEVELOPING SOME PRECIPITATION FRIDAY
AFTERNOON...HOWEVER WITH LIFT AND MOISTURE LACKING...FELT KEEPING
THE FORECAST DRY WAS THE WAY TO GO AT THIS TIME.
RIDGING BUILDS IN FOR THE WEEKEND AS THE LONGWAVE TROUGH MIGRATES
TOWARDS THE EAST COAST AND ANOTHER LOW PRESSURE SYSTEM MOVES INTO
THE PACIFIC NORTHWEST. MODELS ARE ALSO IN FAIR AGREEMENT THAT
THE REMNANTS OF TROPICAL STORM RAYMOND WILL FINALLY MOVE EAST FAR
ENOUGH TO GET CAUGHT UP IN THE MAIN FLOW. CURRENT TIMING FROM
MODEL SOLUTIONS WILL KEEP THE GOOD WARM AIR FROM MOVING INTO THE
FORECAST AREA UNTIL SATURDAY NIGHT...SO CURRENTLY EXPECTING SUNDAY
TO BE THE WARMEST DAY OF THE WEEK.
AS THE PACIFIC NORTHWEST SYSTEM MOVES INLAND THROUGH THE FIRST
PART OF THE WEEK...PLENTIFUL MODEL DIFFERENCES COME INTO PLAY. THE
GFS IS MUCH FASTER PUSHING THE TROUGH ACROSS THE CONUS...WHILE THE
ECMWF AND GEM ARE QUITE A BIT SLOWER. USED A CONSENSUS APPROACH
FOR THE FORECAST FOR THESE PERIODS...HOWEVER RELYING A BIT HEAVIER
ON THE SLOWER SOLUTIONS. THIS WILL BRING RAIN CHANCES TO THE
FORECAST AREA FOR MONDAY THROUGH TUESDAY. THIS BEING SAID...THERE
ISN/T A GREAT DEAL OF MOISTURE ASSOCIATED WITH THE FRONT MOVING
THROUGH...AND ALTHOUGH REMNANTS OF TROPICAL STORM RAYMOND WILL
ALSO HAVE MADE IT TO ON-LAND...THE UPPER LEVEL JET IS SPLIT...WHICH
WILL KEEP A MAJORITY OF THE MOISTURE ASSOCIATED WITH IT ACROSS THE
SOUTHERN STATES.
ALSO...WITH EITHER MODEL SOLUTION TEMPERATURES WILL AGAIN BE QUITE
A BIT COOLER FOR THE FIRST HALF OF THE WORK WEEK. ON BOTH MONDAY
AND TUESDAY...IF PRECIPITATION IS INDEED ONGOING MAY ONLY SEE
HIGHS IN THE 30S TO LOW 40S IN PLACES. IN TERMS OF PRECIPITATION
TYPE WITH THE COLDER AIR BEING INGESTED INTO THE SYSTEM...BELIEVE
ANYTHING WILL START AS RAIN...BUT SHOULD CHANGE TO A RAIN/SNOW
MIX...THEN TO SNOW...BUT BY TUESDAY AFTERNOON ONLY RAIN IS
EXPECTED AS THE SYSTEM PUSHES EAST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1247 PM CDT WED OCT 30 2013
WARMING AND DRYING CONDITIONS ALOFT WILL PROVIDE FOR IMPROVING
FLIGHT CONDITIONS LATE THIS AFTERNOON. THE CLEARING LINE IS JUST
WEST OF KOGA AND KIML AT THIS HOUR /18Z/...WITH NEAR TERM GUIDANCE
INDICATING AT LEAST PARTIAL CLEARING AT KVTN AND KLBF AOA 20Z.
OTHERWISE CLEARING SKIES OVERNIGHT MAY GIVE WAY TO PATCHY FOG
AND/OR STRATUS DEVELOPMENT AT KVTN EARLY THURSDAY. CONFIDENCE IS
LOW AS THE FORECAST MODELS MAY BE OVER SATURATING THE LOWER
LEVELS...THUS WILL LOWER CEILINGS AT KVTN TO IFR...BUT NOT ANY
LOWER AND UPDATE IF NEEDED. WIND SPEEDS AT THE END OF THE TAF
PERIOD WILL BECOME GUSTY...WITH 20KTS OR GREATER POSSIBLE BY 18Z
THURSDAY FOR ALL WESTERN AND NORTH CENTRAL NEBRASKA FLIGHT
TERMINALS.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JACOBS
SHORT TERM...CDC
LONG TERM...BROOKS
AVIATION...JACOBS
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1232 PM CDT WED OCT 30 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 408 AM CDT WED OCT 30 2013
ALOFT: THE FLOW REMAINS SW BETWEEN THE CUT-OFF LOW OVER THE
INTERMOUNTAIN W AND A RIDGE OVER THE MS VALLEY. WATER VAPOR
IMAGERY SHOWED A POTENT SHORTWAVE TROF OVER CO MOVING NE. THE
LOW WILL OPEN UP AND BECOME MOBILE TODAY-TONIGHT AS A RIDGE
BUILDS OVER THE E PACIFIC. THE REMNANTS WILL MOVE THRU HERE AS
A POSITIVE TILT TROF THU. IN THE MEANTIME...THE TAIL OF THE
UPSTREAM SHORTWAVE TROF WILL MOVE THRU THIS MORNING.
SURFACE: A WEAK BUT WELL-DEFINED 1013 MB LOW WAS OVER THE SE
CORNER OF NEB AND MOVING AWAY. THE STALLED FRONT HAS PIVOTED
CYCLONICALLY AS THIS LOW MOVED BY AND IN ITS WAKE THE FRONT IS
NOW DOWN TO THE TX/OK PANHANDLES. A NEW LEE-SIDE LOW WAS NEAR
PUEBLO. THIS LOW WILL REMAIN ANCHORED TO THE PUEBLO AREA...BUT
LIKELY SHED MULTIPLE WEAK LOWS UP THE FRONT. THE FRONT WILL
REMAIN STATIONARY TODAY...BUT THEN SINK SE TONIGHT AS ONE OF
THESE LOWS DEEPENS OVER IA AND HEADS FOR THE GREAT LAKES.
EARLY THIS MORNING: THE LOW-LEVEL JET HAS DEVELOPED AND
STRENGTHENED TO 35 KTS IN RESPONSE TO THE APPROACHING TROF.
HOWEVER...THE 00Z DODGE CITY SOUNDING WAS VERY WARM AND DRY /+18
AT 850 MB WITH A 37C DEWPOINT DEPRESSION/. THE N PLATTE SOUNDING
HAD A PRONOUNCED WARM NOSE AT 700 MB. THE SYNOPTIC AND MESOSCALE
MODELS HAVE BEEN INSISTENT ON DEVELOPING SHWRS/TSTMS OVERNIGHT.
NOTHING DEVELOPED UNTIL 08Z OVER NE KS. WE ARE FINALLY STARTING
TO SEE INCREASING RETURNS OVER SW NEBRASKA...BUT THEY APPEAR
STRONGLY FORCED IN AN AREA OF STABILITY.
THE 07Z HI-RES RAP SUGGESTS THIS AREA COULD EXPAND A LITTLE AND
THAT COULD BE IT AS IT RACES NE OUT OF THE FCST AREA BY 13Z. ALL
THAT WOULD BE LEFT IS A FEW SHWRS FOR N-CNTRL KS AND POSSIBLY SOME
REDEVELOPMENT FROM HEBRON-BELOIT LATE THIS AFTERNOON. THAT LEAVES
MOST OF THE DAY CLOUDY AND QUITE WITH PATCHY FOG.
TODAY: CLOUDY AND CHILLY. LOW-LEVEL MOISTURE IS FCST TO INCREASE
WHICH COULD LEAD TO MORE DRIZZLE. OTHERWISE JUST A CHANCE FOR A
BRIEF SHWR OR TWO...AND POSSIBLY A THUNDERSTORM.
HIGH TEMPS WERE HEAVILY WEIGHTED TOWARD CURRENT TEMPS BLENDED
WITH THE 18Z AND 00Z NAM 2M TEMPS TO NUDGE TEMPS UP JUST A LITTLE
FROM CURRENT VALUES.
MODELS ARE UNANIMOUS IN DECREASING CLOUDS FROM THE NW THIS
AFTERNOON. THIS IS A TOUGH PROPOSITION WHEN THERE ARE NO CLEAR
SKIES ANYWHERE AROUND...BUT BASED ON THE PASSAGE OF THE 850 MB
TROF/FRONT...DECREASING CLOUDS SEEMS REASONABLE TONIGHT.
THUNDER: BASED ON SREF MUCAPE OF 500-900 J/KG...A MENTION OF SMALL
HAIL HAS BEEN INCLUDED IN THE HWO. PART OF MITCHELL COUNTY KS IS
OUTLOOKED FOR SVR TSTMS IN THE DAY 1 OUTLOOK FOR A VERY LOW
PROBABILITY OF 1" HAIL.
TONIGHT: WENT WITH DECREASING CLOUDS BUT THE UPPER TROF WILL
STILL BE TO THE W. SO AM NOT EXPECTING SKIES TO CLEAR COMPLETELY.
AM SOMEWHAT CONCERNED ABOUT FOG REDEVELOPMENT TONIGHT. IT APPEARS
MOISTURE ABOVE THE BOUNDARY LAYER WILL BE WHISKED AWAY BY NW
WINDS. HOWEVER...WINDS WILL BECOME LIGHT/CALM. FOR NOW AM
EXPECTING NOT MUCH MORE THAN GROUND FOG WITH NO WORSE THAN MVFR
VISIBILITIES /3-5 MI/. LOW TEMPS WERE BASED ON BIAS CORRECTED GFS
MOS.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 408 AM CDT WED OCT 30 2013
GUIDANCE FROM THE NAM...OPERATIONAL GFS...EC...AND SREF-MEAN ALL
SUGGEST A MID TO UPPER LEVEL LONG WAVE TROUGH AXIS WILL EXTEND
FROM THE NORTHERN PLAINS INTO PORTIONS OF THE CENTRAL PLAINS AT
12Z THURSDAY...AND THIS TROUGH AXIS IS EXPECTED TO MOVE OFF TO
THE EAST OF OUR AREA THROUGH THE DAY THURSDAY. WITH THE TROUGH
MOVING EAST AND SUBSIDENCE SETTLING IN...CLEARING SKIES AND DRY
CONDITIONS SHOULD BE NOTED ACROSS THE AREA ON THURSDAY. AN
OVERALL LACK IN KINEMATIC FORCING IS ALSO EXPECTED TO PRESENT DRY
CONDITIONS TO THE AREA THURSDAY NIGHT THROUGH SUNDAY NIGHT.
MONDAY INTO TUESDAY...GUIDANCE FROM THE EC AND OPERATIONAL GFS
SUGGEST MID LEVEL THERMAL ADVECTION AHEAD OF AN APPROACHING
TROUGH IS EXPECTED TO PROMOTE PRECIPITATION PRODUCTION ACROSS
PORTIONS OF THE REGION. ALLBLEND RESPONDED BY PROVIDING POPS TO
THE AREA AND THESE POPS WERE LEFT UNCHANGED FOR THE MOST PART.
THE EC SUGGESTS THE LOWER TROPOSPHERE COULD BECOME COOL ENOUGH
FOR AT LEAST A RAIN/SNOW MIX MONDAY NIGHT INTO EARLY TUESDAY
MORNING ACROSS NORTHERN AND WESTERN PORTIONS OF OUR CWA...AND
SUCH AS BEEN PRESENTED IN THE OFFICIAL FORECAST.
LITTLE CHANGE IN THE LOW LEVEL AIRMASS SUGGESTS SIMILAR
TEMPERATURES WILL B E OBSERVED ACROSS THE AREA THURSDAY THROUGH
EARLY NEXT WEEK...WITH AFTERNOON HIGHS IN THE 50S AND 60S AND
OVERNIGHT LOWS IN THE 30S AND 40S FORECAST FOR THE MOST PART.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1227 PM CDT WED OCT 30 2013
LOW LEVEL STRATUS ACROSS THE AREA WILL CONTINUE TO BE THE PRIMARY
CONCERN THROUGH AT LEAST THE REST OF THE DAYTIME HOURS
TODAY...WITH CONFIDENCE IN THE TIMING OF THE CEILING HEIGHTS
IMPROVEMENT IS ON THE LOWER SIDE. OBS CONTINUE TO SHOW LIFR/IFR
CLOUD COVER...WHICH IS EXPECTED TO LINGER INTO THE MID/LATE
AFTERNOON...GRADUALLY IMPROVING TO MVFR...AND EVENTUALLY VFR BY
THE END OF THE TAF PERIOD. WINDS WILL REMAIN LIGHT THROUGH MOST OF
THE PERIOD WITH SURFACE HIGH PRESSURE IN THE AREA...WITH STRONGER
NORTHWEST WINDS MOVING IN BY MID/LATE MORNING TOMORROW ONCE THE
MAIN UPPER LEVEL TROUGH AXIS SWINGS THROUGH.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...HALBLAUB
LONG TERM...BRYANT
AVIATION...ADO
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
955 AM CDT WED OCT 30 2013
.UPDATE...
ISSUED AT 955 AM CDT WED OCT 30 2013
UPDATE TO THE FORECAST TO EXPIRE THE NORTHWEST NEBRASKA WINTER
WEATHER ADVISORY. TEMPERATURES ACROSS THE REGION /SAVE KVTN WHERE
THE CURRENT TEMP IS 0C/ HAVE RISEN ABOVE 0C AND PRECIPITATION IS
CURRENTLY HAVING DIFFICULTLY OVERCOMING DRY LAYERS IN THE LOWER
AND MID LEVELS. OTHERWISE THE FORECAST IS ON TRACK WITH NO OTHER
UPDATES NEEDED AT THIS TIME.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 331 AM CDT WED OCT 30 2013
A 700MB WARM FRONT...CURRENTLY ACROSS NORTHEAST COLORADO WILL
LIFT THROUGH THE PANHANDLE AND WRN NEB THIS MORNING TRIGGERING
RAIN AND FREEZING RAIN. THE WARM AIR ADVECTION IS QUITE
STRONG...NEAR 50 KT FROM 850MB TO 700MB ON THE KGLD RADAR AND
AROUND 40 KT ON THE KFTG RADAR. THIS SHOULD KEEP TEMPERATURES
ABOVE FREEZING 850MB TO 700MB AS INDICATED BY THE RAP MODEL. SFC
OBS ACROSS WRN NEB SUGGEST JUST SHERIDAN AND CHERRY COUNTIES COULD
GET FREEZING RAIN WHILE AREAS TO THE SOUTH UNDERGO WEAK SCOURING.
THIS ELEVATED WARM FRONT SHOULD ALSO TRIGGER SCATTERED SHOWERS
FARTHER EAST THIS MORNING...FROM KIML NORTHEAST THROUGH KVTN AND THE
NAM TSTM PROBABILITY SUGGESTS SOME POTENTIAL FOR AN ISOLATED TSTM
EAST OF HIGHWAY 83. NOTE THE KGLD VWP IS FILLING UP WITH RETURNS
SUGGESTING MOISTURE IS ON THE INCREASE. THE MODELS CAPTURE THIS BUT
SHOW QUITE A SPREAD IN RAIN COVERAGE. SINCE THE RADAR REFLECTIVITY
PRODUCT IS FILLING UP ACROSS WRN THIS MORNING CONFIDENCE IS GOOD
THAT SOME RAIN WILL SPREAD THROUGH THE WRN HALF OF THE FCST AREA.
FARTHER EAST...ECHOS HAVE YET TO DEVELOP. THE SREF IS VERY GENEROUS
WITH THE RAINFALL COVERAGE WHILE THE RAP IS QUITE DRY SHOWING LITTLE
IN THE WAY OF QPF. A FULL MULTIMODEL BLEND WAS USED FOR POPS AND QPF
BUT STILL PRODUCES 1/10 OR AN INCH OR LESS RAINFALL THROUGHOUT THE
FCST AREA. EITHER WAY THE DISTURBANCE SHOULD LIFT THROUGH THE FCST
AREA THIS MORNING AND EXIT THE AREA BY LATE THIS AFTERNOON.
THE NEXT FEATURE IS THE HEAVILY ADVERTISED "CLEARING" FORECAST BY
ALL MODELS ACROSS WRN NEB THIS AFTERNOON. THERE IS VERY LITTLE SFC
FORCING TODAY AS WEAK HIGH PRESSURE AND TRAPPED MOISTURE WILL REMAIN
FROM THE FRONT RANGE EAST THROUGH THE FCST AREA. THE WPC KEEPS A
STATIONARY FRONT PINNED AGAINST THE FRONT RANGE TODAY AND TONIGHT
AND LIFTS THAT FRONT EAST OF THE FCST AREA THURSDAY MORNING ONCE THE
SFC LOW EJECTS NORTHEAST INTO THE UPPER MIDWEST.
THE FCST WILL ALLOW FOR SOME CLEARING WEST OF HIGHWAY 83 THIS
AFTERNOON BUT KEEPS SKIES CLOUDY THROUGHOUT THE DAY EAST OF HIGHWAY
83 WHICH IS VERY CLOSE TO THE RAP MODEL. FOR TONIGHT...THERE IS NO
CHOICE BUT TO BLEND A MULTIMODEL SOLN FOR CLEARING SKIES WITH ONE
CAVEAT. THE NAM12 VISIBILITY PRODUCT AND MODEL SOUNDINGS SHOW A FOG
BANK SPREADING SOUTH INTO THE FCST AREA AFTER MIDNIGHT. THE FOG
SHOULD SPREAD TO NEAR NEBRASKA HIGHWAY 2 BUT NO FURTHER SOUTH. GIVEN
THE PROPENSITY FOR THE NAM TO USE FORECAST SNOWFALL TO GENERATE
SPURIOUS BOUNDARY LAYER MOISTURE THE CONFIDENCE IN FOG DEVELOPMENT
IS LOW. FOR NOW WILL JUST MENTION PATCHY FOG ACROSS THE NORTH.
OTHERWISE THE FORECAST CALLS FOR LIGHT WINDS TODAY AND TONIGHT WITH
HIGHS IN THE 40S TO AROUND 50 AND LOWS TONIGHT IN THE UPPER 20S TO
LOWER 30S. THE FCST HIGHS TODAY ARE COOLER THAN THE GUIDANCE WHILE
TONIGHTS LOWS ARE SLIGHTLY WARMER TO ACCOMMODATE COLD AIR DAMMING
AND TRAPPED MOISTURE.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 331 AM CDT WED OCT 30 2013
THIS PERIOD BEGINS WITH THE UPPER LEVEL SYSTEM NOW OVER THE
INTER-MOUNTAIN WEST TO FINALLY BE MOVING THROUGH THE PLAINS. BY 00Z
FRIDAY...MODELS ARE IN GOOD AGREEMENT THAT THE TROUGH AXIS WILL BE
EAST OF THE AREA AND MOVING INTO THE MISSISSIPPI RIVER VALLEY. THIS
WILL LEAD THE REGION INTO NORTHWEST FLOW WITH THE NEXT SHORTWAVE
TROUGH LOOKING TO MOVE OUT OF ALBERTA AND INTO MONTANA THURSDAY
NIGHT. MEANWHILE...THE RIDGE WILL BE PLACED OVER THE WEST
COAST...WITH TROPICAL STORM RAYMOND WEST OF BAJA CALIFORNIA
WEAKENING...WHILE ONLY MOVING MINIMALLY.
THURSDAY HAS A DECENT SET-UP FOR SOME WINDY CONDITIONS AS AN UPPER
LEVEL VORTICITY MAXIMUM MOVES ACROSS NEBRASKA...WHILE ALSO
CONCURRENTLY EXPECTING GOOD COLD AIR ADVECTION AND SUBSIDENCE IN THE
SFC TO 500MB LAYER. PRESSURE GRADIENT ISN/T REAL TIGHT SO SHOULD BE MORE
OF A SITUATION WITH WINDS MIXING DOWN RATHER THAN STRONG GRADIENT
WINDS. SOUNDINGS ARE SHOWING PRETTY STEEP LAPSE RATES IN THE MIXED
LAYER WHICH TOPS OUT AROUND 800MB ACROSS MUCH OF THE FORECAST
AREA...A BIT HIGHER ACROSS THE WESTERN ARES. MAX WINDS IN THE MIXED
LAYER ARE 30-35KT SO EXPECT GUSTS FROM TIME TO TIME UP TO 35 MPH.
ALTHOUGH GOOD SUNSHINE IS EXPECTED...WILL STILL HAVE NEAR TO BELOW
NORMAL TEMPERATURES FOR MUCH OF THE AREA DUE TO THE COLDER AIR
MOVING IN BEHIND THE SYSTEM AS 850MB TEMPERATURES GENERALLY STAY IN
THE 0C TO 5C RANGE.
THE NEXT SHORTWAVE PUSHES OUT OF CANADA AND INTO THE CENTRAL PLAINS
ON FRIDAY WHICH WILL BRING SIMILAR CONDITIONS TO THURSDAY. THE
SURFACE PRESSURE GRADIENT IS SLIGHTLY TIGHTER THAN ON THURSDAY...AND
WHILE THERE ISN/T AS STRONG OF A MID LEVEL VORTICITY MAX MOVING
ACROSS THE AREA...SUBSIDENCE AND COLD AIR ADVECTION BELOW 500MB
REMAINS STRONG AND WINDS ABOVE THE SURFACE ARE A BIT STRONGER AS
850MB WINDS ARE LOOKING TO BE 30KTS TO 40KTS. SO AGAIN EXPECTING A
BREEZY DAY WITH GUSTS UP TO 35 MPH TO 40 MPH AT TIMES. ALSO...WITH A
REINFORCING SHOT OF COLDER AIR COMING SOUTHWARD BEHIND THIS
SYSTEM...AGAIN LOOKING FOR NEAR TO BELOW NORMAL TEMPERATURES FOR
FRIDAY. A FEW OF THE MODELS ARE DEVELOPING SOME PRECIPITATION FRIDAY
AFTERNOON...HOWEVER WITH LIFT AND MOISTURE LACKING...FELT KEEPING
THE FORECAST DRY WAS THE WAY TO GO AT THIS TIME.
RIDGING BUILDS IN FOR THE WEEKEND AS THE LONGWAVE TROUGH MIGRATES
TOWARDS THE EAST COAST AND ANOTHER LOW PRESSURE SYSTEM MOVES INTO
THE PACIFIC NORTHWEST. MODELS ARE ALSO IN FAIR AGREEMENT THAT
THE REMNANTS OF TROPICAL STORM RAYMOND WILL FINALLY MOVE EAST FAR
ENOUGH TO GET CAUGHT UP IN THE MAIN FLOW. CURRENT TIMING FROM
MODEL SOLUTIONS WILL KEEP THE GOOD WARM AIR FROM MOVING INTO THE
FORECAST AREA UNTIL SATURDAY NIGHT...SO CURRENTLY EXPECTING SUNDAY
TO BE THE WARMEST DAY OF THE WEEK.
AS THE PACIFIC NORTHWEST SYSTEM MOVES INLAND THROUGH THE FIRST
PART OF THE WEEK...PLENTIFUL MODEL DIFFERENCES COME INTO PLAY. THE
GFS IS MUCH FASTER PUSHING THE TROUGH ACROSS THE CONUS...WHILE THE
ECMWF AND GEM ARE QUITE A BIT SLOWER. USED A CONSENSUS APPROACH
FOR THE FORECAST FOR THESE PERIODS...HOWEVER RELYING A BIT HEAVIER
ON THE SLOWER SOLUTIONS. THIS WILL BRING RAIN CHANCES TO THE
FORECAST AREA FOR MONDAY THROUGH TUESDAY. THIS BEING SAID...THERE
ISN/T A GREAT DEAL OF MOISTURE ASSOCIATED WITH THE FRONT MOVING
THROUGH...AND ALTHOUGH REMNANTS OF TROPICAL STORM RAYMOND WILL
ALSO HAVE MADE IT TO ON-LAND...THE UPPER LEVEL JET IS SPLIT...WHICH
WILL KEEP A MAJORITY OF THE MOISTURE ASSOCIATED WITH IT ACROSS THE
SOUTHERN STATES.
ALSO...WITH EITHER MODEL SOLUTION TEMPERATURES WILL AGAIN BE QUITE
A BIT COOLER FOR THE FIRST HALF OF THE WORK WEEK. ON BOTH MONDAY
AND TUESDAY...IF PRECIPITATION IS INDEED ONGOING MAY ONLY SEE
HIGHS IN THE 30S TO LOW 40S IN PLACES. IN TERMS OF PRECIPITATION
TYPE WITH THE COLDER AIR BEING INGESTED INTO THE SYSTEM...BELIEVE
ANYTHING WILL START AS RAIN...BUT SHOULD CHANGE TO A RAIN/SNOW
MIX...THEN TO SNOW...BUT BY TUESDAY AFTERNOON ONLY RAIN IS
EXPECTED AS THE SYSTEM PUSHES EAST.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 624 AM CDT WED OCT 30 2013
LARGE UNCERTAINTY WITH THIS FORECAST AS THE MODELS ARE SCOURING
OUT THE IFR/LIFR CIGS THIS MORNING WHICH COULD BE TOO FAST. THE
FORECAST KEEPS IFR/MVFR THROUGH 18Z WITH IMPROVEMENT TO VFR WEST
TO EAST DURING THE AFTERNOON. MVFR IS EXPECTED ALONG HIGHWAY 83
THIS AFTERNOON WITH IFR EAST OF HIGHWAY 83.
TONIGHT...THE NAM SUGGESTS FOG AND IFR/LIFR CIGS MAY DEVELOP ALONG
HIGHWAY 20 AFTER 06Z. THE CONCERN ELSEWHERE IS FOG OR
REDEVELOPMENT OF LOW CIGS.
NOTE THAT A CLEARING LINE IS DEVELOPING ACROSS ERN COLO THIS
MORNING AND THIS WILL BE CLOSELY TRACKED USING TIMING TOOLS TO
FORECAST THE IMPROVEMENT OF FLIGHT CONDITIONS AT KLBF AND KVTN.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JACOBS
SHORT TERM...CDC
LONG TERM...BROOKS
AVIATION...CDC
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
625 AM CDT WED OCT 30 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 331 AM CDT WED OCT 30 2013
A 700MB WARM FRONT...CURRENTLY ACROSS NORTHEAST COLORADO WILL
LIFT THROUGH THE PANHANDLE AND WRN NEB THIS MORNING TRIGGERING
RAIN AND FREEZING RAIN. THE WARM AIR ADVECTION IS QUITE
STRONG...NEAR 50 KT FROM 850MB TO 700MB ON THE KGLD RADAR AND
AROUND 40 KT ON THE KFTG RADAR. THIS SHOULD KEEP TEMPERATURES
ABOVE FREEZING 850MB TO 700MB AS INDICATED BY THE RAP MODEL. SFC
OBS ACROSS WRN NEB SUGGEST JUST SHERIDAN AND CHERRY COUNTIES COULD
GET FREEZING RAIN WHILE AREAS TO THE SOUTH UNDERGO WEAK SCOURING.
THIS ELEVATED WARM FRONT SHOULD ALSO TRIGGER SCATTERED SHOWERS
FARTHER EAST THIS MORNING...FROM KIML NORTHEAST THROUGH KVTN AND THE
NAM TSTM PROBABILITY SUGGESTS SOME POTENTIAL FOR AN ISOLATED TSTM
EAST OF HIGHWAY 83. NOTE THE KGLD VWP IS FILLING UP WITH RETURNS
SUGGESTING MOISTURE IS ON THE INCREASE. THE MODELS CAPTURE THIS BUT
SHOW QUITE A SPREAD IN RAIN COVERAGE. SINCE THE RADAR REFLECTIVITY
PRODUCT IS FILLING UP ACROSS WRN THIS MORNING CONFIDENCE IS GOOD
THAT SOME RAIN WILL SPREAD THROUGH THE WRN HALF OF THE FCST AREA.
FARTHER EAST...ECHOS HAVE YET TO DEVELOP. THE SREF IS VERY GENEROUS
WITH THE RAINFALL COVERAGE WHILE THE RAP IS QUITE DRY SHOWING LITTLE
IN THE WAY OF QPF. A FULL MULTIMODEL BLEND WAS USED FOR POPS AND QPF
BUT STILL PRODUCES 1/10 OR AN INCH OR LESS RAINFALL THROUGHOUT THE
FCST AREA. EITHER WAY THE DISTURBANCE SHOULD LIFT THROUGH THE FCST
AREA THIS MORNING AND EXIT THE AREA BY LATE THIS AFTERNOON.
THE NEXT FEATURE IS THE HEAVILY ADVERTISED "CLEARING" FORECAST BY
ALL MODELS ACROSS WRN NEB THIS AFTERNOON. THERE IS VERY LITTLE SFC
FORCING TODAY AS WEAK HIGH PRESSURE AND TRAPPED MOISTURE WILL REMAIN
FROM THE FRONT RANGE EAST THROUGH THE FCST AREA. THE WPC KEEPS A
STATIONARY FRONT PINNED AGAINST THE FRONT RANGE TODAY AND TONIGHT
AND LIFTS THAT FRONT EAST OF THE FCST AREA THURSDAY MORNING ONCE THE
SFC LOW EJECTS NORTHEAST INTO THE UPPER MIDWEST.
THE FCST WILL ALLOW FOR SOME CLEARING WEST OF HIGHWAY 83 THIS
AFTERNOON BUT KEEPS SKIES CLOUDY THROUGHOUT THE DAY EAST OF HIGHWAY
83 WHICH IS VERY CLOSE TO THE RAP MODEL. FOR TONIGHT...THERE IS NO
CHOICE BUT TO BLEND A MULTIMODEL SOLN FOR CLEARING SKIES WITH ONE
CAVEAT. THE NAM12 VISIBILITY PRODUCT AND MODEL SOUNDINGS SHOW A FOG
BANK SPREADING SOUTH INTO THE FCST AREA AFTER MIDNIGHT. THE FOG
SHOULD SPREAD TO NEAR NEBRASKA HIGHWAY 2 BUT NO FURTHER SOUTH. GIVEN
THE PROPENSITY FOR THE NAM TO USE FORECAST SNOWFALL TO GENERATE
SPURIOUS BOUNDARY LAYER MOISTURE THE CONFIDENCE IN FOG DEVELOPMENT
IS LOW. FOR NOW WILL JUST MENTION PATCHY FOG ACROSS THE NORTH.
OTHERWISE THE FORECAST CALLS FOR LIGHT WINDS TODAY AND TONIGHT WITH
HIGHS IN THE 40S TO AROUND 50 AND LOWS TONIGHT IN THE UPPER 20S TO
LOWER 30S. THE FCST HIGHS TODAY ARE COOLER THAN THE GUIDANCE WHILE
TONIGHTS LOWS ARE SLIGHTLY WARMER TO ACCOMMODATE COLD AIR DAMMING
AND TRAPPED MOISTURE.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 331 AM CDT WED OCT 30 2013
THIS PERIOD BEGINS WITH THE UPPER LEVEL SYSTEM NOW OVER THE
INTER-MOUNTAIN WEST TO FINALLY BE MOVING THROUGH THE PLAINS. BY 00Z
FRIDAY...MODELS ARE IN GOOD AGREEMENT THAT THE TROUGH AXIS WILL BE
EAST OF THE AREA AND MOVING INTO THE MISSISSIPPI RIVER VALLEY. THIS
WILL LEAD THE REGION INTO NORTHWEST FLOW WITH THE NEXT SHORTWAVE
TROUGH LOOKING TO MOVE OUT OF ALBERTA AND INTO MONTANA THURSDAY
NIGHT. MEANWHILE...THE RIDGE WILL BE PLACED OVER THE WEST
COAST...WITH TROPICAL STORM RAYMOND WEST OF BAJA CALIFORNIA
WEAKENING...WHILE ONLY MOVING MINIMALLY.
THURSDAY HAS A DECENT SET-UP FOR SOME WINDY CONDITIONS AS AN UPPER
LEVEL VORTICITY MAXIMUM MOVES ACROSS NEBRASKA...WHILE ALSO
CONCURRENTLY EXPECTING GOOD COLD AIR ADVECTION AND SUBSIDENCE IN THE
SFC TO 500MB LAYER. PRESSURE GRADIENT ISN/T REAL TIGHT SO SHOULD BE MORE
OF A SITUATION WITH WINDS MIXING DOWN RATHER THAN STRONG GRADIENT
WINDS. SOUNDINGS ARE SHOWING PRETTY STEEP LAPSE RATES IN THE MIXED
LAYER WHICH TOPS OUT AROUND 800MB ACROSS MUCH OF THE FORECAST
AREA...A BIT HIGHER ACROSS THE WESTERN ARES. MAX WINDS IN THE MIXED
LAYER ARE 30-35KT SO EXPECT GUSTS FROM TIME TO TIME UP TO 35 MPH.
ALTHOUGH GOOD SUNSHINE IS EXPECTED...WILL STILL HAVE NEAR TO BELOW
NORMAL TEMPERATURES FOR MUCH OF THE AREA DUE TO THE COLDER AIR
MOVING IN BEHIND THE SYSTEM AS 850MB TEMPERATURES GENERALLY STAY IN
THE 0C TO 5C RANGE.
THE NEXT SHORTWAVE PUSHES OUT OF CANADA AND INTO THE CENTRAL PLAINS
ON FRIDAY WHICH WILL BRING SIMILAR CONDITIONS TO THURSDAY. THE
SURFACE PRESSURE GRADIENT IS SLIGHTLY TIGHTER THAN ON THURSDAY...AND
WHILE THERE ISN/T AS STRONG OF A MID LEVEL VORTICITY MAX MOVING
ACROSS THE AREA...SUBSIDENCE AND COLD AIR ADVECTION BELOW 500MB
REMAINS STRONG AND WINDS ABOVE THE SURFACE ARE A BIT STRONGER AS
850MB WINDS ARE LOOKING TO BE 30KTS TO 40KTS. SO AGAIN EXPECTING A
BREEZY DAY WITH GUSTS UP TO 35 MPH TO 40 MPH AT TIMES. ALSO...WITH A
REINFORCING SHOT OF COLDER AIR COMING SOUTHWARD BEHIND THIS
SYSTEM...AGAIN LOOKING FOR NEAR TO BELOW NORMAL TEMPERATURES FOR
FRIDAY. A FEW OF THE MODELS ARE DEVELOPING SOME PRECIPITATION FRIDAY
AFTERNOON...HOWEVER WITH LIFT AND MOISTURE LACKING...FELT KEEPING
THE FORECAST DRY WAS THE WAY TO GO AT THIS TIME.
RIDGING BUILDS IN FOR THE WEEKEND AS THE LONGWAVE TROUGH MIGRATES
TOWARDS THE EAST COAST AND ANOTHER LOW PRESSURE SYSTEM MOVES INTO
THE PACIFIC NORTHWEST. MODELS ARE ALSO IN FAIR AGREEMENT THAT
THE REMNANTS OF TROPICAL STORM RAYMOND WILL FINALLY MOVE EAST FAR
ENOUGH TO GET CAUGHT UP IN THE MAIN FLOW. CURRENT TIMING FROM
MODEL SOLUTIONS WILL KEEP THE GOOD WARM AIR FROM MOVING INTO THE
FORECAST AREA UNTIL SATURDAY NIGHT...SO CURRENTLY EXPECTING SUNDAY
TO BE THE WARMEST DAY OF THE WEEK.
AS THE PACIFIC NORTHWEST SYSTEM MOVES INLAND THROUGH THE FIRST
PART OF THE WEEK...PLENTIFUL MODEL DIFFERENCES COME INTO PLAY. THE
GFS IS MUCH FASTER PUSHING THE TROUGH ACROSS THE CONUS...WHILE THE
ECMWF AND GEM ARE QUITE A BIT SLOWER. USED A CONSENSUS APPROACH
FOR THE FORECAST FOR THESE PERIODS...HOWEVER RELYING A BIT HEAVIER
ON THE SLOWER SOLUTIONS. THIS WILL BRING RAIN CHANCES TO THE
FORECAST AREA FOR MONDAY THROUGH TUESDAY. THIS BEING SAID...THERE
ISN/T A GREAT DEAL OF MOISTURE ASSOCIATED WITH THE FRONT MOVING
THROUGH...AND ALTHOUGH REMNANTS OF TROPICAL STORM RAYMOND WILL
ALSO HAVE MADE IT TO ON-LAND...THE UPPER LEVEL JET IS SPLIT...WHICH
WILL KEEP A MAJORITY OF THE MOISTURE ASSOCIATED WITH IT ACROSS THE
SOUTHERN STATES.
ALSO...WITH EITHER MODEL SOLUTION TEMPERATURES WILL AGAIN BE QUITE
A BIT COOLER FOR THE FIRST HALF OF THE WORK WEEK. ON BOTH MONDAY
AND TUESDAY...IF PRECIPITATION IS INDEED ONGOING MAY ONLY SEE
HIGHS IN THE 30S TO LOW 40S IN PLACES. IN TERMS OF PRECIPITATION
TYPE WITH THE COLDER AIR BEING INGESTED INTO THE SYSTEM...BELIEVE
ANYTHING WILL START AS RAIN...BUT SHOULD CHANGE TO A RAIN/SNOW
MIX...THEN TO SNOW...BUT BY TUESDAY AFTERNOON ONLY RAIN IS
EXPECTED AS THE SYSTEM PUSHES EAST.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 624 AM CDT WED OCT 30 2013
LARGE UNCERTAINTY WITH THIS FORECAST AS THE MODELS ARE SCOURING
OUT THE IFR/LIFR CIGS THIS MORNING WHICH COULD BE TOO FAST. THE
FORECAST KEEPS IFR/MVFR THROUGH 18Z WITH IMPROVEMENT TO VFR WEST
TO EAST DURING THE AFTERNOON. MVFR IS EXPECTED ALONG HIGHWAY 83
THIS AFTERNOON WITH IFR EAST OF HIGHWAY 83.
TONIGHT...THE NAM SUGGESTS FOG AND IFR/LIFR CIGS MAY DEVELOP ALONG
HIGHWAY 20 AFTER 06Z. THE CONCERN ELSEWHERE IS FOG OR
REDEVELOPMENT OF LOW CIGS.
NOTE THAT A CLEARING LINE IS DEVELOPING ACROSS ERN COLO THIS
MORNING AND THIS WILL BE CLOSELY TRACKED USING TIMING TOOLS TO
FORECAST THE IMPROVEMENT OF FLIGHT CONDITIONS AT KLBF AND KVTN.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL NOON CDT /11 AM MDT/ TODAY FOR
NEZ004-005-094.
&&
$$
SHORT TERM...CDC
LONG TERM...BROOKS
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS HASTINGS NE
409 AM CDT WED OCT 30 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 408 AM CDT WED OCT 30 2013
ALOFT: THE FLOW REMAINS SW BETWEEN THE CUT-OFF LOW OVER THE
INTERMOUNTAIN W AND A RIDGE OVER THE MS VALLEY. WATER VAPOR
IMAGERY SHOWED A POTENT SHORTWAVE TROF OVER CO MOVING NE. THE
LOW WILL OPEN UP AND BECOME MOBILE TODAY-TONIGHT AS A RIDGE
BUILDS OVER THE E PACIFIC. THE REMNANTS WILL MOVE THRU HERE AS
A POSITIVE TILT TROF THU. IN THE MEANTIME...THE TAIL OF THE
UPSTREAM SHORTWAVE TROF WILL MOVE THRU THIS MORNING.
SURFACE: A WEAK BUT WELL-DEFINED 1013 MB LOW WAS OVER THE SE
CORNER OF NEB AND MOVING AWAY. THE STALLED FRONT HAS PIVOTED
CYCLONICALLY AS THIS LOW MOVED BY AND IN ITS WAKE THE FRONT IS
NOW DOWN TO THE TX/OK PANHANDLES. A NEW LEE-SIDE LOW WAS NEAR
PUEBLO. THIS LOW WILL REMAIN ANCHORED TO THE PUEBLO AREA...BUT
LIKELY SHED MULTIPLE WEAK LOWS UP THE FRONT. THE FRONT WILL
REMAIN STATIONARY TODAY...BUT THEN SINK SE TONIGHT AS ONE OF
THESE LOWS DEEPENS OVER IA AND HEADS FOR THE GREAT LAKES.
EARLY THIS MORNING: THE LOW-LEVEL JET HAS DEVELOPED AND
STRENGTHENED TO 35 KTS IN RESPONSE TO THE APPROACHING TROF.
HOWEVER...THE 00Z DODGE CITY SOUNDING WAS VERY WARM AND DRY /+18
AT 850 MB WITH A 37C DEWPOINT DEPRESSION/. THE N PLATTE SOUNDING
HAD A PRONOUNCED WARM NOSE AT 700 MB. THE SYNOPTIC AND MESOSCALE
MODELS HAVE BEEN INSISTENT ON DEVELOPING SHWRS/TSTMS OVERNIGHT.
NOTHING DEVELOPED UNTIL 08Z OVER NE KS. WE ARE FINALLY STARTING
TO SEE INCREASING RETURNS OVER SW NEBRASKA...BUT THEY APPEAR
STRONGLY FORCED IN AN AREA OF STABILITY.
THE 07Z HI-RES RAP SUGGESTS THIS AREA COULD EXPAND A LITTLE AND
THAT COULD BE IT AS IT RACES NE OUT OF THE FCST AREA BY 13Z. ALL
THAT WOULD BE LEFT IS A FEW SHWRS FOR N-CNTRL KS AND POSSIBLY SOME
REDEVELOPMENT FROM HEBRON-BELOIT LATE THIS AFTERNOON. THAT LEAVES
MOST OF THE DAY CLOUDY AND QUITE WITH PATCHY FOG.
TODAY: CLOUDY AND CHILLY. LOW-LEVEL MOISTURE IS FCST TO INCREASE
WHICH COULD LEAD TO MORE DRIZZLE. OTHERWISE JUST A CHANCE FOR A
BRIEF SHWR OR TWO...AND POSSIBLY A THUNDERSTORM.
HIGH TEMPS WERE HEAVILY WEIGHTED TOWARD CURRENT TEMPS BLENDED
WITH THE 18Z AND 00Z NAM 2M TEMPS TO NUDGE TEMPS UP JUST A LITTLE
FROM CURRENT VALUES.
MODELS ARE UNANIMOUS IN DECREASING CLOUDS FROM THE NW THIS
AFTERNOON. THIS IS A TOUGH PROPOSITION WHEN THERE ARE NO CLEAR
SKIES ANYWHERE AROUND...BUT BASED ON THE PASSAGE OF THE 850 MB
TROF/FRONT...DECREASING CLOUDS SEEMS REASONABLE TONIGHT.
THUNDER: BASED ON SREF MUCAPE OF 500-900 J/KG...A MENTION OF SMALL
HAIL HAS BEEN INCLUDED IN THE HWO. PART OF MITCHELL COUNTY KS IS
OUTLOOKED FOR SVR TSTMS IN THE DAY 1 OUTLOOK FOR A VERY LOW
PROBABILITY OF 1" HAIL.
TONIGHT: WENT WITH DECREASING CLOUDS BUT THE UPPER TROF WILL
STILL BE TO THE W. SO AM NOT EXPECTING SKIES TO CLEAR COMPLETELY.
AM SOMEWHAT CONCERNED ABOUT FOG REDEVELOPMENT TONIGHT. IT APPEARS
MOISTURE ABOVE THE BOUNDARY LAYER WILL BE WHISKED AWAY BY NW
WINDS. HOWEVER...WINDS WILL BECOME LIGHT/CALM. FOR NOW AM
EXPECTING NOT MUCH MORE THAN GROUND FOG WITH NO WORSE THAN MVFR
VISIBILITIES /3-5 MI/. LOW TEMPS WERE BASED ON BIAS CORRECTED GFS
MOS.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 408 AM CDT WED OCT 30 2013
GUIDANCE FROM THE NAM...OPERATIONAL GFS...EC...AND SREF-MEAN ALL
SUGGEST A MID TO UPPER LEVEL LONG WAVE TROUGH AXIS WILL EXTEND
FROM THE NORTHERN PLAINS INTO PORTIONS OF THE CENTRAL PLAINS AT
12Z THURSDAY...AND THIS TROUGH AXIS IS EXPECTED TO MOVE OFF TO
THE EAST OF OUR AREA THROUGH THE DAY THURSDAY. WITH THE TROUGH
MOVING EAST AND SUBSIDENCE SETTLING IN...CLEARING SKIES AND DRY
CONDITIONS SHOULD BE NOTED ACROSS THE AREA ON THURSDAY. AN
OVERALL LACK IN KINEMATIC FORCING IS ALSO EXPECTED TO PRESENT DRY
CONDITIONS TO THE AREA THURSDAY NIGHT THROUGH SUNDAY NIGHT.
MONDAY INTO TUESDAY...GUIDANCE FROM THE EC AND OPERATIONAL GFS
SUGGEST MID LEVEL THERMAL ADVECTION AHEAD OF AN APPROACHING
TROUGH IS EXPECTED TO PROMOTE PRECIPITATION PRODUCTION ACROSS
PORTIONS OF THE REGION. ALLBLEND RESPONDED BY PROVIDING POPS TO
THE AREA AND THESE POPS WERE LEFT UNCHANGED FOR THE MOST PART.
THE EC SUGGESTS THE LOWER TROPOSPHERE COULD BECOME COOL ENOUGH
FOR AT LEAST A RAIN/SNOW MIX MONDAY NIGHT INTO EARLY TUESDAY
MORNING ACROSS NORTHERN AND WESTERN PORTIONS OF OUR CWA...AND
SUCH AS BEEN PRESENTED IN THE OFFICIAL FORECAST.
LITTLE CHANGE IN THE LOW LEVEL AIRMASS SUGGESTS SIMILAR
TEMPERATURES WILL B E OBSERVED ACROSS THE AREA THURSDAY THROUGH
EARLY NEXT WEEK...WITH AFTERNOON HIGHS IN THE 50S AND 60S AND
OVERNIGHT LOWS IN THE 30S AND 40S FORECAST FOR THE MOST PART.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1256 AM CDT WED OCT 30 2013
REST OF TONIGHT: IFR CIGS AND CURRENTLY VFR VSBY ARE EXPECTED TO
DECAY TOWARD DAWN. AN ISOLATED SHWR OR TSTM IS POSSIBLE LATE. N
WINDS WITH DECREASE AND BECOME VARIABLE.
WED: HAVE THE HIGHEST CONFIDENCE IN IFR CIGS CONTINUING...BUT VSBY
IS AN UNKNOWN. SOME LATE DAY IMPROVEMENT IS POSSIBLE. LIGHT AND
VARIABLE WINDS SHOULD ORGANIZE FROM THE NNW AT LESS THAN 10 KTS.
WED EVENING: UNCERTAIN. BUT LIGHT PRES GRADIENT AND REMAINING LOW-
LEVEL MOISTURE THREATEN THE REDEVELOPMENT OF FOR/STRATUS.
CIG CONFIDENCE: MEDIUM
VSBY CONFIDENCE: VERY LOW
WIND CONFIDENCE: HIGH
WX CONFIDENCE: MEDIUM
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...HALBLAUB
LONG TERM...BRYANT
AVIATION...HALBLAUB
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
332 AM CDT WED OCT 30 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 331 AM CDT WED OCT 30 2013
A 700MB WARM FRONT...CURRENTLY ACROSS NORTHEAST COLORADO WILL
LIFT THROUGH THE PANHANDLE AND WRN NEB THIS MORNING TRIGGERING
RAIN AND FREEZING RAIN. THE WARM AIR ADVECTION IS QUITE
STRONG...NEAR 50 KT FROM 850MB TO 700MB ON THE KGLD RADAR AND
AROUND 40 KT ON THE KFTG RADAR. THIS SHOULD KEEP TEMPERATURES
ABOVE FREEZING 850MB TO 700MB AS INDICATED BY THE RAP MODEL. SFC
OBS ACROSS WRN NEB SUGGEST JUST SHERIDAN AND CHERRY COUNTIES COULD
GET FREEZING RAIN WHILE AREAS TO THE SOUTH UNDERGO WEAK SCOURING.
THIS ELEVATED WARM FRONT SHOULD ALSO TRIGGER SCATTERED SHOWERS
FARTHER EAST THIS MORNING...FROM KIML NORTHEAST THROUGH KVTN AND THE
NAM TSTM PROBABILITY SUGGESTS SOME POTENTIAL FOR AN ISOLATED TSTM
EAST OF HIGHWAY 83. NOTE THE KGLD VWP IS FILLING UP WITH RETURNS
SUGGESTING MOISTURE IS ON THE INCREASE. THE MODELS CAPTURE THIS BUT
SHOW QUITE A SPREAD IN RAIN COVERAGE. SINCE THE RADAR REFLECTIVITY
PRODUCT IS FILLING UP ACROSS WRN THIS MORNING CONFIDENCE IS GOOD
THAT SOME RAIN WILL SPREAD THROUGH THE WRN HALF OF THE FCST AREA.
FARTHER EAST...ECHOS HAVE YET TO DEVELOP. THE SREF IS VERY GENEROUS
WITH THE RAINFALL COVERAGE WHILE THE RAP IS QUITE DRY SHOWING LITTLE
IN THE WAY OF QPF. A FULL MULTIMODEL BLEND WAS USED FOR POPS AND QPF
BUT STILL PRODUCES 1/10 OR AN INCH OR LESS RAINFALL THROUGHOUT THE
FCST AREA. EITHER WAY THE DISTURBANCE SHOULD LIFT THROUGH THE FCST
AREA THIS MORNING AND EXIT THE AREA BY LATE THIS AFTERNOON.
THE NEXT FEATURE IS THE HEAVILY ADVERTISED "CLEARING" FORECAST BY
ALL MODELS ACROSS WRN NEB THIS AFTERNOON. THERE IS VERY LITTLE SFC
FORCING TODAY AS WEAK HIGH PRESSURE AND TRAPPED MOISTURE WILL REMAIN
FROM THE FRONT RANGE EAST THROUGH THE FCST AREA. THE WPC KEEPS A
STATIONARY FRONT PINNED AGAINST THE FRONT RANGE TODAY AND TONIGHT
AND LIFTS THAT FRONT EAST OF THE FCST AREA THURSDAY MORNING ONCE THE
SFC LOW EJECTS NORTHEAST INTO THE UPPER MIDWEST.
THE FCST WILL ALLOW FOR SOME CLEARING WEST OF HIGHWAY 83 THIS
AFTERNOON BUT KEEPS SKIES CLOUDY THROUGHOUT THE DAY EAST OF HIGHWAY
83 WHICH IS VERY CLOSE TO THE RAP MODEL. FOR TONIGHT...THERE IS NO
CHOICE BUT TO BLEND A MULTIMODEL SOLN FOR CLEARING SKIES WITH ONE
CAVEAT. THE NAM12 VISIBILITY PRODUCT AND MODEL SOUNDINGS SHOW A FOG
BANK SPREADING SOUTH INTO THE FCST AREA AFTER MIDNIGHT. THE FOG
SHOULD SPREAD TO NEAR NEBRASKA HIGHWAY 2 BUT NO FURTHER SOUTH. GIVEN
THE PROPENSITY FOR THE NAM TO USE FORECAST SNOWFALL TO GENERATE
SPURIOUS BOUNDARY LAYER MOISTURE THE CONFIDENCE IN FOG DEVELOPMENT
IS LOW. FOR NOW WILL JUST MENTION PATCHY FOG ACROSS THE NORTH.
OTHERWISE THE FORECAST CALLS FOR LIGHT WINDS TODAY AND TONIGHT WITH
HIGHS IN THE 40S TO AROUND 50 AND LOWS TONIGHT IN THE UPPER 20S TO
LOWER 30S. THE FCST HIGHS TODAY ARE COOLER THAN THE GUIDANCE WHILE
TONIGHTS LOWS ARE SLIGHTLY WARMER TO ACCOMMODATE COLD AIR DAMMING
AND TRAPPED MOISTURE.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 331 AM CDT WED OCT 30 2013
THIS PERIOD BEGINS WITH THE UPPER LEVEL SYSTEM NOW OVER THE
INTER-MOUNTAIN WEST TO FINALLY BE MOVING THROUGH THE PLAINS. BY 00Z
FRIDAY...MODELS ARE IN GOOD AGREEMENT THAT THE TROUGH AXIS WILL BE
EAST OF THE AREA AND MOVING INTO THE MISSISSIPPI RIVER VALLEY. THIS
WILL LEAD THE REGION INTO NORTHWEST FLOW WITH THE NEXT SHORTWAVE
TROUGH LOOKING TO MOVE OUT OF ALBERTA AND INTO MONTANA THURSDAY
NIGHT. MEANWHILE...THE RIDGE WILL BE PLACED OVER THE WEST
COAST...WITH TROPICAL STORM RAYMOND WEST OF BAJA CALIFORNIA
WEAKENING...WHILE ONLY MOVING MINIMALLY.
THURSDAY HAS A DECENT SET-UP FOR SOME WINDY CONDITIONS AS AN UPPER
LEVEL VORTICITY MAXIMUM MOVES ACROSS NEBRASKA...WHILE ALSO
CONCURRENTLY EXPECTING GOOD COLD AIR ADVECTION AND SUBSIDENCE IN THE
SFC TO 500MB LAYER. PRESSURE GRADIENT ISN/T REAL TIGHT SO SHOULD BE MORE
OF A SITUATION WITH WINDS MIXING DOWN RATHER THAN STRONG GRADIENT
WINDS. SOUNDINGS ARE SHOWING PRETTY STEEP LAPSE RATES IN THE MIXED
LAYER WHICH TOPS OUT AROUND 800MB ACROSS MUCH OF THE FORECAST
AREA...A BIT HIGHER ACROSS THE WESTERN ARES. MAX WINDS IN THE MIXED
LAYER ARE 30-35KT SO EXPECT GUSTS FROM TIME TO TIME UP TO 35 MPH.
ALTHOUGH GOOD SUNSHINE IS EXPECTED...WILL STILL HAVE NEAR TO BELOW
NORMAL TEMPERATURES FOR MUCH OF THE AREA DUE TO THE COLDER AIR
MOVING IN BEHIND THE SYSTEM AS 850MB TEMPERATURES GENERALLY STAY IN
THE 0C TO 5C RANGE.
THE NEXT SHORTWAVE PUSHES OUT OF CANADA AND INTO THE CENTRAL PLAINS
ON FRIDAY WHICH WILL BRING SIMILAR CONDITIONS TO THURSDAY. THE
SURFACE PRESSURE GRADIENT IS SLIGHTLY TIGHTER THAN ON THURSDAY...AND
WHILE THERE ISN/T AS STRONG OF A MID LEVEL VORTICITY MAX MOVING
ACROSS THE AREA...SUBSIDENCE AND COLD AIR ADVECTION BELOW 500MB
REMAINS STRONG AND WINDS ABOVE THE SURFACE ARE A BIT STRONGER AS
850MB WINDS ARE LOOKING TO BE 30KTS TO 40KTS. SO AGAIN EXPECTING A
BREEZY DAY WITH GUSTS UP TO 35 MPH TO 40 MPH AT TIMES. ALSO...WITH A
REINFORCING SHOT OF COLDER AIR COMING SOUTHWARD BEHIND THIS
SYSTEM...AGAIN LOOKING FOR NEAR TO BELOW NORMAL TEMPERATURES FOR
FRIDAY. A FEW OF THE MODELS ARE DEVELOPING SOME PRECIPITATION FRIDAY
AFTERNOON...HOWEVER WITH LIFT AND MOISTURE LACKING...FELT KEEPING
THE FORECAST DRY WAS THE WAY TO GO AT THIS TIME.
RIDGING BUILDS IN FOR THE WEEKEND AS THE LONGWAVE TROUGH MIGRATES
TOWARDS THE EAST COAST AND ANOTHER LOW PRESSURE SYSTEM MOVES INTO
THE PACIFIC NORTHWEST. MODELS ARE ALSO IN FAIR AGREEMENT THAT
THE REMNANTS OF TROPICAL STORM RAYMOND WILL FINALLY MOVE EAST FAR
ENOUGH TO GET CAUGHT UP IN THE MAIN FLOW. CURRENT TIMING FROM
MODEL SOLUTIONS WILL KEEP THE GOOD WARM AIR FROM MOVING INTO THE
FORECAST AREA UNTIL SATURDAY NIGHT...SO CURRENTLY EXPECTING SUNDAY
TO BE THE WARMEST DAY OF THE WEEK.
AS THE PACIFIC NORTHWEST SYSTEM MOVES INLAND THROUGH THE FIRST
PART OF THE WEEK...PLENTIFUL MODEL DIFFERENCES COME INTO PLAY. THE
GFS IS MUCH FASTER PUSHING THE TROUGH ACROSS THE CONUS...WHILE THE
ECMWF AND GEM ARE QUITE A BIT SLOWER. USED A CONSENSUS APPROACH
FOR THE FORECAST FOR THESE PERIODS...HOWEVER RELYING A BIT HEAVIER
ON THE SLOWER SOLUTIONS. THIS WILL BRING RAIN CHANCES TO THE
FORECAST AREA FOR MONDAY THROUGH TUESDAY. THIS BEING SAID...THERE
ISN/T A GREAT DEAL OF MOISTURE ASSOCIATED WITH THE FRONT MOVING
THROUGH...AND ALTHOUGH REMNANTS OF TROPICAL STORM RAYMOND WILL
ALSO HAVE MADE IT TO ON-LAND...THE UPPER LEVEL JET IS SPLIT...WHICH
WILL KEEP A MAJORITY OF THE MOISTURE ASSOCIATED WITH IT ACROSS THE
SOUTHERN STATES.
ALSO...WITH EITHER MODEL SOLUTION TEMPERATURES WILL AGAIN BE QUITE
A BIT COOLER FOR THE FIRST HALF OF THE WORK WEEK. ON BOTH MONDAY
AND TUESDAY...IF PRECIPITATION IS INDEED ONGOING MAY ONLY SEE
HIGHS IN THE 30S TO LOW 40S IN PLACES. IN TERMS OF PRECIPITATION
TYPE WITH THE COLDER AIR BEING INGESTED INTO THE SYSTEM...BELIEVE
ANYTHING WILL START AS RAIN...BUT SHOULD CHANGE TO A RAIN/SNOW
MIX...THEN TO SNOW...BUT BY TUESDAY AFTERNOON ONLY RAIN IS
EXPECTED AS THE SYSTEM PUSHES EAST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1147 PM CDT TUE OCT 29 2013
THERE IS HIGH CONFIDENCE THAT CEILINGS 500-1000 FEET WILL CONTINUE
IN CENTRAL AND WESTERN NEBRASKA THROUGH MID TO LATE MORNING
WEDNESDAY. AFTER 16Z...CLOUD BASES WILL BEGIN LIFTING TO ABOVE 1000
FEET AGL...SCATTERING OUT RAPIDLY TOWARD EARLY AFTERNOON LEAVING
ONLY MIDDLE AND HIGH CLOUD CEILINGS. AREAS OF LIGHT DRIZZLE ARE
LIKELY OVER CENTRAL AND WESTERN NEBRASKA WITH LIGHT FREEZING DRIZZLE
EXPECTED NORTH AND WEST OF AN ANW-LBF-OGA LINE. THE LIGHT FREEZING
DRIZZLE IS LIKELY FOR THE AIRPORTS OF VTN...ANW...TIF AND MHN.
SIMILAR CONDITIONS ARE POSSIBLE AT ONL AND BBW...THOUGH THE
UNCERTAINTY IS HIGH.
SHORT RANGE PROJECTIONS INDICATE SOME RAINSHOWERS COMING OUT OF
COLORADO AND ACROSS SOUTH CENTRAL AND CENTRAL NEBRASKA. THE SHOWERS
ARE LIKELY TO GIVE AT LEAST A GLANCING SHOT OF RAIN FOR LBF.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL NOON CDT /11 AM MDT/ TODAY FOR
NEZ004-005-094.
&&
$$
SHORT TERM...CDC
LONG TERM...BROOKS
AVIATION...SPRINGER
AREA FORECAST DISCUSSION
NWS RALEIGH NC
751 PM EDT THU OCT 31 2013
.SYNOPSIS...
A COLD FRONT WILL TRACK SLOWLY TO THE EAST ACROSS THE CAROLINAS ON
FRIDAY AND FRIDAY NIGHT. THEN...DRY HIGH PRESSURE WILL BUILD INTO
THE REGION FOR THE WEEKEND.
&&
.NEAR TERM /TODAY AND TONIGHT/...
AS OF 230 PM THURSDAY...
TEMPERATURES THIS AFTERNOON ARE FOR THE MOST PART ON TRACK TO CLIMB
INTO THE MID TO UPPER 70S IN THE SOUTHEAST AND MAYBE A COUPLE
DEGREES COOLER THAN EXPECTED IN THE EXTREME TRIAD AS THEY STRUGGLE
TO GET TO 70 DEGREES WITH A BIT MORE CLOUD COVER AND SOME
DRIZZLE/SPRINKLES MOVING THROUGH THE AREA OVER THE NEXT COUPLE OF
HOURS. RADAR SHOWS VERY LIGHT RAIN MOVING SOUTHWEST. NEW DEVELOPMENT
ON THE SOUTHERN EDGE OF THIS FEATURE OVER UPSTATE SOUTH CAROLINA
WILL MOVE NORTHEASTWARD INTO OUR SOUTHWEST PIEDMONT LATER IN THE
AFTERNOON. ADVECTION OF THIS FEATURE FURTHER TO THE EAST WILL BE
HARDER AS THE LATEST RUN OF THE RAP SHOWS A SWATH OF DRIER
1000-500MB AIR ASSOCIATED WITH AN UPPER LEVEL HIGH PRESSURE SYSTEM
TO THE SOUTH MOVING UP THROUGH THE TRIANGLE AND POINTS EASTWARD.
THIS SHOULD HELP TO KEEP THINGS DRY OR AT THE VERY LEAST KEEP
SHOWERS TO A MINIMUM. CURRENT WINDS OUT OF THE SOUTH SOUTHWEST AT 10
KNOTS GUSTING TO 20 KNOTS ARE EXPECTED TO CONTINUE THIS AFTERNOON
AND INTO THE EVENING AND POSSIBLY STRENGTHEN A FEW KNOTS IN THE
PROCESS. EXPECT AT LEAST UPPER LEVEL CLOUD COVER TO INCREASE AS THE
DAY GOES ON FROM WEST TO EAST AS THE FRONTAL SYSTEM CROSSING THE
MISSISSIPPI PUSHES FURTHER EAST.
FOR TONIGHT...WINDS ARE EXPECTED TO REMAIN BREEZY OUT OF THE
SOUTHWEST OVERNIGHT BUT THIS ACTIVITY MAY BE MORE SPORADIC DURING
THE EARLY MORNING HOURS. MODEL FORECAST SOUNDINGS SHOWN IN BUFKIT
HAVE A SATURATED LAYER BETWEEN 900 AND 750 MB TONIGHT WHICH IS WHERE
MOISTURE FOR ANY LIGHT SHOWER ACTIVITY WOULD COME FROM...ABOVE THAT
A STRONG TEMPERATURE INVERSION AT 700 MB SHOULD KEEP THINGS CAPPED
OVERNIGHT. WITH LIMITED TO NO INSTABILITY...SHOWER ACTIVITY MAY BE
HARD TO COME BY. LOWS ARE ONLY EXPECTED TO DROP INTO THE MID 60S IN
MOST LOCATIONS.
&&
.SHORT TERM /FRIDAY AND FRIDAY NIGHT/...
AS OF 300 PM THURSDAY...
A FRONTAL SYSTEM ASSOCIATED WITH A STRONG LOW PRESSURE SYSTEM MOVING
NORTHEASTWARD THROUGH THE GREAT LAKES. WILL BE ON THE DOORSTEP BY
FRIDAY MORNING WITH PRECIPITATION EXPECTED TO BEGIN IN THE TRIAD
BETWEEN 9 AND 12Z...15Z AT RDU AND 18Z AT KFAY AND KRWI. INSTABILITY
WILL BE VERY LIMITED WITH THIS SYSTEM ALTHOUGH SHEAR VALUES WILL BE
VERY STRONG THROUGHOUT THE EVENT. GUSTY WINDS OF UP TO 25 KNOTS CAN
BE EXPECTED ON FRIDAY. IT IS NOT OUT OF THE QUESTION THAT A STRONGER
SHOWER COULD HELP TO BRING STRONGER 40-50 KNOT 850 MB WINDS DOWN TO
THE SURFACE. AS THE FRONT MOVES EASTWARD SURFACE WINDS OUT AHEAD OF
THE FRONT WILL BACK AROUND FROM SOUTHWESTERLY TO
SOUTHERLY...ESPECIALLY ACROSS EASTERN NORTH CAROLINA. THIS IS
CLEARLY INDICATED ON MODEL HODOGRAPHS WHICH SHOW SWEEPING CLOCKWISE
HODOGRAPHS FOR MUCH OF THE DAY FRIDAY INDICATING THAT THERE COULD BE
SOME ROTATION PRESENT...ESPECIALLY FOR I-95 AND POINTS EAST. THE
DEVELOPMENT OF A SURFACE LOW ALONG THE FRONT LATER IN THE EVENING
GIVES FURTHER CREDIBILITY TO THIS THEORY BUT CURRENT SIMULATIONS
SHOW THE FRONT PROGRESSING THROUGH OUR CWA BEFORE THIS HAPPENS. AT
THE CURRENT TIME SPC HAS MAINTAINED A SEE TEXT FOR OUR AREA FOR
FRIDAY SIGHTING AN OUTSIDE CHANCE OF DAMAGING WINDS AND A NON-ZERO
TORNADO THREAT BUT ADDING THE CAVEAT THAT VERY LIMITED INSTABILITY
AND LAPSE RATES MAKE THE SEVERE WEATHER THREAT FAIRLY MUNDANE AND
NOT WORTHY OF A SLIGHT RISK AT THIS POINT.
AS FAR AS QPF VALUES ARE CONCERNED THE LATEST RUN OF THE NAM
AVERAGES OUT AROUND A QUARTER OF AN INCH WITH STRONGER PULSES
POTENTIALLY PUSHING THE TOTALS AT SOME LOCATIONS UP TOWARDS A HALF
OF AN INCH. WITH SOUTHWESTERLY FLOW IN PLACE ALL DAY ON
SATURDAY...MAXIMUM TEMPERATURES SHOULD RISE INTO THE UPPER 70S IN
THE EAST WHERE GREATER INSOLATION WILL OCCUR. BACK TO THE
NORTHWEST...CLOUD COVER ASSOCIATED WITH THE FRONT WILL KEEP HIGHS
DOWN CLOSER TO 70. ON FRIDAY NIGHT FRONTAL PASSAGE WITH WIND
SHIFTING TO NORTHWESTERLY IS NOT EXPECTED TO OCCUR UNTIL AFTER 6Z IN
THE TRIAD...CLOSER TO 9Z AT KRDU AND NEAR 12Z IN THE EAST. THIS
TIMING WILL ALSO HELP TO CLEAR THINGS OUT IN THE WEST BEFORE SUNRISE
AND THEREFORE LEAVING ANOTHER STRONG TEMPERATURE GRADIENT IN THE
OVERNIGHT LOWS. WHILE THE TRIAD WILL BE NEAR 50 DEGREES...MIDDLE 60S
ARE STILL LIKELY IN THE SOUTHEAST WHERE SOUTHERLY WINDS AND CLOUDS
WILL HANG ON THE LONGEST.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
AS OF 205 PM THURSDAY...
FOR SATURDAY/SATURDAY NIGHT: LATEST MODEL GUIDANCE INDICATES THAT
THE COLD FRONT WILL BE EAST OF THE CWA... ALONG COASTAL SECTIONS OF
NC BY DAWN SATURDAY. RAIN CHANCES SHOULD EXTEND INTO MID MORNING IN
AREAS ALONG/EAST OF I-95 BEFORE QUICKLY ENDING BY LATE MORNING...
THEN EXPECT A PERIOD OF MOSTLY SUNNY SKIES LATE MORNING THROUGH
EARLY AFTERNOON WITH WNW DOWNSLOPE FLOW AND A DRYING COLUMN. A
SECONDARY SURFACE FRONT... ASSOCIATED WITH THE MID LEVEL TROUGH
AXIS... WILL CROSS CENTRAL NC NW TO SE FROM MID AFTERNOON THROUGH
EARLY EVENING. MID LEVEL DPVA... A SHOT OF UPPER DIVERGENCE... AND
LOW LEVEL LAPSE RATES OF 6.5-7.0 C/KM ARE ANTICIPATED ALONG AND
AHEAD OF THIS FRONT. FORECAST SOUNDINGS DEPICT ENOUGH SATURATION
ACCOMPANYING THESE STEEP LAPSE RATES IN THE 850-600 MB LAYER DURING
THIS TIME TO SUPPORT ADDING A SLIGHT CHANCE OF SHOWERS AREAWIDE. THE
MOIST LAYER EXTENDS UP INTO THE -12C TO -16C RANGE... SO GIVEN THE
EXPECTED INSTABILITY AND AUGMENTED LIFT BY MID-UPPER LEVEL
FORCING... WE COULD SEE A STORM OR TWO AS WELL... BUT WILL HOLD OFF
ADDING THUNDER AT THIS TIME GIVEN THE EXPECTED SPARSITY OF COVERAGE.
THE FAIRLY DEEP AND DRYING SUBCLOUD LAYER SHOULD LIMIT QPF DESPITE
DECENT COVERAGE... AND MANY PLACES MAY SEE JUST A TRACE... BUT THIS
LOW LEVEL DRY AIR COULD ALSO MEAN ENHANCED DOWNDRAFTS AND ISOLATED
OCCURRENCES OF STRONG WIND GUSTS WITH THESE SHOWERS. THERMAL
STRUCTURE ON FORECAST SOUNDINGS SUPPORT HIGHS OF 66-73. LOWS 40-45
WITH CLEARING SKIES... AND COLD AIR ADVECTION BEING OFFSET SOMEWHAT
BY CONTINUED MIXING OVERNIGHT.
FOR SUNDAY THROUGH THURSDAY: QUIET AND MOSTLY DRY WEATHER WITH A
WARMING TREND... AS COOL SURFACE HIGH PRESSURE DRIFTS EASTWARD OVER
EASTERN NOAM BEFORE MODIFYING AND MOVING OFF THE COAST. THE
FULL-LATITUDE MID LEVEL TROUGH THAT AFFECTS NC SATURDAY WILL SHIFT
OFF THE EASTERN SEABOARD EARLY SUNDAY... THEN AN AMPLIFYING LONGWAVE
TROUGH DIGGING OVER THE ROCKIES AND HIGH PLAINS WILL INDUCE
STRENGTHENING RIDGING ALOFT OVER THE SOUTHEAST AND CAROLINAS THROUGH
MID WEEK. BELOW TO MUCH BELOW NORMAL TEMPS ARE EXPECTED
SUNDAY/MONDAY WITH FAIR TO MOSTLY CLEAR SKIES. BY TUESDAY... THE
SURFACE HIGH WILL PASS OFF THE CANADIAN MARITIME COAST WHILE NOSING
SSW INTO NC IN A WEDGE-LIKE FASHION... CAPPED BY A CLOSED MID LEVEL
ANTICYCLONE JUST OFF THE CAROLINAS (ECMWF HAS A STRONGER RIDGE
CLOSER TO OUR COAST WHILE THE GFS IS WEAKER AND A BIT MORE SE). THIS
FAVORS A PATTERN OF MOIST/STABLE LOW LEVELS (WITH INCREASED MOIST
ATLANTIC INFLOW AROUND THE SURFACE RIDGE AND UPSLOPE FLOW ALONG WITH
ISENTROPIC UPGLIDE) CAPPED WITH DRY/STABLE AIR ABOVE 800 MB. WE
SHOULD SEE INCREASING CLOUD COVER TUESDAY INTO THURSDAY... WITH A
SLIGHT CHANCE OF SOME DRIZZLE... PARTICULARLY EARLY TUESDAY MORNING
WITH A BETTER CHANCE TUESDAY NIGHT/WEDNESDAY MORNING... ESPECIALLY
OVER THE WRN PIEDMONT HEADING INTO THE HIGHER TERRAIN. EXPECT NEAR
NORMAL TEMPS TUESDAY... WARMING TO ABOUT A CATEGORY ABOVE NORMAL BY
THURSDAY AS THE WEDGE AIR MASS WEAKENS AND SLOWLY WARMS. THE WESTERN
TROUGH WILL START TO LIFT THROUGH THE CENTRAL US LATE THURSDAY WITH
ITS SURFACE COLD FRONT APPROACHING... BUT ACCORDING TO THE FAVORED
SLOWER ECMWF SOLUTION... THE ATTENDING BAND OF CONVECTION SHOULD
HOLD WEST OF THE FORECAST AREA THROUGH THURSDAY. WILL INCLUDE JUST A
SMALL CHANCE OF PREFRONTAL SHOWERS LATE WEDNESDAY THROUGH THURSDAY
MAINLY IN THE WRN PIEDMONT. -GIH
&&
.AVIATION /00Z FRIDAY THROUGH WEDNESDAY/...
AS OF 745 PM THURSDAY...
AVIATION CONDITIONS ARE EXPECTED TO DETERIORATE OVERNIGHT AS A FRONT
APPROACHES THE AREA. THE MAIN LINE OF PRECIP IS NOT EXPECTED TO
IMPACT THE AREA UNTIL THE PREDAWN HOURS OF FRIDAY...HOWEVER THERE
COULD BE SOME DRIZZLE (ESPECIALLY ACROSS THE WEST) DURING THE
OVERNIGHT HOURS. RIGHT NOW...IT APPEARS THE LEADING EDGE OF THE MAIN
AREA OF PRECIP SHOULD BEGIN TO IMPACT THE TRIAD AROUND 12Z...KRDU
AROUND 15Z AND KFAY/KRWI AROUND 18Z (GIVE OR TAKE AN HOUR OR TWO).
HOWEVER...INCREASING MOISTURE...COURTESY OF THE BREEZY SOUTHWESTERLY
WINDS...SHOULD RESULT IN CIGS LOWERING AFTER MIDNIGHT...MOST LIKELY
INTO THE IFR RANGE. VSBYS ARE NOT EXPECTED TO FALL MUCH BELOW MVFR
DUE TO THE GOOD MIXING EXPECTED ALL NIGHT. WHILE AVIATION CONDITIONS
WILL STAY DOWN...OR EVEN WORSEN ACROSS THE WESTERN HALF OF THE
FORECAST AREA FRIDAY MORNING AS THE MAIN AREA OF PRECIP ARRIVES...
THERE COULD BE SOME IMPROVEMENT IN AVIATION CONDITIONS ACROSS THE
EAST AS HEATING COMMENCES AND THE FACT THAT THE FRONT/PRECIP WILL
STILL BE TO THE WEST. DEPENDING ON HOW MUCH INSOLATION ENDS UP
OCCURRING ACROSS THIS PART OF THE FORECAST AREA...THERE COULD ALSO
BE A FEW THUNDERSTORMS FRIDAY AFTERNOON. WINDS WILL REMAIN BREEZY
AND OUT OF THE SOUTHWEST...WITH GUSTS UP TO 20-25 KNOTS.
OUTLOOK...PRECIP SHOULD COME TO AN END LATE FRIDAY INTO EARLY
SATURDAY AS THE FRONT MOVES EAST OF THE AREA AND THEREFORE A RETURN
TO VFR CONDITIONS IS EXPECTED. HOWEVER...AS THE UPPER LEVEL TROUGH
MOVES ACROSS THE AREA DURING THE DAY ON SATURDAY...THERE COULD BE
SOME ISOLATED SHOWERS. THEN MOSTLY DRY CONDITIONS ARE EXPECTED AS
HIGH PRESSURE TAKES CONTROL OF THE WEATHER ACROSS THE REGION.
HOWEVER...CLOUD COVER COULD BEGIN TO INCREASE EARLY NEXT WEEK AS
PERSISTENT MOIST NORTHEASTERLY FLOW AFFECTS THE AREA.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...KRR
NEAR TERM...ELLIS
SHORT TERM...ELLIS
LONG TERM...HARTFIELD
AVIATION...KRR
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
936 PM EDT THU OCT 31 2013
.SYNOPSIS...
A STRONG COLD FRONT WILL SWEEP THROUGH THE REGION TONIGHT. DRIER
AIR AND SLIGHTLY COOLER TEMPERATURES WILL MOVE IN BEHIND THE FRONT
FOR FRIDAY. AN UPPER LEVEL TROUGH WILL SETTLE INTO THE GREAT LAKES
AND OHIO VALLEY ON SATURDAY WHICH WILL BRINGER MUCH COOLER TEMPERATURES
ALONG WITH A THREAT OF SHOWERS.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
OPERATIONAL MODELS ARE IN FAIRLY DECENT AGREEMENT IN TERMS OF THE
STRENGTH OF THE CURRENT STORM SYSTEM TO AFFECT THE REGION TONIGHT.
THERE ARE SOME DIFFERENCES ON THE MESOSCALE WHICH WILL BE THE MAIN
FOCUS IN REGARDS TO THE POTENTIAL FOR SEVERE WEATHER TONIGHT.
A VIGOROUS MID LEVEL S/WV TROUGH WILL TAKE ON A NEGATIVE TILT AS
IT MOVES FROM THE MIDDLE MS VLY TO THE NORTHERN GREAT LAKES
REGION BY FRIDAY MORNING. IN ASSOCIATION WITH A 140+ KNOT UPR LVL
JET...THIS FEATURE WILL ALLOW A SURFACE LOW TO RAPIDLY DEEPEN AND
BOMB OVER THE UPR GREAT LAKES TONIGHT. THE RESPONSE TO THIS RAPID
DEEPENING WILL BE A VERY STRONG 925 MB-850 MB LLJ TO AFFECT THE
OHIO VALLEY REGION THIS EVENING INTO THE EARLY MORNING HOURS OF
FRIDAY. MODELS VARY ON THE EXACT STRENGTH...BUT TAKING A BLEND OF
THEM...45 TO 55 KNOTS AT 925 MB AND 80+ KNOTS AT 850 MB LOOK
REASONABLE. WILL CONTINUE WITH THE SYNOPTIC SCALE WIND ADVISORY
AS THE THREAT FOR WAA SHOWERS OUT AHEAD OF THE MAIN FRONT MAY
PRODUCE BRIEF DOWNDRAFT/PCPN DRAGGING IN THE FORM OF GUSTS NEAR OR
GREATER THAN 40 KNOTS. THE BIGGEST CONCERN WILL BE A COOL SEASON
QLCS WHICH IS DEVELOPING OVER INDIANA ALONG AN ADVANCING COLD
FRONT AS OF THIS ISSUANCE. SFC CONVERGENCE/LOW LEVEL CONVERGENCE
WILL BE MAXIMIZED WITH THE BEST INSTABILITY OCCURRING WITH A
CONVECTIVE LINE WITH THE FRONT. MESOSCALE MODELS SUCH AS THE
LATEST HRRR SHOW THAT THE CONVECTIVE LINE SHOULD MOVE ACRS OUR
REGION BETWEEN 02Z AND 06Z...PLUS OR MINUS 1 HOUR ON EITHER SIDE
OF THIS. THE NAM CONTINUES TO INDICATE ABOUT 100-200 J/KG OF
MLCAPE WITH 300-400 J/KG OF MUCAPE THROUGH 3 KM IN ASSOCIATION
WITH THIS LINE. THIS MAY OR MAY NOT BE ENOUGH FOR THUNDER.
HOWEVER...AS WE KNOW IN THESE PARTS WITH THIS TYPE OF SCENARIO...A
LINE OF CONVECTIVE SHOWERS CAN ALSO PRODUCE DAMAGING WINDS. IN
ADDITION...GIVEN THAT THE LINE WILL BE MOVING QUICKLY AT ABOUT 60
TO 65 MPH IS A CALL FOR CONCERN AND THIS HAS BEEN HIGHLIGHTED IN
OUR HWO FOR THE POTENTIAL FOR DAMAGING WIND GUSTS. THE THREAT ALSO
EXISTS FOR AN ISOLATED BRIEF SPIN UP TORNADO IF ANY SHALLOW
UPDRAFT BECOMES ROBUST ENOUGH TO LIFT HIGH VALUES OF 0-1 KM
HELICITY INTO THE VERTICAL. THIS IS ALSO HIGHLIGHTED IN THE HWO AS
WELL AS THE SPC SWODY1. SO...AM EXPECTING WIDESPREAD WAA SHOWERS
IN ADVANCE OF THE COLD FRONT THROUGH ABOUT 11 PM EDT THIS EVENING
FOLLOWED BY A FOCUSED LINE OF SHOWERS...PERHAPS EMBEDDED THUNDER
...ALONG THE COLD FRONT AS IT QUICKLY MOVES EAST ACRS OUR AREA
THROUGH THE EARLY MORNING HOURS. STRONG SUBSIDENCE AND DRYING IS
EXPECTED BEHIND THE FRONT SUCH THAT SKIES ARE EXPECTED TO CLEAR
FROM SW TO NE BY SUNRISE FRIDAY. OVERNIGHT LOWS WILL DEPENDED ON
FRONTAL TIMING. HAVE LOWS RANGE FROM THE UPPER 40S WEST TO THE
UPPER 50S FAR EAST.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
VIGOROUS S/WV TROUGH AND DEEP SFC LOW WILL QUICKLY PIVOT AWAY TO
THE NORTHEAST ON FRIDAY. THIS WILL ALLOW DRIER AIR TO BRIEFLY
SETTLE INTO OUR REGION PER DRY SLOT BEHIND THIS STRONG SYSTEM.
CAA WILL BE SLOW TO MOVE IN ON FRIDAY...AND WITH SUNSHINE
EARLY ON...HIGHS SHOULD RANGE FROM THE UPPER 50S NW TO THE MID 60S
SOUTHEAST. UNDER A DEVELOPING NW FLOW ALOFT...S/WV ENERGY WILL
BEGIN TO DIG SE TOWARD OUR REGION LATE FRIDAY AFTERNOON...CONTINUING
INTO FRIDAY NIGHT. THIS PROCESS WILL ALLOW CUMULUS CLOUDS TO
INCREASE FROM THE NW FRIDAY AFTERNOON...FOLLOWED BY STRATOCUMULUS
AND MID LVL MOISTURE FRIDAY NIGHT. HAVE TAKEN A BLEND FOR
LOWS...RANGING FROM THE LOWER TO MID 40S.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
AN AMPLIFIED TROUGH WILL BE IN PLACE ACROSS THE EASTERN HALF OF THE
CONUS SATURDAY WITH A DEPARTING SHORTWAVE AND COLD ADVECTION
AFFECTING OUR AREA. SCATTERED SHOWERS WILL DEVELOP IN THIS COLD
ADVECTION OFF THE GREAT LAKES AND WILL PRIMARILY AFFECT THE
NORTHERN ZONES WITH LESSER CHANCES FOR SHOWERS ACROSS THE SOUTHERN
ZONES MAINLY DURING SATURDAY AFTERNOON. SHOWER ACTIVITY AND CLOUD
COVER WILL DECREASE AFTER SUNSET AS HIGH PRESSURE BUILDS ACROSS THE
REGION. TEMPERATURES ON SATURDAY WILL RUN NEAR NORMAL AS COLDER AIR
MOVES INTO THE AREA UNDER MOSTLY CLOUDY SKIES.
THE HIGH PRESSURE WILL BRING MOSTLY CLEAR SKIES AND FAIR WEATHER TO
OUR AREA LATE SATURDAY NIGHT THROUGH MONDAY AS THE HIGH CROSSES WEST
TO EAST ACROSS OUR REGION. DAYTIME HIGHS WILL START OF COOL ON SUNDAY
WITH HIGHS RANGING FROM THE UPPER 40S ACROSS THE NORTH TO THE MIDDLE
50S ACROSS THE SOUTH. NIGHTTIME LOWS SUNDAY NIGHT WILL BE IN THE 30S.
THE HIGH WILL HAVE SHIFTED EAST OF OUR AREA BY MONDAY WHICH WILL
BEGIN A WARNING TREND THAT WILL LAST UNTIL AT LEAST WEDNESDAY.
TEMPERATURES MONDAY AND MONDAY NIGHT WILL BE NEAR CLIMATOLOGICAL
NORMALS...AND BY TUESDAY/TUESDAY NIGHT TEMPERATURES WILL BE ABOVE
NORMAL.
THE NEXT STORM SYSTEM TO AFFECT OUR AREA WILL BE DURING THE
WEDNESDAY AND THURSDAY TIME FRAME AS A SURFACE LOW AND SHORTWAVE LIFTS
NORTHEASTWARD OUT OF THE PLAINS AND BRINGS A COLD FRONT TOWARD OUR
AREA. THE ECMWF/GFS HAVE BEEN DIFFERING ON THE TIMING OF THIS
STORM SYSTEM`S EFFECTS ON OUR AREA BY ABOUT 12 HOURS. HOWEVER...AT
THIS TIME PRECIPITATION APPEARS LIKELY AT SOME POINT DURING THE TWO
DAY PERIOD. THEREFORE...AM FORECASTING 50 POPS FOR A LONG DURATION
DURING THE TIME PERIOD UNTIL HIGHER POPS CAN BE FOCUSED OVER A
SHORTER TIME...WHEN TIMING CONFIDENCE IS GREATER.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
COLD FRONT EXTENDING FROM GREAT LAKES LOW PRESSURE WILL PUSH
ACROSS TAF SITES TONIGHT. THIS VIGOROUS SYSTEM WILL ADVERSELY
AFFECT TAF SITES WITH CONDITIONS AS LOW AS LIFR UNTIL IT CROSSES
THE AREA LATE TONIGHT. SOUTHERLY SURFACE WINDS TAPPING AN 80 KNOT
850 MB FLOW WILL BE VERY STRONG...WITH GUSTS WELL OVER 30 KNOTS IN
SHOWERS. WINDS WILL DIMINISH AND SHIFT TO SOUTHWEST BEHIND THE
FRONT...THOUGH GUSTS COULD RISE ABOVE 20 KNOTS AGAIN FRIDAY
AFTERNOON.
OUTLOOK...MVFR CEILINGS POSSIBLE SATURDAY NIGHT.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...WIND ADVISORY UNTIL 3 AM EDT FRIDAY FOR OHZ026-034-035-042>046-
051>056-060>065-070>074-077>082-088.
KY...WIND ADVISORY UNTIL 3 AM EDT FRIDAY FOR KYZ089>100.
IN...WIND ADVISORY UNTIL 3 AM EDT FRIDAY FOR INZ050-058-059-066-
073>075-080.
&&
$$
SYNOPSIS...HICKMAN
NEAR TERM...HICKMAN
SHORT TERM...HICKMAN
LONG TERM...LATTO
AVIATION...CONIGLIO
AREA FORECAST DISCUSSION
NWS TULSA OK
309 PM CDT WED OCT 30 2013
.DISCUSSION...
MAIN FORECAST CONCERNS CONTINUE TO BE SHORT TERM FLASH FLOODING
AND ISOLATED SEVERE STORM POTENTIAL ACROSS VARIOUS PARTS OF THE
FORECAST AREA.
OVERNIGHT...THERE WILL LIKELY BE TWO DISTINCT AREAS OF CONVECTIVE
DEVELOPMENT TO AFFECT EASTERN OKLAHOMA AND NORTHWEST ARKANSAS. THE
FIRST IS ASSOCIATED WITH A STRONG LOW LEVEL JET IN SOUTHEAST
OKLAHOMA AND INTO WESTERN ARKANSAS...AND THE SECOND IS IN THE
VICINITY OF THE COLD FRONT THAT SHOULD EVENTUALLY AFFECT ALL OF
THE FORECAST AREA...PERHAPS AFTER MERGING SOMEWHAT WITH THE LOW
LEVEL JET CONVECTION.
SHOWERS AND STORMS IN NORTHEAST TEXAS AND INTO SOUTHEAST OKLAHOMA
HAVE BEEN SLOW TO BECOME ANYTHING MORE THAN SCATTERED THROUGH THE
DAY...BUT DATA INDICATE THAT THINGS SHOULD BEGIN TO FILL IN THIS
EVENING AND INTO THE OVERNIGHT. THERE IS A POSSIBILITY THAT THE
AXIS OF HEAVIEST PRECIPITATION MAY SLIDE JUST SOUTHEAST OF THE
FORECAST AREA...BUT THIS SHIFT IS STILL SOMEWHAT UNCERTAIN...
ESPECIALLY WITH THE HRRR CONTINUING TO NAIL SOUTHEAST OKLAHOMA.
NEVERTHELESS...AS THIS AREA OF STORMS BEGINS TO SET UP...IT IS
LIKELY TO STEAL SOME MOISTURE AND HEAVY RAIN POTENTIAL FROM
CONVECTION FARTHER NORTH.
FURTHER NORTHWEST...ALONG THE FRONTAL BOUNDARY...STRONG TO...AT
TIMES...SEVERE STORMS HAVE ALREADY DEVELOPED ACROSS PARTS OF SOUTH
CENTRAL KANSAS. LACK OF INSTABILITY ACROSS EASTERN OKLAHOMA SHOULD
LIMIT THE SEVERE POTENTIAL AS THEY MOVE TOWARD THE AREA...BUT
STRONG WIND FIELDS WILL KEEP A LIMITED SEVERE THREAT THIS
EVENING...ESPECIALLY NORTHWEST OF TULSA.
BAND OF PERSISTENT RAIN THAT DEVELOPED DURING THE DAY JUST SOUTH
OF THE INTERSTATE 44 CORRIDOR PRODUCED A WIDESPREAD 2 TO 3 INCHES
OF RAIN FROM NORTHERN PARTS OF OKFUSKEE COUNTY NORTHEASTWARD
TOWARD NORTHERN CHEROKEE AND SOUTHERN DELAWARE COUNTIES. ALTHOUGH
AMOUNTS OF THIS MAGNITUDE ARE NOT EXPECTED FROM THE FRONTAL PRECIP
OVERNIGHT...THE ANTECEDENT CONDITIONS WARRANT EXPANDING THE FLASH
FLOOD WATCH NORTHWARD.
STORMS WILL LIKELY LINGER INTO TOMORROW MORNING ACROSS ESPECIALLY
FAR EASTERN OKLAHOMA AND NORTHWEST ARKANSAS BEFORE BEGINNING TO
CLEAR OUT DURING THE AFTERNOON. DRY CONDITIONS WILL PERSIST
THROUGH THE WEEKEND...WITH TEMPERATURES RUNNING CLOSER TO SEASONAL
NORMALS.
ANOTHER STORM SYSTEM WILL MOVE INTO THE WESTERN UNITED STATES AND
AFFECT THE REGION DURING THE FIRST HALF OF NEXT WEEK...WITH MORE
WIDESPREAD STORMS APPEARING LIKELY AT THIS POINT. CURRENTLY...IT
LOOKS LIKE TEMPERATURES BEHIND THIS SYSTEM WILL BE LOWER THAN
BEHIND THE CURRENT ONE. ONE ITEM OF NOTE...THE CURRENT RUN OF THE
ECMWF HAS BEEN DISCOUNTED FOR THIS FORECAST...AS IT IS A HUGE
CHANGE FROM ITS PREVIOUS RUNS AND ALSO FROM THE GFS...ALL OF WHICH
POINT TO A MORE PROGRESSIVE SYSTEM AS OPPOSED TO A CLOSED LOW
SCENARIO.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 66 69 47 70 / 90 60 0 0
FSM 67 74 47 72 / 100 80 0 0
MLC 68 72 47 74 / 80 50 0 0
BVO 62 66 42 69 / 90 50 0 0
FYV 65 70 42 68 / 100 80 0 0
BYV 65 71 45 67 / 100 80 0 0
MKO 66 72 45 71 / 90 60 0 0
MIO 64 68 44 67 / 90 70 0 0
F10 66 70 47 72 / 80 50 0 0
HHW 69 76 47 75 / 90 50 10 0
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...FLASH FLOOD WATCH UNTIL 7 AM THURSDAY FOR OKZ049-OKZ053-OKZ062-
OKZ063-OKZ065-OKZ066-OKZ067-OKZ068-OKZ070-OKZ071-OKZ072-
OKZ073-OKZ074-OKZ075-OKZ076.
AR...FLASH FLOOD WATCH UNTIL 7 AM THURSDAY FOR ARZ019-ARZ020-ARZ029.
&&
$$
SHORT TERM...07
LONG TERM....22
AREA FORECAST DISCUSSION
NWS NORMAN OK
1150 PM CDT TUE OCT 29 2013
.AVIATION...
LOW CLOUDS REDEVELOPED RATHER QUICKLY THIS EVENING
ACROSS CENTRAL OKLAHOMA WITH MAINLY MVFR CEILINGS.
CLOUDS SHOULD CONTINUE TO DEVELOP ELSEWHERE OVERNIGHT.
CONVECTION IN CENTRAL TEXAS IS MAKING DECENT PROGRESS TO THE
NORTH AND EAST. WILL MENTION TSRA AT MOST SOUTHERN/CENTRAL
TERMINALS FOR LATE OVERNIGHT AND EARLY MORNING WEDNESDAY.
SURFACE FRONT LIFTING SLOWLY NORTHWARD TONIGHT AND SOME DRIZZLE
AND SHOWERS MAY FORM NORTH OF THIS BOUNDARY.
BETTER CHANCES FOR THUNDERSTORMS WITH HEAVY RAINFALL MAY
ARRIVE WEDNESDAY EVENING INTO THE OVERNIGHT...WHEN HEIGHT FALLS
ARRIVE WITH TROUGH AND FRONTAL BOUNDARY SURGES SOUTHWARD.
&&
.PREV DISCUSSION... /ISSUED 651 PM CDT TUE OCT 29 2013/
AVIATION...
A NEARLY STATIONARY FRONT IS LOCATED ACROSS NORTH CENTRAL
AND NORTHWEST OKLAHOMA EARLY THIS EVENING. MODELS SUGGEST
THAT WINDS WILL GRADUALLY BECOME EAST AND SOUTHEAST LATE
THIS EVENING AND OVERNIGHT BEHIND THE BOUNDARY. AS THIS
OCCURS...CEILINGS MAY BECOME NEAR IFR WITH SOME FOG/DRIZZLE
POTENTIAL.
ELSEWHERE...CEILINGS ARE MAINLY VFR BUT SHOULD BECOME AT LEAST
MVFR AFTER 6Z OR SO. A FEW MODELS DEVELOP CONVECTION NEAR
SOUTHWEST OKLAHOMA/WESTERN NORTH TEXAS LATER THIS
EVENING/OVERNIGHT IN RESPONSE TO A STRENGTHENING LLJ. STORMS WOULD
THEN EXPAND IN COVERAGE AND DEVELOP EAST AND NORTHEAST. ADDED TSRA
TO MOST CENTRAL AND SOUTHERN TAF SITES MAINLY AFTER 6Z THROUGH 15Z
OR SO. OVERALL CONFIDENCE IN THIS SCENARIO IS LOW.
PREV DISCUSSION... /ISSUED 331 PM CDT TUE OCT 29 2013/
DISCUSSION...
STORM SYSTEM OVER NEVADA WILL MOVE TOWARD THE AREA BRINGING STORM
CHANCES THROUGH THURSDAY MORNING. FOR TONIGHT... WILL FIRST WATCH
FOR ANY CONVECTION THAT MIGHT DEVELOP ALONG THE SURFACE FRONT THAT
CURRENTLY EXTENDS FROM NORTH CENTRAL INTO WEST CENTRAL OKLAHOMA.
SOME INSTABILITY HAS DEVELOPED PER MESOANALYSIS DESPITE THE
CLOUDINESS. RAP... HRRR AND LOCAL WRF SUGGEST THAT SOME
DEVELOPMENT IS AT LEAST POSSIBLE LATE THIS AFTERNOON. THIS
BOUNDARY IS EXPECTED TO WASH OUT AND/OR LIFT NORTH INTO KANSAS.
WITH THIS PRIMARY FOCUS LIFTING INTO KANSAS... THE HIGHEST CHANCE
OF PRECIPITATION WILL BE ACROSS NORTHERN OKLAHOMA ALTHOUGH SOME
NUMERICAL GUIDANCE SUGGEST THAT AT LEAST THE CHANCE FOR SCATTERED
STORMS FARTHER SOUTH. STORMS ARE LIKELY AS THE STORM SYSTEM
APPROACHES WEDNESDAY AND MOVES OVER THE PLAINS THURSDAY MORNING.
HEAVY RAINFALL WILL BE POSSIBLE IN SOUTHEASTERN OKLAHOMA. DID
CONSIDER A SMALL FLASH FLOOD WATCH SOUTHEAST... BUT THE FLASH
FLOOD GUIDANCE IS STILL RELATIVELY HIGH AND THE HEAVIEST RAIN
CURRENTLY LOOKS TO FALL JUST EAST OF THE CWA.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 66 72 61 71 / 30 70 50 20
HOBART OK 67 75 58 70 / 30 50 40 10
WICHITA FALLS TX 67 77 64 73 / 50 70 40 10
GAGE OK 55 75 48 68 / 30 30 30 0
PONCA CITY OK 67 73 59 67 / 60 80 60 30
DURANT OK 68 72 67 77 / 30 90 80 30
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1155 AM CDT WED OCT 30 2013
.UPDATE...
AN UPPER LEVEL LOW IS SPINNING SLOWLY NORTH AND EAST INTO THE
REGION WITH A WELL-DEFINED DRY SLOT PUNCHING UP TOWARD THE REGION
FROM THE SOUTH. ANY PRECIPITATION CHANCES THAT THERE ARE IN THE
FORECAST WILL BE DURING THE TIME WHEN CLOUDS/MOISTURE/LIFT ARE
WORKING NORTH AND EAST OVER THE CWA PRIOR TO THE ONSET OF THE DRY
SLOT. ONCE THE DRY SLOT ESTABLISHES ITSELF OVER THE CWA
TODAY...MEASURABLE PRECIPITATION CHANCES BASICALLY SHUT OFF AND
DRIZZLE/FREEZING DRIZZLE AND FOG PRETTY MUCH REMAIN THE ONLY
VIABLE SENSIBLE WEATHER TYPES FOR THE REST OF TODAY/TONIGHT. HAVE
BACK-PEDDLED EVEN FURTHER FROM WHAT THE MID-SHIFT DID TO CONTINUE
THIS TREND OF DECREASING CHANCES FOR SEEING MEASURABLE
PRECIPITATION TODAY OR TONIGHT. THE 00Z ABRWRF4KM SOLUTION AND
THE LATEST GUIDANCE FROM THE HRRR MODEL LEND SUPPORT TO THIS
DECREASING TREND IN PRECIP CHANCES.
THERE ARE SOME AREAS ACROSS THE CWA THAT HAVE BEGUN SLOWLY WARMING
TO ABOVE FREEZING. HOWEVER...A FEW SPOTS SEEM RESISTANT TO A
WARMING TREND...FOR A SECOND STRAIGHT DAY. THAT BEING SAID...THERE
IS STILL AN EXPECTATION THAT NEUTRAL LOW LEVEL THERMAL ADVECTION
SHOULD BE SWITCHING OVER TO A RATHER WEAK LOW LEVEL WARM AIR
ADVECTION PATTERN...ESPECIALLY AS MIXING LAYER WINDS SLOWLY BEGIN
TO TAKE ON MORE OF A WESTERLY DIRECTION GENERALLY AROUND 5 TO 10
MPH BY LATE THIS AFTERNOON/EARLY THIS EVENING. WILL REFRAIN FROM
ANY HEADLINES AT THIS TIME FOR FREEZING PRECIPITATION PHENOMENA
UNLESS WE BEGIN RECEIVING REPORTS OF FREEZING PRECIPITATION.
UNTIL THIS AREA OF LOW PRESSURE PUSHES OUT OF THE REGION LATER
TONIGHT...MUCH OF THE CWA CAN EXPECT CONTINUED
CLOUDY/FOGGY/DRIZZLY CONDITIONS WITH PERHAPS AN OCCASIONAL PASSING
SHOWER OF LIGHT RAIN. BETWEEN NOW AND 7 PM CDT THIS EVENING...ANY
AREAS WHERE LIGHT FREEZING DRIZZLE OR VERY LIGHT FREEZING RAIN IS
MENTIONED/OCCURRING SHOULD BE EITHER SWITCHED OVER TO JUST A RAIN
OR DRIZZLE MENTION OR SHOULD BE COMPLETELY DONE...WITH A DRYING
TREND DEVELOPING.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH FRIDAY
PRECIPITATION CHANCES TODAY AND TONIGHT WILL BE THE MAIN FORECAST
CHALLENGE.
THE REGION IS CURRENTLY LOCKED UNDER AN EXPANSIVE LOW CLOUD
SHIELD...WITH SOME LOCATIONS REPORTING REDUCED VISIBILITIES. WITH
VERY LITTLE ECHOES ON THE REGIONAL RADAR...HAVE REDUCED POPS
THROUGH THE EARLY MORNING HOURS AND WILL MENTION DRIZZLE AND
FREEZING DRIZZLE. HI-RES MODELS...ALONG WITH THE 0Z ECMWF SHOWS
VERY LITTLE IN THE WAY OF PCPN TODAY FOR LOCATIONS WEST OF THE
JAMES RIVER RIVER. HAVE TRIED TO BACK OFF ON POPS SOME...WHILE
MAINTAINING CONTINUITY FROM PREVIOUS FORECASTS. THE EASTERN CWA
STILL APPEARS TO BE THE BEST LOCATION FOR MEASURABLE PRECIPITATION
TODAY. P-TYPE SHOULD BE RAIN BY THIS AFTERNOON.
MODELS SHOW PCPN ENDING FAIRLY QUICKLY TONIGHT...WITH DRY
CONDITIONS POSSIBLE BY 6Z. DRIER AIR WILL BEGIN TO ADVECT INTO THE
REGION FROM THE WEST AFTER 6Z TONIGHT. THIS DRIER WILL ALSO HELP
USHER IN WARMER TEMPERATURES INTO THE REGION ON THURSDAY WITH
HIGHS RANGING IN THE MID/UPPER 40S.
A CLIPPER LIKE SYSTEM MOVING ACROSS THE REGION ON FRIDAY WILL
BRING SCATTERED SHOWERS TO THE NORTHEASTERN PORTION OF THE CWA.
WITH STEEP LOW LEVEL LAPSE RATES AND DECENT LIFT WITH THIS
SYSTEM...HAVE SIGNIFICANTLY INCREASED POPS TO A HIGH CHANCE.
THERMAL PROFILES SUGGEST AN ALL LIQUID EVENT.
.LONG TERM...FRIDAY NIGHT THROUGH TUESDAY
OVERALL THE LONG TERM SHOULD FEATURE A SLOWLY PROGRESSIVE PATTERN.
RIDGING ALOFT WILL PROVIDE FOR MAINLY DRY CONDITIONS THROUGH THE
WEEKEND. HOWEVER...EARLY NEXT WEEK A FRONTAL BOUNDARY AND UPPER
TROF WILL MAKE ITS WAY EAST INTO THE PLAINS. THIS WILL SET THE
STAGE FOR AT LEAST A CHC OF PCPN AT THAT TIME. THAT SAID MANY
MODEL DETERMINISTIC AND ENSEMBLE PROGS SUGGEST THE BETTER CHANCES
FOR PCPN WILL DEVELOP EAST OF THE CWA WHERE SFC/ALOFT FEATURES
WILL TAP INTO BETTER MOISTURE. MODEL POP BLEND SETTLED OUT TO CHC
CATEGORY FOR TUESDAY AND THAT IS ACCEPTABLE FOR NOW. TEMPERATURES
SHOULD AVERAGE OUT NEAR NORMAL FOR THE PERIOD.
&&
.AVIATION...
12Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
WIDESPREAD IFR CIGS AND PATCHY DRIZZLE/FREEZING DRIZZLE WILL
LIKELY CONTINUE THIS MORNING ACROSS THE AREA. MEANWHILE SFC
TEMPERATURES SHOULD WARM THROUGH THE MORNING SUCH THAT THE
THREAT FOR ANY FREEZING PCPN SHOULD BECOME MINIMAL. CIGS AND VSBYS
ARE EXPECTED TO GRADUALLY CLIMB THROUGH THE DAY SUCH THAT MVFR MAY
PREDOMINATE BY MID AFTERNOON.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...DORN
SHORT TERM...SD
LONG TERM...TDK
AVIATION...TDK
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
401 PM CDT WED OCT 30 2013
.DISCUSSION...
THE NEXT 18 HOURS WILL BE QUITE UNSETTLED ACROSS NORTH TEXAS WITH
PERIODS OF SHOWERS AND THUNDERSTORMS AND THE POTENTIAL FOR BOTH
SEVERE WEATHER AND FLASH FLOODING. WHILE MOST AREAS WILL PICK UP
SOME RAINFALL THROUGH LATE TONIGHT...THE MAIN CHALLENGE WILL BE
NARROWING DOWN THE HIGHEST POTENTIAL FOR HEAVY RAINFALL AND FLASH
FLOODING. THERE ARE A COUPLE OF COMPLICATING FACTORS THAT COULD
HAVE SIGNIFICANT IMPACTS ON THE SHORT TERM FORECAST INCLUDING THE
POTENTIAL FOR UNDERESTIMATING THE SEVERE THREAT.
CONCERNING THE SHORT TERM SEVERE WEATHER THREAT...LATEST SATELLITE
IMAGERY SHOWS SUBSTANTIAL BREAKS IN THE CLOUD COVER ACROSS THE
FAR SOUTHERN PARTS OF THE CWA INTO SOUTHEAST TEXAS. THIS IS
IMPORTANT BECAUSE TEMPERATURES IN HENDERSON AND ANDERSON COUNTIES
ARE IN THE MID 60S WHILE TEMPERATURE ACROSS BELL AND MILAM
COUNTIES ARE IN THE LOWER 80S. THIS DIFFERENTIAL HEATING BOUNDARY
WILL EFFECTIVELY ACT AS A WARM FRONT WITH STRONGLY BACKED WINDS TO
THE NORTH OF THE BOUNDARY. LOCALLY RUN SEVERE PARAMETERS INDICATE
AROUND 2000J/KG OF SURFACE BASED CAPE WITH LITTLE INHIBITION. MORE
IMPORTANTLY...LOW LEVEL TURNING OF THE WINDS IS QUITE STRONG AND
THERE IS AMPLE LOW LEVEL CAPE. GIVEN THE VERY HIGH SURFACE
DEWPOINTS...LCLS ARE LOW AND THIS AREA WOULD NEED TO BE MONITORED
FOR A LOCALLY ENHANCED TORNADO THREAT ESPECIALLY IF STORMS DEVELOP
ALONG THE BOUNDARY ITSELF.
ELSEWHERE...THERE IS A POTENTIAL FOR MORE ISOLATED SEVERE
THUNDERSTORMS THROUGH THE NIGHT ACROSS NORTH TEXAS GIVEN AMPLE
DEEP LAYER SHEAR OF AROUND 50KTS. WITH DEEP MOISTURE IN
PLACE...LAPSE RATES ARE NOT OVERLY STEEP BUT A MARGINALLY SEVERE
HAIL THREAT WOULD EXIST. THERE IS A LAYER OF MID LEVEL DRY AIR
OVER NORTH TEXAS WHICH COULD ENHANCE DOWNDRAFTS LOCALLY SUPPORTING
A LOW END DAMAGING WIND THREAT.
THE MORE SIGNIFICANT HAZARD ACROSS NORTH TEXAS APPEARS TO BE THE
POTENTIAL FOR FLASH FLOODING THROUGH TONIGHT. THE MID LEVEL DRY
AIR MENTIONED ABOVE HAS BEEN A THORN IN OUR SIDE IN TRYING TO
DETERMINE THE LOCATION OF HEAVIEST RAINFALL. MODEL GUIDANCE
CONTINUES TO INDICATE AT LEAST WEAK SUBSIDENCE INCREASING ACROSS
THE WESTERN HALF OF THE CWA THROUGH LATE THIS EVENING. AIRCRAFT
SOUNDINGS FROM DFW AND DAL SHOW THIS LAYER OF DRY AIR FROM ABOUT
700MB TO 550MB. MORE IMPORTANTLY...LATEST SOUNDINGS INDICATE THAT
THIS DRY AIR IS SINKING...IMPLYING DOWNWARD VERTICAL MOTIONS.
LATEST FORECAST WILL FOLLOW THE ASSUMPTION THAT SOME DRIER AIR
WILL REMAIN IN PLACE ACROSS THE WESTERN HALF OF THE CWA...OR MORE
SPECIFIC...FROM SOUTHWEST TO NORTHEAST ACROSS THE CWA FROM NEAR
GOLDTHWAITE TO HILLSBORO TO SHERMAN. THIS WILL BE IN THE FORM OF A
TIGHT THETA-E BOUNDARY ALONG THESE AREAS. AS THE MAIN UPPER LOW
EJECTS EASTWARD LATER TONIGHT LARGE SCALE FORCING WILL CONTINUE TO
INCREASE. THE COVERAGE OF SHOWERS AND THUNDERSTORMS SHOULD
INCREASE DRAMATICALLY AFTER DARK...MAINLY FROM 9PM TO 2AM. THE
AFOREMENTIONED THETA-E BOUNDARY THEN BECOMES ESPECIALLY IMPORTANT
BECAUSE MOST OF THE HEAVY PRECIPITATION WILL BE ALONG AND EAST OF
THIS BOUNDARY. WITH A 50KT LLJ PUMPING RICH MOISTURE INTO THIS
SYSTEM...EXPECT SEVERAL HOURS OF TRAINING SHOWERS AND
THUNDERSTORMS...MAINLY ACROSS THE EAST AND SOUTHEAST COUNTIES. THE
CURRENT FLASH FLOOD WATCH HIGHLIGHTS THE AREAS WHERE WE THINK THE
BEST CHANCE FOR TRAINING THUNDERSTORMS EXISTS. OF COURSE...IF THIS
IS OFF ANY BIT...CONSIDERABLY HEAVIER RAINFALL COULD FALL FARTHER
WEST. THE LAST FEW RUNS OF THE HRRR SEEM TO SUGGEST THAT MUCH
HEAVIER RAINFALL WILL FALL WEST...BUT IT SEEMS TO BE THE OUTLIER
AT THIS TIME AND DOESNT APPEAR TO BE HANDLING THE DRY AIR AS WELL.
THAT BEING SAID...CURRENT FLASH FLOOD WATCH CONFIGURATION WILL
REMAIN THE SAME...BUT IF IT BECOMES APPARENT THAT HEAVIER RAINFALL
WILL OCCUR WEST...WE WILL EXPAND IT THIS EVENING. WITH PWS IN
EXCESS OF 2 INCHES...WHICH IS ANOMALOUSLY HIGH FOR LATE
OCTOBER...AND SURFACE TO 700MB THETA-E DIFFERENCE OF ONLY ABOUT 5
DEG K...VERY HEAVY RAINFALL IS EXPECTED. THUNDERSTORMS SHOULD BE
ABLE TO MAINTAIN EXTREMELY EFFICIENT RAINFALL RATES FOR AN
EXTENDED PERIOD OF TIME. RAINFALL AMOUNTS IN THE WATCH AREA SHOULD
AVERAGE 3 TO 5 INCHES WITH ISOLATED AMOUNTS IN EXCESS OF 7 INCHES.
ALL OF THIS ACTIVITY SHOULD MOVE EAST DURING THE MORNING HOURS
THURSDAY WITH MUCH DRIER AIR MOVING IN. WINDS WILL DIMINISH DURING
THE DAY AND TRICK OR TREATING WEATHER SHOULD BE QUITE NICE. THE
MAIN UPPER TROUGH WILL MOVE EAST AND A LARGE SURFACE HIGH WILL
BUILD IN FOR THE WEEKEND. THIS SHOULD BE SHORT LIVED AS ANOTHER
STRONG SYSTEM MOVES INTO THE WESTERN US EARLY NEXT WEEK. MOISTURE
WILL BE QUICK TO RETURN WITH RAIN CHANCES FOR MONDAY AND TUESDAY.
DUNN
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 70 79 53 77 50 / 80 20 5 0 0
WACO, TX 70 79 47 77 47 / 100 20 5 0 0
PARIS, TX 68 78 50 74 46 / 100 20 5 0 0
DENTON, TX 67 75 50 74 43 / 80 10 5 0 0
MCKINNEY, TX 69 76 50 76 46 / 100 20 5 0 0
DALLAS, TX 72 79 54 78 52 / 90 20 5 0 0
TERRELL, TX 71 78 50 76 47 / 100 20 5 0 0
CORSICANA, TX 70 80 52 75 50 / 100 30 5 0 0
TEMPLE, TX 71 79 48 78 49 / 100 30 5 0 0
MINERAL WELLS, TX 67 75 44 76 45 / 60 10 5 0 0
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH THURSDAY MORNING FOR TXZ095-105>107-
120>123-135-146>148-158-160>162-174-175.
&&
$$
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1253 PM CDT WED OCT 30 2013
.DISCUSSION...
Please see aviation below for my discussion.
&&
.AVIATION...
Well, as I expected this time yesterday, flight weather conditions
across West Central Texas remain challenging. I believe VFR
conditions will return this afternoon. However, return to VFR
conditions will be slow and spotty for the next hour or so. The best
locations for Thunderstorms will be across our eastern counties this
afternoon and evening, where instability will be better.
Huber
&&
.PREV DISCUSSION... /ISSUED 1222 PM CDT WED OCT 30 2013/
UPDATE...
The latest WSR-88D data indicate showers are continuing to develop
across West Central Texas. However, I`m not seeing the thunderstorms
we were expecting. I believe the atmosphere over West Central Texas
is still too stable to initiate any deep convection. Plus, the low
clouds are continuing, and that`s not helping increase the low-level
instability. Anyway, I just completed an update of my Weather, POP,
QPF, and Sky grids; I lowered POPs to no higher than 40 for the
remainder of today, and I decided on weather grids of chance for
rain showers and slight chance for thunderstorms, also for the
remainder of today across all of West Central Texas. In addition 100
percent sky cover looked best for the remainder of today.
Huber
PREV DISCUSSION... /ISSUED 622 AM CDT WED OCT 30 2013/
DISCUSSION...
See the 12z aviation discussion below.
AVIATION...
This is certainly not an easy TAF package. Uncertainty exists
regarding both ceiling heights and convective development.
Basically, we are looking at widespread MVFR ceilings this morning
with possible TEMPO IFR conditions. Elevated radar echoes continue
to increase as upper-level ascent improves over the area and we`ll
see showers and a few thunderstorms develop later this morning into
the afternoon hours. The greatest thunderstorm chances will occur
south and east of KSJT late this afternoon and this evening. Thus,
no mention of thunder was included at KSJT or KABI. However, I did
include vicinity remarks at the remaining terminals after peak
heating.
Winds will be from the south today at 14-18 kts for the most part
but may gust over 25 kts at times. I expect wind speeds to relax
around 00z before veering to the west late tonight as a Pacific cold
front moves across West Central Texas. This will bring drier air
into the area, ending precipitation from west to east after
midnight. I have low confidence in the potential for low ceilings
developing again tonight. Widespread convection over the southeast
terminals may lift cloud bases into VFR category or they could lower
significantly if precip is light. I opted to go with a prevailing
ceiling around 2000 ft at KJCT, KBBD, and KSOA tonight with
prevailing VFR conditions at KSJT and KABI.
Johnson
PREV DISCUSSION... /ISSUED 421 AM CDT WED OCT 30 2013/
SHORT TERM...(Today and tonight)
The deep cyclone over the Great Basin has begun to move east over
the past 12 hours and will continue to do so through tonight. Strong
southwesterly flow downstream of the base of the trough continues to
advect abundant mid/upper-level moisture into the Southern Plains
per the latest water vapor loop. An upper-level jet exceeding 100
kts was analyzed in the 00z RAOB data from southern NM into eastern
CO and the latest RAP analysis suggests that its speed has increased
to near 130 kts. We have already seen scattered showers (and a few
thunderstorms) this evening but low-level forcing remains meager as
of now. However, this H25 jet streak will propagate to the east
during the day. This should place West TX within a favored area for
mesoscale ascent; the right entrance region.
I think precipitation coverage will be limited this morning but
should begin to increase as mesoscale lift is augmented by synoptic
scale ascent associated with the upper trough. When and where
precipitation develops today remains uncertain given the lack of
focused low-level convergence but the greatest rain chances are
expected to be over the Heartland and Northwest Hill Country (as
usual!). Instability and effective shear values will likely be
sufficient for organized convection. However, with precip becoming
more widespread, I think the ability to realize the full scope of
the instability will be limited. We may see a few elevated "hailers"
today but I think the general trend will be showers and garden
variety thunderstorms. However, I will mention the potential for
severe weather in the Hazardous Weather Outlook and graphicasts.
A Pacific cold front will traverse the CWA tonight, bringing much
drier air from the west and effectively ending rain chances from
west to east after midnight. This front will provide the strongest
surface forcing but it will be brief and transient. Some of this
activity may linger into Thursday morning but the bulk will be to
our east by then. I lowered precipitation amounts a bit given the
lack of focus, but precipitable water values of 1.4 to 1.7 inches
suggest that there remains some potential for locally heavy
rainfall. Eastern areas may see around 1 inch on average but most of
the area will likely see less than 1/2 inch.
Johnson
LONG TERM...
/Thursday through Sunday/
Looks like a quiet period across West Central Texas. The upper level
trough will be east of the area, taking the convection with it. The
upper level pattern will bring a low amplitude ridge over the
Southern Plains by this weekend. Surface high pressure will build in
behind a secondary cool front. Also, northwest winds will pick up
behind the current cool front on Thursday with some gusts near 25
mph. However, the airmass behind the front is Pacific so
temperatures will only be slightly cooler for Thursday and Friday.
Highs will be in the 70s to lower 80s. Lows will be mainly in the
40s. It will be slightly cooler for Saturday and Sunday with highs
in the upper 60s to mid 70s with lows in the 40s and 50s.
/Sunday Night through Tuesday/
Pattern begins to shift back to upper level cyclonic flow across the
Southern Plains early next week, with a broad trough located across
the western U.S. This system will bring a chance of showers and
thunderstorms to our area. The ECMWF model is more amplified with
the trough than the GFS model. Will go with more progressive GFS
solution for now. Also, there may be a tropical connection from the
Eastern Pacific. Low level moisture will struggle to return early on
due to surface high pressure over the Gulf of Mexico. However,
modified moisture will return by Monday and Tuesday on southerly
flow with dewpoints in the 50s to possibly lower 60s. Will go with
slight chance to chance POPS for Monday and Tuesday. Temperatures
will remain mild with highs in the 70s. The rain will end by late
Tuesday night and a dry forecast is in store for Wednesday.
21
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 80 60 75 49 75 / 50 50 5 0 0
San Angelo 78 59 78 42 79 / 50 50 5 0 0
Junction 80 64 81 38 80 / 70 70 20 0 0
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
25/21/Johnson/Huber
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1222 PM CDT WED OCT 30 2013
.UPDATE...
The latest WSR-88D data indicate showers are continuing to develop
across West Central Texas. However, I`m not seeing the thunderstorms
we were expecting. I believe the atmosphere over West Central Texas
is still too stable to initiate any deep convection. Plus, the low
clouds are continuing, and that`s not helping increase the low-level
instability. Anyway, I just completed an update of my Weather, POP,
QPF, and Sky grids; I lowered POPs to no higher than 40 for the
remainder of today, and I decided on weather grids of chance for
rain showers and slight chance for thunderstorms, also for the
remainder of today across all of West Central Texas. In addition 100
percent sky cover looked best for the remainder of today.
Huber
&&
.PREV DISCUSSION... /ISSUED 622 AM CDT WED OCT 30 2013/
DISCUSSION...
See the 12z aviation discussion below.
AVIATION...
This is certainly not an easy TAF package. Uncertainty exists
regarding both ceiling heights and convective development.
Basically, we are looking at widespread MVFR ceilings this morning
with possible TEMPO IFR conditions. Elevated radar echoes continue
to increase as upper-level ascent improves over the area and we`ll
see showers and a few thunderstorms develop later this morning into
the afternoon hours. The greatest thunderstorm chances will occur
south and east of KSJT late this afternoon and this evening. Thus,
no mention of thunder was included at KSJT or KABI. However, I did
include vicinity remarks at the remaining terminals after peak
heating.
Winds will be from the south today at 14-18 kts for the most part
but may gust over 25 kts at times. I expect wind speeds to relax
around 00z before veering to the west late tonight as a Pacific cold
front moves across West Central Texas. This will bring drier air
into the area, ending precipitation from west to east after
midnight. I have low confidence in the potential for low ceilings
developing again tonight. Widespread convection over the southeast
terminals may lift cloud bases into VFR category or they could lower
significantly if precip is light. I opted to go with a prevailing
ceiling around 2000 ft at KJCT, KBBD, and KSOA tonight with
prevailing VFR conditions at KSJT and KABI.
Johnson
PREV DISCUSSION... /ISSUED 421 AM CDT WED OCT 30 2013/
SHORT TERM...(Today and tonight)
The deep cyclone over the Great Basin has begun to move east over
the past 12 hours and will continue to do so through tonight. Strong
southwesterly flow downstream of the base of the trough continues to
advect abundant mid/upper-level moisture into the Southern Plains
per the latest water vapor loop. An upper-level jet exceeding 100
kts was analyzed in the 00z RAOB data from southern NM into eastern
CO and the latest RAP analysis suggests that its speed has increased
to near 130 kts. We have already seen scattered showers (and a few
thunderstorms) this evening but low-level forcing remains meager as
of now. However, this H25 jet streak will propagate to the east
during the day. This should place West TX within a favored area for
mesoscale ascent; the right entrance region.
I think precipitation coverage will be limited this morning but
should begin to increase as mesoscale lift is augmented by synoptic
scale ascent associated with the upper trough. When and where
precipitation develops today remains uncertain given the lack of
focused low-level convergence but the greatest rain chances are
expected to be over the Heartland and Northwest Hill Country (as
usual!). Instability and effective shear values will likely be
sufficient for organized convection. However, with precip becoming
more widespread, I think the ability to realize the full scope of
the instability will be limited. We may see a few elevated "hailers"
today but I think the general trend will be showers and garden
variety thunderstorms. However, I will mention the potential for
severe weather in the Hazardous Weather Outlook and graphicasts.
A Pacific cold front will traverse the CWA tonight, bringing much
drier air from the west and effectively ending rain chances from
west to east after midnight. This front will provide the strongest
surface forcing but it will be brief and transient. Some of this
activity may linger into Thursday morning but the bulk will be to
our east by then. I lowered precipitation amounts a bit given the
lack of focus, but precipitable water values of 1.4 to 1.7 inches
suggest that there remains some potential for locally heavy
rainfall. Eastern areas may see around 1 inch on average but most of
the area will likely see less than 1/2 inch.
Johnson
LONG TERM...
/Thursday through Sunday/
Looks like a quiet period across West Central Texas. The upper level
trough will be east of the area, taking the convection with it. The
upper level pattern will bring a low amplitude ridge over the
Southern Plains by this weekend. Surface high pressure will build in
behind a secondary cool front. Also, northwest winds will pick up
behind the current cool front on Thursday with some gusts near 25
mph. However, the airmass behind the front is Pacific so
temperatures will only be slightly cooler for Thursday and Friday.
Highs will be in the 70s to lower 80s. Lows will be mainly in the
40s. It will be slightly cooler for Saturday and Sunday with highs
in the upper 60s to mid 70s with lows in the 40s and 50s.
/Sunday Night through Tuesday/
Pattern begins to shift back to upper level cyclonic flow across the
Southern Plains early next week, with a broad trough located across
the western U.S. This system will bring a chance of showers and
thunderstorms to our area. The ECMWF model is more amplified with
the trough than the GFS model. Will go with more progressive GFS
solution for now. Also, there may be a tropical connection from the
Eastern Pacific. Low level moisture will struggle to return early on
due to surface high pressure over the Gulf of Mexico. However,
modified moisture will return by Monday and Tuesday on southerly
flow with dewpoints in the 50s to possibly lower 60s. Will go with
slight chance to chance POPS for Monday and Tuesday. Temperatures
will remain mild with highs in the 70s. The rain will end by late
Tuesday night and a dry forecast is in store for Wednesday.
21
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 80 60 75 49 75 / 50 50 5 0 0
San Angelo 78 59 78 42 79 / 50 50 5 0 0
Junction 80 64 81 38 80 / 70 70 20 0 0
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
25/21/Johnson/Huber
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
622 AM CDT WED OCT 30 2013
.DISCUSSION...
See the 12z aviation discussion below.
&&
.AVIATION...
This is certainly not an easy TAF package. Uncertainty exists
regarding both ceiling heights and convective development.
Basically, we are looking at widespread MVFR ceilings this morning
with possible TEMPO IFR conditions. Elevated radar echoes continue
to increase as upper-level ascent improves over the area and we`ll
see showers and a few thunderstorms develop later this morning into
the afternoon hours. The greatest thunderstorm chances will occur
south and east of KSJT late this afternoon and this evening. Thus,
no mention of thunder was included at KSJT or KABI. However, I did
include vicinity remarks at the remaining terminals after peak
heating.
Winds will be from the south today at 14-18 kts for the most part
but may gust over 25 kts at times. I expect wind speeds to relax
around 00z before veering to the west late tonight as a Pacific cold
front moves across West Central Texas. This will bring drier air
into the area, ending precipitation from west to east after
midnight. I have low confidence in the potential for low ceilings
developing again tonight. Widespread convection over the southeast
terminals may lift cloud bases into VFR category or they could lower
significantly if precip is light. I opted to go with a prevailing
ceiling around 2000 ft at KJCT, KBBD, and KSOA tonight with
prevailing VFR conditions at KSJT and KABI.
Johnson
&&
.PREV DISCUSSION... /ISSUED 421 AM CDT WED OCT 30 2013/
SHORT TERM...(Today and tonight)
The deep cyclone over the Great Basin has begun to move east over
the past 12 hours and will continue to do so through tonight. Strong
southwesterly flow downstream of the base of the trough continues to
advect abundant mid/upper-level moisture into the Southern Plains
per the latest water vapor loop. An upper-level jet exceeding 100
kts was analyzed in the 00z RAOB data from southern NM into eastern
CO and the latest RAP analysis suggests that its speed has increased
to near 130 kts. We have already seen scattered showers (and a few
thunderstorms) this evening but low-level forcing remains meager as
of now. However, this H25 jet streak will propagate to the east
during the day. This should place West TX within a favored area for
mesoscale ascent; the right entrance region.
I think precipitation coverage will be limited this morning but
should begin to increase as mesoscale lift is augmented by synoptic
scale ascent associated with the upper trough. When and where
precipitation develops today remains uncertain given the lack of
focused low-level convergence but the greatest rain chances are
expected to be over the Heartland and Northwest Hill Country (as
usual!). Instability and effective shear values will likely be
sufficient for organized convection. However, with precip becoming
more widespread, I think the ability to realize the full scope of
the instability will be limited. We may see a few elevated "hailers"
today but I think the general trend will be showers and garden
variety thunderstorms. However, I will mention the potential for
severe weather in the Hazardous Weather Outlook and graphicasts.
A Pacific cold front will traverse the CWA tonight, bringing much
drier air from the west and effectively ending rain chances from
west to east after midnight. This front will provide the strongest
surface forcing but it will be brief and transient. Some of this
activity may linger into Thursday morning but the bulk will be to
our east by then. I lowered precipitation amounts a bit given the
lack of focus, but precipitable water values of 1.4 to 1.7 inches
suggest that there remains some potential for locally heavy
rainfall. Eastern areas may see around 1 inch on average but most of
the area will likely see less than 1/2 inch.
Johnson
LONG TERM...
/Thursday through Sunday/
Looks like a quiet period across West Central Texas. The upper level
trough will be east of the area, taking the convection with it. The
upper level pattern will bring a low amplitude ridge over the
Southern Plains by this weekend. Surface high pressure will build in
behind a secondary cool front. Also, northwest winds will pick up
behind the current cool front on Thursday with some gusts near 25
mph. However, the airmass behind the front is Pacific so
temperatures will only be slightly cooler for Thursday and Friday.
Highs will be in the 70s to lower 80s. Lows will be mainly in the
40s. It will be slightly cooler for Saturday and Sunday with highs
in the upper 60s to mid 70s with lows in the 40s and 50s.
/Sunday Night through Tuesday/
Pattern begins to shift back to upper level cyclonic flow across the
Southern Plains early next week, with a broad trough located across
the western U.S. This system will bring a chance of showers and
thunderstorms to our area. The ECMWF model is more amplified with
the trough than the GFS model. Will go with more progressive GFS
solution for now. Also, there may be a tropical connection from the
Eastern Pacific. Low level moisture will struggle to return early on
due to surface high pressure over the Gulf of Mexico. However,
modified moisture will return by Monday and Tuesday on southerly
flow with dewpoints in the 50s to possibly lower 60s. Will go with
slight chance to chance POPS for Monday and Tuesday. Temperatures
will remain mild with highs in the 70s. The rain will end by late
Tuesday night and a dry forecast is in store for Wednesday.
21
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 80 60 75 49 75 / 50 50 5 0 0
San Angelo 78 59 78 42 79 / 50 50 5 0 0
Junction 80 64 81 38 80 / 70 70 20 0 0
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
25
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
421 AM CDT WED OCT 30 2013
.SHORT TERM...(Today and tonight)
The deep cyclone over the Great Basin has begun to move east over
the past 12 hours and will continue to do so through tonight. Strong
southwesterly flow downstream of the base of the trough continues to
advect abundant mid/upper-level moisture into the Southern Plains
per the latest water vapor loop. An upper-level jet exceeding 100
kts was analyzed in the 00z RAOB data from southern NM into eastern
CO and the latest RAP analysis suggests that its speed has increased
to near 130 kts. We have already seen scattered showers (and a few
thunderstorms) this evening but low-level forcing remains meager as
of now. However, this H25 jet streak will propagate to the east
during the day. This should place West TX within a favored area for
mesoscale ascent; the right entrance region.
I think precipitation coverage will be limited this morning but
should begin to increase as mesoscale lift is augmented by synoptic
scale ascent associated with the upper trough. When and where
precipitation develops today remains uncertain given the lack of
focused low-level convergence but the greatest rain chances are
expected to be over the Heartland and Northwest Hill Country (as
usual!). Instability and effective shear values will likely be
sufficient for organized convection. However, with precip becoming
more widespread, I think the ability to realize the full scope of
the instability will be limited. We may see a few elevated "hailers"
today but I think the general trend will be showers and garden
variety thunderstorms. However, I will mention the potential for
severe weather in the Hazardous Weather Outlook and graphicasts.
A Pacific cold front will traverse the CWA tonight, bringing much
drier air from the west and effectively ending rain chances from
west to east after midnight. This front will provide the strongest
surface forcing but it will be brief and transient. Some of this
activity may linger into Thursday morning but the bulk will be to
our east by then. I lowered precipitation amounts a bit given the
lack of focus, but precipitable water values of 1.4 to 1.7 inches
suggest that there remains some potential for locally heavy
rainfall. Eastern areas may see around 1 inch on average but most of
the area will likely see less than 1/2 inch.
Johnson
.LONG TERM...
/Thursday through Sunday/
Looks like a quiet period across West Central Texas. The upper level
trough will be east of the area, taking the convection with it. The
upper level pattern will bring a low amplitude ridge over the
Southern Plains by this weekend. Surface high pressure will build in
behind a secondary cool front. Also, northwest winds will pick up
behind the current cool front on Thursday with some gusts near 25 mph.
However, the airmass behind the front is Pacific so temperatures
will only be slightly cooler for Thursday and Friday. Highs will be
in the 70s to lower 80s. Lows will be mainly in the 40s. It will be
slightly cooler for Saturday and Sunday with highs in the upper 60s
to mid 70s with lows in the 40s and 50s.
/Sunday Night through Tuesday/
Pattern begins to shift back to upper level cyclonic flow across the
Southern Plains early next week, with a broad trough located across
the western U.S. This system will bring a chance of showers and
thunderstorms to our area. The ECMWF model is more amplified with
the trough than the GFS model. Will go with more progressive GFS
solution for now. Also, there may be a tropical connection from the
Eastern Pacific. Low level moisture will struggle to return early on
due to surface high pressure over the Gulf of Mexico. However,
modified moisture will return by Monday and Tuesday on southerly
flow with dewpoints in the 50s to possibly lower 60s. Will go with
slight chance to chance POPS for Monday and Tuesday. Temperatures
will remain mild with highs in the 70s. The rain will end by late
Tuesday night and a dry forecast is in store for Wednesday.
21
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 80 60 75 49 75 / 50 50 5 0 0
San Angelo 78 59 78 42 79 / 50 50 5 0 0
Junction 80 64 81 38 80 / 70 70 20 0 0
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
1131 PM CDT TUE OCT 29 2013
.DISCUSSION...
SEE AVIATION FOR THE 06Z TAF DISCUSSION.
&&
.AVIATION...
AT 04Z MVFR CIGS WERE DEVELOPING ACROSS SOUTH CENTRAL TEXAS. FLIGHT
CONDITIONS WILL DETERIORATE TO IFR BETWEEN 09Z AND 11Z WITH THE
DEVELOPMENT OF -DZ/-SHRA. CONDITIONS WILL GRADUALLY IMPROVE TO VFR
BY 20Z. ISOLATED TO SCATTERED SHOWERS WILL OCCUR OVERNIGHT WITH
THUNDERSTORMS ON THE INCREASE WEDNESDAY AFTERNOON AND EVENING. SFC
WINDS OVERNIGHT WILL BE SE AT 5 TO 10 KTS...10 TO 15 KTS WEDNESDAY
AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 943 PM CDT TUE OCT 29 2013/
UPDATE...
ISOLATED SHOWERS AND THUNDERSTORMS DEVELOPED OVER THE HILL COUNTRY
AND RIO GRANDE PLAINS EARLIER THIS EVENING AND MOST HAVE CURRENTLY
MOVED NORTH OF THE HILL COUNTRY. HAVE RESTRICTED THUNDER MENTION
FOR THE REST OF THIS EVENING TO HILL COUNTRY AND EDWARDS PLATEAU.
PWS HAVE RISEN TO 1.5 TO 1.8 INCHES OVER SOUTH CENTRAL TEXAS WITH
AN AREA NEAR 2 INCHES MOVING TOWARD THE LOWER TEXAS COAST AS NOTED
ON EVENING SATELLITE DERIVED PW AND SOUNDING DATA. SHOWERS ARE
SEEN BY RADAR OFF THE LOWER TEXAS COAST IN THE HIGHER PW TROPICAL
AIRMASS. THESE SHOWERS WILL MOVE INTO THE COASTAL PLAINS OVERNIGHT
AND BE NEARING THE I-3 CORRIDOR BY WEDNESDAY MORNING. HAVE BOOSTED
POPS ALONG AND EAST OF I-35. SHOWERS AND THUNDERSTORMS OVER NORTH
CENTRAL MEXICO IN ASSOCIATION AN UPPER LEVEL SPEED MAX ARE MOVING
TOWARD SOUTH CENTRAL TEXAS AND WILL BE CROSSING THE RIO GRANDE
OVERNIGHT. HAVE ALSO BOOSTED POPS OVER THE SOUTHERN RIO GRANDE
PLAINS. REMAINDER OF THE SOUTH CENTRAL TEXAS FORECAST IS ON TRACK
BASED ON 18Z MODELS CONSISTENCY WITH 12Z MODELS. SCATTERED TO
NUMEROUS SHOWERS AND THUNDERSTORMS PRODUCING RAINFALL TOTALS OF
1 TO 2 INCHES ARE EXPECTED WITH LOCALLY HEAVY RAINFALL AND TOTALS
OF 4 TO 5 INCHES IS POSSIBLE WEDNESDAY INTO THURSDAY.
PREV DISCUSSION... /ISSUED 632 PM CDT TUE OCT 29 2013/
DISCUSSION...
SEE AVIATION FOR THE 00Z TAF DISCUSSION.
AVIATION...
THIS EVENING ISOLATED SHOWERS AND THUNDERSTORMS HAVE FORMED ACROSS
THE RIO GRANDE PLAINS AND EDWARDS PLATEAU. THE INDIVIDUAL CELLS WERE
MOVING NORTHEAST AT 25 TO 30 MPH. THE HI-RES ARW...TTU 3KM WRF AND
3KM HRRR ALL INDICATE THAT THE BEST CHANCE FOR SHOWERS AND THUNDERSTORMS
THIS EVENING WILL BE ACROSS THE RIO GRANDE PLAINS...EDWARDS PLATEAU
AND WESTERN HILL COUNTRY. THUS THE KDRT TERMINAL WILL HAVE THE HIGHEST
RISK OF BEING IMPACTED BY CONVECTION THIS EVENING. ANY CONVECTION
AFTER MIDNIGHT WILL BE STREAMER TYPE SHOWERS EMBEDDED IN THE WARM
S TO SE FLOW FROM THE GULF. THESE SHOWERS MAY PASS OVER THE I-35
TERMINALS OVERNIGHT BUT WILL NOT IMPACT THE PREVAILING FLIGHT
CATEGORIES. THE CHANCE FOR THUNDERSTORMS INCREASES DRAMATICALLY
WEDNESDAY AFTERNOON AND EVENING AND THIS WILL BE REFLECTED WITH
THE INCLUSION OF TEMPO GROUPS FOR THE I-35 TAF SITES AND A PROB30
GROUP FOR THE KDRT TAF SITE. OTHERWISE VFR CONDITIONS WILL PREVAIL
THIS EVENING LOWERING TO MVFR BETWEEN 04Z AND 06Z. IFR CONDITIONS
BY 10Z WITH -DZ/BR POSSIBLE. CONDITIONS WILL IMPROVE TO MVFR BY
15Z AND VFR BY 20Z.
PREV DISCUSSION... /ISSUED 327 PM CDT TUE OCT 29 2013/
SHORT TERM (TONIGHT THROUGH WEDNESDAY NIGHT)...
AN UNSEASONABLY WARM-BREEZY LATE OCTOBER AFTERNOON...AS DEEP SLY
LOW LEVEL WINDS BROUGHT WARM MOIST AIR OFF THE GULF. THE BRISK SLY
WINDS WERE A RESULT OF A BROAD LOW PRESSURE SYSTEM DROPPING
TOWARDS/INTO THE GREAT BASIN REGION...WHICH WAS IN TURN LOWERING
SURFACE PRESSURES ON THE LEE SIDE OF THE ROCKIES. THEREFORE
ANOTHER WARM NIGHT WITH BETTER CHANCES FOR SHOWERS(STORMS FAR
WEST) AS MINOR DISTURBANCES TRACK NEWD ACROSS TX. RAIN CHANCES
INCREASE DRAMATICALLY WEDNESDAY INTO WEDNESDAY NIGHT. DISTURBANCES
IN THE STRONG SWLY FLOW ALOFT INTERACT WITH DEEP MOISTURE(PW`S
NEAR 2 INCHES) AND A COLD FRONT PUSHING SEWD INTO THE NWRN CWA
LATE WED NIGHT. HAVE DECIDED TO HOLD OFF ON A FLASH FLOOD WATCH
FOR THE MOMENT...ALTHOUGH RAIN CHANCES ARE VERY HIGH...MODELS
HAVE BACKED OFF SLIGHTLY WITH QPF AMOUNTS. HAVE GENERALLY ACCEPTED
HPC QPF VALUES WITH SLIGHT ADJUSTMENTS TO BLEND IN WITH SURROUNDING
WFO`S. THE GFS AND NAM BOTH SIMILAR WITH 1-2 INCH STORM TOTAL
AMOUNTS MAINLY ALONG/EAST OF 281 AND ALONG/NORTH OF I10. LOCALLY
HEAVIER ISOLATED AMOUNTS OF 4-5 INCHES POSSIBLE WITH
TRAINING/BACK-BUILDING STORMS NEAR THE COLD FRONT. FOR NOW WILL
HANDLE WITH MENTION OF LOCALLY HEAVY RAIN.
LONG TERM (THURSDAY THROUGH TUESDAY)...
RAIN CHANCES DROPPING OFF DRAMATICALLY FROM THE NORTHWEST DURING
THE DAY THURSDAY AS THE UPPER TROUGH RACES EASTWARD AND A DRIER
AIRMASS BUILDS IN FROM THE WEST. SPLIT UP POPS FOR MORNING AND
AFTERNOON TO SHOW DECREASING POPS FROM THE WEST...CLEARING
THURSDAY NIGHT. DRIER WEST-NWLY FLOW ALOFT FRIDAY INTO SUNDAY
NIGHT AS AN UPPER RIDGE BUILDS IN FROM THE WEST. DRY PLEASANT
WEATHER FRIDAY INTO SATURDAY NIGHT. NEAR NORMAL TEMPERATURES WITH
MILD- COOL NIGHTS AND WARM DURING THE DAY. RAIN CHANCES INCREASE
FROM THE WEST LATE SUNDAY INTO MONDAY-TUESDAY AS THE UPPER RIDGE
PUSHES EAST AND A MOIST SWLY FLOW AGAIN DEVELOPS ALOFT.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 71 80 72 83 53 / 30 80 80 50 -
AUSTIN BERGSTROM INTL AIRPORT 70 81 72 82 47 / 30 80 80 50 10
NEW BRAUNFELS MUNI AIRPORT 68 81 70 83 49 / 30 80 80 50 10
BURNET MUNI AIRPORT 69 78 67 80 49 / 30 80 80 30 -
DEL RIO INTL AIRPORT 74 82 67 84 53 / 30 40 30 10 -
GEORGETOWN MUNI AIRPORT 69 78 70 81 47 / 30 80 80 40 -
HONDO MUNI AIRPORT 74 84 72 86 50 / 20 60 70 40 10
SAN MARCOS MUNI AIRPORT 69 80 70 83 49 / 30 80 80 50 10
LA GRANGE - FAYETTE REGIONAL 72 84 73 83 54 / 30 80 80 60 10
SAN ANTONIO INTL AIRPORT 73 84 73 85 52 / 20 70 70 50 10
STINSON MUNI AIRPORT 73 85 73 86 53 / 20 70 70 50 10
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...13
SYNOPTIC/GRIDS...04
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
913 PM EDT THU OCT 31 2013
.SYNOPSIS...
LOW PRESSURE OVER THE CENTRAL PLAINS WILL MOVE NORTHEAST INTO
SOUTHERN ONTARIO BY FRIDAY MORNING. A STRONG COLD FRONT TRAILING
SOUTH FROM THE LOW WILL SWEEP ACROSS THE EASTERN UNITED STATES
FRIDAY. COOL HIGH PRESSURE WILL BUILD INTO THE AREA FROM THE WEST
FOR SATURDAY AND SUNDAY.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 845 PM EDT THURSDAY...
UPDATE MAINLY TO REDUCE POPS IN THE NEAR TERM PER LACK OF MUCH
RAINFALL ATTM GIVEN THE MID LEVEL DRY AIR STILL SEEN ON AREA RAOBS
THIS EVENING. HOWEVER AS THE UPPER SYSTEM TO THE WEST HEADS
QUICKLY OFF TO THE NE AFTER MIDNIGHT...SHOULD SEE INCREASING
MOISTURE TRANSPORT BEGIN TO FILL IN SHOWERS AT LEAST OVER THE
WEST AHEAD OF THE ARRIVAL OF A POTENTIAL LOW TOPPED LINE LATE THAT
IS CURRENTLY WELL OFF TO THE WEST ATTM. MOST GUIDANCE CONTINUES
TO SLOW DOWN THE EASTWARD PUSH TO ANY STRONGER LOW TOPPED SHOWER
BAND(S) WITH BOTH THE LOCAL RNK- WRF AND HRRR NOT CROSSING THE
WESTERN SLOPES UNTIL JUST BEFORE DAYBREAK. THEREFORE ALSO PULLED
BACK HIGHER POPS WEST UNTIL AFTER MIDNIGHT AND CUT BACK SOME OUT
EAST WHERE COULD BE EARLY FRIDAY BEFORE THE RESIDUAL LINE MAKES
IT OVER THE BLUE RIDGE.
OTRW WINDS AHEAD OF AND WITHIN ANY DEEPER SHOWERS THE MAIN
CONCERN OVERNIGHT WITH EVENING RAOBS ALREADY SHOWING 50+ KTS
AROUND 85H. HAVE TOYED WITH UPGRADING THE BLF/TAZEWELL REGION
TO A HIGH WIND WARNING BUT GIVEN SHORT DURATION OF THE HIGHER
SPEEDS WHEN THE FLOW IS TURNING MORE SW DECIDED TO HOLD OFF
RAMPING UP THE ADVISORY FOR NOW. HOWEVER DOES APPEAR THAT LATE
TONIGHT/EARLY FRIDAY THE BETTER JET WILL END UP EAST OF THE
MOUNTAINS WHERE ALSO BOOSTED SPEEDS EAST OF THE CURRENT ADVISORY.
TEMPS LOOK TO STAY ABOUT STEADY UNDER CLOUDS AND INCREASED MIXING
SO KEPT THE FAR SE IN THE MID TO UPPER 60S WITH 55-62 ELSW.
PREVIOUS VALID DISCUSSION...
NOT TOO MUCH CHANGE TO THE FORECAST EXPECTED. STILL LOOKING AT THE
STRONG LOW LVL JET OF 45-65 KNOTS ACROSS MS/WRN TN/WRN KY TO MOVE
EAST NORTHEAST THROUGH OUR AREA LATE THIS EVENING AND EARLY
OVERNIGHT. THIS WILL BE COMING THROUGH ALONG A LINE OF SHOWERS. THE
FLOW SUGGESTS THAT SOME HIGHER GUSTS ACROSS RIDGES ABOVE 3000 FEET
WILL MEET WIND ADVISORY LEVELS SO NO CHANGES PLANNED TO THE ONGOING
ADVISORY. WILL HAVE TO WATCH FOR ENHANCED GUSTS WITH ANY BOWING
POTENTIAL FROM THE SHOWERS. MODEL HELICITIES INDICATE 300-400 M2/S2
ARRIVING THIS EVENING IN THE WEST AND SHIFTING EAST OF THE BLUE
RIDGE FRIDAY MORNING. THIS IN THE 0-1KM RANGE. NOT THAT CONCERNED
WITH SPINUPS AND TIMING SUGGEST LACK OF INSTABILITY...BUT THE WINDS
WILL BE GUSTY.
AM MAKING A FORECAST BASED ON NAM/ECMWF BLEND. THESE MODELS SHOWING
THE FRONT ENTERING THE MTNS LATE TONIGHT AND THEN SLOWING UP AS WAVE
OF LOW PRESSURE SHIFTS FROM NRN GA INTO THE VA PIEDMONT THROUGH FRI
AFTN. THIS SHOULD HOLD PRECIP IN LONGER OUT EAST AND MODELS INDICATE
MARGINAL INSTABILITY SO LEFT THUNDER IN THE EAST WITH GUSTY WINDS.
NOT TOO CONCERNED WITH THUNDER IN THE MTNS TONIGHT.
SO LOOKING AT CATEGORICAL POPS WEST BY MIDNIGHT HEADING EAST OF THE
BLUE RIDGE BEFORE DAWN...THEN DRYING WORKING INTO THE MTNS AFTER 12Z-
15Z...BUT KEEPING HIGHER CHANCE TO CAT POPS ACROSS THE EAST UNTIL
MID AFTERNOON.
FOR TEMPS WILL KEEP LOWS MILD TONIGHT WITH MID 50S WEST TO LOWER 60S
EAST...AND TOMORROW WILL BE SIMILAR TO TODAY WITH LITTLE CHANGE IN
TEMPS ALOFT BUT MAINLY A DEWPOINT FRONT....SO WITH SHOWERS AROUND
ESPECIALLY EAST WENT CLOSE TO MET/LOCAL MOS IN THE EAST AND LOCAL
MOS WEST...WHICH COMES OUT TO LOWER 70S EAST TO MID TO UPPER 60S
WEST.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
AS OF 400 PM EDT THURSDAY...
FRONT SHOULD BE EXITING THE EASTERN CWA FRIDAY EVENING ALONG WITH
ANY LEFT-OVER SHOWERS ALTHOUGH SEVERAL MODELS ARE HINTING AT WEAK
ONE OR MORE WEAK WAVE DEVELOPING ALONG THE FRONT WHICH MAY SERVE TO
HOLD CLOUDS AND SLIGHT CHC OF POPS A FEW HOURS LATER INTO FRIDAY
NIGHT OVER THE PIEDMONT. COLD AIR PUSH UNIMPRESSIVE FRIDAY NIGHT
WITH H85 TEMPS ROUGHLY 3-5C BY SATURDAY MORNING BUT COOLER AIR
FILTERING IN DURING THE DAY FINALLY REACHING 0C IN THE NORTHWEST
SATURDAY NIGHT. TEMPS WILL STILL HAVE A CHANCE TO REBOUND TO NEAR
OR SLIGHTLY ABOVE SEASONAL CLIMO DURING THE DAY SATURDAY FROM
MID-50S NW TO M/U 60S FAR SOUTHEAST.
THE INCREASING NORTHWEST FLOW SATURDAY AND SATURDAY NIGHT BEGINS
TO GENERATE UPSLOPE CLOUDS AND THEN SOME RAIN AND/OR SNOW SHOWERS
ESPECIALLY AT HIGHER ELEVATIONS IN THE WEST. LITTLE SIGNIFICANT
QPF AND A DUSTING OF SNOW AT HIGHER ELEVATIONS BY SUNDAY MORNING.
CAN`T RULE OUR A STRAY SHOWER MAKING IT EAST OF THE BLUE RIDGE
SATURDAY EVENING PER LATE AFTERNOON INSTABILITY...BUT THIS SHOULD
GO AWAY SATURDAY NIGHT...SKIES CLEARING EAST OF THE MOUNTAINS.
CLOUDS WILL LINGER OVER THE MOUNTAINS INTO SUNDAY MORNING BEFORE
CLEARING THERE TOO.
SUNDAY LOOKS COOL BUT DRY AS HIGH PRESSURE PASSES OVHD...TEMPS IN
THE 40S/50S...AND FALLING SHY OF NORMALS. THIS WILL SET STAGE FOR
FROSTY NIGHT SUNDAY NIGHT AND MONDAY MORNING WITH TMINS IN THE
20S/30S.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 400 PM EDT THURSDAY...
HIGH PRESSURE IS EXPECTED TO PASS OVERHEAD MONDAY...THE COOLEST
TEMPERATURES NEXT WEEK OCCURRING MONDAY MORNING. AFTER
THAT...THICKNESSES RISE PER RIDGE OF HIGH PRESSURE BUILDING OVER
THE SOUTHEAST STATES. THIS WILL RESULTING IN A RETURN TO
SOUTHERLY FLOW ACROSS OUR AREA BY MID WEEK ASSOCIATED WITH
MODERATING TEMPERATURES. NEXT APPRECIABLE THREAT FOR PRECIP IS
EXPECTED THURSDAY ASSOCIATED WITH THE NEXT UPPER LEVEL TROUGH.
&&
.AVIATION /01Z FRIDAY THROUGH TUESDAY/...
AS OF 635 PM EDT THURSDAY...
COLD FRONT ALONG THE MISSISSIPPI RIVER MOVES EAST INTO THE
APPALACHIANS AROUND DAYBREAK AND THEN ACROSS THE BLUE RIDGE
REACHING THE PIEDMONT LATER FRIDAY. LOW LEVEL JET WILL
DRAMATICALLY INCREASE THIS EVENING AND OVERNIGHT JUST AHEAD OF
THE MAIN BAND OF SHOWERS THAT LOOK TO PUSH ACROSS THE FAR WEST
JUST BEFORE DAWN ON FRIDAY.
MODEL GUIDANCE HAS CONTINUED TO INCREASE THE WINDS ALOFT...WITH
WINDS APPROACHING 50 KT AT 2000 FT AGL FOR ROA/LYH/DAN. THESE
WINDS MAY REACH 55-60 KT AT 2000 FT AGL FOR BLF/LWB/BCB.
THUS...THE MENTION OF LOW LEVEL WIND SHEAR DUE TO NON-CONVECTIVE
EFFECTS WAS KEPT IN THE TAFS WHERE RAIN SHOWERS WERE NOT
SPECIFICALLY MENTIONED INTO EARLY TONIGHT. THE THREAT FOR
CONVECTIVE WIND SHEAR AND TURBULENCE SHOULD BE QUITE HIGH ONCE THE
DOWNWARD MIXING OF THE HIGHER MOMENTUM AIR ALOFT TAKES PLACE WHEN
THE SHOWERS ARRIVE AT BLF/LWB/BCB AFTER MIDNIGHT 07-09Z/3-5 AM...AND
ROA/LYH/DAN AROUND 10-12Z/6-8 AM. SURFACE WINDS SHOULD ALSO
INCREASE INTO THE 10-20 KNOT RANGE OVERNIGHT BUT COULD GUST ABOVE
30-35 KTS ALONG THE RIDGES ESPCLY WHEN THE MAIN AXIS OF SHOWERS
PIVOTS THROUGH LATER TONIGHT OR EARLY FRIDAY. OTRW DROPPING CIGS
FROM VFR LEVELS EARLY THIS EVENING INTO MVFR OVERNIGHT BUT A BIT
SLOWER THAN PREVIOUS PER CURRENT TRENDS AND MODEL FORECASTS. A
PERIOD OF IFR CIGS ALSO POSSIBLE AROUND BLF/LWB AND BCB WHEN THE
HEAVIER SHRA ARRIVE LATE INTO EARLY FRIDAY SO KEPT A PERIOD OF
HIGH END IFR IN SPOTS FOR NOW.
GUIDANCE HAS AGAIN SLOWED DOWN THE EASTWARD EXODUS OF THE SHOWERS
ON FRIDAY WITH BANDS LIKELY LINGERING OVER THE EASTERN SITES AS
ANOTHER WEAK WAVE FORMS ALONG THE SLOWING BOUNDARY. THIS MAY
PROLONG THE LOWER POST FRONTAL CIGS AT BLF/LWB AS WELL AS MVFR
CIGS AND SHOWERS FROM DAN TO LYH FRIDAY AFTERNOON SO DELAYED
IMPROVEMENT IN FLYING CONDITIONS BY A FEW HOURS LATE FRIDAY.
HOWEVER STILL EXPECTING A RETURN TO VFR BY THE END OF THE DAY
FRIDAY AS DRY ADVECTION KICKS IN WITH CLEARING SKIES ALONG/WEST OF
THE BLUE RIDGE BY FRIDAY EVENING. HIGH PRESSURE EVENTUALLY MOVES
TOWARD THE OHIO RIVER VALLEY DURING SATURDAY...BUT GUSTY NORTH TO
NORTHWEST WINDS WILL PROVIDE SOME MVFR CONDITIONS IN THE MOUNTAINS
ALONG WITH SCATTERED UPSLOPE SHOWERS. THE HIGH SHOULD BUILD
OVERHEAD BY LATE SUNDAY INTO MONDAY...WHICH WILL BRING OVERALL
GOOD FLYING WEATHER THROUGH TUESDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...WIND ADVISORY UNTIL 7 AM EDT FRIDAY FOR VAZ007-009>020-022>024-
032>035.
NC...WIND ADVISORY UNTIL 7 AM EDT FRIDAY FOR NCZ001>003-018-019.
WV...WIND ADVISORY UNTIL 7 AM EDT FRIDAY FOR WVZ042>045.
&&
$$
SYNOPSIS...AMS
NEAR TERM...JH/WP
SHORT TERM...PC/PM
LONG TERM...PM
AVIATION...JH/PW
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
149 PM EDT WED OCT 30 2013
.SYNOPSIS...
LOW PRESSURE OVER THE CENTRAL PLAINS AND ITS WARM FRONT WILL MOVE
NORTHEAST AND BY FRIDAY MORNING WILL BE OVER ONTARIO WITH A STRONG
TRAILING COLD FRONT PUSHING ACROSS THE EASTERN UNITED STATES.
HIGH PRESSURE WILL BUILD IN OVER THE EAST FOR SATURDAY AND SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 130 PM EDT WEDNESDAY...
RAIN ASSOCIATED WITH SHORTWAVE ENDING AS IT MOVES EAST INTO THE
ATLANTIC OCEAN. AREAS OF SHOWERS TO OUR WEST IN KENTUCKY
DECREASING IN COVERAGE AND INTENSITY. CUT BACK POPS FOR THIS
AFTERNOON. SATELLITE IMAGES SHOWED CLOUD COVER BREAKING UP
ESPECIALLY IN THE SOUTH. ADJUSTED TEMPERATURES FOR SOME SUNSHINE
THIS AFTERNOON.
AS OF 955 AM EDT WEDNESDAY...
THE COMBINATION OF WARM FRONT LIFTING NORTH ACROSS THE REGION AND
A COUPLE OF SHORTWAVES MOVING EASTWARD AROUND THE UPPER RIDGE
RESULTING IN AREAS OF RAIN THIS MORNING. THE 12Z/8AM RNK SOUNDING
SHOWED PLENTY OF MOISTURE UP 550 MB WITH A WEST TO SOUTHWEST FLOW
AND PWATS THAT HAVE CLIMBED TO 1.05 INCHES. HRRR AND RNK WRFARW
CONTINUE PRECIPITATION INTO THIS AFTERNOON ESPECIALLY IN THE
WEST. DECIDED TO RAISE POPS FOR THIS MORNING INTO THIS AFTERNOON.
ADJUSTED TEMPERATURES AND DEW POINTS FOR OBS AND MODEL TRENDS.
WILL WAIT TO SEE EVOLUTION OF SHOWERS ACROSS KENTUCKY THIS MORNING
ASSOCIATED WITH ANOTHER SHORTWAVE FOR ADJUSTMENTS IN POPS AND
TEMPERATURES THIS AFTERNOON. MORE CHANGES LATER...
AS OF 400 AM EDT WEDNESDAY...
BUFKIT CONTINUE TO SHOW A DEEP LAYER OF MOISTURE THROUGH MUCH OF
THE DAY. DESPITE WARM FRONT...BOTH AT THE SURFACE AND THROUGH
850MB...CROSSING THROUGH THE AREA FROM SOUTHWEST TO NORTHEAST BY
THIS EVENING...DO NOT EXPECT TO SEE ANY DECENT BREAKS IN THE
CLOUDS UNTIL THIS EVENING.
TWO SHORT WAVE ON THE NORTH SIDE OF THE BUILDING UPPER RIDGE
TRACK FROM THE TENNESSEE VALLEY INTO THE CAROLINAS AND FROM
SOUTHERN OHIO ACROSS THE MID ATLANTIC REGION. THESE WAVES COMBINED WITH
ISENTROPIC LIFT OVER THE FORECAST AREA WILL PRODUCE
SHOWERS...ESPECIALLY OVER THE MOUNTAINS AND NORTH OF THE WARM
FRONT THIS MORNING. HAVE INCREASED THE PROBABILITY OF
PRECIPITATION TO ACCOUNT FOR THE RAIN ALREADY MOVING INTO THE
WESTERN COUNTY WARNING AREA.
FORECAST AREA MOVES INTO A WARMER AIR MASS FOR TODAY AND TONIGHT.
DESPITE THE CLOUD COVER AND PRECIPITATION...TEMPERATURES WERE
STARTING OUT MILD SO MAXIMUM TEMPERATURES WILL END UP SLIGHTLY
ABOVE NORMAL FOR TODAY. KEPT TEMPERATURES MILD FOR TONIGHT
LEANING TOWARD THE WARMER MET GUIDANCE FOR OVERNIGHT LOWS.
HAVE ALSO ADDED FOG IN THE WESTERN VALLEYS FOR TONIGHT. LOW LEVEL
MOISTURE WILL REMAIN HIGH ENOUGH IN LOCATIONS THAT GET RAIN FOR AT
LEAST PATCHY FOG.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
AS OF 300 AM EDT WEDNESDAY...
HIGH PRESSURE WILL BE SHIFTING OFF THE EAST COAST DURING THURSDAY AS
UPPER TROUGH AMPLIFIES AND DEEPENING SURFACE LOW LIFTS INTO THE
NORTHERN GREAT LAKES PUSHING A WELL-ADVERTISED FRONTAL BOUNDARY FROM
THE OHIO VALLEY TOWARDS THE EAST COAST. THURSDAY WILL BE VERY MILD
AGAIN WITH TEMPS HELD DOWN SLIGHTLY BY CLOUD COVER BUT STILL
REACHING WELL ABOVE NORMAL UPPER 60S WEST TO MID-70S EAST. FRONTAL
TIMING ON LATEST MODELS DOES NOT APPEAR TO BE MUCH DIFFERENT THAN
PREVIOUS RUNS WITH FRONT REACHING WESTERN MOUNTAINS DURING EARLY
MORNING HOURS OF FRIDAY.
A BAND OF WARM ADVECTION RAINFALL WILL ACCOMPANY THE FRONT WITH
MODERATE QPF AMOUNTS FORECAST RANGING GENERALLY FROM 0.25 TO 0.75
INCHES. THIS DESPITE VERY HIGH MOISTURE FOR LATE OCTOBER WITH BOTH
NAM/GFS PWATS OF 1.45 INCHES AT KRNK WHICH IS >99 PERCENTILE (+3
SD) FOR AT LEAST SEVERAL HOURS IN THE EARLY MORNING FRIDAY. THIS
WILL BE OFFSET BY THE FAIRLY RAPID EASTWARD MOVEMENT OF THE BEST
FORCING LIMITING THE DURATION OF RAINFALL. STILL IF THE BOUNDARY
IS HELD UP FOR A FEW MORE HOURS QPF AMOUNTS COULD BE
HIGHER..APPROACHING 1 INCH.
MAIN CONTINUING CONCERN IS STILL DUE TO POTENTIAL FOR STRONG
WINDS AND SHEAR AHEAD AND ALONG THE BOUNDARY AS SPC SHOWS SLIGHT
RISK JUST TO OUR WEST OVER THE OH/TN VALLEYS BY 12Z/FRI. POSSIBLE
SVR GUSTS COULD DEVELOP IN ANY STRONGER SHOWERS OR LOW-TOPPED
CONVECTION THAT FORMS AS BUFKIT PROFILES SHOW SSW WINDS AT H85
RANGING FROM 50 TO 65 MPH ON GFS/NAM ROUGHLY BETWEEN 03Z-09Z FRI.
CAPE IS OBVIOUSLY VERY LIMITED OR NEGLIGIBLE DURING THIS TIME BUT
CHANCES FOR STRONG WIND GUSTS MAY BE ENHANCED SOMEWHAT OVER THE
EASTERN PIEDMONT COUNTIES TOWARD MID TO LATE DAY FRIDAY AND
ESPECIALLY IF THE BOUNDARY IS HELD UP AT ALL TO ALLOW FOR LIMITED
SURFACE HEATING.
FRONT AND ASSOCIATED WEATHER SHOULD BE EAST OF CWA BY FRIDAY
EVENING WITH COOLER BUT NOT PARTICULARLY COLD AIR DROPPING IN
BEHIND THE FRONT OVERNIGHT AS H85 TEMPS ONLY FALL OFF TO AROUND 5C
BY EARLY SATURDAY. START OF THE WEEKEND LOOKS TO BE DRY AND
SEASONABLE WITH HIGH SATURDAY FROM UPPER 50S WEST TO MID 60S
EAST.
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
AS OF 1245 PM EDT TUESDAY...
SATURDAY NIGHT...NORTHWEST FLOW WILL INCREASE ACROSS THE REGION
WHILE A SHORTWAVE TROUGH SWINGS THROUGH THE OHIO VALLEY. THE
COMBINATION OF THESE FACTORS WILL LEND THEMSELVES TO A TREND
TOWARD LOWER TEMPERATURES... AND THE DEVELOPMENT OF UPSLOPE
RAIN/SNOW SHOWERS ACROSS THE PREFERRED AREAS OF SOUTHEAST WEST
VIRGINIA SOUTH INTO THE NORTHERN MOUNTAINS OF NORTH CAROLINA.
ACROSS THE PIEDMONT...THE NORTHWEST FLOW WILL YIELD A DOWNSLOPE
SUBSIDENCE FLOW THAT WILL GREATLY LIMITED THE AMOUNT OF CLOUDS IN
THIS REGION AND ADD AN ELEMENT OF COMPRESSIONAL WARMING THAT WILL
ONLY SLIGHTLY OFFSET THE EFFECTS OF STRONG COLD AIR ADVECTION. SATURDAY
NIGHT WILL BRING LOWS IN THE LOWER 30S ACROSS THE MOUNTAINS WITH
MID TO UPPER 30S ACROSS THE PIEDMONT.
ON SUNDAY...SURFACE HIGH PRESSURE WILL BUILD OVER THE REGION AND LOW
LEVEL WINDS WILL VEER NORTH AND THEN NORTHEAST AS THE DAY
PROGRESSES. THIS SCENARIO WILL BRING AN END TO THE UPSLOPE RAIN/SNOW
SHOWERS ACROSS THE SOUTHEAST WEST VIRGINIA MOUNTAINS...AND LIMITED
CLOUD COVER ACROSS THE ENTIRE REGION BY THE LATE AFTERNOON.
AS WE HEAD INTO EARLY NEXT WEEK...THE CENTER OF THE HIGH SHIFTS TO
THE COAST. CLOCKWISE FLOW AROUND THIS HIGH WILL BRING ATLANTIC
MOISTURE ONSHORE THE SC/GA COASTS WHICH WILL THEN HEAD NORTHWARD
ALONG THE SPINE OF THE APPALACHIANS. THIS TREND WILL ALLOW FOR
MODERATING TEMPERATURES...AND INCREASING MOISTURE ACROSS THE AREA
THROUGH TUESDAY. CURRENTLY WE ARE ONLY FORECASTING THAT MOISTURE TO
BE REALIZED IN CLOUD COVER.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 130 PM EDT WEDNESDAY...
THE MAIN SHORTWAVE MOVING OVER BUILDING UPPER RIDGE WILL EXIT OUR
REGION THIS AFTERNOON. POCKETS OF RAIN AND LOWER CLOUDS ARE ENDING
AND LIFTING THIS AFTERNOON.
CEILINGS WILL LIFT BACK TO VFR BEHIND THE SHORTWAVE AS A WARM
FRONT CROSSES THROUGH THE AREA. LIGHT SURFACE AND LOW LEVEL WINDS
WILL BECOME SOUTHWEST TO WEST TONIGHT SOUTH OF THE FRONT. DUE TO
THE RAIN THIS MORNING...AREAS OF FOG ARE EXPECTED TONIGHT BUT
WILL DEPEND ON HOW MUCH THE CLOUDS CLEAR OUT. LWB HAS THE BEST
CHANCE FOR LIFR/IFR FOG.
MEDIUM TO HIGH CONFIDENCE IN CEILINGS AND VISIBILITY
DURING THE TAF PERIOD. HIGH CONFIDENCE IN WINDS DURING THE PERIOD.
MVFR CONDITIONS ARE EXPECTED THROUGH MUCH OF THE DAY THURSDAY
WITH EXTENSIVE MID/HIGH CLOUDS IN ADVANCE OF A STRONG WEATHER
SYSTEM/COLD FRONT APPROACHING FROM THE WEST. A LINE OF HEAVY RAIN
SHOWERS WITH GUSTY WINDS WILL APPROACH THE AREA FROM THE WEST THU
NIGHT/EARLY FRI...WITH IFR-LIFR CIGS AND MVFR-IFR CIGS/VSBYS IN
+SHRA BR/FG. CANNOT RULE OUT OCCASIONAL -SHRA IN ADVANCE OF THIS
FRONT THU AFTERNOON...BUT MUCH OF THU SHOULD BE RAIN FREE. EXPECT
GUSTY SW WINDS AND POTENTIAL FOR LOW-LEVEL WIND SHEAR THURSDAY IN
ADVANCE OF THIS FRONT AS WELL.
IN THE WAKE OF THE COLD FRONT...LOOK FOR INCREASING NORTHWEST
FLOW BEHIND THE COLD FRONT. THIS WILL RESULT IN UPSLOPE RAIN/SNOW
SHOWERS ACROSS THE PREFERRED UPSLOPE REGIONS OF SOUTHEAST WEST
VIRGINIA SATURDAY INTO SUNDAY ALONG WITH IFR-MVFR CEILINGS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS/KK
NEAR TERM...AMS/KK
SHORT TERM...PC
LONG TERM...DS
AVIATION...AMS/KK
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
956 AM EDT WED OCT 30 2013
.SYNOPSIS...
LOW PRESSURE WAS OVER THE CENTRAL PLAINS THIS MORNING WITH A WARM
FRONT EXTENDING INTO WESTERN VIRGINIA. THIS LOW WILL MOVE
NORTHEAST AND BY FRIDAY MORNING WILL BE OVER ONTARIO WITH A
STRONG COLD FRONT PUSHING ACROSS THE EASTERN UNITED STATES. HIGH
PRESSURE WILL BUILD IN OVER THE EAST FOR SATURDAY AND SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 955 AM EDT WEDNESDAY...
THE COMBINATION OF WARM FRONT LIFTING NORTH ACROSS THE REGION AND
A COUPLE OF SHORTWAVES MOVING EASTWARD AROUND THE UPPER RIDGE
RESULTING IN AREAS OF RAIN THIS MORNING. THE 12Z/8AM RNK SOUNDING
SHOWED PLENTY OF MOISTURE UP 550 MB WITH A WEST TO SOUTHWEST FLOW
AND PWATS THAT HAVE CLIMBED TO 1.05 INCHES. HRRR AND RNK WRFARW
CONTINUE PRECIPITATION INTO THIS AFTERNOON ESPECIALLY IN THE
WEST. DECIDED TO RAISE POPS FOR THIS MORNING INTO THIS AFTERNOON.
ADJUSTED TEMPERATURES AND DEW POINTS FOR OBS AND MODEL TRENDS.
WILL WAIT TO SEE EVOLUTION OF SHOWERS ACROSS KENTUCKY THIS MORNING
ASSOCIATED WITH ANOTHER SHORTWAVE FOR ADJUSTMENTS IN POPS AND
TEMPERATURES THIS AFTERNOON. MORE CHANGES LATER...
AS OF 400 AM EDT WEDNESDAY...
BUFKIT CONTINUE TO SHOW A DEEP LAYER OF MOISTURE THROUGH MUCH OF
THE DAY. DESPITE WARM FRONT...BOTH AT THE SURFACE AND THROUGH
850MB...CROSSING THROUGH THE AREA FROM SOUTHWEST TO NORTHEAST BY
THIS EVENING...DO NOT EXPECT TO SEE ANY DECENT BREAKS IN THE
CLOUDS UNTIL THIS EVENING.
TWO SHORT WAVE ON THE NORTH SIDE OF THE BUILDING UPPER RIDGE
TRACK FROM THE TENNESSEE VALLEY INTO THE CAROLINAS AND FROM
SOUTHERN OHIO ACROSS THE MID ATLANTIC REGION. THESE WAVES COMBINED WITH
ISENTROPIC LIFT OVER THE FORECAST AREA WILL PRODUCE
SHOWERS...ESPECIALLY OVER THE MOUNTAINS AND NORTH OF THE WARM
FRONT THIS MORNING. HAVE INCREASED THE PROBABILITY OF
PRECIPITATION TO ACCOUNT FOR THE RAIN ALREADY MOVING INTO THE
WESTERN COUNTY WARNING AREA.
FORECAST AREA MOVES INTO A WARMER AIR MASS FOR TODAY AND TONIGHT.
DESPITE THE CLOUD COVER AND PRECIPITATION...TEMPERATURES WERE
STARTING OUT MILD SO MAXIMUM TEMPERATURES WILL END UP SLIGHTLY
ABOVE NORMAL FOR TODAY. KEPT TEMPERATURES MILD FOR TONIGHT
LEANING TOWARD THE WARMER MET GUIDANCE FOR OVERNIGHT LOWS.
HAVE ALSO ADDED FOG IN THE WESTERN VALLEYS FOR TONIGHT. LOW LEVEL
MOISTURE WILL REMAIN HIGH ENOUGH IN LOCATIONS THAT GET RAIN FOR AT
LEAST PATCHY FOG.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
AS OF 300 AM EDT WEDNESDAY...
HIGH PRESSURE WILL BE SHIFTING OFF THE EAST COAST DURING THURSDAY AS
UPPER TROUGH AMPLIFIES AND DEEPENING SURFACE LOW LIFTS INTO THE
NORTHERN GREAT LAKES PUSHING A WELL-ADVERTISED FRONTAL BOUNDARY FROM
THE OHIO VALLEY TOWARDS THE EAST COAST. THURSDAY WILL BE VERY MILD
AGAIN WITH TEMPS HELD DOWN SLIGHTLY BY CLOUD COVER BUT STILL
REACHING WELL ABOVE NORMAL UPPER 60S WEST TO MID-70S EAST. FRONTAL
TIMING ON LATEST MODELS DOES NOT APPEAR TO BE MUCH DIFFERENT THAN
PREVIOUS RUNS WITH FRONT REACHING WESTERN MOUNTAINS DURING EARLY
MORNING HOURS OF FRIDAY.
A BAND OF WARM ADVECTION RAINFALL WILL ACCOMPANY THE FRONT WITH
MODERATE QPF AMOUNTS FORECAST RANGING GENERALLY FROM 0.25 TO 0.75
INCHES. THIS DESPITE VERY HIGH MOISTURE FOR LATE OCTOBER WITH BOTH
NAM/GFS PWATS OF 1.45 INCHES AT KRNK WHICH IS >99 PERCENTILE (+3
SD) FOR AT LEAST SEVERAL HOURS IN THE EARLY MORNING FRIDAY. THIS
WILL BE OFFSET BY THE FAIRLY RAPID EASTWARD MOVEMENT OF THE BEST
FORCING LIMITING THE DURATION OF RAINFALL. STILL IF THE BOUNDARY
IS HELD UP FOR A FEW MORE HOURS QPF AMOUNTS COULD BE
HIGHER..APPROACHING 1 INCH.
MAIN CONTINUING CONCERN IS STILL DUE TO POTENTIAL FOR STRONG
WINDS AND SHEAR AHEAD AND ALONG THE BOUNDARY AS SPC SHOWS SLIGHT
RISK JUST TO OUR WEST OVER THE OH/TN VALLEYS BY 12Z/FRI. POSSIBLE
SVR GUSTS COULD DEVELOP IN ANY STRONGER SHOWERS OR LOW-TOPPED
CONVECTION THAT FORMS AS BUFKIT PROFILES SHOW SSW WINDS AT H85
RANGING FROM 50 TO 65 MPH ON GFS/NAM ROUGHLY BETWEEN 03Z-09Z FRI.
CAPE IS OBVIOUSLY VERY LIMITED OR NEGLIGIBLE DURING THIS TIME BUT
CHANCES FOR STRONG WIND GUSTS MAY BE ENHANCED SOMEWHAT OVER THE
EASTERN PIEDMONT COUNTIES TOWARD MID TO LATE DAY FRIDAY AND
ESPECIALLY IF THE BOUNDARY IS HELD UP AT ALL TO ALLOW FOR LIMITED
SURFACE HEATING.
FRONT AND ASSOCIATED WEATHER SHOULD BE EAST OF CWA BY FRIDAY
EVENING WITH COOLER BUT NOT PARTICULARLY COLD AIR DROPPING IN
BEHIND THE FRONT OVERNIGHT AS H85 TEMPS ONLY FALL OFF TO AROUND 5C
BY EARLY SATURDAY. START OF THE WEEKEND LOOKS TO BE DRY AND
SEASONABLE WITH HIGH SATURDAY FROM UPPER 50S WEST TO MID 60S
EAST.
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
AS OF 1245 PM EDT TUESDAY...
SATURDAY NIGHT...NORTHWEST FLOW WILL INCREASE ACROSS THE REGION
WHILE A SHORTWAVE TROUGH SWINGS THROUGH THE OHIO VALLEY. THE
COMBINATION OF THESE FACTORS WILL LEND THEMSELVES TO A TREND
TOWARD LOWER TEMPERATURES... AND THE DEVELOPMENT OF UPSLOPE
RAIN/SNOW SHOWERS ACROSS THE PREFERRED AREAS OF SOUTHEAST WEST
VIRGINIA SOUTH INTO THE NORTHERN MOUNTAINS OF NORTH CAROLINA.
ACROSS THE PIEDMONT...THE NORTHWEST FLOW WILL YIELD A DOWNSLOPE
SUBSIDENCE FLOW THAT WILL GREATLY LIMITED THE AMOUNT OF CLOUDS IN
THIS REGION AND ADD AN ELEMENT OF COMPRESSIONAL WARMING THAT WILL
ONLY SLIGHTLY OFFSET THE EFFECTS OF STRONG COLD AIR ADVECTION. SATURDAY
NIGHT WILL BRING LOWS IN THE LOWER 30S ACROSS THE MOUNTAINS WITH
MID TO UPPER 30S ACROSS THE PIEDMONT.
ON SUNDAY...SURFACE HIGH PRESSURE WILL BUILD OVER THE REGION AND LOW
LEVEL WINDS WILL VEER NORTH AND THEN NORTHEAST AS THE DAY
PROGRESSES. THIS SCENARIO WILL BRING AN END TO THE UPSLOPE RAIN/SNOW
SHOWERS ACROSS THE SOUTHEAST WEST VIRGINIA MOUNTAINS...AND LIMITED
CLOUD COVER ACROSS THE ENTIRE REGION BY THE LATE AFTERNOON.
AS WE HEAD INTO EARLY NEXT WEEK...THE CENTER OF THE HIGH SHIFTS TO
THE COAST. CLOCKWISE FLOW AROUND THIS HIGH WILL BRING ATLANTIC
MOISTURE ONSHORE THE SC/GA COASTS WHICH WILL THEN HEAD NORTHWARD
ALONG THE SPINE OF THE APPALACHIANS. THIS TREND WILL ALLOW FOR
MODERATING TEMPERATURES...AND INCREASING MOISTURE ACROSS THE AREA
THROUGH TUESDAY. CURRENTLY WE ARE ONLY FORECASTING THAT MOISTURE TO
BE REALIZED IN CLOUD COVER.
&&
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
AS OF 730 AM EDT WEDNESDAY...
SHORT WAVE MOVING OVER BUILDING UPPER RIDGE WILL RESULT IN
SCATTERED SHOWERS ACROSS THE FORECAST AREA THIS MORNING. AT 11Z
CEILINGS WERE FINALLY LOWERING TO MVFR. EXPECT MVFR CEILINGS WEST
OF THE BLUE RIDGE THIS MORNING. EAST OF THE BLUE RIDGE THERE IS
LOWER CONFIDENCE THAT CEILINGS WILL DROP BELOW 3000FT.
CEILINGS WILL LIFT BACK TO VFR BEHIND THE SHORT WAVE AS A WARM
FRONT CROSSES THROUGH THE AREA. SREF AND LOCAL WRF...AS WELL AS
OTHER MODELS... BRING SURFACE AND LOW LEVEL WINDS BECOME
SOUTHWEST TO WEST OVERNIGHT SOUTH OF THE FRONT. MEDIUM CONFIDENCE
WITH TIMING. THE LONGER IT TAKES THE WARM FRONT TO PUSH NORTHEAST
THROUGH THE AREA THE LONGER CEILINGS WILL BE MVFR IN THE
MOUNTAINS. DUE TO THE RAIN THIS MORNING...FOG FORMATION IS
POSSIBLE TONIGHT BUT WILL DEPEND ON HOW MUCH THE CLOUDS CLEAR OUT.
THE AIR MASS CERTAINLY STAYS MOIST ENOUGH AT LOW LEVELS TO SUPPORT
FOG.
MVFR CONDITIONS ARE EXPECTED THROUGH MUCH OF THE DAY THURSDAY
WITH EXTENSIVE MID/HIGH CLOUDS IN ADVANCE OF A STRONG WEATHER
SYSTEM/COLD FRONT APPROACHING FROM THE WEST. A LINE OF HEAVY RAIN
SHOWERS WITH GUSTY WINDS WILL APPROACH THE AREA FROM THE WEST THU
NIGHT/EARLY FRI...WITH IFR-LIFR CIGS AND MVFR-IFR CIGS/VSBYS IN
+SHRA BR/FG. CANNOT RULE OUT OCCASIONAL -SHRA IN ADVANCE OF THIS
FRONT THU AFTERNOON...BUT MUCH OF THU SHOULD BE RAIN FREE. EXPECT
GUSTY SW WINDS AND POTENTIAL FOR LOW-LEVEL WIND SHEAR THURSDAY IN
ADVANCE OF THIS FRONT AS WELL.
IN THE WAKE OF THE COLD FRONT...LOOK FOR INCREASING NORTHWEST
FLOW BEHIND THE COLD FRONT. THIS WILL RESULT IN UPSLOPE RAIN/SNOW
SHOWERS ACROSS THE PREFERRED UPSLOPE REGIONS OF SOUTHEAST WEST
VIRGINIA SATURDAY INTO SUNDAY ALONG WITH IFR-MVFR CEILINGS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/KK
SHORT TERM...PC
LONG TERM...DS
AVIATION...AMS/RAB
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1100 PM CDT THU OCT 31 2013
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 317 PM CDT THU OCT 31 2013
MAIN FORECAST CONCERNS ARE ON LIGHT RAIN CHANCES TONIGHT AND LATE
FRIDAY AFTERNOON INTO FRIDAY NIGHT.
LATEST WATER VAPOR IMAGERY AND 500 MB RAP ANALYSIS SHOWED A TROUGH
EXTENDING FROM THE UPPER MISSISSIPPI RIVER VALLEY SOUTH THROUGH THE
SOUTHERN PLAINS AND MOVING EAST. AN EMBEDDED SHORTWAVE WAS LIFTING
NORTHEAST THROUGH NORTHERN ILLINOIS INTO SOUTHEAST WISCONSIN.
SURFACE OBSERVATIONS SHOWED LOW PRESSURE OVER NORTHEAST WISCONSIN
WITH A COLD FRONT EXTENDING SOUTH ALONG THE INTERSTATE 39 CORRIDOR
INTO THROUGH NORTH CENTRAL ILLINOIS MOVING EAST. EXTENSIVE CLOUD
COVER NOTED OVER THE REGION THIS AFTERNOON WITH TEMPERATURES
RANGING FROM THE UPPER 30S TO LOWER 40S OVER SOUTHEAST MINNESOTA
TO THE MID 50S OVER CENTRAL WISCONSIN.
THE SURFACE LOW WILL DEEPEN AND SHIFT EAST OVER NORTHERN LOWER
MICHIGAN/EASTERN UPPER MICHIGAN TONIGHT AS THE TROUGH LIFTS INTO THE
GREAT LAKES. LOW LEVEL MOISTURE WILL CONTINUE TO BRING ABUNDANT
CLOUD COVER THE AREA AS WELL AS THE POTENTIAL FOR SOME LIGHT RAIN OR
DRIZZLE LATE TONIGHT INTO EARLY FRIDAY MORNING. A WEAK SHORTWAVE AND
SURFACE TROUGH WILL SLIDE ACROSS CENTRAL WISCONSIN TONIGHT INTO
FRIDAY MORNING AND MAY GENERATE SOME LIGHT RAIN OR DRIZZLE OVER
PORTIONS OF WESTERN INTO CENTRAL WISCONSIN. OTHERWISE...PLAN ON
A CLOUDY AND COOL NIGHT WITH LOWS FALLING INTO THE UPPER 30S TO
LOWER 40S. CLOUDS WILL REMAIN ACROSS THE REGION ON FRIDAY AS
ANOTHER TROUGH DROPS SOUTH OUT OF SOUTHERN MANITOBA/SASKATCHEWAN.
THE TROUGH IS EXPECTED TO SLIDE ACROSS THE UPPER MISSISSIPPI RIVER
VALLEY LATE FRIDAY AFTERNOON INTO FRIDAY NIGHT BRINGING A CHANCE
OF LIGHT RAIN TO THE AREA. GIVEN THE CLOUDS IN PLACE ACROSS THE
REGION ON FRIDAY AND THE PRECIPITATION MOVING IN LATE DECIDED TO
COOL HIGHS A FEW DEGREES ON FRIDAY WITH HIGHS RANGING FROM THE MID
40S OVER NORTH CENTRAL WISCONSIN TO AROUND 50 ACROSS NORTHEAST
IOWA.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 317 PM CDT THU OCT 31 2013
HIGH PRESSURE GRADUALLY BUILDS INTO THE UPPER MISSISSIPPI RIVER
VALLEY ON SATURDAY WITH DECREASING CLOUDS EXPECTED BY LATE
AFTERNOON. AN UPPER RIDGE WILL SLIDE OVER THE AREA ON SUNDAY
PROVIDING MOSTLY SUNNY SKIES. BREEZY SOUTHEAST WINDS WILL DEVELOP ON
SUNDAY AS THE SURFACE HIGH SLIDES OFF OT THE EAST AND A TROUGH
DEVELOPS OVER THE PLAINS. THE OPEN AREAS OF SOUTHEAST MINNESOTA AND
NORTHEAST IOWA WILL SEE THE STRONGEST WINDS WHERE SPEEDS DURING THE
AFTERNOON WILL RANGE FROM THE 15 TO 20 MPH WITH GUSTS TO AROUND 30
MPH. A RIDGE DIGS INTO THE WESTERN CONUS FOR THE START OF THE WORK
WEEK PUSHING A COLD FRONT TOWARD THE AREA FROM THE NORTHERN PLAINS.
ACTIVE SOUTHWEST FLOW SETS UP OVER THE REGION FROM MONDAY INTO
WEDNESDAY WITH SEVERAL ROUNDS OF PRECIPITATION POSSIBLE. RAIN
CHANCES SPREAD BACK INTO THE AREA ON MONDAY AS THE FRONT MOVES INTO
THE UPPER MISSISSIPPI RIVER VALLEY AND STALLS OVER THE FORECAST
AREA. SHORTWAVES WITHIN THE SOUTHWEST FLOW ALOFT WILL INTERACT WITH
THE FRONT AND WILL LIKELY BRING SHOWERS TO THE AREA THROUGH TUESDAY.
FORECAST MODELS ARE IN CLOSE AGREEMENT ON PUSHING THE COLD FRONT
ACROSS THE AREA TUESDAY NIGHT INTO WEDNESDAY AS A STRONGER
SHORTWAVES LIFTS NORTHEAST ACROSS THE AREA...SO WILL GO WITH LIKELY
PRECIPITATION CHANCES. TEMPERATURES COOL BEHIND THE FRONT WEDNESDAY
INTO THURSDAY. HIGHS ON WEDNESDAY ARE EXPECTED TO RANGE FORM THE MID
TO UPPER 40S...THEN COOL INTO THE LOWER 40S FOR THURSDAY. CANNOT
RULE OUT SOME SNOW MIXING IN WITH THE RAIN LATE TUESDAY NIGHT WEST
OF THE MISSISSIPPI RIVER THEN AGAIN LATE WEDNESDAY NIGHT OVER
NORTHEAST IOWA INTO CENTRAL WISCONSIN BEFORE THE PRECIPITATION
DEPARTS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1100 PM CDT THU OCT 31 2013
LOW CIGS WILL PERSIST THROUGH THE OVERNIGHT HOURS - GENERALLY
HOVERING NEAR 1 KFT - AS A LOW PRESSURE SYSTEM EXITS TO THE EAST.
NOT MUCH VSBY RESTRICTIONS VIA LATEST SFC OBS...OUTSIDE OF AREAS OF
-DZ/-SHRA ACROSS NORTHWEST WI. DON/T EXPECT FOG TO THICKEN
TONIGHT...UNLIKE LAST NIGHT...AS WINDS STAY FAIRLY STIRRED OUT OF
THE WEST/NORTHWEST.
CIGS SHOULD START TO IMPROVE BY MID MORNING FRIDAY...AND COULD GET A
BUMP INTO VFR BY 18Z. WILL PLAY THIS MORE PESSIMISTICALLY...WAITING
UNTIL LATER IN THE AFTERNOON. FALL/WINTER CAN BE NOTORIOUS FOR
HANGING ONTO LOW CIGS LONGER THAN THE MODELS WOULD SUGGEST.
BITS OF UPPER LEVEL ENERGY AND A SFC TROUGH HAVE SPARKED -DZ/-SHRA
FROM CENTRAL MN INTO NORTHWEST WI. RAP13/HRRR/NAM12 FAVOR THE BETTER
CHANCES ALONG I-94 NORTH/EAST...BUT RADAR TRENDS SUGGEST SOME LIGHT
PCPN COULD REACH KRST/KLSE. WILL ADD -DZ FOR A FEW HOURS TO THE
FORECAST.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM....WETENKAMP
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
325 PM CDT WED OCT 30 2013
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 325 PM CDT WED OCT 30 2013
MAIN FORECAST CONCERNS ARE ON RAIN/ISOLATED THUNDERSTORM CHANCES THIS
EVENING THROUGH THE OVERNIGHT HOURS. FOCUS THEN TURNS TO RAIN
CHANCES ON THURSDAY AND FRIDAY AFTERNOON INTO FRIDAY NIGHT.
LATEST SURFACE OBSERVATIONS SHOWED LOW PRESSURE OVER SOUTHEAST IOWA
WITH A WARM FRONT AS SITUATED JUST SOUTH OF THE INTERSTATE 80
CORRIDOR WITH A SECONDARY WARM FRONT EXTENDING FROM NORTHWEST IOWA
THROUGH NORTH CENTRAL WISCONSIN. WATER VAPOR IMAGERY SHOWED A
TROUGH OVER THE CENTRAL/SOUTHERN ROCKIES WITH A SHORTWAVE NOTED
OVER THE CENTRAL PLAINS LIFTING NORTHEAST TOWARD THE UPPER
MISSISSIPPI RIVER VALLEY.
THE LOW WILL LIFT NORTHEAST ACROSS THE FORECAST AREA THIS EVENING
AS THE SHORTWAVE TROUGH LIFTS ACROSS THE UPPER MISSISSIPPI RIVER
VALLEY. SHOWERS AND POSSIBLY ISOLATED THUNDERSTORMS ARE POSSIBLE
ACROSS THE FORECAST AREA FROM THIS EVENING INTO THE LATE NIGHT
HOURS. LATEST MESOSCALE MODEL GUIDANCE STRUGGLES TO PRODUCE
PRECIPITATION UNTIL LATE EVENING. WHEN THEY FINALLY DO PRODUCE
PRECIPITATION IT IS LIGHT TO PERHAPS MODERATE AND MAINLY FOCUSED
OVER SOUTHEAST SECTIONS OF THE FORECAST AREA. PRECIPITABLE WATER
VALUES INCREASE TO 1.2 INCHES TONIGHT...WHICH IS 230 PERCENT OF
NORMAL. WITH THIS INCREASE IN PRECIPITABLE WATER ANY ISOLATED
STORMS WOULD BE CAPABLE OF PRODUCING BRIEF HEAVY DOWNPOURS. THE
HIGHEST RAINFALL AMOUNTS ARE EXPECTED OVER FAR NORTHEAST IOWA INTO
SOUTHWEST WISCONSIN WHERE UP TO 1/2 INCH OF RAIN IS POSSIBLE. THE
LOW WILL PUSH EAST OVER LOWER MICHIGAN ON THURSDAY AS THE TROUGH
MOVES EAST ACROSS THE DAKOTAS AND INTO THE UPPER MISSISSIPPI RIVER
VALLEY THURSDAY INTO THURSDAY EVENING. FORECAST MODELS ARE SHOWING
SOME LIGHT PRECIPITATION LINGERING OVER THE FORECAST AREA AS THE
TROUGH MOVES THROUGH SO WOULD EXPECT TO SEE SOME SCATTERED SHOWERS
OR POSSIBLY SOME DRIZZLE HALLOWEEN AFTERNOON INTO HALLOWEEN
EVENING. LOOKING AT FORECAST SOUNDINGS...MOISTURE LINGERS IN THE
2-4.5 KFT RANGE. WEAK OMEGA IN THIS MOISTURE MAY BE ENOUGH TO
GENERATE SPRINKLES OR POSSIBLY DRIZZLE. TEMPERATURES WILL FALL
THURSDAY AFTERNOON INTO THURSDAY EVENING. TEMPERATURE ARE EXPECTED
TO START OUT RANGING FROM THE LOWER 50S OVER SOUTHEAST MINNESOTA
TO THE UPPER 50S TO AROUND 60 OVER CENTRAL WISCONSIN. TEMPERATURES
THEN FALL THROUGH THE AFTERNOON INTO THE EVENING AND BY EARLY EVEN
WILL RANGE FROM THE LOWER TO MID 40S.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 325 PM CDT WED OCT 30 2013
THE TROUGH FINALLY MOVES EAST OF THE FORECAST AREA INTO THE EASTERN
GREAT LAKES LATE THURSDAY NIGHT INTO FRIDAY MORNING.
MEANWHILE...ANOTHER TROUGH WILL DROP SOUTH OUT OF SOUTHERN
MANITOBA/SASKATCHEWAN. MOISTURE LINGERS ACROSS THE FORECAST AREA IN
THE 900-850 MB LAYER...ESPECIALLY ALONG AND EAST OF THE MISSISSIPPI
RIVER. THIS WILL LEAD TO MOSTLY CLOUDY SKIES THROUGH EARLY FRIDAY
MORNING WITH SOME BREAKS POSSIBLE DURING THE DAY ON FRIDAY. THE
TROUGH THEN MOVES SOUTHEAST INTO THE UPPER MISSISSIPPI RIVER VALLEY
LATE FRIDAY AFTERNOON INTO FRIDAY EVENING. THIS WILL LIKELY BRING
LIGHT RAIN TO THE AREA...MAINLY FRIDAY NIGHT. THE TROUGH THEN
SHIFTS EAST OF THE REGION BY SATURDAY AFTERNOON. LINGERING MOISTURE
SATURDAY MORNING WILL LEAD TO MOSTLY CLOUDY SKIES BUT WE SHOULD SEE
SOME BREAKS IN THE CLOUD COVER SATURDAY AFTERNOON AS HIGH PRESSURE
BUILDS IN. SURFACE HIGH PRESSURE THEN BUILDS INTO THE UPPER
MISSISSIPPI RIVER VALLEY SATURDAY NIGHT INTO SUNDAY AS A RIDGE BUILDS
OVER THE DAKOTAS AND PUSHES EAST. SUNDAY IS SHAPING UP TO BE A
PLEASANT FALL DAY ACROSS THE AREA WITH MOSTLY SUNNY SKIES EXPECTED
AND HIGHS RANGING FROM THE MID 40S OVER NORTH CENTRAL WISCONSIN TO
THE MID TO UPPER 50S ACROSS NORTHEAST IOWA. IT WILL BE BREEZY ON
SUNDAY ACROSS NORTHEAST AND SOUTHEAST MINNESOTA AS THE PRESSURE
GRADIENT TIGHTENS OVER THE REGION AS LOW PRESSURE DEVELOPS OVER THE
PLAINS. HIGH PRESSURE WILL SLIDE EAST OF THE REGION SUNDAY NIGHT
ONTO MONDAY AS A TROUGH DIGS OVER THE WESTERN CONUS. A COLD FRONT
WILL APPROACH THE REGION FROM THE NORTHERN PLAINS MONDAY INTO
TUESDAY BRINGING CHANCES FOR RAIN TO THE AREA. SOUTHWEST FLOW SETS
UP OVER THE AREA FROM THE EARLY TO THE MIDDLE PART OF NEXT WEEK AS
AN ACTIVE PATTERN DEVELOPS OVER THE LOWER AND MIDDLE MISSISSIPPI
RIVER VALLEY. THE COOLER AIR WILL WORK BACK INTO THE THE REGION ON
WEDNESDAY AS THE FRONT SHIFTS OFF TO THE EAST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1211 PM CDT WED OCT 30 2013
THE FOG HAS CONTINUED TO EXPAND NORTH ACROSS THE REGION AHEAD OF
THE WARM FRONT ACROSS SOUTHERN IOWA AND THE INVERTED TROUGH OF LOW
PRESSURE ACROSS WESTERN IOWA. THE 30.12Z RAP INDICATES THERE WILL
BE VERY LITTLE CHANGE IN THE BOUNDARY LAYER THROUGH MUCH OF THE
AFTERNOON...SO EXPECT THE FOG TO REMAIN IN PLACE TO KEEP THE
CEILINGS AND VISIBILITY IN THE IFR CATEGORY. THE 30.12Z NAM
INDICATES A SHORT WAVE TROUGH WILL START TO MOVE TOWARD THE REGION
THIS EVENING AND PUSH THE INVERTED TROUGH AND A SURFACE LOW INTO
THE AREA. AS THIS OCCURS...THE FORCING WILL BE STRONG ENOUGH TO
PRODUCE WIDESPREAD RAIN AND WILL CONTINUE THE TREND OF BRINGING
RAIN INTO BOTH TAF SITES FOR THE EVENING INTO THE OVERNIGHT HOURS.
SOME POTENTIAL FOR A RUMBLE OR TWO OF THUNDER AS SOME ELEVATED
CAPE IS POSSIBLE. CONFIDENCE ON THIS OCCURRING IS NOT VERY HIGH SO
WILL NOT INCLUDE IN THE FORECAST AT THIS TIME. THE INVERTED TROUGH
IS EXPECTED TO MOVE THROUGH OVERNIGHT AND SWING THE WINDS AROUND
TO THE WEST/NORTHWEST. AS THIS HAPPENS...THE BEST MOISTURE
TRANSPORT WILL BECOME FOCUSED EAST OF THE AIRPORTS SO EXPECT THE
RAIN TO COME TO AN END. HOWEVER...ENOUGH LOW LEVEL MOISTURE WILL
REMAIN IN PLACE AFTER THE WIND SHIFT TO KEEP THE CEILINGS LOW AND
IN THE IFR CATEGORY. SOME IMPROVEMENT IN THE VISIBILITY MAY OCCUR
BY MID TO LATE MORNING AS SOME SLIGHTLY DRIER AIR AT THE SURFACE
STARTS TO MOVE IN SO INCREASED THE VISIBILITY TO MVFR AS THIS HAPPENS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM...WETENKAMP
AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1211 PM CDT WED OCT 30 2013
.UPDATE...
ISSUED AT 1038 AM CDT WED OCT 30 2013
NO SIGNIFICANT CHANGES HAVE OCCURRED THIS MORNING WITH THE DENSE
FOG. VISIBILITIES REMAIN AROUND A QUARTER OF A MILE ACROSS MUCH OF
NORTHEAST IOWA AND OVER PARTS OF SOUTHEAST MINNESOTA AND SOUTHWEST
WISCONSIN. THE AREA HAS SLOWLY EXPANDED NORTH SOME AS THE FOG IS
GETTING ADVECTED IN THE SOUTHEAST LOW LEVEL FLOW. THE 30.12Z RAP
AND NAM DO NOT SHOW ANY REAL CHANGES OCCURRING IN THE BOUNDARY
LAYER THROUGH AT THE LEAST THE MIDDLE OF THE AFTERNOON WHEN THE
BOUNDARY ACROSS THE IOWA/MISSOURI BORDER POSSIBLY GETS LIFTED
NORTH INTO THE REGION. IN ADDITION...THE RAIN OVER CENTRAL AND
SOUTHWEST IOWA HAS THE POTENTIAL TO MISS THE AREA TO THE SOUTH IF
IT CONTINUES ON ITS CURRENT MOVEMENT. WILL EXTEND THE DENSE FOG
ADVISORY OUT THROUGH MUCH OF THE AFTERNOON AND EXPAND IT SLIGHTLY
TO COVER WHERE THE FOG IS CURRENTLY AND EXPECTED TO BE.
UPDATE ISSUED AT 814 AM CDT WED OCT 30 2013
DENSE FOG WITH VISIBILITIES LESS THAN 1/4 MILE AT TIMES ARE
SPREADING INTO NORTHEAST IOWA AND FAR SOUTHWEST WISCONSIN THANKS
TO THE COMBINATION OF LIGHT WINDS AND A VERY MOIST AIR MASS. A
DENSE FOG ADVISORY WAS ISSUED FOR OUR NORTHEAST IOWA
COUNTIES...AND RICHLAND AND GRANT COUNTIES IN WISCONSIN. EXPECTING
THIS DENSE FOG TO PERSIST THROUGH THE MID TO POSSIBLY LATE MORNING
HOURS. ONCE THE NEXT WAVE OF LOW PRESSURE BEGINS TO INFLUENCE ON
THE AREA LATER THIS MORNING...CONDITIONS ARE EXPECTED TO IMPROVE.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
326 AM CDT WED OCT 30 2013
MAIN CONCERN IN THE SHORT TERM IS PRECIPITATION CHANCE TODAY
THROUGH THURSDAY. 08Z SURFACE ANALYSIS SHOWS LOW PRESSURE OVER KS
WITH AN INVERTED TROUGH REACHING NORTH INTO SOUTHERN MN. BROAD
ISENTROPIC UPGLIDE IN WARM ADVECTION REGIME AHEAD OF THE
APPROACHING SYSTEM AND ASSOCIATED SHORT WAVE TROUGH ALOFT LEADING
TO INCREASING AMOUNTS OF LIGHT RAIN OR DRIZZLE ACROSS IA AND INTO
MN/WI. INDEED RADAR LOOPS AND SURFACE OBS ARE SHOWING INCREASING
AMOUNTS OF LIGHT PRECIPITATION. APPEARS MORE AND MORE LIKELY THAT
WE WILL SEE OCCASIONAL LIGHT RAIN OR DRIZZLE ACROSS MUCH OF THE
AREA THROUGH THE DAY. IT MAY NOT AMOUNT TO MUCH...WITH TRACE TO
PERHAPS A COUPLE OF HUNDREDTHS OF AN INCH FOR MOST PLACES.
MAIN WAVE AND SURFACE LOW/TROUGH TO MOVE NORTHEAST ACROSS THE
FORECAST AREA TONIGHT. THIS WILL SPREAD A BETTER CHANCE FOR RAIN
ACROSS THE FORECAST AREA...WITH THE HIGHEST CHANCE FOR MORE
SIGNIFICANT RAINFALL ACROSS NORTHEAST IA AND SOUTHWEST WI. MODELS
DO SHOW SOME MINIMAL CAPE NOSING INTO THE SOUTHERN COUNTIES BY
EVENING...AND THERE COULD BE SOME ISOLATED THUNDER IN THERE.
SYSTEM BEGINS TO MOVE OUT OF THE AREA ON THURSDAY...WITH RAIN
CHANCES DIMINISHING FROM WEST TO EAST THROUGH THE DAY.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
326 AM CDT WED OCT 30 2013
BRIEF PERIOD OF DRY WEATHER ANTICIPATED THURSDAY NIGHT INTO EARLY
FRIDAY...BUT THE NEXT SHORT WAVE TROUGH WILL MOVE RAPIDLY OUT OF
SOUTHERN CANADA AND INTO THE AREA BY AFTERNOON. LIMITED MOISTURE
AVAILABLE...BUT APPEARING LIKE THERE WILL BE ENOUGH DYNAMIC AND
THERMODYNAMIC SUPPORT TO GENERATE A CHANCE FOR SHOWERS DURING THE
AFTERNOON AND INTO FRIDAY EVENING...ESPECIALLY FROM NORTHERN MN
INTO NORTHERN WI. THAT SYSTEM SHOULD DEPART BY SATURDAY...AS UPPER
RIDGING BEGINS TO BUILD...AND SURFACE HIGH PRESSURE TAKES OVER TO
PROVIDE DRY WEATHER FOR THE WEEKEND.
A STRONG SHORT WAVE TROUGH WILL MOVE ACROSS SOUTHERN CANADA LATE
MONDAY INTO TUESDAY...BUT THE TRACK OF THIS ONE WILL KEEP THE BULK
OF THE PRECIPITATION WELL TO THE NORTH OF THE REGION. HOWEVER...A
TRAILING COLD FRONT WILL MOVE THROUGH ON MONDAY...AND COULD BRING
A CHANCE FOR SOME SHOWERS. MODELS SOLUTIONS REALLY DIVERGE AT
ABOUT THIS POINT...WITH THE ECMWF DIGGING A DEEPER LONG WAVE
TROUGH INTO THE FOUR-CORNERS REGION. SHORT WAVE TROUGHS IN THE
FLOW AHEAD OF THIS EJECT INTO THE UPPER MIDWEST...SLOWING THE
FRONTAL PROGRESSION AND FEEDING PERIODIC CHANCES FOR SHOWERS AND
PERHAPS EVEN SOME THUNDER FROM MONDAY NIGHT INTO TUESDAY. WITH
UNCERTAINTY DID NOT ADD THE THUNDER...BUT DID GO WITH THE WETTER
ECMWF SOLUTION FOR THE TIME BEING.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1211 PM CDT WED OCT 30 2013
THE FOG HAS CONTINUED TO EXPAND NORTH ACROSS THE REGION AHEAD OF
THE WARM FRONT ACROSS SOUTHERN IOWA AND THE INVERTED TROUGH OF LOW
PRESSURE ACROSS WESTERN IOWA. THE 30.12Z RAP INDICATES THERE WILL
BE VERY LITTLE CHANGE IN THE BOUNDARY LAYER THROUGH MUCH OF THE
AFTERNOON...SO EXPECT THE FOG TO REMAIN IN PLACE TO KEEP THE
CEILINGS AND VISIBILITY IN THE IFR CATEGORY. THE 30.12Z NAM
INDICATES A SHORT WAVE TROUGH WILL START TO MOVE TOWARD THE REGION
THIS EVENING AND PUSH THE INVERTED TROUGH AND A SURFACE LOW INTO
THE AREA. AS THIS OCCURS...THE FORCING WILL BE STRONG ENOUGH TO
PRODUCE WIDESPREAD RAIN AND WILL CONTINUE THE TREND OF BRINGING
RAIN INTO BOTH TAF SITES FOR THE EVENING INTO THE OVERNIGHT HOURS.
SOME POTENTIAL FOR A RUMBLE OR TWO OF THUNDER AS SOME ELEVATED
CAPE IS POSSIBLE. CONFIDENCE ON THIS OCCURRING IS NOT VERY HIGH SO
WILL NOT INCLUDE IN THE FORECAST AT THIS TIME. THE INVERTED TROUGH
IS EXPECTED TO MOVE THROUGH OVERNIGHT AND SWING THE WINDS AROUND
TO THE WEST/NORTHWEST. AS THIS HAPPENS...THE BEST MOISTURE
TRANSPORT WILL BECOME FOCUSED EAST OF THE AIRPORTS SO EXPECT THE
RAIN TO COME TO AN END. HOWEVER...ENOUGH LOW LEVEL MOISTURE WILL
REMAIN IN PLACE AFTER THE WIND SHIFT TO KEEP THE CEILINGS LOW AND
IN THE IFR CATEGORY. SOME IMPROVEMENT IN THE VISIBILITY MAY OCCUR
BY MID TO LATE MORNING AS SOME SLIGHTLY DRIER AIR AT THE SURFACE
STARTS TO MOVE IN SO INCREASED THE VISIBILITY TO MVFR AS THIS HAPPENS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...DENSE FOG ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR WIZ053>055-
061.
MN...DENSE FOG ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR MNZ094>096.
IA...DENSE FOG ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR IAZ008>011-
018-019-029-030.
&&
$$
UPDATE...04
SHORT TERM...MW
LONG TERM...MW
AVIATION...04
AREA FORECAST DISCUSSION
NWS TAUNTON MA
417 AM EDT FRI NOV 1 2013
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE REGION TODAY AND STALL NEAR
THE COAST TONIGHT AS A WEAK WAVE OF LOW PRESSURE DEVELOPS SOUTH OF
NEW ENGLAND. UNSEASONABLY MILD AND WINDY TODAY WITH A BAND OF
SHOWERS MOVING ACROSS THE REGION. ANOTHER PERIOD OF SHOWERS AFFECT
THE CAPE AND ISLANDS TONIGHT INTO EARLY SATURDAY...THEN COLDER
AND BLUSTERY CONDITIONS ARRIVE FOR SUNDAY INTO EARLY NEXT WEEK.
HIGH PRESSURE BY THE MIDDLE OF THE WEEK WILL ALLOW FOR MODERATING
TEMPERATURES.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
DRY SLOT AND PRECIP LULL LIFTING NWD ACROSS SNE EARLY THIS MORNING
WHICH IS WELL FORECAST BY SHORT RANGE MODEL SUITE INCLUDING HRRR.
EDGE OF THE DRY SLOT WILL BE ACROSS FAR NW ZONES WHERE OCCASIONAL
SHOWERS WILL CONTINUE...WITH THESE SHOWERS MOVING BACK TO THE
EAST TOWARD DAYBREAK. WARM SECTOR AIRMASS IN WELL ENTRENCHED WITH
TEMPS UPPER 50S TO MID 60S.
ANOMALOUS LOW PRES -4SD LIFTS NE FROM GT LAKES TODAY WITH +3SD LOW
LEVEL JET MOVING ACROSS SNE TODAY. PWAT ANOMALY ALSO +3SD. THIS
WILL RESULT IN A PERIOD OF LOCALLY HEAVY SHOWERS MOVING WEST TO
EAST THIS MORNING INTO THE AFTERNOON ASSOCD WITH IMPRESSIVE LOW
LEVEL MOISTURE TRANSPORT AND RIGHT ENTRANCE REGION OF THE UPPER
JET.
ALSO CONCERNED WITH A POSSIBLE FINE LINE OF CONVECTION ALONG THE
FRONT LATER THIS MORNING PER HRRR SOLUTION. MODELS ARE GENERATING
MARGINAL INSTABILITY WITH SBCAPES 200-400 J/KG SO THIS SCENARIO
SEEMS PLAUSIBLE. LOW RISK OF ISOLD THUNDER AND IF FINE LINE DOES
DEVELOP THIS WOULD ENHANCE THE RISK OF STRONGER WINDS MIXING DOWN
TO THE SURFACE. THE SPEED OF THIS SYSTEM AND MARGINAL INSTABILITY
WILL LIMIT RAINFALL AMOUNTS WITH QPF LESS THAN 0.5" FOR MOST
LOCATIONS...WITH UP TO 1" ACROSS FAR W ZONES. LOCALIZED MINOR
URBAN AND POOR DRAINAGE FLOODING IS POSSIBLE THIS MORNING...MAINLY
IN THE INTERIOR. SHOWERS WILL BE EXITING W ZONES LATE MORNING TO
MIDDAY...AND EARLY AFTERNOON IN THE COASTAL PLAIN. BUT SHOWERS
COULD LINGER THROUGH THE DAY OVER THE OUTER CAPE/ISLANDS AS FRONT
STALLS.
WIND THREAT...CORE OF THE LOW LEVEL JET WILL BE MOVING ACROSS SNE
12-18Z. SOUNDINGS INDICATE VERY SHALLOW PREFRONTAL MIXING BUT
POTENTIAL FOR GUSTS TO 40+ KTS THIS MORNING. HEAVIER SHOWERS AND
POTENTIAL FINE LINE WOULD ALSO AID IN TRANSPORTING STRONGER WINDS
TO THE SURFACE. STRONGEST WINDS WILL LIKELY BE ACROSS PORTIONS
OF RI AND INTERIOR E MA WHERE MILDEST TEMPS INTO THE LOWER 70S
PROMOTE DEEPER MIXING. SOUNDINGS INDICATE THE POTENTIAL FOR
ANOTHER PULSE OF STRONG POST-FRONTAL WINDS TO 40+ KTS THIS
AFTERNOON AS BOUNDARY LAYER MIXING DEEPENS. STRONGEST POST-
FRONTAL WINDS MORE LIKELY ACROSS THE INTERIOR WITH LESS WIND
ALONG THE COAST. WIND ADVISORY WILL CONTINUE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/...
FRONT STALLS NEAR THE COAST TONIGHT AS A WAVE IS FORECAST TO
DEVELOP S OF NEW ENG. THIS WILL KEEP THE THREAT OF SHOWERS GOING
TONIGHT ACROSS SE COASTAL NEW ENG...ESPECIALLY THE OUTER CAPE AND
ISLANDS WHILE DRY CONDITIONS PREVAIL IN THE INTERIOR. AMERICAN
MODELS KEEP MOST OF THE RAIN OFFSHORE WHILE INTERNATIONAL MODELS
BRING A DECENT SLUG OF RAIN TO THE OUTER CAPE/ISLANDS LATE
TONIGHT. WITH FRONT STALLING NEAR THE COAST...WE TRENDED FORECAST
TOWARD WETTER SOLUTION AND HAVE LIKELY POPS TO ACK WITH CHC POPS
TO THE CAPE AND S COASTAL MA. LOW PROB THAT SHOWERS COULD BACK IN
TO THE BOS-PVD CORRIDOR LATE TONIGHT BUT WE KEPT IT DRY FOR NOW.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
HIGHLIGHTS...
* COASTAL LOW DEVELOPS FOR SATURDAY...CLIPPING THE CAPE AND ISLANDS
* COLDER AND BLUSTERY CONDITIONS WILL RETURN ON SUNDAY AND MONDAY
* MODERATING TEMPERATURES AND DRY WEATHER BY MID NEXT WEEK.
* POSSIBLE SYSTEM APPROACHING THURSDAY/FRIDAY
CONFIDENCE LEVEL/MODEL GUIDANCE...
MODERATE CONFIDENCE IN THE OVERALL FORECAST. HAVE HIGH CONFIDENCE IN
THE OVERALL TRENDS YET LOW CONFIDENCE ON EXACT PRECIP TIMING. LONG
WAVE TROUGH IS STILL PROGGED TO IMPACT NEW ENGLAND WITH SEVERAL
SHORTWAVES MOVING THROUGH THE FLOW. THE FIRST ONE IS MOVING THROUGH
TODAY WITH A SECOND SHORTWAVE APPROACHING THE REGION BY TOMORROW.
EXPECT THIS EXPANSIVE NEGATIVE HEIGHT ANOMALY TO INDUCE AN AREA OF
LOW PRESSURE ALONG THE MID-ATLANTIC COAST WHICH WILL SLIDE NORTHWARD
TOWARD THE CANADIAN MARITIMES. 00Z MODEL GUIDANCE ALL AGREE WITH
THIS COASTAL LOW DEVELOPMENT...WHICH COULD BRING MORE SHOWERS ACROSS
THE IMMEDIATE SOUTH COAST...CAPE AND ISLANDS ON SATURDAY. THERE ARE
SOME MODEL DISCREPANCIES ON EXACT PLACEMENT OF THE LOW...WITH THE EC
ON THE FASTER END AND THE GFS ON THE SLOW SIDE. TRENDED IN THE
MIDDLE FOR NOW. FINALLY THE LAST IMPULSE WILL PUSH A STRONG COLD
FRONT THROUGH THE REGION ON SUNDAY DROPPING TEMPS BACK TOWARDS
SEASONABLE. BY EARLY NEXT WEEK MODELS CONCUR WITH A WESTERN TROUGH
TO STRONGLY AMPLIFY RESULTING IN RIDGING TO BUILD OVER THE EASTERN
HALF OF THE U.S. HOWEVER THIS WESTERN TROUGH WILL APPROACH NEW
ENGLAND BY THURSDAY BRINGING ANOTHER ROUND OF RAIN AND WIND. EXACT
TIMING FOR THIS SYSTEM IS STILL UNCERTAIN.
DETAILS...
SATURDAY...
MID-ATLANTIC LOW WILL DEVELOP AND HEAD TOWARDS SOUTHERN NEW ENGLAND
DURING THE MORNING HOURS. AS MENTIONED BEFORE...TRENDED TOWARDS THE
MIDDLE OF THE ROAD COMPARED TO THE GFS AND EC. BELIEVE THERE WILL BE
A SHARP CUT OFF IN TERMS OF WHERE THE RAIN WILL AND WILL NOT FALL.
HAVE THE HIGHEST CONFIDENCE THAT THIS SYSTEM WILL BRING SOME SHOWERS
ACROSS THE IMMEDIATE SOUTH COAST...CAPE AND ISLANDS. HOWEVER WITH
THE ONSHORE FLOW...COULD SEE A SHOWER OR TWO ACROSS THE SOUTHEAST
COASTAL SIDE OF MASSACHUSETTS. THIS COASTAL LOW WILL MOVE UP TO THE
MARITIMES BY THE SATURDAY NIGHT SO CHANCE OF PRECIP WILL WANE BY THE
AFTERNOON HOURS. REGARDLESS SATURDAY WILL STILL BE MILD WITH TEMPS
IN THE 60S AND LESS WINDY. DEFINITELY AN IMPROVEMENT COMPARED TO
TODAY.
SUNDAY...
THE UNSEASONABLE WARM WEATHER WILL COME TO AN END ON SUNDAY AS THE
THIRD AND LAST IMPULSE PUSHES A STRONG COLD FRONT THROUGH THE REGION
BY LATE SATURDAY/EARLY SUNDAY. THIS FRONT WILL HAVE STRONG CAA
BEHIND IT DROPPING TEMPERATURES ACROSS THE REGION CLOSER TO
SEASONABLE. IN FACT 850 MB TEMPS DROP BETWEEN -6 TO -9C RESULTING IN
HIGH TEMPS TO BE BE IN THE MID 40S TO LOW 50S. WITH COASTAL LOW WAY
OUT IN THE MARITIMES AND CANADIAN HIGH BUILDING ACROSS THE NORTH
COUNTRY...DUE NORTH WINDS ARE ANTICIPATED. THESE NORTHERLY WINDS
WILL ALLOW FOR SOME POSSIBLE OCEAN EFFECT SHOWERS TO DEVELOP AND
MOVE ALONG THE EAST COAST LINE AND ACROSS THE CAPE AND ISLANDS. HAVE
KEPT A SLIGHT CHANCE MENTIONED FOR NOW. THESE SHOWERS WILL BE VERY
ISOLATED IN NATURE. ALTHOUGH TEMPS ALOFT ARE DROPPING
QUICKLY...BELIEVE LIQUID PRECIP WILL HOLD OUT AS SURFACE AND BL
TEMPS WILL STILL STAY ABOVE FREEZING.
SUNDAY NIGHT INTO WEDNESDAY....
CANADIAN HIGH PRESSURE WILL BEGIN TO MOVE INTO THE REGION LATE
SUNDAY NIGHT INTO MONDAY...AND BUILD OVER THE NORTHEAST THROUGH AT
LEAST WEDNESDAY. THIS HIGH PRESSURE WILL ALLOW FOR LIGHT WINDS AND
CLEAR SKIES ESP DURING THE OVERNIGHT HOURS. THIS WILL ALLOW FOR
RADIATIONAL COOLING ON SUNDAY NIGHT AND ON MONDAY NIGHT. SUNDAY
NIGHT APPEARS TO BE THE COLDEST WITH TEMPS DROPPING INTO THE MID
TEENS TO MID 20S. MONDAY WILL BE THE COOLEST THE REGION HAS SEEN
IN AWHILE WITH HIGHS BELOW AVERAGE...LOW TO MID 40S.
AN UPPER LEVEL RIDGE WILL BEGIN TO BUILD ACROSS THE EASTERN SEABOARD
RESULTING IN DRY WEATHER AND A WARMING TREND. IN FACT MID 60S RETURN
TO THE FORECAST BY WEDNESDAY AND POSSIBLY ON THURSDAY.
THURSDAY AND BEYOND...
MODELS BEGIN TO DRIVE THE WESTERN TROUGH TOWARDS THE EAST COAST BY
THURSDAY. APPEARS THAT THIS LOW PRESSURE SYSTEM WILL BRING HEAVY
RAIN AS WELL AS STRONG WINDS TO THE REGION BY THURSDAY MORNING
LASTING INTO FRIDAY MORNING. BECAUSE THIS SYSTEM IS SEVERAL DAYS
AWAY...A LOT CAN CHANGE SO STAY TUNED TO THE LATEST FORECAST.
&&
.AVIATION /07Z FRIDAY THROUGH TUESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
THROUGH 12Z...CIGS BEGINNING TO LOWER TO MVFR AND EXPECT AREAS OF
IFR TO DEVELOP. FOG WILL NOT BE A BIG CONCERN WITH PATCHY MVFR
VSBYS AT TIMES...ESPECIALLY IN ANY SHOWERS WHICH WILL BE CONFINED
MOSTLY TO FAR NW ZONES. WIND GUSTS TO 25-35 KT DEVELOPING.
FRI...IFR-MVFR WITH A BAND OF LOCALLY HEAVY SHOWERS MOVING ACROSS
THE REGION...EXITING 16-20Z FROM WEST TO EAST WITH IMPROVING
CONDITIONS TO MVFR VFR. STRONG S/SW WINDS GUSTING UP TO 40-45 KT
RI AND EASTERN MA IN THE MORNING...THEN SHIFTING TO WSW IN THE
AFTERNOON WITH GUSTS 30-40 KT. HIGH CONFIDENCE ON TRENDS.
TONIGHT...LINGERING MVFR/IFR IN OCCASIONAL SHOWERS AT
ACK...POSSIBLY AS FAR N AS CAPE COD. OTHERWISE VFR WITH
DIMINISHING WIND. MODERATE CONFIDENCE.
KBOS TAF...HIGH CONFIDENCE IN TRENDS...LOWER IN EXACT TIMING.
KBDL TAF...HIGH CONFIDENCE IN TRENDS...LOWER IN EXACT TIMING.
OUTLOOK...SATURDAY THROUGH TUESDAY...
SATURDAY...MVFR/IFR CONDITIONS TO START WILL IMPROVE TO VFR FROM
WEST TO EAST.
SUNDAY...VFR. NNW WINDS COULD GUST TO 25 KTS.
MONDAY AND TUESDAY...VFR.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
TODAY...SW GALE FORCE WINDS TO 35-40 KT. SCATTERED HEAVY SHOWERS
EXIT OFFSHORE DURING THE AFTERNOON...HOWEVER MAY LINGER OVER
SOUTHEAST WATERS. HIGH CONFIDENCE.
TONIGHT...DIMINISHING WIND AND SEAS. OCCASIONAL SHOWERS WILL
CONTINUE ACROSS SE WATERS...OTHERWISE MAINLY DRY. MODERATE
CONFIDENCE ON NW EXTENT OF SHOWERS.
OUTLOOK...SATURDAY THROUGH TUESDAY...HIGH CONFIDENCE.
SATURDAY AND SUNDAY...SMALL CRAFT ADVISORIES WILL LIKELY BE
NECESSARY FOR SEAS OVER 5 FEET AND NORTHWESTERLY WINDS GUSTING TO 30
KTS. THERE IS A LOW PROBABILITY THAT NORTH GALES WILL OCCUR ACROSS
THE EASTERN OUTER WATERS ON SUNDAY. VISIBILITIES MAY BE LIMITED IN
INTERMITTENT SHOWERS.
MONDAY AND TUESDAY...WINDS AND SEAS DIMINISH AS HIGH PRESSURE MOVES
OVER SOUTHERN NEW ENGLAND AND OVER THE WATERS. LIGHT NORTHERLY
WINDS SHIFT TO THE EAST AND THEN SOUTH THROUGH THIS TIME PERIOD.
&&
.TIDES/COASTAL FLOODING...
COASTAL FLOODING CONCERNS ALONG THE SOUTH COAST ARE MINIMAL. NOT
MUCH OF A SURGE GIVEN SURFACE LOW AND PRESSURE FALLS ARE TRACKING
SO FAR NORTHWEST OF NEW ENGLAND. WILL HAVE MODEST TO LARGE WAVE
ACTION ON THE SOUTH COAST BUT TIDES WILL NOT BE HIGH ENOUGH TO
WARRANT ANY FLOODING.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WIND ADVISORY UNTIL 6 PM EDT THIS EVENING FOR CTZ002>004.
MA...WIND ADVISORY UNTIL 6 PM EDT THIS EVENING FOR MAZ002>024-026.
NH...WIND ADVISORY UNTIL 6 PM EDT THIS EVENING FOR NHZ011-012-015.
RI...WIND ADVISORY UNTIL 6 PM EDT THIS EVENING FOR RIZ001>008.
MARINE...GALE WARNING UNTIL 6 PM EDT THIS EVENING FOR ANZ230>237-250-
251-254>256.
&&
$$
SYNOPSIS...KJC/DUNTEN
NEAR TERM...KJC/DUNTEN
SHORT TERM...KJC/DUNTEN
LONG TERM...DUNTEN
AVIATION...KJC/DUNTEN
MARINE...KJC/DUNTEN
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
151 AM EDT FRI NOV 1 2013
.PREV DISCUSSION... /ISSUED 858 PM EDT THU OCT 31 2013/
PREV DISCUSSION... /ISSUED 320 PM EDT THU OCT 31 2013/
SHORT TERM /TONIGHT THROUGH FRIDAY/...
OBVIOUSLY THE MAIN QUESTION THROUGH THE SHORT TERM IS TIMING OF THE
FRONT AND PRECIP ASSOCIATED WITH IT. DEEP UPPER TROUGH OVER THE
CENTER OF THE COUNTRY IS BEGINNING TO LIFT OUT. STRONG SURFACE LOW
OVER THE GREAT LAKES WILL CONTINUE MOVING NORTHEAST...DRAGGING A
COLD FRONT THROUGH THE SOUTHEAST TONIGHT AND TOMORROW AS THE SURFACE
LOW OCCLUDES. MOST OF THE PRECIP WILL BE OUT OF THE AREA BY THE END
OF THE SHORT TERM WITH THE EXCEPTION OF EXTREME SOUTHEAST ZONES.
STRONG SOUTHERLY FLOW IS IN PLACE ACROSS THE SOUTHEAST AHEAD OF THE
FRONT AT AFD TIME...WITH SOME PATCHY RETURNS SHOWING UP HERE AND
THERE ON RADAR. IT IS DOUBTFUL THAT ANYTHING IS REACHING THE GROUND
FROM THESE WEAK ECHOES BUT THEIR EXISTENCE DOES LEND SOME CREDENCE
TO THE HRRR SOLUTION FOR THIS AFTERNOON AND EARLY EVENING. GUIDANCE
IS ALL REALLY COMING INTO AGREEMENT WITH THE PROGRESSION OF THE
FRONT AND IT LOOKS LIKE FOR THE MOST PART THE CWA WILL REMAIN
PRECIP-FREE UNTIL AFTER 00Z. MAY SEE SOME SPRINKLES NORTHWEST BUT
REALLY HAVE NOT STARTED INCREASING POPS UNTIL AFTER THAT POINT.
SHOULD ENCROACH UPON THE METRO AREA NEAR OR JUST AFTER MIDNIGHT...
AND TOWARDS CENTRAL GEORGIA /MACON AREA/ BY 12Z. SO TRICK-OR-
TREATING SHOULD BE IN GOOD SHAPE THIS EVENING.
ONTO SOME DETAILS...STARTING WITH QPF...NOT OVERLY CONCERNED ABOUT
OVERALL BASIN-AVERAGE VALUES WHICH GENERALLY REMAIN BELOW AN INCH
THROUGH THE EVENT. NAM IS A LITTLE MORE AGGRESSIVE WITH QPF VALUES
ESPECIALLY 12-18Z FRIDAY BUT IT SEEMS TO BE A BIT OF AN OUTLIER.
CANNOT RULE OUT SOME ISOLATED PRECIP ISSUES ESPECIALLY WITH ANY
OROGRAPHIC ENHANCEMENT IN THE NORTH GEORGIA MOUNTAINS...BUT THAT
WILL HAVE TO BE HANDLED ON A CASE-BY-CASE BASIS.
OTHER CONCERN IS SEVERE POTENTIAL. AS IS ALWAYS THE CASE...NAM IS
MORE UNSTABLE THAN OTHER GUIDANCE BUT THE GFS IS COMING IN WITH
SLIGHTLY HIGHER MUCAPE FRIDAY AFTERNOON THAN PREVIOUS RUNS WITH OVER
700 J/KG...NOT THAT DIFFERENT FROM THE NAM. EXPECT THAT ANY PRECIP
THIS EVENING AND THROUGH MOST OF THE OVERNIGHT PERIOD WILL REMAIN AS
SHOWERS...THOUGH DID BRING SLIGHT CHANCE THUNDER IN STARTING AT 06Z
NORTHWEST...BUT GENERALLY ONLY WHERE POPS ARE LIKELY OR HIGHER.
SWATH OF INSTABILITY WILL BE ACROSS THE METRO AREA BY AROUND
12Z...AND CENTRAL GEORGIA BY 18Z. SO OVERALL VERY...VERY LITTLE
INSTABILITY TO WORK WITH BUT WHEN CONTRASTED WITH THE VERY STRONG
SHEAR...WE CANNOT LET OUR GUARD DOWN. 0-1KM BULK SHEAR VALUES BY 06Z
TONIGHT ARE OVER 40KT IN NORTHWEST GEORGIA...WITH 60-70KT 0-6KM
SHEAR. 0-1KM SHEAR DROPS OFF THROUGH TIME TO GENERALLY BELOW 35KT BY
12Z FRIDAY...AND LESS THAN 30KT BY 18Z FRIDAY...BUT DEEP LAYER SHEAR
REMAINS QUITE STRONG AT OVER 60KT. SO WE HAVE A TREND OF INCREASING
INSTABILITY FROM 06-18Z FRIDAY AND DECREASING SHEAR. SOMEWHERE IN
THERE A PERFECT JUXTAPOSITION CANNOT BE RULED OUT. SPC HAS A SEE
TEXT FOR DAY2 ACROSS CENTRAL GEORGIA AND SREF GUIDANCE SEEMS TO
POINT TO FRIDAY LATE MORNING AND EARLY AFTERNOON BEING OF GREATER
CONCERN THAN OVERNIGHT TONIGHT. SHERB PARAMETER...WHICH WAS
CALIBRATED TO INDICATE A FAVORABLE ENVIRONMENT FOR HIGH SHEAR LOW
CAPE SEVERE WEATHER...IS MAXIMIZED LATE THIS EVENING IN NORTHWEST
GEORGIA WITH ANOTHER MAXIMUM JUST BEFORE 18Z TOMORROW /RIGHT BEFORE
FROPA/ AROUND THE METRO AREA.
OF COURSE...ALL THAT SAID /OR WRITTEN/...OVERALL CONCERN FOR SEVERE
IS NOT PARTICULARLY HIGH. IT JUST CANNOT BE RULED OUT.
USED A BLEND FOR TEMPERATURES BUT PULLED BACK ON BIAS ADJUSTMENT DUE
TO WIDESPREAD CLOUDS AND IMPENDING AIRMASS CHANGE.
TDP
LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
COLD FRONT EXPECTED TO EXIT THE SE CWA FRIDAY NIGHT WITH PRECIP
CHANCES DIMINISHING. UPPER TROUGH MOVES ACROSS THE AREA ON SATURDAY
WITH SOME MOISTURE ASSOCIATED OVER THE FAR NORTHERN COUNTIES. CAN
NOT RULE OUT SOME LIGHT SHOWERS OR SPRINKLES DURING THE DAY.
TEMPERATURES TRENDING TO BELOW NORMAL INTO EARLY NEXT WEEK.
BDL
PREVIOUS DISCUSSION...
MODELS IN GOOD AGREEMENT WITH CONTINUING TO PUSH THE COLD FRONT AND
ASSOCIATED MOISTURE OUT OF THE CWA BY SATURDAY MORNING LEAVING THE
LONG TERM DRY UNTIL THE MIDDLE OF NEXT WEEK. THE H5 TROUGH WILL EXIT
THE U.S. SATURDAY WITH A RIDGE BUILDING OVER THE EASTERN U.S. SUNDAY
THROUGH EARLY NEXT WEEK. SOME DIFFERENCES IN THE NEXT SYSTEM APPEAR
BETWEEN THE 00Z GFS AND THE 12Z ECMWF WITH THE ECMWF HOLDING ONTO
THE H5 HIGH OVER THE SOUTHEAST WHILE THE GFS WEAKENS THE HIGH AND
BRINGS A FAST MOVING TROUGH AND ASSOCIATED COLD FRONT INTO THE CWA
BY WEDNESDAY NIGHT AND THURSDAY. AT THIS TIME WILL MAINTAIN CHANCE
POPS BEGINNING WEDNESDAY.
17
&&
.AVIATION...
06Z UPDATE...
MAIN CONCERN FOR AVIATION ARE THE CEILINGS AND WIND. RAIN MOVING
THROUGH THE AREA HAS CAUSED CEILINGS TO DROP INTO THE MVFR RANGE.
EXPECT THIS TREND TO CONTINUE WITH POSSIBLE IFR CONDITIONS NEAR
12Z. SOME GUSTS HAVE BEEN REPORTED AS SHOWERS MOVE THROUGH THE
AREA. EXPECT GUSTS WITH THE RAIN SHOWERS TO CONTINUE. WITH FROPA
NW WINDS AND CLEARING SKIES ARE EXPECTED.
//ATL CONFIDENCE...06Z UPDATE...
MEDIUM CONFIDENCE IN CEILINGS...HIGH CONFIDENCE ON ALL OTHER ELEMENTS.
ARG
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 70 48 69 42 / 90 10 0 0
ATLANTA 71 50 67 43 / 80 10 0 0
BLAIRSVILLE 71 43 61 38 / 60 20 20 0
CARTERSVILLE 73 44 67 40 / 60 5 0 0
COLUMBUS 73 51 72 44 / 90 10 0 0
GAINESVILLE 72 49 67 42 / 80 10 10 0
MACON 74 49 74 41 / 90 20 0 0
ROME 72 43 66 40 / 50 5 0 0
PEACHTREE CITY 72 45 69 38 / 90 10 0 0
VIDALIA 78 58 76 48 / 90 80 0 0
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...ARG
LONG TERM....17
AVIATION...ARG
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
312 AM CDT FRI NOV 1 2013
.DISCUSSION...
312 AM CDT
PRIMARY FORECAST CHALLENGES THIS MORNING INCLUDE CLOUD COVER AND ITS
EFFECT ON TEMPS THE NEXT COUPLE DAYS...SHOWER CHANCES LATER THIS
AFTERNOON AND EVENING...FOLLOWED BY WHAT LOOKS TO BE A POSSIBLE
REPEAT OF THIS WEEK`S EVENTS NEXT WEEK!
AFTER DEEPENING 15MB IN THE PAST 12 HOURS THE POWERHOUSE AUTUMN
STORM CONTINUES TO SLOWLY DEEPEN AS IT LIFTS NORTHEAST OUT OF THE
REGION. RAIN HAS ENDED BUT GUSTY WEST WINDS ARE USHERING IN A
STARKLY DIFFERENT AIR MASS COMPARED WITH 24 HOURS AGO WITH 24
TEMP/TD CHANGES OF 20-25F. COMBINATION OF COLD AIR STRATOCUMULUS
WRAPPING AROUND THE SYSTEM INTO THE AREA AND CONTINUATION OF WEAK
COLD AIR ADVECTION THROUGH THE DAY SHOULD ALLOW VERY LITTLE TEMP
RECOVERY AND HAVE UNDERCUT GUIDANCE FOR HIGHS TODAY...MAINLY
NORTHERN CWA WHERE PROSPECTS FOR SUNSHINE ARE DIMMER (PARDON THE
PUN).
WATER VAPOR IMAGERY SHOWS A PAIR OF WELL DEFINED SHORTWAVE TROUGHS
OVER EASTERN NEBRASKA AND WESTERN NEBRASKA EARLY THIS MORNING.
MODELS BRING BOTH OF THESE WAVES EASTWARD INTO OUR AREA THIS
AFTERNOON AND EVENING. WHILE CLOUD COVER WILL LIMIT SFC HEATING
TODAY...MUCH COLDER MID LEVEL TEMPS WILL ADVECT INTO THE AREA WITH
THESE SECONDARY WAVES WHICH WILL STEEPEN THE LOW AND MID LEVEL LAPSE
RATES. THE STEEP LAPSE RATES AND LARGE SCALE ASCENT WITH THE
APPROACHING WAVES SHOULD ALLOW FOR SCATTERED SHOWERS TO MOVE ACROSS
THE CWA LATER THIS AFTERNOON INTO THE EVENING...ESPECIALLY NORTHERN
HALF OF THE CWA. FREEZING LEVELS DROP TO JUST OVER 3K FT AGL AND
GIVEN THE CONVECTIVE NATURE OF THE SHOWERS IT WOULDNT BE SURPRISED
TO SEE A FEW GRAUPEL REPORTS LATER TODAY INTO EARLY THIS EVENING
BEFORE SHORTWAVE RIDGING RESULTS IN DECREASING SHOWER CHANCES
OVERNIGHT.
CYCLONIC LOW LEVEL FLOW AND FRONTAL INVERSION LIKELY TO RESULT IN
STRATUS HANGING AROUND TONIGHT INTO SATURDAY AND POSSIBLY INTO PART
OF SATURDAY NIGHT BEFORE FLOW BECOMES MORE ANTICYCLONIC AS WAA
BEGINS. THE EXTENSIVE CLOUD COVER TODAY THROUGH SATURDAY SHOULD
RESULT IN SMALL DIURNAL TEMP SWING AND HAVE GONE BELOW GUIDANCE FOR
HIGHS TODAY AND SATURDAY AND ABOVE GUIDANCE FOR LOW TEMPS TONIGHT.
ASSUMING STRATUS FINALLY CLEARS SAT NIGHT HAVE ALLOWED FOR A HEALTHY
DROP IN TEMPS WITH CLEARING SKIES AND LIGHT WINDS.
SUNDAY INTO MONDAY WILL MARK A TRANSITION PERIOD AS LONG WAVE TROUGH
MOVES OUT OF THE AREA AND IS REPLACED BY LONGWAVE RIDGING IN ADVANCE
OF THE NEXT SIGNIFICANT TROUGH DIGGING INTO THE WEST. INITIALLY WARM
AIR ADVECTION WILL BE MOST PRONOUNCED ALOFT SUNDAY BUT SOUTHEAST
WINDS AND MORE SUNSHINE SHOULD STILL ALLOW TEMPS TO WARM A
COUPLE/FEW DEGREES OVER SATURDAY. FURTHER WARMING IS EXPECTED MONDAY
AS SOUTHERLY WINDS RAMP UP...THOUGH INCREASING MID-HIGH LEVEL CLOUDS
COULD FILTER SUNSHINE AND TEMPER THE WARM UP A BIT.
NEXT SIGNIFICANT LONG WAVE TROUGH WILL BEGIN TO AFFECT THE REGION
TUESDAY AND ESPECIALLY TUESDAY NIGHT INTO WEDNESDAY. SUSPECT THE
SYSTEM COULD SLOW SOMEWHAT FROM WHAT CURRENT GUIDANCE IS
SHOWING...MUCH LIKE HAPPENED WITH THIS WEEK`S SYSTEM. STILL LOOK FOR
GRADUALLY INCREASING RAIN CHANCES TUESDAY...BUT THE BEST RAIN BET
APPEARS TO BE TUESDAY NIGHT INTO WEDNESDAY MORNING. PWATS ONCE AGAIN
ARE PROGGED TO CLIMB TO WELL OVER AN INCH...OR OVER 200% OF NORMAL
WITH SOME GUIDANCE EVEN SUGGESTING THAT SOME OF THE MID-UPPER LEVEL
MOISTURE FROM 97E OVER THE TROPICAL EASTERN PACIFIC POSSIBLY GETTING
ENTANGLED INTO THIS SYSTEM...SO ONCE AGAIN WE WILL NEED TO WATCH OUT
FOR A POSSIBILITY OF A HEALTHY RAIN EVENT.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 03Z...
* MVFR CIGS THROUGH MUCH OF THE PERIOD WITH A SHORT PERIOD OF
IMPROVEMENT TO VFR TOMORROW AFTERNOON.
* GUSTY NNWLY WINDS BACKING TO WLY. GUSTS SUBSIDING FOR THE
OVERNIGHT HOURS.
KREIN
//DISCUSSION...UPDATED 00Z...
THE COLD FRONT HAS PUSHED THROUGH THE TERMINALS AND THE BULK OF
THE ASSOCIATED PCPN HAS MOVED OFF TO THE EAST. THERE MAY BE SOME
SCT SHRA FOR A FEW MORE HRS THIS EVENING...BUT SHOULD NOT BE A
PREVAILING CONDITION. WITH THE WARM..HUMID AIR PUSHING TO THE EAST
WITH THE COLD FRONT...COOLER AIR IS FILTERING IN ACROSS THE
REGION. THE IFR CIGS HAVE ENDED WITH THE LOSS OF THE WARM...HUMID
AIRMASS...BUT PERSISTENT COOL CYCLONIC FLOW ALOFT SHOULD KEEP MVFR
CIGS FOR MUCH OF THE REMAINDER OF THE PERIOD. SOME DIURNAL WARMING
TOMORROW AFTERNOON SHOULD ALLOW CIGS TO LIFT TO VFR FOR A BRIEF
PERIOD...BUT SHOULD THEN LOWER BACK TO MVFR AFTER SUNSET. WINDS
WILL WILL REMAIN GUSTY TO 20-25KT FOR A FEW HOURS FOLLOWING THE
FRONTAL PASSAGE WITH THE STRONGEST COLD ADVECTION...BUT SHOULD
THEN TAPER OFF FOR THE OVERNIGHT HOURS. ANOTHER MID LEVEL IMPULSE
DROPPING AROUND THE SWRN PERIPHERY OF THE MAIN UPPER LOW WILL
BRING ANOTHER SHOT OF REINFORCING COOLER AIR...BRINGING ANOTHER
CHANCE FOR SOME SCT SHRA AS WELL AS RENEWED GUSTINESS FOR THE LATE
AFTERNOON HOURS.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 03Z...
* MODERATE CONFIDENCE IN CIG TRENDS.
* MODERATE CONFIDENCE IN WIND TRENDS.
* MODERATE TO HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z...
SATURDAY...SLIGHT CHANCE OF SHOWERS EARLY...OTHERWISE VFR.
SUNDAY...VFR. WX NIL.
MONDAY...CHANCE OF SHOWERS LATE...OTHERWISE VFR.
TUESDAY...RAIN LIKELY. CHANCE MVFR CIGS/VIS.
WEDNESDAY...RAIN LIKELY EARLY THEN CHANCE OF SHOWERS. CHANCE
MVFR CIGS/VIS EARLY. VFR LIKELY LATE.
KREIN
&&
.MARINE...
209 PM CDT
DEVELOPING STORM SYSTEM THIS EVENING AS IT NEARS LAKE MICHIGAN. NO
CHANGES TO THE GOING HEADLINES OF GALES FOR THE ENTIRE LAKE AND
INDIANA NEARSHORE WATERS.
AN ELONGATED TROUGH OF LOW PRESSURE STRETCHED FROM CENTRAL WISCONSIN
SOUTH THROUGH SOUTHWEST ILLINOIS THIS AFTERNOON...AND IS FORECAST TO
CONSOLIDATE INTO A LOW OVER CENTRAL LAKE MICHIGAN EARLY THIS EVENING
AND RAPIDLY DEEPEN. AS THE LOW QUICKLY INTENSIFIES...THE PRESSURE
GRADIENT OVER THE LAKE WILL ALSO TIGHTEN. THIS WILL RESULT IN GALES
DEVELOPING WITH NEARLY 40-44KT ACROSS THE SOUTHERN HALF OF LAKE
MICHIGAN FROM THE WEST. TIMING CONTINUES TO BE AROUND MIDNIGHT. THE
STRONG LOW PRESSURE WILL CONTINUE TO DEEPEN AS IT SLIDES NORTHEAST
ACROSS NORTHEASTERN LAKE HURON INTO EASTERN ONTARIO AND WESTERN
QUEBEC FRI AFTN/EVE. THE GRADIENT WILL THEN QUICKLY DIMINISH LATE
FRI MORNING...WITH GALES ENDING BY MID-MORNING FRI.
WINDS WILL CONTINUE TO BE WESTERLY UNTIL THE UPPER LEVEL TROUGH
ARRIVES FRI EVE...THEN WINDS WILL TURN NORTHWESTERLY. A BROAD RIDGE
OF HIGH PRESSURE CONTINUES TO BE FORECAST TO SLIDE ACROSS THE
CENTRAL/SOUTHERN PLAINS. THIS WILL RESULT IN A PROLONGED PERIOD OF
NORTH/NORTHWEST WINDS FOR SAT. THE GRADIENT DOESN/T COMPLETELY GO
AWAY...WITH SPEEDS REMAINING ARND 10-20KT WITH GUSTS TO 25KT OVER
THE OPEN WATERS. THEN THIS HIGH PRESSURE SLIDES EAST AND STRETCHES
TO COVER LAKE MICHIGAN SAT NIGHT/SUN...WITH A PERIOD OF LIGHTER
WINDS. THE WEATHER REMAINS PROGRESSIVE AND THE HIGH PRESSURE WILL
PUSH EAST WITH WINDS SHIFTING TO SOUTHEASTERLY/SOUTHERLY FOR EARLY
NEXT WEEK.
FORECAST GUIDANCE IS BEGINNING TO POINT TOWARDS ANOTHER STRONG STORM
SYSTEM TO DEVELOP AND APPROACH THE GREAT LAKES REGION FOR THE MIDDLE
PART OF NEXT WEEK.
CONFIDENCE IN GALES TONIGHT/FRI MORNING...HIGH.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 9 AM FRIDAY.
GALE WARNING...INDIANA NEARSHORE WATERS UNTIL 4 AM FRIDAY.
SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 10 AM FRIDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
[top]
Area Forecast Discussion
National Weather Service Lincoln IL
304 AM CDT Fri Nov 1 2013
.DISCUSSION...
ISSUED 303 AM CDT Fri Nov 1 2013
SHORT TERM...Today through Sunday
Northwesterly upper flow pattern will keep plenty of cloud cover
in place across at least the northern half of the KILX CWA today.
07z/2am satellite imagery shows overcast conditions upstream over
much of Iowa, with satellite timing tools generally keeping the
clouds along/north of the I-74 corridor as they work eastward this
morning. Further south, mostly clear skies will be noted along and
south of a Springfield to Paris line initially: however, cooling
aloft will create fairly steep lapse rates and additional diurnal
cloud development. CU rule remains most negative across the
northern CWA, but still suggests SCT-BKN cloud cover even across
the south. End result will be mostly cloudy skies north and partly
sunny conditions far south. Short-wave trough currently evident on
water vapor imagery over eastern Montana will drop southeastward
later today into tonight. Weak lift ahead of this feature may
trigger a few sprinkles late this afternoon, particularly across
the northern CWA. Based on latest HRRR and 4km WRF-NMM, have
included scattered sprinkles for locations north of Peoria late
this afternoon. Despite weak lift ahead of the approaching wave,
forecast soundings remain too dry to support measurable precip
through tonight.
Cool/dry weather will be the rule through the weekend, as high
pressure builds into the region. High temperatures will only be in
the 50s both Saturday and Sunday, while lows dip into the lower to
middle 30s by Sunday morning.
LONG TERM...Monday through Thursday
Challenges in the extended continue to focus on strength of
building upper ridge over the southeast CONUS and timing of
approaching short-wave next week. Previous runs of the ECMWF had
featured an unseasonably strong 594dm 500mb high developing over
the Carolinas by Monday/Tuesday. This strong ridge essentially
slowed the eastward progress of an upper short-wave over the
Plains, resulting in an extended period of rain chances across
central Illinois from Tuesday through Thursday. Meanwhile, both
the GFS and GEM were slightly weaker with the high and thus
brought the Plains wave and associated cold front eastward a bit
faster. 00z Nov 1 run of the ECMWF has now come into much better
agreement with the GFS/GEM, leading to increased confidence in a
more progressive pattern next week. As such, will continue to
focus highest POPs during the Tuesday night/Wednesday time frame
when strongest lift and deepest moisture will be present. Have
opted to go with a dry forecast for Thursday, as all model
guidance pushes front east of the region.
Barnes
&&
.AVIATION...
ISSUED 1154 PM CDT Thu Oct 31 2013
MVFR clouds look to be holding tough in the post frontal airmass.
Even some IFR cigs down to 700-900 ft will be possible in the
first few hours of the tafs. Wrap around moisture will have an
opportunity to rotate into IL on brisk west winds, before the
surface and upper lows make progress to the NE. Forecast soundings
are looking more pessimistic on clouds even on Friday as strato-
cumulus develop in the 3500ft layer. We should remain VFR, but a
bit cloudier than previous forecasts. No precip is expected, but
Friday evening will see showers in N IL drop toward I-74 by
midnight, or the later hours of this taf period.
Winds will remain brisk from the WSW, with gusts to 22-24kt at
times...mainly in response to the deepening surface low across the
Great Lakes and building high pressure in the Plains. Winds should
veer to the NW on Friday.
Vis reductions may dip 5sm br due to saturated boundary levels,
but steady winds should preclude vis dropping much lower than that
the rest of tonight.
Shimon
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS JACKSON KY
318 AM EDT FRI NOV 1 2013
.UPDATE...
ISSUED AT 100 AM EDT FRI NOV 1 2013
ZONES WERE UPDATED TO REFLECT SEVERE THUNDERSTORM WATCH NUMBER 557
FOR THE ENTIRE CWA UNTIL 6 AM EDT. A LINE OF SHOWERS WITH NO DETECTED
LIGHTNING...ALTHOUGH HAVING THE RADAR APPEARANCE OF THUNDERSTORMS AND
WIND GUST IMPACTS OF THUNDERSTORMS WILL PUSH RATHER RAPIDLY EAST TO
THE WV BORDER BY 4 AM EDT. DAMAGE HAS BEEN REPORTED OVER THE
BLUEGRASS REGION AND WE EXPECT AT LEAST THE NORTHERN TWO THIRDS OF
THE CWA TO BE UNDER THE THREAT OF DAMAGING WIND GUSTS DOWNING TREES
OVER THE NEXT COUPLE OF HOURS. THERE ARE SOME KINKS WITHING THIS LINE
AND GIVEN THE VERY STRONG LOW LEVEL SHEAR A STRAY WEAK SPIN UP IS NOT
OUT OF THE QUESTION. THE GRIDS WILL UPDATED TO REFLECT RECENT OBS SHORTLY.
UPDATE ISSUED AT 1055 PM EDT THU OCT 31 2013
DID ANOTHER UPDATE TO FINE TUNE THE MOVEMENT OF THE SQUALL LINE
THROUGH OUR AREA OVER THE NEXT SEVERAL HOURS. USED THIS LINE TO
HIGHLIGHT THE HIGHEST WINDS AND BEST THUNDER CHANCES. ALSO TWEAKED
THE T AND TD GRIDS TO REFLECT THE LATEST OBS AND TRENDS. UPDATES HAVE
BEEN SENT TO THE NDFD AND WEB SERVERS.
UPDATE ISSUED AT 810 PM EDT THU OCT 31 2013
23Z SFC ANALYSIS SHOWS A DEEP AREA OF LOW PRESSURE MOVING INTO THE
GREAT LAKES. A POWERFUL COLD FRONT ASSOCIATED WITH THIS IS SLICING
EAST THROUGH THE MIDWEST...NOW APPROACHING WESTERN KENTUCKY. AHEAD OF
THIS...THE WEAKER PATCHES OF SHOWERS ARE BREAKING UP...CLEARING THE
WAY FOR MORE BANDED CLUSTERS AND EVEN SOME LINEAR THUNDERSTORMS. IN
THIS ENVIRONMENT...HIGH SHEAR AND PASSING 850 MB JET AT 75+ KTS...
THESE HAVE THE DISTINCT POTENTIAL OF BRINGING DOWN DAMAGING WINDS
GUSTS AND A SMALL THREAT OF SHORT LIVED TORNADOES. THE MAIN QUESTION
IS HOW THESE STORMS EVOLVE TO OUR WEST AND MOVE THROUGH EAST KENTUCKY
LATER TONIGHT. THE LATEST HRRR SUGGESTS THAT A SQUALL LINE WILL MOVE
THROUGH JUST AHEAD OF THE FRONT WITH THE HEAVIEST RAINS AND WINDS
PASSING THROUGH EAST KENTUCKY FROM 04 TO 08Z. HAVE SET UP THE LATEST
GRIDS TO REFLECT THIS AND READJUSTED THE WIND/GUST GRIDS TO BETTER
FOCUS ON THIS POTENTIAL LINE. FOR TEMPERATURES AND DEWPOINTS...HAVE
ADJUSTED THEM TOWARD THE LATEST CONSSHORT EXPECTING THEM TO STAY UP
UNTIL THE MAIN BOUNDARY AND RAIN APPROACHES LATER THIS EVENING. HAVE
ALSO UPDATED THE NPW TO REFLECT THESE LATEST THOUGHTS WITH A ZFP AND
HWO UPDATE TO FOLLOW. GRIDS HAVE BEEN SENT TO THE NDFD AND WEB
SERVERS.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 349 PM EDT THU OCT 31 2013
DEEPENING AREA OF SURFACE LOW PRESSURE IS CURRENTLY LOCATED ACROSS
NORTHEASTERN WISCONSIN...WITH A TRAILING SURFACE COLD FRONT ALIGNED
SOUTH ALONG CENTRAL ILLINOIS AND THEN BACK ACROSS SOUTHWESTERN
MISSOURI. A STOUT PRESSURE GRADIENT SETTING UP BETWEEN THE LOW AND
HIGH PRESSURE LOCATED ACROSS THE NORTHERN ATLANTIC...HAS ALLOWED FOR
SUSTAINED SOUTHERLY WINDS OF 10 TO 20 MPH...WITH OCCASIONAL GUSTS
RANGING IN THE 30 TO 40 MILE PER HOUR RANGE.
THE MODELS ARE IN GOOD AGREEMENT THROUGH THE SHORT TERM...PLOWING THE
COLD FRONT THROUGH THE COMMONWEALTH TONIGHT...BRINGING WIDESPREAD
RAINS...STRONG WIND GUSTS...AND PERHAPS A FEW THUNDERSTORMS. THE
THREAT FOR SEVERE WEATHER LOOKS LOW GIVEN THE LACK OF
INSTABILITY...HOWEVER WITH SUCH STRONG WINDS AVAILABLE NOT FAR OFF
THE SURFACE...STILL EXPECT WIND GUSTS AROUND 40 MPH...ESPECIALLY
WITHIN ANY BETTER BANDS OF THE PRE-FRONTAL SHOWERS.
SHOWER ACTIVITY WILL COME TO AN END QUICKLY FROM WEST TO EAST AS THE
FRONT PULLS AWAY EARLY FRIDAY MORNING. SKIES WILL CLEAR OUT DURING
THE DAY ON FRIDAY...WITH HIGHS RETURNING TO THE MID 60S FOR MOST
LOCATIONS.
CLOUDS WILL THEN MOVE BACK IN LATE FRIDAY NIGHT...AS A TROUGH AXIS
APPROACHES FROM THE WEST...ALTHOUGH ANY PRECIPITATION CHANCES LOOK
TO HOLD OFF UNTIL SATURDAY. LOWS FRIDAY NIGHT WILL BE MUCH
COOLER THAN WE HAVE SEEN OVER THE PAST FEW DAYS...WITH LOW TO MID
40S EXPECTED.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 318 AM EDT FRI NOV 1 2013
SOME DISCREPANCY BETWEEN THE GFS AND ECMWF MODELS AS OF THEIR
RESPECTIVE 0Z RUNS. THE ECMWF WAS QUITE A BIT SLOWER THAN THE GFS
FROM WEDNESDAY NIGHT ONWARD...WITH THE GFS MOVING ITS COLD FRONT OUT
OF THE AREA BY 18Z THURSDAY...AND THE ECMWF MOVING ITS FRONT AND
PRECIPITATION THROUGH THE AREA BETWEEN 6 AND 12Z ON FRIDAY. AFTER
INGESTING THE BLENDED MODEL DATA...MADE THE FOLLOWING MODIFICATIONS
TO THE NEW FORECAST GRIDS...ADJUSTED THE MUCH SLOWER ECWMF SOLUTION
ABOUT 30 PERCENT TOWARDS THE FASTER GFS...ACCOUNTING FOR THE STRONGER
WINDS ALOFT COMMON THIS TIME OF YEAR. THE PERIOD IS SET TO START OFF
DRY SATURDAY NIGHT THROUGH WEDNESDAY MORNING...AS A LARGE RIDGE OF
HIGH PRESSURE SETTLES OVER THE AREA. THE MODEL DIFFERENCES BEGIN FROM
THIS POINT FORWARD...AS THE ECMWF PRODUCES A STRONG LONGER LASTING
RIDGE THAT IS SLOWER TO BREAKDOWN AND MOVE EAST RELATIVE TO THE GFS.
THE MODIFIED BLEND BETWEEN THE TWO MODELS SEEMED REASONABLE
CONSIDERING THE AMOUNT OF DIFFERENCE BETWEEN THE TWO. ADJUSTED THE
QPF...SKY COVER AND WEATHER TYPE GRIDS TO ACCOUNT FOR THE MODIFIED
POP FORECAST. WENT WITH GENERAL 40 TO 5O POPS DURING FRONTAL
PASSAGE...AND KEPT THOSE NUMBERS LOWER THAN THE SEEMINGLY TOO HIGH
POPS IN BOTH SETS OF EXTENDED MOS GUIDANCE. BASED ON THE LACK OF
INSTABILITY AVAILABLE...WILL ONCE AGAIN LEAVE THUNDER OUT OF THE
FORECAST.
TEMPERATURES WILL START OUT AROUND NORMAL JUST BEHIND A DEPARTING
COLD FRONT...AS COOL NORTHWEST FLOW SETS UP ON SUNDAY. AFTER THAT...A
GRADUAL WARM UP IS EXPECTED TO OCCUR AS HIGH PRESSURE BUILDS ACROSS
THE AREA. HIGHS ON MONDAY WILL LIKELY TOP OUT AROUND 60
DEGREES...WITH A PEAK IN THE WARMTH TAKING PLACE ON WEDNESDAY WITH
CLIMBING INTO THE UPPER 60S ACROSS THE BOARD. ANOTHER SMALL COOL DOWN
IS EXPECTED TO END THE WEAK...AS A COLD FRONT AND ITS ASSOCIATED
PRECIPITATION MOVE ACROSS THE AREA.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 820 PM EDT THU OCT 31 2013
EXPECT VFR CONDITIONS AND SOME VCSH TO CONTINUE THROUGH THE REST OF
THE EVENING ACROSS THE FORECAST AREA. AROUND MIDNIGHT...THOUGH...A
BETTER AND MORE ORGANIZED BAND OF SHOWERS...POSSIBLY INCLUDING A FEW
THUNDERSTORMS...IS EXPECTED TO PUSH INTO AND SLOWLY THROUGH EAST
KENTUCKY. THIS BAND WILL HAVE THE HIGHEST WINDS AND LOWEST VIS IN
HEAVIER RAIN WITH A VCTS AND CB INCLUDED IN THE TAFS. THE HEAVIEST
RAINS SHOULD END TOWARD 08Z FROM WEST TO EAST LEAVING BEHIND LIGHTER
WINDS AND MVFR CIGS. CONDITIONS WILL CONTINUE TO IMPROVE INTO FRIDAY
MORNING AS THE LOWER CLOUDS SUBSEQUENTLY BREAK UP AND WINDS SETTLE
FROM THE WEST. VFR CONDITIONS FOLLOW THROUGH THE REST OF THE AVIATION
PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 6 AM EDT EARLY THIS MORNING FOR KYZ044-
050>052-058>060-068-069-079-080-083>088-104-106>120.
&&
$$
UPDATE...JP
SHORT TERM...GEOGERIAN
LONG TERM...AR
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
300 AM EDT FRI NOV 1 2013
.UPDATE...
ISSUED AT 100 AM EDT FRI NOV 1 2013
ZONES WERE UPDATED TO REFLECT SEVERE THUNDERSTORM WATCH NUMBER 557
FOR THE ENTIRE CWA UNTIL 6 AM EDT. A LINE OF SHOWERS WITH NO DETECTED
LIGHTNING...ALTHOUGH HAVING THE RADAR APPEARANCE OF THUNDERSTORMS AND
WIND GUST IMPACTS OF THUNDERSTORMS WILL PUSH RATHER RAPIDLY EAST TO
THE WV BORDER BY 4 AM EDT. DAMAGE HAS BEEN REPORTED OVER THE
BLUEGRASS REGION AND WE EXPECT AT LEAST THE NORTHERN TWO THIRDS OF
THE CWA TO BE UNDER THE THREAT OF DAMAGING WIND GUSTS DOWNING TREES
OVER THE NEXT COUPLE OF HOURS. THERE ARE SOME KINKS WITHING THIS LINE
AND GIVEN THE VERY STRONG LOW LEVEL SHEAR A STRAY WEAK SPIN UP IS NOT
OUT OF THE QUESTION. THE GRIDS WILL UPDATED TO REFLECT RECENT OBS SHORTLY.
UPDATE ISSUED AT 1055 PM EDT THU OCT 31 2013
DID ANOTHER UPDATE TO FINE TUNE THE MOVEMENT OF THE SQUALL LINE
THROUGH OUR AREA OVER THE NEXT SEVERAL HOURS. USED THIS LINE TO
HIGHLIGHT THE HIGHEST WINDS AND BEST THUNDER CHANCES. ALSO TWEAKED
THE T AND TD GRIDS TO REFLECT THE LATEST OBS AND TRENDS. UPDATES HAVE
BEEN SENT TO THE NDFD AND WEB SERVERS.
UPDATE ISSUED AT 810 PM EDT THU OCT 31 2013
23Z SFC ANALYSIS SHOWS A DEEP AREA OF LOW PRESSURE MOVING INTO THE
GREAT LAKES. A POWERFUL COLD FRONT ASSOCIATED WITH THIS IS SLICING
EAST THROUGH THE MIDWEST...NOW APPROACHING WESTERN KENTUCKY. AHEAD OF
THIS...THE WEAKER PATCHES OF SHOWERS ARE BREAKING UP...CLEARING THE
WAY FOR MORE BANDED CLUSTERS AND EVEN SOME LINEAR THUNDERSTORMS. IN
THIS ENVIRONMENT...HIGH SHEAR AND PASSING 850 MB JET AT 75+ KTS...
THESE HAVE THE DISTINCT POTENTIAL OF BRINGING DOWN DAMAGING WINDS
GUSTS AND A SMALL THREAT OF SHORT LIVED TORNADOES. THE MAIN QUESTION
IS HOW THESE STORMS EVOLVE TO OUR WEST AND MOVE THROUGH EAST KENTUCKY
LATER TONIGHT. THE LATEST HRRR SUGGESTS THAT A SQUALL LINE WILL MOVE
THROUGH JUST AHEAD OF THE FRONT WITH THE HEAVIEST RAINS AND WINDS
PASSING THROUGH EAST KENTUCKY FROM 04 TO 08Z. HAVE SET UP THE LATEST
GRIDS TO REFLECT THIS AND READJUSTED THE WIND/GUST GRIDS TO BETTER
FOCUS ON THIS POTENTIAL LINE. FOR TEMPERATURES AND DEWPOINTS...HAVE
ADJUSTED THEM TOWARD THE LATEST CONSSHORT EXPECTING THEM TO STAY UP
UNTIL THE MAIN BOUNDARY AND RAIN APPROACHES LATER THIS EVENING. HAVE
ALSO UPDATED THE NPW TO REFLECT THESE LATEST THOUGHTS WITH A ZFP AND
HWO UPDATE TO FOLLOW. GRIDS HAVE BEEN SENT TO THE NDFD AND WEB
SERVERS.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 349 PM EDT THU OCT 31 2013
DEEPENING AREA OF SURFACE LOW PRESSURE IS CURRENTLY LOCATED ACROSS
NORTHEASTERN WISCONSIN...WITH A TRAILING SURFACE COLD FRONT ALIGNED
SOUTH ALONG CENTRAL ILLINOIS AND THEN BACK ACROSS SOUTHWESTERN
MISSOURI. A STOUT PRESSURE GRADIENT SETTING UP BETWEEN THE LOW AND
HIGH PRESSURE LOCATED ACROSS THE NORTHERN ATLANTIC...HAS ALLOWED FOR
SUSTAINED SOUTHERLY WINDS OF 10 TO 20 MPH...WITH OCCASIONAL GUSTS
RANGING IN THE 30 TO 40 MILE PER HOUR RANGE.
THE MODELS ARE IN GOOD AGREEMENT THROUGH THE SHORT TERM...PLOWING THE
COLD FRONT THROUGH THE COMMONWEALTH TONIGHT...BRINGING WIDESPREAD
RAINS...STRONG WIND GUSTS...AND PERHAPS A FEW THUNDERSTORMS. THE
THREAT FOR SEVERE WEATHER LOOKS LOW GIVEN THE LACK OF
INSTABILITY...HOWEVER WITH SUCH STRONG WINDS AVAILABLE NOT FAR OFF
THE SURFACE...STILL EXPECT WIND GUSTS AROUND 40 MPH...ESPECIALLY
WITHIN ANY BETTER BANDS OF THE PRE-FRONTAL SHOWERS.
SHOWER ACTIVITY WILL COME TO AN END QUICKLY FROM WEST TO EAST AS THE
FRONT PULLS AWAY EARLY FRIDAY MORNING. SKIES WILL CLEAR OUT DURING
THE DAY ON FRIDAY...WITH HIGHS RETURNING TO THE MID 60S FOR MOST
LOCATIONS.
CLOUDS WILL THEN MOVE BACK IN LATE FRIDAY NIGHT...AS A TROUGH AXIS
APPROACHES FROM THE WEST...ALTHOUGH ANY PRECIPITATION CHANCES LOOK
TO HOLD OFF UNTIL SATURDAY. LOWS FRIDAY NIGHT WILL BE MUCH
COOLER THAN WE HAVE SEEN OVER THE PAST FEW DAYS...WITH LOW TO MID
40S EXPECTED.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 330 PM EDT THU OCT 31 2013
THE MODELS START OUT IN VERY GOOD AGREEMENT WITH A FAIRLY SHARP AND
STRONG UPPER TROUGH OVER WESTERN KENTUCKY. THIS TROUGH WILL HELL TO
GENERATE SOME SCATTERED SHOWERS ACROSS THE AREA IN THE COLD AIR
BEHIND THE FRONT. CONSIDERED THE POSSIBILITY OF AN ISOLATED
THUNDERSTORM...HOWEVER THE TQ INDEX...WAS A LITTLE TOO LOW TO
SUPPORT THUNDER. WOULD NOT BE TOO SURPRISED TO SEE SOME GRAUPEL WITH
THESE SHOWERS. AS THE TROUGH MOVES OFF TO THE EAST...HIGH PRESSURE
WILL BE BUILDING IN FROM THE WEST. THIS WILL USHER IN A DRY PERIOD
UNTIL THE LEADING EDGE OF THE NEXT FRONT MOVES INT THE AREA ON
WEDNESDAY EVENING. BY WEDNESDAY EVENING THE MODELS START TO DIFFER
SOME ON SPEED WITH THE ARRIVAL OF THE NEXT SYSTEM. THE FRONT WILL
MOST LIKELY TO MOVE THROUGH THE AREA ON THURSDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 300 AM EDT FRI NOV 1 2013
AN ORGANIZED BAND OF SHOWERS...POSSIBLY INCLUDING A FEW
THUNDERSTORMS...IS EXPECTED TO PUSH INTO AND SLOWLY THROUGH EAST
KENTUCKY OVER THE NEXT FEW HOURS. THIS BAND WILL HAVE THE HIGHEST
WINDS AND LOWEST VIS IN HEAVIER RAIN WITH A VCTS AND CB INCLUDED IN
THE TAFS. THE HEAVIEST RAINS SHOULD END BETWEEN 08 TO 10Z FROM WEST
TO EAST LEAVING BEHIND IMPROVING VIS...LIGHTER WINDS AND MVFR CIGS.
CONDITIONS WILL CONTINUE TO IMPROVE INTO FRIDAY MORNING AS THE LOWER
CLOUDS SUBSEQUENTLY BREAK UP AND WINDS SETTLE FROM THE WEST. VFR
CONDITIONS FOLLOW THROUGH THE REST OF THE AVIATION PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 6 AM EDT EARLY THIS MORNING FOR KYZ044-
050>052-058>060-068-069-079-080-083>088-104-106>120.
&&
$$
UPDATE...JP
SHORT TERM...GEOGERIAN
LONG TERM...JJ
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
105 AM EDT FRI NOV 1 2013
.UPDATE...
ISSUED AT 100 AM EDT FRI NOV 1 2013
ZONES WERE UPDATED TO REFLECT SEVERE THUNDERSTORM WATCH NUMBER 557
FOR THE ENTIRE CWA UNTIL 6 AM EDT. A LINE OF SHOWERS WITH NO DETECTED
LIGHTNING...ALTHOUGH HAVING THE RADAR APPEARANCE OF THUNDERSTORMS AND
WIND GUST IMPACTS OF THUNDERSTORMS WILL PUSH RATHER RAPIDLY EAST TO
THE WV BORDER BY 4 AM EDT. DAMAGE HAS BEEN REPORTED OVER THE
BLUEGRASS REGION AND WE EXPECT AT LEAST THE NORTHERN TWO THIRDS OF
THE CWA TO BE UNDER THE THREAT OF DAMAGING WIND GUSTS DOWNING TREES
OVER THE NEXT COUPLE OF HOURS. THERE ARE SOME KINKS WITHING THIS LINE
AND GIVEN THE VERY STRONG LOW LEVEL SHEAR A STRAY WEAK SPIN UP IS NOT
OUT OF THE QUESTION. THE GRIDS WILL UPDATED TO REFLECT RECENT OBS SHORTLY.
UPDATE ISSUED AT 1055 PM EDT THU OCT 31 2013
DID ANOTHER UPDATE TO FINE TUNE THE MOVEMENT OF THE SQUALL LINE
THROUGH OUR AREA OVER THE NEXT SEVERAL HOURS. USED THIS LINE TO
HIGHLIGHT THE HIGHEST WINDS AND BEST THUNDER CHANCES. ALSO TWEAKED
THE T AND TD GRIDS TO REFLECT THE LATEST OBS AND TRENDS. UPDATES HAVE
BEEN SENT TO THE NDFD AND WEB SERVERS.
UPDATE ISSUED AT 810 PM EDT THU OCT 31 2013
23Z SFC ANALYSIS SHOWS A DEEP AREA OF LOW PRESSURE MOVING INTO THE
GREAT LAKES. A POWERFUL COLD FRONT ASSOCIATED WITH THIS IS SLICING
EAST THROUGH THE MIDWEST...NOW APPROACHING WESTERN KENTUCKY. AHEAD OF
THIS...THE WEAKER PATCHES OF SHOWERS ARE BREAKING UP...CLEARING THE
WAY FOR MORE BANDED CLUSTERS AND EVEN SOME LINEAR THUNDERSTORMS. IN
THIS ENVIRONMENT...HIGH SHEAR AND PASSING 850 MB JET AT 75+ KTS...
THESE HAVE THE DISTINCT POTENTIAL OF BRINGING DOWN DAMAGING WINDS
GUSTS AND A SMALL THREAT OF SHORT LIVED TORNADOES. THE MAIN QUESTION
IS HOW THESE STORMS EVOLVE TO OUR WEST AND MOVE THROUGH EAST KENTUCKY
LATER TONIGHT. THE LATEST HRRR SUGGESTS THAT A SQUALL LINE WILL MOVE
THROUGH JUST AHEAD OF THE FRONT WITH THE HEAVIEST RAINS AND WINDS
PASSING THROUGH EAST KENTUCKY FROM 04 TO 08Z. HAVE SET UP THE LATEST
GRIDS TO REFLECT THIS AND READJUSTED THE WIND/GUST GRIDS TO BETTER
FOCUS ON THIS POTENTIAL LINE. FOR TEMPERATURES AND DEWPOINTS...HAVE
ADJUSTED THEM TOWARD THE LATEST CONSSHORT EXPECTING THEM TO STAY UP
UNTIL THE MAIN BOUNDARY AND RAIN APPROACHES LATER THIS EVENING. HAVE
ALSO UPDATED THE NPW TO REFLECT THESE LATEST THOUGHTS WITH A ZFP AND
HWO UPDATE TO FOLLOW. GRIDS HAVE BEEN SENT TO THE NDFD AND WEB
SERVERS.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 349 PM EDT THU OCT 31 2013
DEEPENING AREA OF SURFACE LOW PRESSURE IS CURRENTLY LOCATED ACROSS
NORTHEASTERN WISCONSIN...WITH A TRAILING SURFACE COLD FRONT ALIGNED
SOUTH ALONG CENTRAL ILLINOIS AND THEN BACK ACROSS SOUTHWESTERN
MISSOURI. A STOUT PRESSURE GRADIENT SETTING UP BETWEEN THE LOW AND
HIGH PRESSURE LOCATED ACROSS THE NORTHERN ATLANTIC...HAS ALLOWED FOR
SUSTAINED SOUTHERLY WINDS OF 10 TO 20 MPH...WITH OCCASIONAL GUSTS
RANGING IN THE 30 TO 40 MILE PER HOUR RANGE.
THE MODELS ARE IN GOOD AGREEMENT THROUGH THE SHORT TERM...PLOWING THE
COLD FRONT THROUGH THE COMMONWEALTH TONIGHT...BRINGING WIDESPREAD
RAINS...STRONG WIND GUSTS...AND PERHAPS A FEW THUNDERSTORMS. THE
THREAT FOR SEVERE WEATHER LOOKS LOW GIVEN THE LACK OF
INSTABILITY...HOWEVER WITH SUCH STRONG WINDS AVAILABLE NOT FAR OFF
THE SURFACE...STILL EXPECT WIND GUSTS AROUND 40 MPH...ESPECIALLY
WITHIN ANY BETTER BANDS OF THE PRE-FRONTAL SHOWERS.
SHOWER ACTIVITY WILL COME TO AN END QUICKLY FROM WEST TO EAST AS THE
FRONT PULLS AWAY EARLY FRIDAY MORNING. SKIES WILL CLEAR OUT DURING
THE DAY ON FRIDAY...WITH HIGHS RETURNING TO THE MID 60S FOR MOST
LOCATIONS.
CLOUDS WILL THEN MOVE BACK IN LATE FRIDAY NIGHT...AS A TROUGH AXIS
APPROACHES FROM THE WEST...ALTHOUGH ANY PRECIPITATION CHANCES LOOK
TO HOLD OFF UNTIL SATURDAY. LOWS FRIDAY NIGHT WILL BE MUCH
COOLER THAN WE HAVE SEEN OVER THE PAST FEW DAYS...WITH LOW TO MID
40S EXPECTED.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 330 PM EDT THU OCT 31 2013
THE MODELS START OUT IN VERY GOOD AGREEMENT WITH A FAIRLY SHARP AND
STRONG UPPER TROUGH OVER WESTERN KENTUCKY. THIS TROUGH WILL HELL TO
GENERATE SOME SCATTERED SHOWERS ACROSS THE AREA IN THE COLD AIR
BEHIND THE FRONT. CONSIDERED THE POSSIBILITY OF AN ISOLATED
THUNDERSTORM...HOWEVER THE TQ INDEX...WAS A LITTLE TOO LOW TO
SUPPORT THUNDER. WOULD NOT BE TOO SURPRISED TO SEE SOME GRAUPEL WITH
THESE SHOWERS. AS THE TROUGH MOVES OFF TO THE EAST...HIGH PRESSURE
WILL BE BUILDING IN FROM THE WEST. THIS WILL USHER IN A DRY PERIOD
UNTIL THE LEADING EDGE OF THE NEXT FRONT MOVES INT THE AREA ON
WEDNESDAY EVENING. BY WEDNESDAY EVENING THE MODELS START TO DIFFER
SOME ON SPEED WITH THE ARRIVAL OF THE NEXT SYSTEM. THE FRONT WILL
MOST LIKELY TO MOVE THROUGH THE AREA ON THURSDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 820 PM EDT THU OCT 31 2013
EXPECT VFR CONDITIONS AND SOME VCSH TO CONTINUE THROUGH THE REST OF
THE EVENING ACROSS THE FORECAST AREA. AROUND MIDNIGHT...THOUGH...A
BETTER AND MORE ORGANIZED BAND OF SHOWERS...POSSIBLY INCLUDING A FEW
THUNDERSTORMS...IS EXPECTED TO PUSH INTO AND SLOWLY THROUGH EAST
KENTUCKY. THIS BAND WILL HAVE THE HIGHEST WINDS AND LOWEST VIS IN
HEAVIER RAIN WITH A VCTS AND CB INCLUDED IN THE TAFS. THE HEAVIEST
RAINS SHOULD END TOWARD 08Z FROM WEST TO EAST LEAVING BEHIND LIGHTER
WINDS AND MVFR CIGS. CONDITIONS WILL CONTINUE TO IMPROVE INTO FRIDAY
MORNING AS THE LOWER CLOUDS SUBSEQUENTLY BREAK UP AND WINDS SETTLE
FROM THE WEST. VFR CONDITIONS FOLLOW THROUGH THE REST OF THE AVIATION
PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 6 AM EDT EARLY THIS MORNING FOR KYZ044-
050>052-058>060-068-069-079-080-083>088-104-106>120.
&&
$$
UPDATE...JP
SHORT TERM...GEOGERIAN
LONG TERM...JJ
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1206 AM EDT FRI NOV 1 2013
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 336 PM EDT THU OCT 31 2013
STRONG LOW PRESSURE WILL WILL BRING RAIN THIS EVENING AND HIGH
WINDS AFTER MIDNIGHT. SCATTERED POWER OUTAGES ARE EXPECTED AS
WINDS GUST OVER 50 MPH AT TIMES. THE WEATHER WILL COME DOWN FRIDAY
MORNING BUT SCATTERED SHOWERS WILL CONTINUE INTO SATURDAY. FAIR
AND COOL WEATHER IS EXPECTED FOR SUNDAY.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 336 PM EDT THU OCT 31 2013
FORECAST ISSUES ARE FOR HIGH WIND LATE TONIGHT...AND THUNDER/RAIN
THIS EVENING.
WENT WITH A WIND ADVISORY FOR LATE TONIGHT AS THE LOW DEEPENS AND
COLD AIR ADVECTION BEGINS AFTER MIDNIGHT SOME STRONG WINDS COULD
MIX DOWN. BOTH THE NAM AND GFS SHOW 50 KNOTS OF WIND CLOSE TO OR
IN THE MIXING LAYER. THE 12Z EURO IS A BIT WEAKER AND FASTER WITH
THE SFC LOW. WENT WITH A HIGH WIND ADVISORY...ALTHOUGH THERE IS A
CHANCE OF SOME SPOTS GUSTING TO 50 KNOTS ACROSS THE EASTERN
FORECAST AREA AROUND 09Z.
BEFORE THEN...WILL BE WATCHING THE RADAR EVOLUTION OF THE PRECIP
CURRENTLY ACROSS CENTRAL ILLINOIS. DRY SLOT CURRENTLY OVER WESTERN
LOWER MICHIGAN...BUT STILL SEEING DRIZZLE AND SOLID CLOUD
COVER...SO LITTLE IN THE WAY OF SFC INSTABILITY EXPECTED LATE THIS
AFTERNOON/EVENING. A WEAK NCFR COULD STILL FORM AS HINTED AT BY A
FEW RUNS OF THE HRRR AND RADAR ACROSS CENTRAL ILLINOIS. THIS COULD
BRING A BRIEF BURST OF RAIN AND WIND THIS EVENING...OTHERWISE IT
SHOULD JUST BE A SOGGY AND MILD TIME FOR TRICK OT TREATING. THE
SYNOPTIC WIND THREAT ARRIVES LATER.
NO REAL IMPACTS EXPECTED AFTER FRIDAY MORNING. SOME SNOWFLAKES ARE
POSSIBLE SATURDAY EVENING AS 850 MB TEMPS FALL BLO MINUS 6C AND
LAKE EFFECT CONTINUES...BUT THESE SHOULD NOT AMOUNT TO MUCH.
.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 336 PM EDT THU OCT 31 2013
FAIR WEATHER WITH SEASONABLY COOL TEMPERATURES IS EXPECTED SUNDAY
WITH HIGH PRESSURE IN PLACE. STRONG SOUTHERLY RETURN FLOW WARM AIR
ADVECTION WILL DEVELOP EARLY TO MID NEXT WEEK AS THE RIDGE MOVES
EAST. WARM AIR ADVECTION SHOWERS MAY DEVELOP AS EARLY AS LATE MONDAY
NIGHT AND TUESDAY.
HOWEVER THE BETTER CHANCE FOR RAIN WILL HOLD OFF UNTIL WEDNESDAY
THROUGH THURSDAY AS THE NEXT LOW PRESSURE SYSTEM MOVES THROUGH THE
GREAT LAKES REGION. MAX TEMPS MONDAY THROUGH WEDNESDAY WILL REACH
THE 50S BEFORE COOLING TO THE 40S BEHIND THAT SYSTEM FOR LATE NEXT
WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1206 AM EDT FRI NOV 01 2013
CONDITIONS HAVE IMPROVED TO MVFR AT MOST LOCATIONS...BUT SOME IFR
WILL CONTINUE IN SPOTS THROUGH ABOUT 09Z AS THE LAST BATCH OF RAIN
MOVES THROUGH. AFTER ABOUT 09Z...THE RAIN SHOULD HAVE SWEPT TO THE
NORTHEAST LEAVING BEHIND MVFR CEILINGS. WINDY CONDITIONS WILL
CONTINUE OVERNIGHT IN THE WAKE OF THE COLD FRONTAL PASSAGE.
WEST-SOUTHWEST WINDS OF 12-28 KNOTS CAN BE EXPECTED.
MVFR CEILINGS WILL PREVAIL THROUGH THE DAY ON FRIDAY WITH SOME
LAKE EFFECT RAIN SHOWERS FIRING UP THROUGH THE COURSE OF THE DAY.
KMKG AND KGRR WILL BE MOST AFFECTED BY THE SHOWERS ON FRIDAY. THE
WINDS WILL DECREASE SOME INTO FRIDAY MORE INTO THE 10-22 KNOT
RANGE.
&&
.MARINE...
ISSUED AT 336 PM EDT THU OCT 31 2013
NO CHANGES TO THE SMALL CRAFT ADVISORY OR GALE WARNING. WINDS
WILL DIMINISH ON FRIDAY MORNING AND THE GALE WARNING WILL BE
REPLACED WITH ANOTHER SMALL CRAFT ADVISORY AT THAT TIME.
&&
.HYDROLOGY...
ISSUED AT 336 PM EDT THU OCT 31 2013
SOME RAIN TOTALS OVER 3 INCHES IN VAN BUREN COUNTY AND EXPECT
ANOTHER HALF INCH TO INCH BEFORE THE HEAVY RAIN ENDS TONIGHT. WE
WILL CONTINUE TO SEE SHARP RISES ON SOME STREAMS AND CREEKS WITH
RISES ON MANY OF THE MAINSTEM RIVERS INTO EARLY NEXT WEEK. AFTER A
BREAK...ANOTHER ROUND OF RAIN IS EXPECTED BY WEDNESDAY OF NEXT
WEEK.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WIND ADVISORY UNTIL 8 AM EDT FRIDAY FOR MIZ037>040-043>046-
050>052-056>059-064>067-071>074.
LM...GALE WARNING UNTIL 10 AM EDT FRIDAY FOR LMZ844>849.
&&
$$
SYNOPSIS...OSTUNO
SHORT TERM...OSTUNO
LONG TERM...LAURENS
AVIATION...DUKE
HYDROLOGY...OSTUNO
MARINE...OSTUNO
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1140 PM CDT Thu Oct 31 2013
.UPDATE:
Issued at 813 PM CDT Thu Oct 31 2013
Grids and products have been updated to reflect the slightly
quicker exit of precipitation. After the rain ends across
southwest IL, no further precipitation is expected for the rest of
the night across the LSX CWA.
Kanofsky
&&
.SHORT TERM: (Through Tonight)
Issued at 221 PM CDT Thu Oct 31 2013
Focus for tonight will be pops as the upper trof moves thru the
area.
Upper trof just starting to enter far nwrn MO with dry slot
spreading over much of the area. Vort max rounding the base of the
trof now will help eject the trof ewd along with the precip. Have
trended pops this eve twd the 4km local WRF and the HRRR which are
in fairly good agreement along with much of the other guidance as
well. These solns suggest a line of TSRA across far ern portions of
the CWA with some stratiform precip behind that, but exiting the
area quickly. The CWA shud be dry by 03z if not before.
With clouds clearing out of the area tonight, have trended twd the
cooler guidance. That said, do not anticipate temps dropping too
much tonight with mixing persisting thru the night and with no
substantial cooler or drier air advecting into the region.
Tilly
.LONG TERM: (Friday through Next Thursday)
Issued at 321 PM CDT Thu Oct 31 2013
Period begins with focus on temps thru the weekend.
With ample clouds expected across much of the area on Fri and with
the sfc ridge building into the area on Sat, have trended twd the
cooler guidance thru the weekend. Warm up shud begin on Sun as the
sfc ridge starts to retreat and as the thermal ridge starts moving
nwd into the area.
For the extd, focus turns to pops late Mon thru Wed. Mdls have
come into better agreement with trof timing and phasing. Have
lowered pops on Mon and on Thurs with better agreement among mdls.
Increased pops between these times where mdls were in better
agreement regarding precip. Some uncertainty still remains and
will continue to adjust as needed.
Tilly
&&
.AVIATION: (For the 06z TAFs through 06z Friday Night)
Issued at 1138 PM CDT Thu Oct 31 2013
VFR conditions are expected to dominate through the forecast
period with clear skies and patchy cu tonight, then scattered
diurnal cu and gusty west northwest surface winds on Friday.
Specifics for KSTL:
VFR conditions are expected to dominate through the forecast
period with clear skies and patchy cu tonight, then scattered
diurnal cu and gusty west northwest surface winds on Friday.
Glass
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
433 AM EDT FRI NOV 1 2013
.SYNOPSIS...
A STRONG COLD FRONT APPROACHING FROM THE WEST WILL MOVE ACROSS THE
AREA SATURDAY MORNING. IT WILL BECOME WINDY AHEAD OF THIS FRONT WITH
A HIGH RISK FOR SHOWERS AND POSSIBLY A THUNDERSTORM. SIGNIFICANT
RAINFALL IS POSSIBLE. HIGH PRESSURE WILL FOLLOW LATE SATURDAY
THROUGH SUNDAY BRINGING WITH IT COLDER AND DRIER CONDITIONS. HIGH
PRESSURE WILL PERSIST THROUGH THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 AM FRIDAY...STRONG SURFACE LOW PRESSURE IN THE GREAT LAKES
IS ASSOCIATED WITH AN ENERGETIC UPPER LEVEL SYSTEM LIFTING NORTHEAST
ACROSS INTO SOUTHERN ONTARIO. A SURFACE COLD FRONT EXTENDING SOUTH
OF THE LOW IS NOW ENTERING THE SOUTHERN AND CENTRAL APPALACHIANS.
TROPICAL MOISTURE IS PRESENT WITH PRECIPITABLE WATER VALUES EXPECTED
TO EXCEED 2.0 INCHES BY THIS EVENING JUST AHEAD OF THE FRONT. TO PUT
THAT IN PERSPECTIVE...2.0 INCHES IS THE 99TH PERCENTILE FOR NOVEMBER
PRECIP WATER AT CHS...AND COULD BE A RECORD NOVEMBER PW VALUE AT MHX.
THE FRONT WILL MAKE STEADY EASTWARD PROGRESS...AND THE BAND OF
SHOWERS AND EMBEDDED T-STORMS SHOULD SLIDE INTO THE CENTRAL
CAROLINAS EARLY THIS AFTERNOON. I HAVE INCREASED POPS ALONG AND WEST
OF INTERSTATE 95 INTO THE 80-100 PERCENT RANGE BY LATE AFTERNOON...
WITH THE MOST SUBSTANTIAL COVERAGE OF PRECIPITATION EXPECTED ALONG
THE COAST AFTER DARK WHERE I HAVE BUMPED POPS UP TO 80-90 PERCENT.
STORM TOTAL RAINFALL COULD EXCEED 1 INCH...WITH HEAVIER AMOUNTS
POSSIBLE IF/WHERE CONVECTIVE TRAINING OCCURS.
RADAR VERTICAL WIND PROFILES ARE CONFIRMING MODEL FORECASTS OF A
HEALTHY LOW LEVEL JET BLOWING OVERHEAD CURRENTLY. WINDS AT 1000 FT
AGL ARE AROUND 30 KNOTS WITH 40 KNOTS MEASURED AT 2000 FT. AS THE
BOUNDARY LAYER DEEPENS LATER THIS MORNING WITH RISING
TEMPERATURES...EXPECT STRONGER WINDS TO MIX DOWN WITH 30-35 MPH
GUSTS EXPECTED BY 10-11 AM. HELICITY (0-1 KM) SHOULD RANGE FROM
150-200 WITH 0-6 KM BULK SHEAR 40-50 KT. THESE VALUES ARE ALSO
SUPPORTIVE OF A SEVERE WEATHER THREAT. THE LIMITING FACTOR COULD END
UP BEING INSTABILITY: FORECAST CAPE VALUES ONLY RANGE FROM 200-400
J/KG WITH PERHAPS SOME 700 J/KG NUMBERS SHOWING UP THIS EVENING
ALONG THE COAST IF DEWPOINTS CAN SURGE INTO THE UPPER 60S. THE STORM
PREDICTION CENTER CURRENTLY HAS A "SEE TEXT" 5 PERCENT PROBABILITY
FOR DAMAGING WIND GUSTS IN THE CAROLINAS.
TEMPERATURES TODAY SHOULD BE VERY WARM BY NOVEMBER STANDARDS...
COURTESY OF TROPICAL AIR ADVECTED NORTHWARD AHEAD OF THE FRONT. 850
MB TEMPS EXPECTED TO RISE TO +15C ARE IN THE 95-98TH PERCENTILE FOR
NOVEMBER. TEMPERATURES SHOULD LEAP WITH THE FIRST TOUCH OF SUNLIGHT
THIS MORNING...AND HIGHS SHOULD AGAIN REACH 80 DEGREES FOR AREAS
EAST OF INTERSTATE 95 AND AT LEAST A FEW MILES INLAND FROM THE
BEACHES. THE FRONT WILL MOVE ACROSS THE AREA LATE TONIGHT WITH COLD
ADVECTION NOT REACHING THE COAST UNTIL JUST A FEW HOURS BEFORE
DAYBREAK. THERE IS SOME UNCERTAINTY WITH TONIGHT`S LOW TEMPERATURES
SINCE WEAKER WINDS BEHIND THE FRONT COULD ALLOW FOR BOUNDARY LAYER
DECOUPLING JUST BEFORE SUNRISE...BUT IT APPEARS LOWS SHOULD RANGE
FROM THE MID 60S ON THE COAST TO THE UPPER 50S INLAND.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 330 AM FRIDAY...COLD FRONT WILL BE MAKING ITS WAY OFF SHORE
SAT MORNING. DRY AND COOLER AIR WILL BEGIN TO FEED INTO AREA
BEHIND THE FRONT BUT DEEP NW FLOW WITH GREATEST CAA WILL COME LATER
ON SAT AS MID TO UPPER TROUGH FINALLY SWINGS THROUGH. MAY SEE SOME
CLOUDS WITH ITS PASSAGE BUT THINK MOST CLOUDS AND ANY CHC OF A
SPRINKLE WILL REMAIN TO THE NORTH WHERE BETTER SHORTWAVE ENERGY
WILL BE.
AFTER A WARM START TO THE DAY ON SAT...TEMPS WILL REACH INTO THE 70S
AS SKIES CLEAR FROM WEST TO EAST THROUGH THE DAY. 850 TEMPS
PLUMMET THROUGH SAT INTO SUNDAY MORNING DROPPING DOWN TO 2 TO 3C
BY SUN. DEWPOINT TEMPS WILL DROP OUT AS WELL WITH READING IN THE
LOWER 30S BY MON MORNING. EXPECT TEMPS TO DROP A GOOD 10 DEGREES
SAT NIGHT FROM PREVIOUS MIN TEMPS AND THEN AN ADDITIONAL DROP SUN
NIGHT IN BETTER RADIATIONAL COOLING WITH READINGS RIGHT AROUND 40 MOST
PLACES.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 3 PM THURSDAY...STRONG HIGH PRESSURE WILL RIDGE DOWN INTO
THE SOUTHEAST AS IT SHIFTS EAST THROUGH THE WEEK. AFTER A COLD
START MONDAY TEMPS WILL ONLY RECOVER TO AROUND 60 DEGREES IN COOL
NORTHERLY FLOW. AS THE HIGH SHIFTS EAST FURTHER OFF THE NEW
ENGLAND COAST THROUGH MID WEEK...A MOIST ON SHORE FLOW WILL
DEVELOP. A WEDGE LIKE PATTERN WILL SET UP WITH POTENTIAL FOR LOW
CLOUDS AND SPOTTY DRIZZLE OR SPRINKLES AS EARLY AS MONDAY NIGHT
AND POSSIBLY LASTING FOR A FEW DAYS BEFORE A COLD FRONT MAKES ITS
WAY ACROSS THE CAROLINAS BY THURS. EXPECT INCREASED CHC OF PCP ON
THURS AHEAD OF THIS COLD FRONT.
MONDAY WILL BE THE COOLEST DAY BUT WILL MODIFY SLOWLY THROUGH
MID WEEK. BUILDING RIDGE ALOFT WITH RISING H5 HEIGHTS WILL HELP TO
BRING TEMPS BACK UP ABOVE NORMAL BY WEDNESDAY. HIGHS WILL MAINLY
BE IN THE 60S THROUGH TUES AND WILL REACH BACK INTO THE 70S ON
WED. A WARMER AND MORE HUMID SOUTHERLY RETURN FLOW SHOULD SET UP
BRIEFLY BY THURS AHEAD OF NEXT FRONT. THIS WILL HELP BRING TEMPS
BACK ABOVE NORMAL REACHING WELL INTO THE 70S.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 06Z...EXPECT MAINLY VFR TONIGHT WITH PERHAPS SOME MVFR STRATUS
IN THE 09-12Z RANGE AND THE LOWEST CIGS INLAND. IFR CIGS CANNOT BE
RULED OUT FOR KFLO/KLBT...BUT CONFIDENCE IS FAIRLY LOW...AND ANY
CIGS BELOW 1KFT WOULD LIKELY BE VERY TEMPO IN NATURE. HRRR STILL
SHOWS SOME LIGHT -SHRA ALONG THE COAST BEFORE 12Z...WHICH SEEMS
REASONABLE BASED ON CURRENT RADAR TRENDS. AN APPROACHING COLD FRONT
WILL BRING PLENTY OF RAIN TO OUR CWA LATER TODAY. THE BEST PCPN
CHANCES FOR OUR AREA WILL BE AFTER 18Z...BEGINNING AT KFLO/KLBT
FOLLOWED BY THE COASTAL SITES A FEW HOURS LATER. ISOLATED TSTMS ARE
POSSIBLE...BUT WITH THE LIMITED INSTABILITY CHOSE NOT TO MENTION
TSTMS WITH THIS ISSUANCE. HEAVIER SHOWERS COULD RESULT IN PERIODS OF
MVFR CIGS/VSBYS...ESPECIALLY AFTER 00Z SATURDAY. EXPECT GUSTY
SOUTHWEST WINDS 10-20 KTS DURING THE DAY AS THE GRADIENT TIGHTENS
AHEAD OF THE FRONT.
EXTENDED OUTLOOK...MVFR/IFR CIGS POSSIBLE ON TUESDAY. OTHERWISE VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 300 AM FRIDAY...A STRONG COLD FRONT NOW ENTERING THE SOUTHERN
APPALACHIANS SHOULD SWEEP EAST AND ACROSS THE CAROLINA COASTAL
WATERS AFTER MIDNIGHT. AHEAD OF THE FRONT STRONG SOUTH WINDS SHOULD
AVERAGE 20-25 KNOTS THROUGH TONIGHT. MODELS ARE IN EXCELLENT
AGREEMENT WITH THE MAGNITUDE OF THIS MILD SOUTHERLY FLOW. A COUPLE
WAVES OF SHOWERS HAVE AFFECTED THE COASTAL WATERS THIS MORNING...
AND ADDITIONAL ISOLATED TO SCATTERED SHOWERS COULD OCCUR DURING THE
DAY. THE HEAVIER SHOWERS AND EMBEDDED THUNDERSTORMS WITH THE ACTUAL
COLD FRONT SHOULD NOT ARRIVE UNTIL TONIGHT BUT COULD POSE A SAFETY
RISK FOR MARINERS WITH STRONG GUSTY WINDS...LIGHTNING... AND REDUCED
VISIBILITY IN HEAVY RAIN. WINDS WILL SHIFT WESTERLY BEHIND THE FRONT
AND DECREASE LATE.
SEAS ARE CURRENTLY 5 FEET AT THE FRYING PAN SHOALS BUOY AND 4 FT AT
THE BUOY SEVERAL MILES SOUTH OF BALD HEAD ISLAND. WITH CONTINUED
SOUTH WINDS SEAS SHOULD BUILD TO AS HIGH AS 6-7 FEET 10-20 MILES OFF
THE SOUTH CAROLINA COAST...AND AS HIGH AS 7-8 FEET OFF THE NORTH
CAROLINA COAST. SEAS SHOULD BEGIN TO SUBSIDE LATE TONIGHT AS WINDS
SHIFT WESTERLY.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 330 AM FRIDAY...WINDS WILL VEER TO THE W TO NW ON SATURDAY
AS COLD FRONT PROGRESSES FURTHER OFF SHORE. DEEPER LAYER NORTHERLY
FLOW WILL DEVELOP SAT NIGHT AS MID TO UPPER TROUGH CROSSES THE
WATERS. WINDS WILL DIMINISH THROUGH SATURDAY DOWN TO 15 KTS BUT
WILL SPIKE UP AGAIN WITH DEEP COLD AND DRY ADVECTION THROUGH SAT
NIGHT. SEAS WILL SUBSIDE AS WINDS SUBSIDE ON SATURDAY DROPPING
BELOW SCA THRESHOLDS THROUGH SAT MORNING. AS WINDS BECOME
OFFSHORE IN DIRECTION SAT AND SAT NIGHT...SIGNIFICANT SEAS WILL
SUBSIDE TO 2 TO 5 FT...BUT WILL BUILD AGAIN OVERNIGHT SUNDAY AS
STRONG HIGH PRESSURE BUILDS DOWN INTO THE WATERS.
LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 330 AM FRIDAY...NORTHERLY WINDS WILL PERSIST AND VEER SLOWLY
AS STRONG HIGH PRESSURE REACHING DOWN FROM CANADA SHIFTS EAST OFF
THE NEW ENGLAND COAST BY TUES MORNING. WINDS WILL BE UP TO 15 TO
25 KTS ON MONDAY AS HIGH CONTINUES TO RIDGE INTO WATERS FROM THE
NORTH. GRADIENT WILL BECOME MORE PINCHED MON INTO TUES AS WEDGE
LIKE PATTERN SETS UP...KEEPING A PERSISTENT N-NE FLOW OVER THE
WATERS. THIS WILL PRODUCE AN INCREASE IN SEAS POSSIBLY REACHING
SCA THRESHOLDS.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EDT SATURDAY FOR AMZ250-252-
254-256.
&&
$$
NEAR TERM...TRA
SHORT TERM...RGZ
LONG TERM...RGZ
AVIATION...TRA/BJR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
327 AM EDT FRI NOV 1 2013
.SYNOPSIS...
A STRONG COLD FRONT APPROACHING FROM THE WEST WILL MOVE ACROSS THE
AREA SATURDAY MORNING. IT WILL BECOME WINDY AHEAD OF THIS FRONT WITH
A HIGH RISK FOR SHOWERS AND POSSIBLY A THUNDERSTORM. SIGNIFICANT
RAINFALL IS POSSIBLE. HIGH PRESSURE WILL FOLLOW LATE SATURDAY
THROUGH SUNDAY BRINGING WITH IT COLDER AND DRIER CONDITIONS. HIGH
PRESSURE WILL PERSIST THROUGH THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 AM FRIDAY...STRONG SURFACE LOW PRESSURE IN THE GREAT LAKES
IS ASSOCIATED WITH AN ENERGETIC UPPER LEVEL SYSTEM LIFTING NORTHEAST
ACROSS INTO SOUTHERN ONTARIO. A SURFACE COLD FRONT EXTENDING SOUTH
OF THE LOW IS NOW ENTERING THE SOUTHERN AND CENTRAL APPALACHIANS.
TROPICAL MOISTURE IS PRESENT WITH PRECIPITABLE WATER VALUES EXPECTED
TO EXCEED 2.0 INCHES BY THIS EVENING JUST AHEAD OF THE FRONT. TO PUT
THAT IN PERSPECTIVE...2.0 INCHES IS THE 99TH PERCENTILE FOR NOVEMBER
PRECIP WATER AT CHS...AND COULD BE A RECORD NOVEMBER PW VALUE AT MHX.
THE FRONT WILL MAKE STEADY EASTWARD PROGRESS...AND THE BAND OF
SHOWERS AND EMBEDDED T-STORMS SHOULD SLIDE INTO THE CENTRAL
CAROLINAS EARLY THIS AFTERNOON. I HAVE INCREASED POPS ALONG AND WEST
OF INTERSTATE 95 INTO THE 80-100 PERCENT RANGE BY LATE AFTERNOON...
WITH THE MOST SUBSTANTIAL COVERAGE OF PRECIPITATION EXPECTED ALONG
THE COAST AFTER DARK WHERE I HAVE BUMPED POPS UP TO 80-90 PERCENT.
STORM TOTAL RAINFALL COULD EXCEED 1 INCH...WITH HEAVIER AMOUNTS
POSSIBLE IF/WHERE CONVECTIVE TRAINING OCCURS.
RADAR VERTICAL WIND PROFILES ARE CONFIRMING MODEL FORECASTS OF A
HEALTHY LOW LEVEL JET BLOWING OVERHEAD CURRENTLY. WINDS AT 1000 FT
AGL ARE AROUND 30 KNOTS WITH 40 KNOTS MEASURED AT 2000 FT. AS THE
BOUNDARY LAYER DEEPENS LATER THIS MORNING WITH RISING
TEMPERATURES...EXPECT STRONGER WINDS TO MIX DOWN WITH 30-35 MPH
GUSTS EXPECTED BY 10-11 AM. HELICITY (0-1 KM) SHOULD RANGE FROM
150-200 WITH 0-6 KM BULK SHEAR 40-50 KT. THESE VALUES ARE ALSO
SUPPORTIVE OF A SEVERE WEATHER THREAT. THE LIMITING FACTOR COULD END
UP BEING INSTABILITY: FORECAST CAPE VALUES ONLY RANGE FROM 200-400
J/KG WITH PERHAPS SOME 700 J/KG NUMBERS SHOWING UP THIS EVENING
ALONG THE COAST IF DEWPOINTS CAN SURGE INTO THE UPPER 60S. THE STORM
PREDICTION CENTER CURRENTLY HAS A "SEE TEXT" 5 PERCENT PROBABILITY
FOR DAMAGING WIND GUSTS IN THE CAROLINAS.
TEMPERATURES TODAY SHOULD BE VERY WARM BY NOVEMBER STANDARDS...
COURTESY OF TROPICAL AIR ADVECTED NORTHWARD AHEAD OF THE FRONT. 850
MB TEMPS EXPECTED TO RISE TO +15C ARE IN THE 95-98TH PERCENTILE FOR
NOVEMBER. TEMPERATURES SHOULD LEAP WITH THE FIRST TOUCH OF SUNLIGHT
THIS MORNING...AND HIGHS SHOULD AGAIN REACH 80 DEGREES FOR AREAS
EAST OF INTERSTATE 95 AND AT LEAST A FEW MILES INLAND FROM THE
BEACHES. THE FRONT WILL MOVE ACROSS THE AREA LATE TONIGHT WITH COLD
ADVECTION NOT REACHING THE COAST UNTIL JUST A FEW HOURS BEFORE
DAYBREAK. THERE IS SOME UNCERTAINTY WITH TONIGHT`S LOW TEMPERATURES
SINCE WEAKER WINDS BEHIND THE FRONT COULD ALLOW FOR BOUNDARY LAYER
DECOUPLING JUST BEFORE SUNRISE...BUT IT APPEARS LOWS SHOULD RANGE
FROM THE MID 60S ON THE COAST TO THE UPPER 50S INLAND.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 330 PM THURSDAY...SATURDAY MORNING...WILL BE LOOKING AT
SOME DRYING TO OCCUR ACROSS THE FA. THE DRIER AIR THROUGH THE ATM
COLUMN AND THE DECENT COLD AIR ADVECTION WILL OCCUR SATURDAY
NIGHT...AFTER THE PASSAGE OF THE UPPER LONGWAVE TROF AXIS AND ITS
ASSOCIATED SFC TROF. A FEW ISOLATED SHOWERS ARE POSSIBLE DURING
ITS PASSAGE BUT TOO LOW OF A PROBABILITY TO PLACE IN THE OFFICIAL
FORECAST. PARTLY TO MOSTLY CLOUDY SKIES ON SATURDAY WILL FINALLY
CLEAR OUT SATURDAY NIGHT. WITH THE GFS BEING THE MODEL RELIED
UPON...MAX/MIN TEMPS FROM THE GFS MOS GUIDANCE WILL BE UTILIZED.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 3 PM THURSDAY...THE OVERALL MID LEVEL PATTERN WILL CONSIST
OF A DEPARTING MID LEVEL TROUGH ACROSS THE EAST SUNDAY FOLLOWED
BY SIGNIFICANT HEIGHT FALLS OUT WEST AND RIDGING ACROSS THE
SOUTHEAST.
THE DILEMMA FOR THE EXTENDED IS THE POSSIBILITY OF A COASTAL TROUGH
DEVELOPING AS HIGH PRESSURE BECOMES ANCHORED ACROSS THE NORTHEAST.
THIS WILL ALLOW WINDS TO BECOME ORIENTED MORE FROM THE EAST THUS
ALLOWING MODIFICATION FROM THE GULF STREAM. THE GFS IS AND HAS BEEN
FOR THAT MATTER SOMEWHAT BULLISH ON DEVELOPING QPF ACROSS THE
SOUTHEAST COAST TUESDAY AND WEDNESDAY. THE ECMWF IS SHOWING WHAT I
BELIEVE IS MORE REPRESENTATIVE...VERY LIGHT QPF WHICH IN REALITY IS
PROBABLY A STRATUS LAYER. THE GFS IS SHOWING EIGHT MICROBARS/SECOND
OF OMEGA AROUND THE 850MB LEVEL WHICH IS VERY SUSPECT. I HAVE
REMOVED ANY MENTION OF POPS FOR THESE DAYS WITH A SYSTEM
ASSOCIATED WITH THE AFOREMENTIONED WESTERN TROUGH WARRANTING POPS
FOR THE NEW FORECAST DAY THURSDAY. TEMPERATURE TRENDS CONSIST OF
SLIGHTLY BELOW NORMAL VALUES EARLY WARMING TO ABOVE CLIMATOLOGY BY
THE END OF THE PERIOD.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 06Z...EXPECT MAINLY VFR TONIGHT WITH PERHAPS SOME MVFR STRATUS
IN THE 09-12Z RANGE AND THE LOWEST CIGS INLAND. IFR CIGS CANNOT BE
RULED OUT FOR KFLO/KLBT...BUT CONFIDENCE IS FAIRLY LOW...AND ANY
CIGS BELOW 1KFT WOULD LIKELY BE VERY TEMPO IN NATURE. HRRR STILL
SHOWS SOME LIGHT -SHRA ALONG THE COAST BEFORE 12Z...WHICH SEEMS
REASONABLE BASED ON CURRENT RADAR TRENDS. AN APPROACHING COLD FRONT
WILL BRING PLENTY OF RAIN TO OUR CWA LATER TODAY. THE BEST PCPN
CHANCES FOR OUR AREA WILL BE AFTER 18Z...BEGINNING AT KFLO/KLBT
FOLLOWED BY THE COASTAL SITES A FEW HOURS LATER. ISOLATED TSTMS ARE
POSSIBLE...BUT WITH THE LIMITED INSTABILITY CHOSE NOT TO MENTION
TSTMS WITH THIS ISSUANCE. HEAVIER SHOWERS COULD RESULT IN PERIODS OF
MVFR CIGS/VSBYS...ESPECIALLY AFTER 00Z SATURDAY. EXPECT GUSTY
SOUTHWEST WINDS 10-20 KTS DURING THE DAY AS THE GRADIENT TIGHTENS
AHEAD OF THE FRONT.
EXTENDED OUTLOOK...MVFR/IFR CIGS POSSIBLE ON TUESDAY. OTHERWISE VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 300 AM FRIDAY...A STRONG COLD FRONT NOW ENTERING THE SOUTHERN
APPALACHIANS SHOULD SWEEP EAST AND ACROSS THE CAROLINA COASTAL
WATERS AFTER MIDNIGHT. AHEAD OF THE FRONT STRONG SOUTH WINDS SHOULD
AVERAGE 20-25 KNOTS THROUGH TONIGHT. MODELS ARE IN EXCELLENT
AGREEMENT WITH THE MAGNITUDE OF THIS MILD SOUTHERLY FLOW. A COUPLE
WAVES OF SHOWERS HAVE AFFECTED THE COASTAL WATERS THIS MORNING...
AND ADDITIONAL ISOLATED TO SCATTERED SHOWERS COULD OCCUR DURING THE
DAY. THE HEAVIER SHOWERS AND EMBEDDED THUNDERSTORMS WITH THE ACTUAL
COLD FRONT SHOULD NOT ARRIVE UNTIL TONIGHT BUT COULD POSE A SAFETY
RISK FOR MARINERS WITH STRONG GUSTY WINDS...LIGHTNING... AND REDUCED
VISIBILITY IN HEAVY RAIN. WINDS WILL SHIFT WESTERLY BEHIND THE FRONT
AND DECREASE LATE.
SEAS ARE CURRENTLY 5 FEET AT THE FRYING PAN SHOALS BUOY AND 4 FT AT
THE BUOY SEVERAL MILES SOUTH OF BALD HEAD ISLAND. WITH CONTINUED
SOUTH WINDS SEAS SHOULD BUILD TO AS HIGH AS 6-7 FEET 10-20 MILES OFF
THE SOUTH CAROLINA COAST...AND AS HIGH AS 7-8 FEET OFF THE NORTH
CAROLINA COAST. SEAS SHOULD BEGIN TO SUBSIDE LATE TONIGHT AS WINDS
SHIFT WESTERLY.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 330 PM THURSDAY...WINDS WILL VEER TO THE W TO NW AT 15-25
KT ON SATURDAY...THEN FURTHER VEER TO THE NNW SAT NIGHT DUE TO THE
PASSAGE OF A SFC TROF. SPEEDS WILL CONTINUE AT 15 TO 25 KT SPEEDS
DUE TO THE CONTINUED TIGHTENED SFC PG AND COLD AIR ADVECTION.
SIGNIFICANT SEAS OF 4 TO 8 FT WILL OCCUR ACROSS THE ILM WATERS FRI
INTO FRIDAY NIGHT WITH LOCALLY HIGHER SEAS ACROSS THE OUTER WATERS
OFF CAPE FEAR. AS WINDS BECOME OFFSHORE IN DIRECTION SAT AND SAT
NIGHT...SIGNIFICANT SEAS WILL SUBSIDE TO 2 TO 5 FT. THE EXCEPTION
WILL BE THE WATERS FROM CAPE FEAR SOUTH TO LITTLE RIVER INLET
WHERE SEAS WILL TAKE LONGER TO SUBSIDE DUE TO WINDS TAKING A BIT
LONGER TO BECOME TRULY OFFSHORE GIVEN THE ORIENTATION OF THE
CAROLINA COASTS. WIND DRIVEN WAVES WILL DOMINATE SIGNIFICANT SEAS
THROUGHOUT THE SHORT TERM...WITH DOMINANT PERIODS OF 5 TO 6
SECONDS.
LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 3 PM THURSDAY...A BRISK NORTHWEST FLOW ON THE ORDER OF
15-20 KNOTS WILL GREET MARINERS AT THE BEGINNING OF THE PERIOD AS
HIGH PRESSURE BUILDS IN FROM THE MISSISSIPPI VALLEY. THE HIGH WILL
MOVE MORE TOWARD THE EAST THAN SOUTH ALLOWING A PROLONGED
NORTHEASTERLY FLOW TO DEVELOP BY SUNDAY EVENING. SPEEDS DURING
THIS TIME WILL BE 15-20 KNOTS AS WELL. THESE ELEMENTS WILL PERSIST
THROUGH THE END OF THE PERIOD. SIGNIFICANT SEAS WILL INITIALLY BE
2-3 FEET MUTED BY THE OFFSHORE FLOW. AS THE NORTHEAST FLOW
PERSISTS...SEAS WILL RISE TO 3-5 FEET AND POSSIBLY SOME SIX
FOOTERS ACROSS THE OUTER WATERS TUESDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EDT SATURDAY FOR AMZ250-252-
254-256.
&&
$$
SYNOPSIS...
NEAR TERM...TRA
SHORT TERM...RGZ
LONG TERM...RGZ
AVIATION...TRA/BJR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1238 AM EDT FRI NOV 1 2013
.SYNOPSIS...
A STRONG COLD FRONT APPROACHING FROM THE WEST WILL MOVE ACROSS THE
AREA SATURDAY MORNING. IT WILL BECOME WINDY AHEAD OF THIS FRONT WITH
A HIGH RISK FOR SHOWERS AND POSSIBLY A THUNDERSTORM. SIGNIFICANT
RAINFALL IS POSSIBLE. HIGH PRESSURE WILL FOLLOW LATE SATURDAY
THROUGH SUNDAY BRINGING WITH IT COLDER AND DRIER CONDITIONS. HIGH
PRESSURE WILL PERSIST THROUGH THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
AS OF 100 AM FRIDAY...A WELL-DEFINED LINE OF SHOWERS EXTENDING FROM
FAYETTEVILLE THROUGH WHITEVILLE...TO SUNSET BEACH AND OVER 100 MILES
OFFSHORE HAS TAKEN ON A LIFE OF ITS OWN OVER THE PAST FEW HOURS.
THIS LINE OF CONVECTION SHOULD MOVE ACROSS WILMINGTON IN ABOUT
ONE HOUR. OTHERWISE CLOUDY SKIES...BREEZY SOUTH WINDS...AND
UNSEASONABLY MILD TEMPERATURES ARE EXPECTED THROUGH THE REMAINDER OF
THE NIGHT. A RECENT WIND OBSERVATION FROM SPRINGMAID PIER AT MYRTLE
BEACH SHOWED 30 MPH GUSTS DEVELOPING...THEREFORE I HAVE INCREASED
FORECAST WIND SPEEDS THROUGH THE REMAINDER OF THE NIGHT NEAR THE
BEACHES. PREVIOUS DISCUSSION FROM 1000 PM FOLLOWS...
A SMALL AREA OF SPRINKLES/SHOWERS HAVE DEVELOPED A LITTLE EARLIER
AND FURTHER INLAND THAN PREVIOUSLY THOUGHT. THE GRIDS HAVE BEEN
ADJUSTED TO ACCOUNT FOR THIS AND AT LEAST SPRINKLES HAVE BEEN
INCLUDED FOR THE ENTIRE FORECAST AREA FOR THE REMAINDER OF THE NIGHT.
WINDS TEMPORARILY DIMINISHED AS THE BOUNDARY LAYER DECOUPLED THIS
EVE. HOWEVER...LOW-LEVEL JETTING IS EXPECTED TO INCREASE TO 35 TO 45
MPH OVERNIGHT AND THIS WILL MAKE IT DIFFICULT FOR THE BOUNDARY LAYER
TO REMAIN DECOUPLED AFTER MIDNIGHT. THUS...WE DO EXPECT IT TO TURN
BREEZY OVERNIGHT. SUSTAINED SSW TO SW WINDS WILL BE ON THE ORDER OF
10 TO 20 MPH WITH GUSTS AS HIGH AS 25 TO 35 MPH...HIGHEST ALONG THE
IMMEDIATE COAST.
CLOUDS CONTINUE TO THICKEN ACROSS THE FORECAST AREA THIS EVE...A
TREND THAT WILL CONTINUE. THESE CLOUDS ALONG WITH INCREASING WINDS
WILL KEEP TEMPS MUCH HIGHER TONIGHT AS COMPARED TO THU NIGHT.
DEWPOINTS WILL ALSO CREEP HIGHER OVERNIGHT AS LOW-LEVEL MOISTURE
SLOWLY INCREASES. TEMPS SHOULD TEND TO BOTTOM OUT VERY LATE THIS EVE
AND THEN BEGIN TO STABILIZE IF NOT RISE A DEG OR TWO TOWARD MORNING.
THIS SHOULD PUT LOWS MAINLY IN THE UPPER 60S TO AROUND 70 DEGREES.
A VERY WEAK MID-LEVEL IMPULSE IS EXPECTED TO MOVE RAPIDLY N ALONG
THE CAROLINA COAST OVERNIGHT. SOME OF THE HIGHER RESOLUTION
NEAR-TERM MODELS ARE INDICATING SOME OCEAN SHOWERS WILL DEVELOP AS
LOW LEVEL JETTING INCREASES AND SOME OF THESE SHOWERS SHOULD SKIRT
COASTAL AREAS.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
AS OF 330 PM THURSDAY...A PROGRESSIVE WEATHER PATTERN BOTH SFC AND
ALOFT DURING THIS TIME FRAME. THE MAIN BUT DAMPENING UPPER S/W
TROF...ITS CORRESPONDING SFC LOW...AND THE ASSOCIATED
DYNAMICS...WILL PUSH NORTHEAST THROUGH THE GREAT LAKES AND INTO
CANADA FRIDAY INTO FRIDAY NIGHT. THE NE-SW ORIENTED SFC COLD FRONT
BECOMES SOMEWHAT DETACHED FROM THE LOW IN CANADA BY FRIDAY NIGHT
INTO SATURDAY. THIS WILL SLOW THE COLD FRONTS EASTWARD PROGRESSION
COME FRIDAY NIGHT INTO SAT AS FLOW ALOFT TEMPORARILY BECOMES
PARALLEL WITH THE SFC COLD FRONT. THE LONGWAVE TROF ALOFT IS
PROGGED TO AMPLIFY LATE FRIDAY THROUGH SATURDAY AS WEAK MID-
LEVEL S/W TROFS OR VORTS/IMPULSES ROTATE THROUGH IT. THIS
SHARPENING FLOW WILL AID IN FINALLY PUSHING THE COLD FRONT OFF THE
COAST AROUND DAYBREAK SAT. THE SLIGHTLY SLOWER GFS CFP...COMPARED
TO OTHER MODELS...WILL BE RELIED UPON THIS SHORT TERM PACKAGE.
ONE OF THESE VORTS COULD PRODUCE A SFC LOW ALONG THIS FRONT AND IN
THE NEIGHBORHOOD FRIDAY NIGHT...BEFORE FINALLY RACING OFF TO THE
NE. DYNAMICS FROM THE UPPER IMPULSE MAY BE ABLE TO TAP THOSE 40-50
KT LOW LEVEL JET WINDS...AND BRING THEM TO THE SFC AS STRONG TO
POSSIBLY SEVERE WIND GUSTS. THIS IN ASSOCIATION WITH THE
CONVECTION THAT WILL BE ONGOING ACROSS THE ILM CWA...MAINLY ALONG
AND JUST AHEAD OF THE COLD FRONT. MOISTURE FROM BOTH THE GULF OF
MEXICO AND ATLANTIC WILL REMAIN OPEN TO SUSTAIN CONVECTION AHEAD
OF THE COLD FRONT. QUESTIONABLE INSTABILITY WILL BE A PROBLEM FOR
THUNDERSTORM DEVELOPMENT AND SUSTAINABILITY...AND THEREFORE WILL
ONLY INDICATE ISOLATED IN COVERAGE. VARIOUS MODEL SOUNDINGS
INDICATE A SWATH OF 2.00 INCH PWS TO PUSH ACROSS THE FA
IMMEDIATELY AHEAD OF THE COLD FRONT FRIDAY NIGHT. OVERALL...HAVE
SUFFIXED THE ISOLATED CONVECTION WITH HEAVY RAINS POSSIBLE...AS
WELL AS STRONG GUSTY WINDS POSSIBLE. THE HWO WILL CONTAIN THE
ISOLATED SEVERE THREAT FOR FRIDAY AFTN AND EVENING.
AFTER THE CFP SATURDAY MORNING...WILL BE LOOKING AT SOME DRYING TO
OCCUR ACROSS THE FA. THE DRIER AIR THRU THE ATM COLUMN AND THE
DECENT COLD AIR ADVECTION WILL OCCUR SATURDAY NIGHT...AFTER THE
PASSAGE OF THE UPPER LONGWAVE TROF AXIS AND ITS ASSOCIATED SFC
TROF OR SECONDARY CFP. A FEW ISOLATED SHOWERS ARE POSSIBLE DURING
ITS PASSAGE BUT TOO LOW OF A PROBABILITY TO PLACE IN THE OFFICIAL
FORECAST. PARTLY TO MOSTLY CLOUDY SKIES ON SATURDAY WILL FINALLY
CLEAR OUT SATURDAY NIGHT. WITH THE GFS BEING THE MODEL RELIED
UPON...MAX/MIN TEMPS FROM THE GFS MOS GUIDANCE WILL BE UTILIZED.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 3 PM THURSDAY...THE OVERALL MID LEVEL PATTERN WILL CONSIST
OF A DEPARTING MID LEVEL TROUGH ACROSS THE EAST SUNDAY FOLLOWED
BY SIGNIFICANT HEIGHT FALLS OUT WEST AND RIDGING ACROSS THE
SOUTHEAST.
THE DILEMMA FOR THE EXTENDED IS THE POSSIBILITY OF A COASTAL TROUGH
DEVELOPING AS HIGH PRESSURE BECOMES ANCHORED ACROSS THE NORTHEAST.
THIS WILL ALLOW WINDS TO BECOME ORIENTED MORE FROM THE EAST THUS
ALLOWING MODIFICATION FROM THE GULF STREAM. THE GFS IS AND HAS BEEN
FOR THAT MATTER SOMEWHAT BULLISH ON DEVELOPING QPF ACROSS THE
SOUTHEAST COAST TUESDAY AND WEDNESDAY. THE ECMWF IS SHOWING WHAT I
BELIEVE IS MORE REPRESENTATIVE...VERY LIGHT QPF WHICH IN REALITY IS
PROBABLY A STRATUS LAYER. THE GFS IS SHOWING EIGHT MICROBARS/SECOND
OF OMEGA AROUND THE 850MB LEVEL WHICH IS VERY SUSPECT. I HAVE
REMOVED ANY MENTION OF POPS FOR THESE DAYS WITH A SYSTEM
ASSOCIATED WITH THE AFOREMENTIONED WESTERN TROUGH WARRANTING POPS
FOR THE NEW FORECAST DAY THURSDAY. TEMPERATURE TRENDS CONSIST OF
SLIGHTLY BELOW NORMAL VALUES EARLY WARMING TO ABOVE CLIMATOLOGY BY
THE END OF THE PERIOD.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 06Z...EXPECT MAINLY VFR TONIGHT WITH PERHAPS SOME MVFR STRATUS
IN THE 09-12Z RANGE AND THE LOWEST CIGS INLAND. IFR CIGS CANNOT BE
RULED OUT FOR KFLO/KLBT...BUT CONFIDENCE IS FAIRLY LOW...AND ANY
CIGS BELOW 1KFT WOULD LIKELY BE VERY TEMPO IN NATURE. HRRR STILL
SHOWS SOME LIGHT -SHRA ALONG THE COAST BEFORE 12Z...WHICH SEEMS
REASONABLE BASED ON CURRENT RADAR TRENDS. AN APPROACHING COLD FRONT
WILL BRING PLENTY OF RAIN TO OUR CWA LATER TODAY. THE BEST PCPN
CHANCES FOR OUR AREA WILL BE AFTER 18Z...BEGINNING AT KFLO/KLBT
FOLLOWED BY THE COASTAL SITES A FEW HOURS LATER. ISOLATED TSTMS ARE
POSSIBLE...BUT WITH THE LIMITED INSTABILITY CHOSE NOT TO MENTION
TSTMS WITH THIS ISSUANCE. HEAVIER SHOWERS COULD RESULT IN PERIODS OF
MVFR CIGS/VSBYS...ESPECIALLY AFTER 00Z SATURDAY. EXPECT GUSTY
SOUTHWEST WINDS 10-20 KTS DURING THE DAY AS THE GRADIENT TIGHTENS
AHEAD OF THE FRONT.
EXTENDED OUTLOOK...MVFR/IFR CIGS POSSIBLE ON TUESDAY. OTHERWISE VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 100 AM FRIDAY...BASED ON LATEST OBS FROM SPRINGMAID PIER AT
MYRTLE BEACH (GUSTING TO 25 KNOTS) I HAVE INCREASED FORECAST
NEARSHORE WIND SPEEDS TO MATCH OFFSHORE WINDS THROUGH THE REMAINDER
OF THE NIGHT. A LINE OF LIGHT TO MODERATE SHOWERS HAVE TAKEN ON A
LIFE OF ITS OWN...AND SHOULD APPROACH CAPE FEAR IN THE NEXT
HOUR...LATER AFFECTING THE NEW HANOVER AND PENDER COUNTY COASTAL
WATERS BETWEEN 2-4 AM. SEAS ARE BUILDING DUE TO THE INCREASING WINDS
AND NO SIGNIFICANT CHANGES ARE NEEDED THERE. PREVIOUS DISCUSSION
FROM 1000 PM FOLLOWS...
SMALL CRAFT ADVISORY CONDITIONS WILL DEVELOP AFTER MIDNIGHT AS
LOW-LEVEL JETTING INCREASES UP TO 35 TO 45 KT. THESE WINDS WILL MIX
MOST EFFICIENTLY TO THE SURFACE ACROSS THE OUTERMOST WATERS AND
BEYOND WHERE WATER TEMPS HAVE NOT COOLED BELOW 70 DEGREES.
HOWEVER...WE ARE STILL FORECASTING SUSTAINED SSW TO SW WINDS TO
INCREASE TO AROUND 20 KT OVERNIGHT AND THEN FURTHER ON FRI. THE
WINDS COULD GUST TO 30 KT. SEAS WILL BUILD TO 5 TO 7 FT BY SUNRISE.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 330 PM THURSDAY...TIGHTENED SFC PG AHEAD OF THE APPROACHING
COLD FRONT FRIDAY INTO FRIDAY NIGHT WILL YIELD A SW WIND 20-25 KT
WITH GUSTS OVER 30 KT NOT OUT OF THE QUESTION. THE SFC PRESSURE
PATTERN FRIDAY NIGHT COULD RESULT WITH WINDS BACKING TO S OR SSW
JUST PRIOR TO THE CFP. WINDS MAY BACK TO S-SSW JUST AHEAD OF THE
PASSAGE OF THE COLD FRONT AROUND DAYBREAK SATURDAY. THIS POSSIBLY
DUE TO A WEAK UPPER IMPULSE THAT AIDS IN A SFC LOW DEVELOPING
ALONG THE COLD FRONT PRIOR TO ITS PASSAGE. HAVE LEANED TOWARD THE
SLIGHTLY SLOWER GFS COMPARED TO THE OTHER AVAILABLE MODELS WITH
REGARD TO THE TIMING OF THE CFP. AFTER FROPA...WINDS WILL VEER TO
THE W TO NW AT 15-25 KT ON SATURDAY...THEN FURTHER VEER TO THE NNW
SAT NIGHT DUE TO THE PASSAGE OF A SFC TROF. SPEEDS WILL CONTINUE
AT 15 TO 25 KT SPEEDS DUE TO THE CONTINUED TIGHTENED SFC PG AND
COLD AIR ADVECTION. SIGNIFICANT SEAS OF 4 TO 8 FT WILL OCCUR
ACROSS THE ILM WATERS FRI INTO FRIDAY NIGHT WITH LOCALLY HIGHER
SEAS ACROSS THE OUTER WATERS OFF CAPE FEAR. AS WINDS BECOME
OFFSHORE IN DIRECTION SAT AND SAT NIGHT...SIGNIFICANT SEAS WILL
SUBSIDE TO 2 TO 5 FT. THE EXCEPTION WILL BE THE WATERS FROM CAPE
FEAR SOUTH TO LITTLE RIVER INLET WHERE SEAS WILL TAKE LONGER TO
SUBSIDE DUE TO WINDS TAKING A BIT LONGER TO BECOME TRULY OFFSHORE
GIVEN THE ORIENTATION OF THE CAROLINA COASTS. WIND DRIVEN WAVES
WILL DOMINATE SIGNIFICANT SEAS THROUGHOUT THE SHORT TERM...WITH
DOMINANT PERIODS OF 5 TO 6 SECONDS.
LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 3 PM THURSDAY...A BRISK NORTHWEST FLOW ON THE ORDER OF
15-20 KNOTS WILL GREET MARINERS AT THE BEGINNING OF THE PERIOD AS
HIGH PRESSURE BUILDS IN FROM THE MISSISSIPPI VALLEY. THE HIGH WILL
MOVE MORE TOWARD THE EAST THAN SOUTH ALLOWING A PROLONGED
NORTHEASTERLY FLOW TO DEVELOP BY SUNDAY EVENING. SPEEDS DURING
THIS TIME WILL BE 15-20 KNOTS AS WELL. THESE ELEMENTS WILL PERSIST
THROUGH THE END OF THE PERIOD. SIGNIFICANT SEAS WILL INITIALLY BE
2-3 FEET MUTED BY THE OFFSHORE FLOW. AS THE NORTHEAST FLOW
PERSISTS...SEAS WILL RISE TO 3-5 FEET AND POSSIBLY SOME SIX
FOOTERS ACROSS THE OUTER WATERS TUESDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EDT
SATURDAY FOR AMZ250-252-254-256.
&&
$$
NEAR TERM...RJD/TRA
SHORT TERM...DCH
LONG TERM...SHK
AVIATION...BJR
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
208 AM EDT FRI NOV 1 2013
.SYNOPSIS...
LOW PRESSURE OVER THE CENTRAL PLAINS WILL MOVE NORTHEAST INTO
SOUTHERN ONTARIO BY FRIDAY MORNING. A STRONG COLD FRONT TRAILING
SOUTH FROM THE LOW WILL SWEEP ACROSS THE EASTERN UNITED STATES
FRIDAY. COOL HIGH PRESSURE WILL BUILD INTO THE AREA FROM THE WEST
FOR SATURDAY AND SUNDAY.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 845 PM EDT THURSDAY...
UPDATE MAINLY TO REDUCE POPS IN THE NEAR TERM PER LACK OF MUCH
RAINFALL ATTM GIVEN THE MID LEVEL DRY AIR STILL SEEN ON AREA RAOBS
THIS EVENING. HOWEVER AS THE UPPER SYSTEM TO THE WEST HEADS
QUICKLY OFF TO THE NE AFTER MIDNIGHT...SHOULD SEE INCREASING
MOISTURE TRANSPORT BEGIN TO FILL IN SHOWERS AT LEAST OVER THE
WEST AHEAD OF THE ARRIVAL OF A POTENTIAL LOW TOPPED LINE LATE THAT
IS CURRENTLY WELL OFF TO THE WEST ATTM. MOST GUIDANCE CONTINUES
TO SLOW DOWN THE EASTWARD PUSH TO ANY STRONGER LOW TOPPED SHOWER
BAND(S) WITH BOTH THE LOCAL RNK- WRF AND HRRR NOT CROSSING THE
WESTERN SLOPES UNTIL JUST BEFORE DAYBREAK. THEREFORE ALSO PULLED
BACK HIGHER POPS WEST UNTIL AFTER MIDNIGHT AND CUT BACK SOME OUT
EAST WHERE COULD BE EARLY FRIDAY BEFORE THE RESIDUAL LINE MAKES
IT OVER THE BLUE RIDGE.
OTRW WINDS AHEAD OF AND WITHIN ANY DEEPER SHOWERS THE MAIN
CONCERN OVERNIGHT WITH EVENING RAOBS ALREADY SHOWING 50+ KTS
AROUND 85H. HAVE TOYED WITH UPGRADING THE BLF/TAZEWELL REGION
TO A HIGH WIND WARNING BUT GIVEN SHORT DURATION OF THE HIGHER
SPEEDS WHEN THE FLOW IS TURNING MORE SW DECIDED TO HOLD OFF
RAMPING UP THE ADVISORY FOR NOW. HOWEVER DOES APPEAR THAT LATE
TONIGHT/EARLY FRIDAY THE BETTER JET WILL END UP EAST OF THE
MOUNTAINS WHERE ALSO BOOSTED SPEEDS EAST OF THE CURRENT ADVISORY.
TEMPS LOOK TO STAY ABOUT STEADY UNDER CLOUDS AND INCREASED MIXING
SO KEPT THE FAR SE IN THE MID TO UPPER 60S WITH 55-62 ELSW.
PREVIOUS VALID DISCUSSION...
NOT TOO MUCH CHANGE TO THE FORECAST EXPECTED. STILL LOOKING AT THE
STRONG LOW LVL JET OF 45-65 KNOTS ACROSS MS/WRN TN/WRN KY TO MOVE
EAST NORTHEAST THROUGH OUR AREA LATE THIS EVENING AND EARLY
OVERNIGHT. THIS WILL BE COMING THROUGH ALONG A LINE OF SHOWERS. THE
FLOW SUGGESTS THAT SOME HIGHER GUSTS ACROSS RIDGES ABOVE 3000 FEET
WILL MEET WIND ADVISORY LEVELS SO NO CHANGES PLANNED TO THE ONGOING
ADVISORY. WILL HAVE TO WATCH FOR ENHANCED GUSTS WITH ANY BOWING
POTENTIAL FROM THE SHOWERS. MODEL HELICITIES INDICATE 300-400 M2/S2
ARRIVING THIS EVENING IN THE WEST AND SHIFTING EAST OF THE BLUE
RIDGE FRIDAY MORNING. THIS IN THE 0-1KM RANGE. NOT THAT CONCERNED
WITH SPINUPS AND TIMING SUGGEST LACK OF INSTABILITY...BUT THE WINDS
WILL BE GUSTY.
AM MAKING A FORECAST BASED ON NAM/ECMWF BLEND. THESE MODELS SHOWING
THE FRONT ENTERING THE MTNS LATE TONIGHT AND THEN SLOWING UP AS WAVE
OF LOW PRESSURE SHIFTS FROM NRN GA INTO THE VA PIEDMONT THROUGH FRI
AFTN. THIS SHOULD HOLD PRECIP IN LONGER OUT EAST AND MODELS INDICATE
MARGINAL INSTABILITY SO LEFT THUNDER IN THE EAST WITH GUSTY WINDS.
NOT TOO CONCERNED WITH THUNDER IN THE MTNS TONIGHT.
SO LOOKING AT CATEGORICAL POPS WEST BY MIDNIGHT HEADING EAST OF THE
BLUE RIDGE BEFORE DAWN...THEN DRYING WORKING INTO THE MTNS AFTER 12Z-
15Z...BUT KEEPING HIGHER CHANCE TO CAT POPS ACROSS THE EAST UNTIL
MID AFTERNOON.
FOR TEMPS WILL KEEP LOWS MILD TONIGHT WITH MID 50S WEST TO LOWER 60S
EAST...AND TOMORROW WILL BE SIMILAR TO TODAY WITH LITTLE CHANGE IN
TEMPS ALOFT BUT MAINLY A DEWPOINT FRONT....SO WITH SHOWERS AROUND
ESPECIALLY EAST WENT CLOSE TO MET/LOCAL MOS IN THE EAST AND LOCAL
MOS WEST...WHICH COMES OUT TO LOWER 70S EAST TO MID TO UPPER 60S
WEST.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
AS OF 400 PM EDT THURSDAY...
FRONT SHOULD BE EXITING THE EASTERN CWA FRIDAY EVENING ALONG WITH
ANY LEFT-OVER SHOWERS ALTHOUGH SEVERAL MODELS ARE HINTING AT WEAK
ONE OR MORE WEAK WAVE DEVELOPING ALONG THE FRONT WHICH MAY SERVE TO
HOLD CLOUDS AND SLIGHT CHC OF POPS A FEW HOURS LATER INTO FRIDAY
NIGHT OVER THE PIEDMONT. COLD AIR PUSH UNIMPRESSIVE FRIDAY NIGHT
WITH H85 TEMPS ROUGHLY 3-5C BY SATURDAY MORNING BUT COOLER AIR
FILTERING IN DURING THE DAY FINALLY REACHING 0C IN THE NORTHWEST
SATURDAY NIGHT. TEMPS WILL STILL HAVE A CHANCE TO REBOUND TO NEAR
OR SLIGHTLY ABOVE SEASONAL CLIMO DURING THE DAY SATURDAY FROM
MID-50S NW TO M/U 60S FAR SOUTHEAST.
THE INCREASING NORTHWEST FLOW SATURDAY AND SATURDAY NIGHT BEGINS
TO GENERATE UPSLOPE CLOUDS AND THEN SOME RAIN AND/OR SNOW SHOWERS
ESPECIALLY AT HIGHER ELEVATIONS IN THE WEST. LITTLE SIGNIFICANT
QPF AND A DUSTING OF SNOW AT HIGHER ELEVATIONS BY SUNDAY MORNING.
CAN`T RULE OUR A STRAY SHOWER MAKING IT EAST OF THE BLUE RIDGE
SATURDAY EVENING PER LATE AFTERNOON INSTABILITY...BUT THIS SHOULD
GO AWAY SATURDAY NIGHT...SKIES CLEARING EAST OF THE MOUNTAINS.
CLOUDS WILL LINGER OVER THE MOUNTAINS INTO SUNDAY MORNING BEFORE
CLEARING THERE TOO.
SUNDAY LOOKS COOL BUT DRY AS HIGH PRESSURE PASSES OVHD...TEMPS IN
THE 40S/50S...AND FALLING SHY OF NORMALS. THIS WILL SET STAGE FOR
FROSTY NIGHT SUNDAY NIGHT AND MONDAY MORNING WITH TMINS IN THE
20S/30S.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 400 PM EDT THURSDAY...
HIGH PRESSURE IS EXPECTED TO PASS OVERHEAD MONDAY...THE COOLEST
TEMPERATURES NEXT WEEK OCCURRING MONDAY MORNING. AFTER
THAT...THICKNESSES RISE PER RIDGE OF HIGH PRESSURE BUILDING OVER
THE SOUTHEAST STATES. THIS WILL RESULTING IN A RETURN TO
SOUTHERLY FLOW ACROSS OUR AREA BY MID WEEK ASSOCIATED WITH
MODERATING TEMPERATURES. NEXT APPRECIABLE THREAT FOR PRECIP IS
EXPECTED THURSDAY ASSOCIATED WITH THE NEXT UPPER LEVEL TROUGH.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 155 AM EDT FRIDAY...
COLD FRONT ALONG THE MISSISSIPPI RIVER MOVES EAST INTO THE
APPALACHIANS AROUND DAYBREAK AND THEN ACROSS THE BLUE RIDGE
REACHING THE PIEDMONT LATER TODAY. VWP SHOWED A LOW LEVEL JET
SHOWED A 50-60 KNOT JET AT 3000FT AGL JUST AHEAD OF THE MAIN BAND
OF SHOWERS. THE FRONT AND ASSOCIATED SHOWERS WILL REACH KBLF AND
KLWB AROUND 09Z/5AM AND PUSH EAST TO KLYH AND KDAN BY 15Z/10AM.
WINDS WILL BE FROM THE SOUTH TO SOUTHWEST AHEAD OF THE FRONT WITH
GUSTS UP TO 40 KNOTS. BEHIND THE FRONT WINDS WILL BE FROM THE WEST
WITH GUSTS AS HIGH AS 30 KNOTS.
CEILINGS WILL LOWER TO MVFR WITH THE SHOWERS ALONG THE FRONT.
IFR CEILINGS AND VISIBILITIES ARE POSSIBLE WITH THE STRONGEST
SHOWERS AS WELL AS GUSTS UP TO 50 KNOTS. CONFIDENCE IS HIGH WITH
THE WIND FORECAST AND TIMING OF THE FRONTAL PASSAGE. AMOUNT OF
SHOWERS EAST OF THE BLUE RIDGE IS MORE QUESTIONABLE. COVERAGE OF
SHOWERS MAY DIMINISH MOVING THROUGH THE MOUNTAINS THEN REDEVELOP
FARTHER EAST...POSSIBLE EAST OF KLYH AND KDAN.
EXPECTING A RETURN TO VFR BY THE END OF THE DAY EAST OF THE BLUE
RIDGE AS DRY AIR AND DOWNSLOPING WIND MOVES INTO THE AREA.
UPSLOPE WINDS WILL KEEP LOW VFR TO MVFR CEILINGS IN AT KLWB AND
KBLF FOR MUCH OF THE DAY BEHIND THE FRONT.
HIGH PRESSURE MOVES TOWARD THE OHIO RIVER VALLEY DURING
SATURDAY...BUT GUSTY NORTH TO NORTHWEST WINDS WILL PROVIDE SOME
MVFR CONDITIONS IN THE MOUNTAINS ALONG WITH SCATTERED UPSLOPE
RAIN AND SNOW SHOWERS. THE HIGH SHOULD BUILD OVERHEAD BY LATE
SUNDAY INTO MONDAY...WHICH WILL BRING OVERALL VFR CONDITIONS THROUGH
TUESDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...WIND ADVISORY UNTIL 7 AM EDT THIS MORNING FOR VAZ007-009>020-
022>024-032>035.
NC...WIND ADVISORY UNTIL 7 AM EDT THIS MORNING FOR NCZ001>003-018-
019.
WV...WIND ADVISORY UNTIL 7 AM EDT THIS MORNING FOR WVZ042>045.
&&
$$
SYNOPSIS...AMS
NEAR TERM...JH/WP
SHORT TERM...PC/PM
LONG TERM...PM
AVIATION...AMS/JH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
221 AM CDT FRI NOV 1 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 221 AM CDT FRI NOV 1 2013
MAIN FORECAST CONCERNS ARE ON SHOWER/DRIZZLE POTENTIAL THROUGH
THIS EVENING.
CURRENTLY AS OF 07Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED RIDGING ALONG THE WEST COAST OF THE U.S. WHILE TROUGHING
ENCOMPASSED AN AREA FROM HUDSON BAY SOUTHWESTWARD INTO THE CENTRAL
PLAINS. ONE POTENT SHORTWAVE MOVING THROUGH THE TROUGH WAS OVER
LOWER MICHIGAN. COLD AIR ADVECTION IN THE WAKE OF THIS SHORTWAVE
ALONG WITH LINGERING LOW LEVEL MOISTURE HAS RESULTED IN PERSISTENT
STRATUS ACROSS THE WESTERN GREAT LAKES. THIS STRATUS WAS EVIDENT IN
00Z MPX AND GRB SOUNDINGS WITH PLENTIFUL MOISTURE BELOW 700MB. OTHER
WEAK SHORTWAVES MOVING THROUGH THE UPPER TROUGH ACROSS THE FORECAST
AREA...COMBINED WITH WEAK SURFACE TROUGHS ALSO MOVING THROUGH AND
TURBULENCE IN THE STRATUS DECK HAS PRODUCED POCKETS OF SHOWERS AND
DRIZZLE. THERE IS SOME CLEARING OF THE STRATUS DECK UPSTREAM OVER
THE DAKOTAS WITH DRIER AIR PRESENT ON THE 00Z BIS/ABR SOUNDINGS.
HOWEVER...ANOTHER SHORTWAVE MOVING THROUGH THE TROUGHING COMING INTO
WESTERN NORTH DAKOTA WAS BRINGING MORE LIGHT SHOWER ACTIVITY THERE.
REGARDING THE AFOREMENTIONED COLD ADVECTION...AT MPX...925MB AND
850MB TEMPS DROPPED ABOUT 4C BETWEEN 12Z YESTERDAY AND 00Z...WITH
READINGS OF 2C AND -1C RESPECTIVELY. THESE READINGS ARE ABOUT 0.5
STANDARD DEVIATION BELOW NORMAL.
MODELS ARE IN GOOD AGREEMENT MAINTAINING UPPER TROUGHING OVER THE
FORECAST AREA THROUGH TONIGHT. HOWEVER...THE OVERALL TROUGHING WILL
START TO PROGRESS EAST TONIGHT AS THE RIDGING ALONG THE WEST COAST
OF THE U.S. GETS PUSHED FURTHER INLAND. THE MAIN SHORTWAVE FOCUS FOR
THE SHORT TERM IS THE ONE APPROACHING WESTERN NORTH DAKOTA. MODELS
TAKE THIS SHORTWAVE INTO WESTERN IOWA BY 00Z AND SOUTHERN ILLINOIS
BY 12Z SAT. LIGHT RAIN SHOWERS ACCOMPANYING THIS SHORTWAVE COULD
IMPACT FAR WESTERN PORTIONS OF THE FORECAST AREA LATE THIS AFTERNOON
INTO THIS EVENING...THOUGH MODEL CONSENSUS WOULD SUGGEST THE BEST
DYNAMICAL FORCING AND BULK OF THE PRECIPITATION STAYS SOUTH AND WEST
OF THE AREA.
OTHERWISE THE MAIN FOCUS FOR THE SHORT TERM PERIOD IS ON THE CURRENT
STRATUS DECK AND POCKETS OF DRIZZLE/SHOWERS. WEAK TROUGHS AS WELL AS
TURBULENCE IN THE STRATUS DECK LOOKS TO CONTINUE THROUGH THIS
EVENING...THUS POCKETS OF DRIZZLE AND SHOWERS ARE LIKELY TO PERSIST
UNTIL THE DECK CLEARS. REGARDING CLEARING...NORTHWEST WINDS OF 10-20
KT BELOW 800MB WILL HELP TO ADVECT THE DRIER AIR OVER THE DAKOTAS
TOWARDS THE FORECAST AREA. RAP/NAM 950-900MB RH PROGS SUGGEST
LOCATIONS WEST OF THE MISSISSIPPI RIVER SHOULD CLEAR OUT OF THE
STRATUS THIS AFTERNOON...WHILE LOCATIONS EAST OF THE MISSISSIPPI
RIVER CLEAR OUT DURING THE EVENING. THERE COULD STILL BE SOME
LINGERING CLOUDS OVERNIGHT...BUT THESE WOULD BE MORE OF THE
ALTOSTRATUS VARIETY AND LESS OF A CONCERN FOR PRECIP.
EXPECT ANOTHER COOL DAY TODAY DUE TO 925MB TEMPS ONLY CLIMBING TO
2-5C...CLOUDS...PRECIP AND WIND. COOL CONDITIONS CONTINUE INTO
TONIGHT AS 925MB TEMPS FALL TO AROUND 0C.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 221 AM CDT FRI NOV 1 2013
MAIN FORECAST CONCERNS ARE ON WINDS SUNDAY AND PRECIPITATION
CHANCES SUNDAY NIGHT THROUGH TUESDAY NIGHT.
THE UPPER LEVEL PATTERN IS FORECAST TO UNDERGO MAJOR CHANGES DURING
THE LONG TERM PERIOD...MUCH OF WHICH OCCURS DURING THE WEEKEND.
BETWEEN 12Z SATURDAY AND 00Z MONDAY...THE WESTERN U.S. GOES FROM
RIDGING TO A FAIRLY DEEP TROUGH. THE NET RESULT IS FOR 500MB HEIGHTS
TO RISE DRAMATICALLY DOWNSTREAM OVER THE EASTERN U.S....INCLUDING
THE FORECAST AREA...ALONG WITH DEEPENING LOW PRESSURE ALONG THE LEE
OF THE ROCKIES. THERE IS STRONG MODEL CONSENSUS FOR THE WESTERN
TROUGH TO GRADUALLY EJECT EAST-NORTHEAST THROUGH THE MIDDLE OF NEXT
WEEK...AND THIS EJECTION TIMING WILL BE CRITICAL ON HOW THE WEATHER
PANS OUT.
FOR THE WEEKEND...ONE MORE SURFACE TROUGH IS PROGGED TO DROP THROUGH
WISCONSIN ON SATURDAY WHICH COULD BRING SOME LIGHT PRECIP TO
LOCATIONS NORTHEAST OF I-94. OTHERWISE...DRY CONDITIONS WILL PREVAIL
AS A RIDGE OF HIGH PRESSURE MAKES ITS WAY ACROSS THE FORECAST AREA.
TEMPERATURES LOOK TO REMAIN ON THE COOL SIDE SATURDAY AS 925MB TEMPS
ARE HELD DOWN TO NO MORE THAN 2C. HOWEVER...AS THE RIDGE PASSES OFF
TO THE EAST ON SUNDAY...WINDS REALLY START TO CRANK UP OUT OF THE
SOUTHEAST. 925MB SPEEDS ARE PROGGED AT 25-40 KT BY 00Z MONDAY...
STRONGEST OUT WEST. THESE WINDS HELP TO BRING THE 925MB TEMPS UP TO
3-5C...AND WITH SUNSHINE SHOULD HELP TO PROPEL HIGH TEMPS INTO THE
MID 40S TO LOW 50S. RIGHT NOW IT APPEARS A STRONG ENOUGH SURFACE
INVERSION WILL BE IN PLACE TO PREVENT A WIND ADVISORY SITUATION
SUNDAY OR SUNDAY NIGHT. STILL...EXPECT WINDY CONDITIONS...ESPECIALLY
OVER THE HIGHER TERRAIN OF SOUTHEAST MN AND NORTHEAST IA.
AS WE HEAD FROM SUNDAY NIGHT THROUGH THE MIDDLE OF NEXT WEEK...DEEP
LAYER MOISTURE WILL INCREASE AHEAD OF THE GRADUALLY EJECTING WESTERN
TROUGH. PRECIPITABLE WATER VALUES CLIMB FROM NEAR 0.5 INCH SUNDAY
NIGHT TO AROUND 1 INCH BY LATE TUESDAY PER THE 01.00Z GFS. THE
INCREASING MOISTURE BRINGS UP CONCERNS FOR PRECIPITATION GIVEN ITS
ALSO A WARM ADVECTION PATTERN. THE 01.00Z CANADIAN ALREADY DEVELOPS
PRECIPITATION OVER THE NORTHWEST HALF OF THE AREA SUNDAY NIGHT...
ASSOCIATED WITH A SHORTWAVE TROUGH ALL MODELS SHOW...THOUGH IT IS
THE ONLY MODEL TO DO SO. THEN ON MONDAY...THE 01.00Z ECMWF BECOMES
THE ONLY MODEL TO OVERSPREAD PRECIP ACROSS MUCH OF THE FORECAST
AREA. THIS IS ASSOCIATED WITH A WARM CONVEYOR BELT AHEAD OF A POTENT
SHORTWAVE LIFTING NORTHEAST THROUGH THE DAKOTAS. GIVEN GOOD
CONTINUITY IN THE ECMWF...SOME LOW END PRECIPITATION CHANCES ARE
REQUIRED. CHANCES FOR PRECIPITATION LOOK INCREASINGLY LIKELY FOR
TUESDAY AND TUESDAY NIGHT AS THE POTENT SHORTWAVE AT THE BASE OF THE
TROUGH APPROACHES. HAVE RAISED CHANCES ABOUT 10 PERCENT WITH FURTHER
INCREASES LIKELY NEEDED IN LATER FORECASTS. VERY LITTLE INSTABILITY
SUGGESTED THUS NO MENTION OF THUNDER AT THIS TIME. PRECIPITATION
CHANCES THEN DECLINE WEDNESDAY INTO WEDNESDAY NIGHT AS THAT POTENT
SHORTWAVE LIFTS OFF TO THE NORTHEAST OF THE AREA. HIGH PRESSURE
LOOKS TO BUILD IN FOR THURSDAY TO DRY THINGS OUT ENTIRELY.
TEMPERATURES FOR MONDAY AND TUESDAY SHOULD BE NEAR OR SLIGHTLY ABOVE
NORMAL IN THE WARM ADVECTION AHEAD OF EJECTING WESTERN TROUGH...
AIDED TOO BY BREEZY SOUTHERLY WINDS AND HIGHER MOISTURE. CONDITIONS
COOL BACK DOWN TO BELOW NORMAL FOR WEDNESDAY AND THURSDAY AS COLD
AIR FLOWS IN THE WAKE OF THE POTENT SHORTWAVE. OVERALL MUCH OF THE
AFOREMENTIONED PRECIPITATION THAT FALLS LOOKS TO OCCUR WHEN THE
BOUNDARY LAYER IS WARM ENOUGH FOR RAIN.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1100 PM CDT THU OCT 31 2013
LOW CIGS WILL PERSIST THROUGH THE OVERNIGHT HOURS - GENERALLY
HOVERING NEAR 1 KFT - AS A LOW PRESSURE SYSTEM EXITS TO THE EAST.
NOT MUCH VSBY RESTRICTIONS VIA LATEST SFC OBS...OUTSIDE OF AREAS OF
-DZ/-SHRA ACROSS NORTHWEST WI. DON/T EXPECT FOG TO THICKEN
TONIGHT...UNLIKE LAST NIGHT...AS WINDS STAY FAIRLY STIRRED OUT OF
THE WEST/NORTHWEST.
CIGS SHOULD START TO IMPROVE BY MID MORNING FRIDAY...AND COULD GET A
BUMP INTO VFR BY 18Z. WILL PLAY THIS MORE PESSIMISTICALLY...WAITING
UNTIL LATER IN THE AFTERNOON. FALL/WINTER CAN BE NOTORIOUS FOR
HANGING ONTO LOW CIGS LONGER THAN THE MODELS WOULD SUGGEST.
BITS OF UPPER LEVEL ENERGY AND A SFC TROUGH HAVE SPARKED -DZ/-SHRA
FROM CENTRAL MN INTO NORTHWEST WI. RAP13/HRRR/NAM12 FAVOR THE BETTER
CHANCES ALONG I-94 NORTH/EAST...BUT RADAR TRENDS SUGGEST SOME LIGHT
PCPN COULD REACH KRST/KLSE. WILL ADD -DZ FOR A FEW HOURS TO THE
FORECAST.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1040 AM EDT FRI NOV 1 2013
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE REGION TODAY AND STALL NEAR
THE COAST TONIGHT AS A WEAK WAVE OF LOW PRESSURE DEVELOPS SOUTH OF
NEW ENGLAND. UNSEASONABLY MILD AND WINDY TODAY WITH A BAND OF
SHOWERS MOVING ACROSS THE REGION. ANOTHER PERIOD OF SHOWERS AFFECT
THE CAPE AND ISLANDS TONIGHT INTO EARLY SATURDAY...THEN COLDER
AND BLUSTERY CONDITIONS ARRIVE FOR SUNDAY INTO EARLY NEXT WEEK.
HIGH PRESSURE BY THE MIDDLE OF THE WEEK WILL ALLOW FOR MODERATING
TEMPERATURES.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1030 AM UPDATE...
FINE LINE OF LOW TOP CONVECTION CONTINUES TO BECOME FRAGMENTED
ACROSS WESTERN MA AND SOUTHWEST NH. MEANWHILE SOUTHERN PORTION OF
THE LINE IS MORE ROBUST ACROSS CT/LONG ISLAND AND THE NEARBY
COASTAL WATERS. LATEST MESOANALYSIS INDICATES BEST MUCAPE /ALBEIT
MINIMAL/ IS OVER CT AND POINTS SOUTH. THUS EXPECTING STRONGEST
WIND AND RAIN ASSOCIATED WITH SOUTHERN PORTION OF THE LINE. AS
RESULT THREAT FOR STRONGEST WINDS WILL BE ACROSS CT AND POSSIBLY
INTO RI AND SOUTHEAST MA IF LINE REMAINS IN TACT.
SURPRISINGLY PAST FEW RUNS OF THE HRRR NOT HANDLING/CAPTURING THIS
LINE VERY WELL. ITS SURPRISINGLY GIVEN HRRR USUALLY PERFORMS WELL
IN STRONGLY FORCED SYNOPTIC ENVIRONMENTS.
THIS LINE OF CONVECTION IS MARKED BY A COLD FRONT AND A PRES
RISE/FALL COUPLET. POST FRONTAL AIRMASS IS NOT MUCH
COOLER...STILL MILD BEHIND THE FRONT BUT NOTICEABLY DRIER WITH DEW
PTS FALLING FROM THE 60S INTO THE 50S. THIS DRIER AIR AND A WIND
SHIFT TO WSW WILL HELP STEEPEN LOW LEVEL LAPSE RATES TO SUPPORT
GUSTS UP TO 40 KT THIS AFTERNOON...ESPECIALLY ACROSS NORTHERN MA
INTO SOUTHWEST NH. EARLIER DISCUSSION BELOW.
------------------------------------------------------------------
DRY SLOT AND PRECIP LULL LIFTING NWD ACROSS SNE EARLY THIS
MORNING WHICH IS WELL FORECAST BY SHORT RANGE MODEL SUITE
INCLUDING HRRR. EDGE OF THE DRY SLOT WILL BE ACROSS FAR NW ZONES
WHERE OCCASIONAL SHOWERS WILL CONTINUE...WITH THESE SHOWERS MOVING
BACK TO THE EAST TOWARD DAYBREAK. WARM SECTOR AIRMASS IN WELL
ENTRENCHED WITH TEMPS UPPER 50S TO MID 60S.
ANOMALOUS LOW PRES -4SD LIFTS NE FROM GT LAKES TODAY WITH +3SD LOW
LEVEL JET MOVING ACROSS SNE TODAY. PWAT ANOMALY ALSO +3SD. THIS
WILL RESULT IN A PERIOD OF LOCALLY HEAVY SHOWERS MOVING WEST TO
EAST THIS MORNING INTO THE AFTERNOON ASSOCD WITH IMPRESSIVE LOW
LEVEL MOISTURE TRANSPORT AND RIGHT ENTRANCE REGION OF THE UPPER
JET.
ALSO CONCERNED WITH A POSSIBLE FINE LINE OF CONVECTION ALONG THE
FRONT LATER THIS MORNING PER HRRR SOLUTION. MODELS ARE GENERATING
MARGINAL INSTABILITY WITH SBCAPES 200-400 J/KG SO THIS SCENARIO
SEEMS PLAUSIBLE. LOW RISK OF ISOLD THUNDER AND IF FINE LINE DOES
DEVELOP THIS WOULD ENHANCE THE RISK OF STRONGER WINDS MIXING DOWN
TO THE SURFACE. THE SPEED OF THIS SYSTEM AND MARGINAL INSTABILITY
WILL LIMIT RAINFALL AMOUNTS WITH QPF LESS THAN 0.5" FOR MOST
LOCATIONS...WITH UP TO 1" ACROSS FAR W ZONES. LOCALIZED MINOR
URBAN AND POOR DRAINAGE FLOODING IS POSSIBLE THIS MORNING...MAINLY
IN THE INTERIOR. SHOWERS WILL BE EXITING W ZONES LATE MORNING TO
MIDDAY...AND EARLY AFTERNOON IN THE COASTAL PLAIN. BUT SHOWERS
COULD LINGER THROUGH THE DAY OVER THE OUTER CAPE/ISLANDS AS FRONT
STALLS.
WIND THREAT...CORE OF THE LOW LEVEL JET WILL BE MOVING ACROSS SNE
12-18Z. SOUNDINGS INDICATE VERY SHALLOW PREFRONTAL MIXING BUT
POTENTIAL FOR GUSTS TO 40+ KTS THIS MORNING. HEAVIER SHOWERS AND
POTENTIAL FINE LINE WOULD ALSO AID IN TRANSPORTING STRONGER WINDS
TO THE SURFACE. STRONGEST WINDS WILL LIKELY BE ACROSS PORTIONS
OF RI AND INTERIOR E MA WHERE MILDEST TEMPS INTO THE LOWER 70S
PROMOTE DEEPER MIXING. SOUNDINGS INDICATE THE POTENTIAL FOR
ANOTHER PULSE OF STRONG POST-FRONTAL WINDS TO 40+ KTS THIS
AFTERNOON AS BOUNDARY LAYER MIXING DEEPENS. STRONGEST POST-
FRONTAL WINDS MORE LIKELY ACROSS THE INTERIOR WITH LESS WIND
ALONG THE COAST. WIND ADVISORY WILL CONTINUE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/...
FRONT STALLS NEAR THE COAST TONIGHT AS A WAVE IS FORECAST TO
DEVELOP S OF NEW ENG. THIS WILL KEEP THE THREAT OF SHOWERS GOING
TONIGHT ACROSS SE COASTAL NEW ENG...ESPECIALLY THE OUTER CAPE AND
ISLANDS WHILE DRY CONDITIONS PREVAIL IN THE INTERIOR. AMERICAN
MODELS KEEP MOST OF THE RAIN OFFSHORE WHILE INTERNATIONAL MODELS
BRING A DECENT SLUG OF RAIN TO THE OUTER CAPE/ISLANDS LATE
TONIGHT. WITH FRONT STALLING NEAR THE COAST...WE TRENDED FORECAST
TOWARD WETTER SOLUTION AND HAVE LIKELY POPS TO ACK WITH CHC POPS
TO THE CAPE AND S COASTAL MA. LOW PROB THAT SHOWERS COULD BACK IN
TO THE BOS-PVD CORRIDOR LATE TONIGHT BUT WE KEPT IT DRY FOR NOW.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
HIGHLIGHTS...
* COASTAL LOW DEVELOPS FOR SATURDAY...CLIPPING THE CAPE AND ISLANDS
* COLDER AND BLUSTERY CONDITIONS WILL RETURN ON SUNDAY AND MONDAY
* MODERATING TEMPERATURES AND DRY WEATHER BY MID NEXT WEEK.
* POSSIBLE SYSTEM APPROACHING THURSDAY/FRIDAY
CONFIDENCE LEVEL/MODEL GUIDANCE...
MODERATE CONFIDENCE IN THE OVERALL FORECAST. HAVE HIGH CONFIDENCE IN
THE OVERALL TRENDS YET LOW CONFIDENCE ON EXACT PRECIP TIMING. LONG
WAVE TROUGH IS STILL PROGGED TO IMPACT NEW ENGLAND WITH SEVERAL
SHORTWAVES MOVING THROUGH THE FLOW. THE FIRST ONE IS MOVING THROUGH
TODAY WITH A SECOND SHORTWAVE APPROACHING THE REGION BY TOMORROW.
EXPECT THIS EXPANSIVE NEGATIVE HEIGHT ANOMALY TO INDUCE AN AREA OF
LOW PRESSURE ALONG THE MID-ATLANTIC COAST WHICH WILL SLIDE NORTHWARD
TOWARD THE CANADIAN MARITIMES. 00Z MODEL GUIDANCE ALL AGREE WITH
THIS COASTAL LOW DEVELOPMENT...WHICH COULD BRING MORE SHOWERS ACROSS
THE IMMEDIATE SOUTH COAST...CAPE AND ISLANDS ON SATURDAY. THERE ARE
SOME MODEL DISCREPANCIES ON EXACT PLACEMENT OF THE LOW...WITH THE EC
ON THE FASTER END AND THE GFS ON THE SLOW SIDE. TRENDED IN THE
MIDDLE FOR NOW. FINALLY THE LAST IMPULSE WILL PUSH A STRONG COLD
FRONT THROUGH THE REGION ON SUNDAY DROPPING TEMPS BACK TOWARDS
SEASONABLE. BY EARLY NEXT WEEK MODELS CONCUR WITH A WESTERN TROUGH
TO STRONGLY AMPLIFY RESULTING IN RIDGING TO BUILD OVER THE EASTERN
HALF OF THE U.S. HOWEVER THIS WESTERN TROUGH WILL APPROACH NEW
ENGLAND BY THURSDAY BRINGING ANOTHER ROUND OF RAIN AND WIND. EXACT
TIMING FOR THIS SYSTEM IS STILL UNCERTAIN.
DETAILS...
SATURDAY...
MID-ATLANTIC LOW WILL DEVELOP AND HEAD TOWARDS SOUTHERN NEW ENGLAND
DURING THE MORNING HOURS. AS MENTIONED BEFORE...TRENDED TOWARDS THE
MIDDLE OF THE ROAD COMPARED TO THE GFS AND EC. BELIEVE THERE WILL BE
A SHARP CUT OFF IN TERMS OF WHERE THE RAIN WILL AND WILL NOT FALL.
HAVE THE HIGHEST CONFIDENCE THAT THIS SYSTEM WILL BRING SOME SHOWERS
ACROSS THE IMMEDIATE SOUTH COAST...CAPE AND ISLANDS. HOWEVER WITH
THE ONSHORE FLOW...COULD SEE A SHOWER OR TWO ACROSS THE SOUTHEAST
COASTAL SIDE OF MASSACHUSETTS. THIS COASTAL LOW WILL MOVE UP TO THE
MARITIMES BY THE SATURDAY NIGHT SO CHANCE OF PRECIP WILL WANE BY THE
AFTERNOON HOURS. REGARDLESS SATURDAY WILL STILL BE MILD WITH TEMPS
IN THE 60S AND LESS WINDY. DEFINITELY AN IMPROVEMENT COMPARED TO
TODAY.
SUNDAY...
THE UNSEASONABLE WARM WEATHER WILL COME TO AN END ON SUNDAY AS THE
THIRD AND LAST IMPULSE PUSHES A STRONG COLD FRONT THROUGH THE REGION
BY LATE SATURDAY/EARLY SUNDAY. THIS FRONT WILL HAVE STRONG CAA
BEHIND IT DROPPING TEMPERATURES ACROSS THE REGION CLOSER TO
SEASONABLE. IN FACT 850 MB TEMPS DROP BETWEEN -6 TO -9C RESULTING IN
HIGH TEMPS TO BE BE IN THE MID 40S TO LOW 50S. WITH COASTAL LOW WAY
OUT IN THE MARITIMES AND CANADIAN HIGH BUILDING ACROSS THE NORTH
COUNTRY...DUE NORTH WINDS ARE ANTICIPATED. THESE NORTHERLY WINDS
WILL ALLOW FOR SOME POSSIBLE OCEAN EFFECT SHOWERS TO DEVELOP AND
MOVE ALONG THE EAST COAST LINE AND ACROSS THE CAPE AND ISLANDS. HAVE
KEPT A SLIGHT CHANCE MENTIONED FOR NOW. THESE SHOWERS WILL BE VERY
ISOLATED IN NATURE. ALTHOUGH TEMPS ALOFT ARE DROPPING
QUICKLY...BELIEVE LIQUID PRECIP WILL HOLD OUT AS SURFACE AND BL
TEMPS WILL STILL STAY ABOVE FREEZING.
SUNDAY NIGHT INTO WEDNESDAY....
CANADIAN HIGH PRESSURE WILL BEGIN TO MOVE INTO THE REGION LATE
SUNDAY NIGHT INTO MONDAY...AND BUILD OVER THE NORTHEAST THROUGH AT
LEAST WEDNESDAY. THIS HIGH PRESSURE WILL ALLOW FOR LIGHT WINDS AND
CLEAR SKIES ESP DURING THE OVERNIGHT HOURS. THIS WILL ALLOW FOR
RADIATIONAL COOLING ON SUNDAY NIGHT AND ON MONDAY NIGHT. SUNDAY
NIGHT APPEARS TO BE THE COLDEST WITH TEMPS DROPPING INTO THE MID
TEENS TO MID 20S. MONDAY WILL BE THE COOLEST THE REGION HAS SEEN
IN AWHILE WITH HIGHS BELOW AVERAGE...LOW TO MID 40S.
AN UPPER LEVEL RIDGE WILL BEGIN TO BUILD ACROSS THE EASTERN SEABOARD
RESULTING IN DRY WEATHER AND A WARMING TREND. IN FACT MID 60S RETURN
TO THE FORECAST BY WEDNESDAY AND POSSIBLY ON THURSDAY.
THURSDAY AND BEYOND...
MODELS BEGIN TO DRIVE THE WESTERN TROUGH TOWARDS THE EAST COAST BY
THURSDAY. APPEARS THAT THIS LOW PRESSURE SYSTEM WILL BRING HEAVY
RAIN AS WELL AS STRONG WINDS TO THE REGION BY THURSDAY MORNING
LASTING INTO FRIDAY MORNING. BECAUSE THIS SYSTEM IS SEVERAL DAYS
AWAY...A LOT CAN CHANGE SO STAY TUNED TO THE LATEST FORECAST.
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
1030 AM UPDATE...
LINE OF LOW TOP SHOWERS ACROSS WESTERN NEW ENGLAND WILL WEAKEN AS
MOVES INTO EASTERN NEW ENGLAND. SOUTHERN PORTION OF THE LINE WILL
BE STRONGER ACROSS CT AND POSSIBLY RI AND SOUTHEAST MA IF LINE
REMAINS IN TACT. SSW WINDS GUSTS TO 45 KT INTO THROUGH THIS
MORNING...THEN SHIFT TO WSW THIS AFTERNOON WITH G40KT ESPECIALLY
NORTHERN MA INTO NH. EARLIER DISCUSSION BELOW.
-------------------------------------------------------------------
TODAY...IFR-MVFR WITH A BAND OF LOCALLY HEAVY SHOWERS MOVING
ACROSS THE REGION...EXITING 18-21Z FROM WEST TO EAST WITH
IMPROVING CONDITIONS TO VFR. STRONG S/SW WINDS GUSTING UP TO 40-45
KT RI AND EASTERN MA IN THE MORNING...THEN SHIFTING TO WSW IN THE
AFTERNOON WITH GUSTS 30-40 KT. HIGH CONFIDENCE ON TRENDS.
TONIGHT...LINGERING MVFR/IFR IN OCCASIONAL SHOWERS AT
ACK...POSSIBLY AS FAR N AS CAPE COD. OTHERWISE VFR WITH
DIMINISHING WIND. MODERATE CONFIDENCE.
KBOS TAF...HIGH CONFIDENCE IN TRENDS...LOWER IN EXACT TIMING.
KBDL TAF...HIGH CONFIDENCE IN TRENDS...LOWER IN EXACT TIMING.
OUTLOOK...SATURDAY THROUGH TUESDAY...
SATURDAY...MVFR/IFR CONDITIONS TO START WILL IMPROVE TO VFR FROM
WEST TO EAST.
SUNDAY...VFR. NNW WINDS COULD GUST TO 25 KTS.
MONDAY AND TUESDAY...VFR.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
TODAY...SW GALE FORCE WINDS TO 35-40 KT. SCATTERED HEAVY SHOWERS
EXIT OFFSHORE DURING THE AFTERNOON...HOWEVER MAY LINGER OVER
SOUTHEAST WATERS. HIGH CONFIDENCE.
TONIGHT...DIMINISHING WIND AND SEAS. OCCASIONAL SHOWERS WILL
CONTINUE ACROSS SE WATERS...OTHERWISE MAINLY DRY. MODERATE
CONFIDENCE ON NW EXTENT OF SHOWERS.
OUTLOOK...SATURDAY THROUGH TUESDAY...HIGH CONFIDENCE.
SATURDAY AND SUNDAY...SMALL CRAFT ADVISORIES WILL LIKELY BE
NECESSARY FOR SEAS OVER 5 FEET AND NORTHWESTERLY WINDS GUSTING TO 30
KTS. THERE IS A LOW PROBABILITY THAT NORTH GALES WILL OCCUR ACROSS
THE EASTERN OUTER WATERS ON SUNDAY. VISIBILITIES MAY BE LIMITED IN
INTERMITTENT SHOWERS.
MONDAY AND TUESDAY...WINDS AND SEAS DIMINISH AS HIGH PRESSURE MOVES
OVER SOUTHERN NEW ENGLAND AND OVER THE WATERS. LIGHT NORTHERLY
WINDS SHIFT TO THE EAST AND THEN SOUTH THROUGH THIS TIME PERIOD.
&&
.TIDES/COASTAL FLOODING...
COASTAL FLOODING CONCERNS ALONG THE SOUTH COAST ARE MINIMAL. NOT
MUCH OF A SURGE GIVEN SURFACE LOW AND PRESSURE FALLS ARE TRACKING
SO FAR NORTHWEST OF NEW ENGLAND. WILL HAVE MODEST TO LARGE WAVE
ACTION ON THE SOUTH COAST BUT TIDES WILL NOT BE HIGH ENOUGH TO
WARRANT ANY FLOODING.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WIND ADVISORY UNTIL 6 PM EDT THIS EVENING FOR CTZ002>004.
MA...WIND ADVISORY UNTIL 6 PM EDT THIS EVENING FOR MAZ002>024-026.
NH...WIND ADVISORY UNTIL 6 PM EDT THIS EVENING FOR NHZ011-012-015.
RI...WIND ADVISORY UNTIL 6 PM EDT THIS EVENING FOR RIZ001>008.
MARINE...GALE WARNING UNTIL 6 PM EDT THIS EVENING FOR ANZ230>237-250-
251-254>256.
&&
$$
SYNOPSIS...KJC/DUNTEN
NEAR TERM...NOCERA
SHORT TERM...KJC/DUNTEN
LONG TERM...DUNTEN
AVIATION...KJC/NOCERA/DUNTEN
MARINE...KJC/DUNTEN
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS TAUNTON MA
907 AM EDT FRI NOV 1 2013
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE REGION TODAY AND STALL NEAR
THE COAST TONIGHT AS A WEAK WAVE OF LOW PRESSURE DEVELOPS SOUTH OF
NEW ENGLAND. UNSEASONABLY MILD AND WINDY TODAY WITH A BAND OF
SHOWERS MOVING ACROSS THE REGION. ANOTHER PERIOD OF SHOWERS AFFECT
THE CAPE AND ISLANDS TONIGHT INTO EARLY SATURDAY...THEN COLDER
AND BLUSTERY CONDITIONS ARRIVE FOR SUNDAY INTO EARLY NEXT WEEK.
HIGH PRESSURE BY THE MIDDLE OF THE WEEK WILL ALLOW FOR MODERATING
TEMPERATURES.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
9 AM UPDATE...
FINE LINE OF LOW TOP CONVECTION ACROSS EASTERN NY STATE AND
WESTERN NJ WILL WEAKEN AND BECOME FRAGMENTED AS IT APPROACHES AND
ENTERS WESTERN NEW ENGLAND. THIS WILL BE ESPECIALLY TRUE FOR THE
NORTHERN PORTION OF THE LINE...AS BEST INSTABILITY AND FORCING FOR
ASCENT WILL SLIDE SOUTH OF NEW ENGLAND ACROSS NYC/LONG ISLAND AND
THE SOUTHERN NEW ENGLAND COASTAL WATERS.
NEVERTHELESS WIND THREAT REMAINS HIGH AS OUR KBOX RADAR VAD WIND
PROFILE DETECTING 60 KT OF WIND AT 2 KFT HERE IN TAUNTON MA. CORE
OF 60-70 KT LOW LEVEL JET WILL REMAIN OVER RI AND SOUTHEAST MA
THROUGH 15Z/11AM...THEN BEGINNING TO SLIDE OFFSHORE. HOWEVER WIND
THREAT REMAINS HIGH ACROSS THE ENTIRE REGION AS HEAVIER SHOWERS
WILL HELP TRANSPORT STRONGER WINDS ALOFT TO THE SURFACE. ALSO
HIGHER TERRAIN REMAIN AT RISK GIVEN CLOSER PROXIMITY TO STRONGER
WINDS ALOFT.
STRONG WINDS WILL PERSIST BEHIND FRONTAL PASSAGE AND DEPARTURE OF
SHOWERS THIS AFTERNOON...AS LOW LEVEL LAPSE RATES STEEPEN IN POST
FRONTAL AIRMASS YIELDING GUSTS UP TO 50 MPH. STRONGEST WINDS THIS
AFTERNOON WILL BE ACROSS NORTHERN MA INTO SOUTHWEST NH. THUS
EXPECT A WINDY DAY FROM START TO FINISH WITH WINDS FINALLY EASING
AROUND SUNSET.
ONLY CHANGE TO FORECAST WILL BE TO INCREASE HIGH TEMPS AS 9 AM
READINGS ARE ALREADY NEAR 70 /70 AT MARSHFIELD/! WILL KEEP AN EYE
ON RECORD HIGHS FOR TODAY WHICH ARE IN THE U70S /BOS AND PVD/ L70S
FOR ORH AND L80S FOR BDL. NOT SURPRISING REGARDING THIS NEAR
RECORD WARMTH GIVEN STRENGTH OF LOW LEVEL JET BEING +3 STD FROM
CLIMO. EARLIER DISCUSSION BELOW.
------------------------------------------------------------------
PREVIOUS DISCUSSION... DRY SLOT AND PRECIP LULL LIFTING NWD
ACROSS SNE EARLY THIS MORNING WHICH IS WELL FORECAST BY SHORT
RANGE MODEL SUITE INCLUDING HRRR. EDGE OF THE DRY SLOT WILL BE
ACROSS FAR NW ZONES WHERE OCCASIONAL SHOWERS WILL CONTINUE...WITH
THESE SHOWERS MOVING BACK TO THE EAST TOWARD DAYBREAK. WARM SECTOR
AIRMASS IN WELL ENTRENCHED WITH TEMPS UPPER 50S TO MID 60S.
ANOMALOUS LOW PRES -4SD LIFTS NE FROM GT LAKES TODAY WITH +3SD LOW
LEVEL JET MOVING ACROSS SNE TODAY. PWAT ANOMALY ALSO +3SD. THIS
WILL RESULT IN A PERIOD OF LOCALLY HEAVY SHOWERS MOVING WEST TO
EAST THIS MORNING INTO THE AFTERNOON ASSOCD WITH IMPRESSIVE LOW
LEVEL MOISTURE TRANSPORT AND RIGHT ENTRANCE REGION OF THE UPPER
JET.
ALSO CONCERNED WITH A POSSIBLE FINE LINE OF CONVECTION ALONG THE
FRONT LATER THIS MORNING PER HRRR SOLUTION. MODELS ARE GENERATING
MARGINAL INSTABILITY WITH SBCAPES 200-400 J/KG SO THIS SCENARIO
SEEMS PLAUSIBLE. LOW RISK OF ISOLD THUNDER AND IF FINE LINE DOES
DEVELOP THIS WOULD ENHANCE THE RISK OF STRONGER WINDS MIXING DOWN
TO THE SURFACE. THE SPEED OF THIS SYSTEM AND MARGINAL INSTABILITY
WILL LIMIT RAINFALL AMOUNTS WITH QPF LESS THAN 0.5" FOR MOST
LOCATIONS...WITH UP TO 1" ACROSS FAR W ZONES. LOCALIZED MINOR
URBAN AND POOR DRAINAGE FLOODING IS POSSIBLE THIS MORNING...MAINLY
IN THE INTERIOR. SHOWERS WILL BE EXITING W ZONES LATE MORNING TO
MIDDAY...AND EARLY AFTERNOON IN THE COASTAL PLAIN. BUT SHOWERS
COULD LINGER THROUGH THE DAY OVER THE OUTER CAPE/ISLANDS AS FRONT
STALLS.
WIND THREAT...CORE OF THE LOW LEVEL JET WILL BE MOVING ACROSS SNE
12-18Z. SOUNDINGS INDICATE VERY SHALLOW PREFRONTAL MIXING BUT
POTENTIAL FOR GUSTS TO 40+ KTS THIS MORNING. HEAVIER SHOWERS AND
POTENTIAL FINE LINE WOULD ALSO AID IN TRANSPORTING STRONGER WINDS
TO THE SURFACE. STRONGEST WINDS WILL LIKELY BE ACROSS PORTIONS
OF RI AND INTERIOR E MA WHERE MILDEST TEMPS INTO THE LOWER 70S
PROMOTE DEEPER MIXING. SOUNDINGS INDICATE THE POTENTIAL FOR
ANOTHER PULSE OF STRONG POST-FRONTAL WINDS TO 40+ KTS THIS
AFTERNOON AS BOUNDARY LAYER MIXING DEEPENS. STRONGEST POST-
FRONTAL WINDS MORE LIKELY ACROSS THE INTERIOR WITH LESS WIND
ALONG THE COAST. WIND ADVISORY WILL CONTINUE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/...
FRONT STALLS NEAR THE COAST TONIGHT AS A WAVE IS FORECAST TO
DEVELOP S OF NEW ENG. THIS WILL KEEP THE THREAT OF SHOWERS GOING
TONIGHT ACROSS SE COASTAL NEW ENG...ESPECIALLY THE OUTER CAPE AND
ISLANDS WHILE DRY CONDITIONS PREVAIL IN THE INTERIOR. AMERICAN
MODELS KEEP MOST OF THE RAIN OFFSHORE WHILE INTERNATIONAL MODELS
BRING A DECENT SLUG OF RAIN TO THE OUTER CAPE/ISLANDS LATE
TONIGHT. WITH FRONT STALLING NEAR THE COAST...WE TRENDED FORECAST
TOWARD WETTER SOLUTION AND HAVE LIKELY POPS TO ACK WITH CHC POPS
TO THE CAPE AND S COASTAL MA. LOW PROB THAT SHOWERS COULD BACK IN
TO THE BOS-PVD CORRIDOR LATE TONIGHT BUT WE KEPT IT DRY FOR NOW.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
HIGHLIGHTS...
* COASTAL LOW DEVELOPS FOR SATURDAY...CLIPPING THE CAPE AND ISLANDS
* COLDER AND BLUSTERY CONDITIONS WILL RETURN ON SUNDAY AND MONDAY
* MODERATING TEMPERATURES AND DRY WEATHER BY MID NEXT WEEK.
* POSSIBLE SYSTEM APPROACHING THURSDAY/FRIDAY
CONFIDENCE LEVEL/MODEL GUIDANCE...
MODERATE CONFIDENCE IN THE OVERALL FORECAST. HAVE HIGH CONFIDENCE IN
THE OVERALL TRENDS YET LOW CONFIDENCE ON EXACT PRECIP TIMING. LONG
WAVE TROUGH IS STILL PROGGED TO IMPACT NEW ENGLAND WITH SEVERAL
SHORTWAVES MOVING THROUGH THE FLOW. THE FIRST ONE IS MOVING THROUGH
TODAY WITH A SECOND SHORTWAVE APPROACHING THE REGION BY TOMORROW.
EXPECT THIS EXPANSIVE NEGATIVE HEIGHT ANOMALY TO INDUCE AN AREA OF
LOW PRESSURE ALONG THE MID-ATLANTIC COAST WHICH WILL SLIDE NORTHWARD
TOWARD THE CANADIAN MARITIMES. 00Z MODEL GUIDANCE ALL AGREE WITH
THIS COASTAL LOW DEVELOPMENT...WHICH COULD BRING MORE SHOWERS ACROSS
THE IMMEDIATE SOUTH COAST...CAPE AND ISLANDS ON SATURDAY. THERE ARE
SOME MODEL DISCREPANCIES ON EXACT PLACEMENT OF THE LOW...WITH THE EC
ON THE FASTER END AND THE GFS ON THE SLOW SIDE. TRENDED IN THE
MIDDLE FOR NOW. FINALLY THE LAST IMPULSE WILL PUSH A STRONG COLD
FRONT THROUGH THE REGION ON SUNDAY DROPPING TEMPS BACK TOWARDS
SEASONABLE. BY EARLY NEXT WEEK MODELS CONCUR WITH A WESTERN TROUGH
TO STRONGLY AMPLIFY RESULTING IN RIDGING TO BUILD OVER THE EASTERN
HALF OF THE U.S. HOWEVER THIS WESTERN TROUGH WILL APPROACH NEW
ENGLAND BY THURSDAY BRINGING ANOTHER ROUND OF RAIN AND WIND. EXACT
TIMING FOR THIS SYSTEM IS STILL UNCERTAIN.
DETAILS...
SATURDAY...
MID-ATLANTIC LOW WILL DEVELOP AND HEAD TOWARDS SOUTHERN NEW ENGLAND
DURING THE MORNING HOURS. AS MENTIONED BEFORE...TRENDED TOWARDS THE
MIDDLE OF THE ROAD COMPARED TO THE GFS AND EC. BELIEVE THERE WILL BE
A SHARP CUT OFF IN TERMS OF WHERE THE RAIN WILL AND WILL NOT FALL.
HAVE THE HIGHEST CONFIDENCE THAT THIS SYSTEM WILL BRING SOME SHOWERS
ACROSS THE IMMEDIATE SOUTH COAST...CAPE AND ISLANDS. HOWEVER WITH
THE ONSHORE FLOW...COULD SEE A SHOWER OR TWO ACROSS THE SOUTHEAST
COASTAL SIDE OF MASSACHUSETTS. THIS COASTAL LOW WILL MOVE UP TO THE
MARITIMES BY THE SATURDAY NIGHT SO CHANCE OF PRECIP WILL WANE BY THE
AFTERNOON HOURS. REGARDLESS SATURDAY WILL STILL BE MILD WITH TEMPS
IN THE 60S AND LESS WINDY. DEFINITELY AN IMPROVEMENT COMPARED TO
TODAY.
SUNDAY...
THE UNSEASONABLE WARM WEATHER WILL COME TO AN END ON SUNDAY AS THE
THIRD AND LAST IMPULSE PUSHES A STRONG COLD FRONT THROUGH THE REGION
BY LATE SATURDAY/EARLY SUNDAY. THIS FRONT WILL HAVE STRONG CAA
BEHIND IT DROPPING TEMPERATURES ACROSS THE REGION CLOSER TO
SEASONABLE. IN FACT 850 MB TEMPS DROP BETWEEN -6 TO -9C RESULTING IN
HIGH TEMPS TO BE BE IN THE MID 40S TO LOW 50S. WITH COASTAL LOW WAY
OUT IN THE MARITIMES AND CANADIAN HIGH BUILDING ACROSS THE NORTH
COUNTRY...DUE NORTH WINDS ARE ANTICIPATED. THESE NORTHERLY WINDS
WILL ALLOW FOR SOME POSSIBLE OCEAN EFFECT SHOWERS TO DEVELOP AND
MOVE ALONG THE EAST COAST LINE AND ACROSS THE CAPE AND ISLANDS. HAVE
KEPT A SLIGHT CHANCE MENTIONED FOR NOW. THESE SHOWERS WILL BE VERY
ISOLATED IN NATURE. ALTHOUGH TEMPS ALOFT ARE DROPPING
QUICKLY...BELIEVE LIQUID PRECIP WILL HOLD OUT AS SURFACE AND BL
TEMPS WILL STILL STAY ABOVE FREEZING.
SUNDAY NIGHT INTO WEDNESDAY....
CANADIAN HIGH PRESSURE WILL BEGIN TO MOVE INTO THE REGION LATE
SUNDAY NIGHT INTO MONDAY...AND BUILD OVER THE NORTHEAST THROUGH AT
LEAST WEDNESDAY. THIS HIGH PRESSURE WILL ALLOW FOR LIGHT WINDS AND
CLEAR SKIES ESP DURING THE OVERNIGHT HOURS. THIS WILL ALLOW FOR
RADIATIONAL COOLING ON SUNDAY NIGHT AND ON MONDAY NIGHT. SUNDAY
NIGHT APPEARS TO BE THE COLDEST WITH TEMPS DROPPING INTO THE MID
TEENS TO MID 20S. MONDAY WILL BE THE COOLEST THE REGION HAS SEEN
IN AWHILE WITH HIGHS BELOW AVERAGE...LOW TO MID 40S.
AN UPPER LEVEL RIDGE WILL BEGIN TO BUILD ACROSS THE EASTERN SEABOARD
RESULTING IN DRY WEATHER AND A WARMING TREND. IN FACT MID 60S RETURN
TO THE FORECAST BY WEDNESDAY AND POSSIBLY ON THURSDAY.
THURSDAY AND BEYOND...
MODELS BEGIN TO DRIVE THE WESTERN TROUGH TOWARDS THE EAST COAST BY
THURSDAY. APPEARS THAT THIS LOW PRESSURE SYSTEM WILL BRING HEAVY
RAIN AS WELL AS STRONG WINDS TO THE REGION BY THURSDAY MORNING
LASTING INTO FRIDAY MORNING. BECAUSE THIS SYSTEM IS SEVERAL DAYS
AWAY...A LOT CAN CHANGE SO STAY TUNED TO THE LATEST FORECAST.
&&
.AVIATION /13Z FRIDAY THROUGH TUESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
9 AM UPDATE...
LINE OF LOW TOP SHOWERS ACROSS EASTERN NY AND WESTERN NJ WILL
WEAKEN AS IT ENTERS NEW ENGLAND. SOUTHERN PORTION OF THE LINE WILL
BE STRONGER ACROSS NYC/LONG ISLAND AND THE NEW ENGLAND COASTAL
WATERS. SSW WINDS GUSTS TO 45 KT INTO THROUGH THIS MORNING...THEN
SHIFT TO WSW THIS AFTERNOON WITH G45KT ESPECIALLY NORTHERN MA INTO
NH. EARLIER DISCUSSION BELOW.
-------------------------------------------------------------------
TODAY...IFR-MVFR WITH A BAND OF LOCALLY HEAVY SHOWERS MOVING
ACROSS THE REGION...EXITING 18-21Z FROM WEST TO EAST WITH
IMPROVING CONDITIONS TO VFR. STRONG S/SW WINDS GUSTING UP TO 40-45
KT RI AND EASTERN MA IN THE MORNING...THEN SHIFTING TO WSW IN THE
AFTERNOON WITH GUSTS 30-40 KT. HIGH CONFIDENCE ON TRENDS.
TONIGHT...LINGERING MVFR/IFR IN OCCASIONAL SHOWERS AT
ACK...POSSIBLY AS FAR N AS CAPE COD. OTHERWISE VFR WITH
DIMINISHING WIND. MODERATE CONFIDENCE.
KBOS TAF...HIGH CONFIDENCE IN TRENDS...LOWER IN EXACT TIMING.
KBDL TAF...HIGH CONFIDENCE IN TRENDS...LOWER IN EXACT TIMING.
OUTLOOK...SATURDAY THROUGH TUESDAY...
SATURDAY...MVFR/IFR CONDITIONS TO START WILL IMPROVE TO VFR FROM
WEST TO EAST.
SUNDAY...VFR. NNW WINDS COULD GUST TO 25 KTS.
MONDAY AND TUESDAY...VFR.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
TODAY...SW GALE FORCE WINDS TO 35-40 KT. SCATTERED HEAVY SHOWERS
EXIT OFFSHORE DURING THE AFTERNOON...HOWEVER MAY LINGER OVER
SOUTHEAST WATERS. HIGH CONFIDENCE.
TONIGHT...DIMINISHING WIND AND SEAS. OCCASIONAL SHOWERS WILL
CONTINUE ACROSS SE WATERS...OTHERWISE MAINLY DRY. MODERATE
CONFIDENCE ON NW EXTENT OF SHOWERS.
OUTLOOK...SATURDAY THROUGH TUESDAY...HIGH CONFIDENCE.
SATURDAY AND SUNDAY...SMALL CRAFT ADVISORIES WILL LIKELY BE
NECESSARY FOR SEAS OVER 5 FEET AND NORTHWESTERLY WINDS GUSTING TO 30
KTS. THERE IS A LOW PROBABILITY THAT NORTH GALES WILL OCCUR ACROSS
THE EASTERN OUTER WATERS ON SUNDAY. VISIBILITIES MAY BE LIMITED IN
INTERMITTENT SHOWERS.
MONDAY AND TUESDAY...WINDS AND SEAS DIMINISH AS HIGH PRESSURE MOVES
OVER SOUTHERN NEW ENGLAND AND OVER THE WATERS. LIGHT NORTHERLY
WINDS SHIFT TO THE EAST AND THEN SOUTH THROUGH THIS TIME PERIOD.
&&
.TIDES/COASTAL FLOODING...
COASTAL FLOODING CONCERNS ALONG THE SOUTH COAST ARE MINIMAL. NOT
MUCH OF A SURGE GIVEN SURFACE LOW AND PRESSURE FALLS ARE TRACKING
SO FAR NORTHWEST OF NEW ENGLAND. WILL HAVE MODEST TO LARGE WAVE
ACTION ON THE SOUTH COAST BUT TIDES WILL NOT BE HIGH ENOUGH TO
WARRANT ANY FLOODING.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WIND ADVISORY UNTIL 6 PM EDT THIS EVENING FOR CTZ002>004.
MA...WIND ADVISORY UNTIL 6 PM EDT THIS EVENING FOR MAZ002>024-026.
NH...WIND ADVISORY UNTIL 6 PM EDT THIS EVENING FOR NHZ011-012-015.
RI...WIND ADVISORY UNTIL 6 PM EDT THIS EVENING FOR RIZ001>008.
MARINE...GALE WARNING UNTIL 6 PM EDT THIS EVENING FOR ANZ230>237-250-
251-254>256.
&&
$$
SYNOPSIS...KJC/DUNTEN
NEAR TERM...NOCERA
SHORT TERM...KJC/DUNTEN
LONG TERM...DUNTEN
AVIATION...KJC/DUNTEN
MARINE...KJC/DUNTEN
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS TAUNTON MA
726 AM EDT FRI NOV 1 2013
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE REGION TODAY AND STALL NEAR
THE COAST TONIGHT AS A WEAK WAVE OF LOW PRESSURE DEVELOPS SOUTH OF
NEW ENGLAND. UNSEASONABLY MILD AND WINDY TODAY WITH A BAND OF
SHOWERS MOVING ACROSS THE REGION. ANOTHER PERIOD OF SHOWERS AFFECT
THE CAPE AND ISLANDS TONIGHT INTO EARLY SATURDAY...THEN COLDER
AND BLUSTERY CONDITIONS ARRIVE FOR SUNDAY INTO EARLY NEXT WEEK.
HIGH PRESSURE BY THE MIDDLE OF THE WEEK WILL ALLOW FOR MODERATING
TEMPERATURES.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
730 AM UPDATE...
OVERALL FORECAST REMAINS ON TRACK FOR THIS MORNING. BULK OF THE
PRECIP CONTINUES TO SIT ACROSS THE BERKSHIRES AND INTO SOUTHERN
NEW HAMPSHIRE. THIS WILL SLOWLY MOVE EASTWARD DURING THE MORNING
HOURS. MAIN CONCERN HOWEVER IS THE FINE LINE OUT ACROSS NY/PA.
HAVE NOT SEEN A LOT OF DAMAGE REPORTS FROM THIS FINE
LINE...HOWEVER WITH TEMPS REACHING INTO THE 70S AHEAD OF THE
FRONT...COULD SEE SOME MIXING OF THE LLJ DOWN TO THE SURFACE. THIS
LLJ IS ALREADY NEARING 55-65 KTS PER LATEST VWP DATA. WITH THAT
BEING SAID...STRONG GUSTS OF 60 MPH CANNOT BE RULED OUT ALLOWING
FOR DOWN TREE LIMBS AND POSSIBLE POWER OUTAGES.
CURRENTLY GUSTS ARE BETWEEN 20-35 KTS AND EXPECT THIS TO CONTINUE
TO INCREASE THROUGH THE MORNING HOURS. THEREFORE CHANGES TO
ONGOING HAZARDS IS NOT NEEDED. PRECIP AT THIS TIME LOOKS TO WANE
BETWEEN 18-21Z ALLOWING FOR THE LATE AFTERNOON TO BE SOMEWHAT
PLEASANT.
PREVIOUS DISCUSSION...
DRY SLOT AND PRECIP LULL LIFTING NWD ACROSS SNE EARLY THIS MORNING
WHICH IS WELL FORECAST BY SHORT RANGE MODEL SUITE INCLUDING HRRR.
EDGE OF THE DRY SLOT WILL BE ACROSS FAR NW ZONES WHERE OCCASIONAL
SHOWERS WILL CONTINUE...WITH THESE SHOWERS MOVING BACK TO THE
EAST TOWARD DAYBREAK. WARM SECTOR AIRMASS IN WELL ENTRENCHED WITH
TEMPS UPPER 50S TO MID 60S.
ANOMALOUS LOW PRES -4SD LIFTS NE FROM GT LAKES TODAY WITH +3SD LOW
LEVEL JET MOVING ACROSS SNE TODAY. PWAT ANOMALY ALSO +3SD. THIS
WILL RESULT IN A PERIOD OF LOCALLY HEAVY SHOWERS MOVING WEST TO
EAST THIS MORNING INTO THE AFTERNOON ASSOCD WITH IMPRESSIVE LOW
LEVEL MOISTURE TRANSPORT AND RIGHT ENTRANCE REGION OF THE UPPER
JET.
ALSO CONCERNED WITH A POSSIBLE FINE LINE OF CONVECTION ALONG THE
FRONT LATER THIS MORNING PER HRRR SOLUTION. MODELS ARE GENERATING
MARGINAL INSTABILITY WITH SBCAPES 200-400 J/KG SO THIS SCENARIO
SEEMS PLAUSIBLE. LOW RISK OF ISOLD THUNDER AND IF FINE LINE DOES
DEVELOP THIS WOULD ENHANCE THE RISK OF STRONGER WINDS MIXING DOWN
TO THE SURFACE. THE SPEED OF THIS SYSTEM AND MARGINAL INSTABILITY
WILL LIMIT RAINFALL AMOUNTS WITH QPF LESS THAN 0.5" FOR MOST
LOCATIONS...WITH UP TO 1" ACROSS FAR W ZONES. LOCALIZED MINOR
URBAN AND POOR DRAINAGE FLOODING IS POSSIBLE THIS MORNING...MAINLY
IN THE INTERIOR. SHOWERS WILL BE EXITING W ZONES LATE MORNING TO
MIDDAY...AND EARLY AFTERNOON IN THE COASTAL PLAIN. BUT SHOWERS
COULD LINGER THROUGH THE DAY OVER THE OUTER CAPE/ISLANDS AS FRONT
STALLS.
WIND THREAT...CORE OF THE LOW LEVEL JET WILL BE MOVING ACROSS SNE
12-18Z. SOUNDINGS INDICATE VERY SHALLOW PREFRONTAL MIXING BUT
POTENTIAL FOR GUSTS TO 40+ KTS THIS MORNING. HEAVIER SHOWERS AND
POTENTIAL FINE LINE WOULD ALSO AID IN TRANSPORTING STRONGER WINDS
TO THE SURFACE. STRONGEST WINDS WILL LIKELY BE ACROSS PORTIONS
OF RI AND INTERIOR E MA WHERE MILDEST TEMPS INTO THE LOWER 70S
PROMOTE DEEPER MIXING. SOUNDINGS INDICATE THE POTENTIAL FOR
ANOTHER PULSE OF STRONG POST-FRONTAL WINDS TO 40+ KTS THIS
AFTERNOON AS BOUNDARY LAYER MIXING DEEPENS. STRONGEST POST-
FRONTAL WINDS MORE LIKELY ACROSS THE INTERIOR WITH LESS WIND
ALONG THE COAST. WIND ADVISORY WILL CONTINUE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/...
FRONT STALLS NEAR THE COAST TONIGHT AS A WAVE IS FORECAST TO
DEVELOP S OF NEW ENG. THIS WILL KEEP THE THREAT OF SHOWERS GOING
TONIGHT ACROSS SE COASTAL NEW ENG...ESPECIALLY THE OUTER CAPE AND
ISLANDS WHILE DRY CONDITIONS PREVAIL IN THE INTERIOR. AMERICAN
MODELS KEEP MOST OF THE RAIN OFFSHORE WHILE INTERNATIONAL MODELS
BRING A DECENT SLUG OF RAIN TO THE OUTER CAPE/ISLANDS LATE
TONIGHT. WITH FRONT STALLING NEAR THE COAST...WE TRENDED FORECAST
TOWARD WETTER SOLUTION AND HAVE LIKELY POPS TO ACK WITH CHC POPS
TO THE CAPE AND S COASTAL MA. LOW PROB THAT SHOWERS COULD BACK IN
TO THE BOS-PVD CORRIDOR LATE TONIGHT BUT WE KEPT IT DRY FOR NOW.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
HIGHLIGHTS...
* COASTAL LOW DEVELOPS FOR SATURDAY...CLIPPING THE CAPE AND ISLANDS
* COLDER AND BLUSTERY CONDITIONS WILL RETURN ON SUNDAY AND MONDAY
* MODERATING TEMPERATURES AND DRY WEATHER BY MID NEXT WEEK.
* POSSIBLE SYSTEM APPROACHING THURSDAY/FRIDAY
CONFIDENCE LEVEL/MODEL GUIDANCE...
MODERATE CONFIDENCE IN THE OVERALL FORECAST. HAVE HIGH CONFIDENCE IN
THE OVERALL TRENDS YET LOW CONFIDENCE ON EXACT PRECIP TIMING. LONG
WAVE TROUGH IS STILL PROGGED TO IMPACT NEW ENGLAND WITH SEVERAL
SHORTWAVES MOVING THROUGH THE FLOW. THE FIRST ONE IS MOVING THROUGH
TODAY WITH A SECOND SHORTWAVE APPROACHING THE REGION BY TOMORROW.
EXPECT THIS EXPANSIVE NEGATIVE HEIGHT ANOMALY TO INDUCE AN AREA OF
LOW PRESSURE ALONG THE MID-ATLANTIC COAST WHICH WILL SLIDE NORTHWARD
TOWARD THE CANADIAN MARITIMES. 00Z MODEL GUIDANCE ALL AGREE WITH
THIS COASTAL LOW DEVELOPMENT...WHICH COULD BRING MORE SHOWERS ACROSS
THE IMMEDIATE SOUTH COAST...CAPE AND ISLANDS ON SATURDAY. THERE ARE
SOME MODEL DISCREPANCIES ON EXACT PLACEMENT OF THE LOW...WITH THE EC
ON THE FASTER END AND THE GFS ON THE SLOW SIDE. TRENDED IN THE
MIDDLE FOR NOW. FINALLY THE LAST IMPULSE WILL PUSH A STRONG COLD
FRONT THROUGH THE REGION ON SUNDAY DROPPING TEMPS BACK TOWARDS
SEASONABLE. BY EARLY NEXT WEEK MODELS CONCUR WITH A WESTERN TROUGH
TO STRONGLY AMPLIFY RESULTING IN RIDGING TO BUILD OVER THE EASTERN
HALF OF THE U.S. HOWEVER THIS WESTERN TROUGH WILL APPROACH NEW
ENGLAND BY THURSDAY BRINGING ANOTHER ROUND OF RAIN AND WIND. EXACT
TIMING FOR THIS SYSTEM IS STILL UNCERTAIN.
DETAILS...
SATURDAY...
MID-ATLANTIC LOW WILL DEVELOP AND HEAD TOWARDS SOUTHERN NEW ENGLAND
DURING THE MORNING HOURS. AS MENTIONED BEFORE...TRENDED TOWARDS THE
MIDDLE OF THE ROAD COMPARED TO THE GFS AND EC. BELIEVE THERE WILL BE
A SHARP CUT OFF IN TERMS OF WHERE THE RAIN WILL AND WILL NOT FALL.
HAVE THE HIGHEST CONFIDENCE THAT THIS SYSTEM WILL BRING SOME SHOWERS
ACROSS THE IMMEDIATE SOUTH COAST...CAPE AND ISLANDS. HOWEVER WITH
THE ONSHORE FLOW...COULD SEE A SHOWER OR TWO ACROSS THE SOUTHEAST
COASTAL SIDE OF MASSACHUSETTS. THIS COASTAL LOW WILL MOVE UP TO THE
MARITIMES BY THE SATURDAY NIGHT SO CHANCE OF PRECIP WILL WANE BY THE
AFTERNOON HOURS. REGARDLESS SATURDAY WILL STILL BE MILD WITH TEMPS
IN THE 60S AND LESS WINDY. DEFINITELY AN IMPROVEMENT COMPARED TO
TODAY.
SUNDAY...
THE UNSEASONABLE WARM WEATHER WILL COME TO AN END ON SUNDAY AS THE
THIRD AND LAST IMPULSE PUSHES A STRONG COLD FRONT THROUGH THE REGION
BY LATE SATURDAY/EARLY SUNDAY. THIS FRONT WILL HAVE STRONG CAA
BEHIND IT DROPPING TEMPERATURES ACROSS THE REGION CLOSER TO
SEASONABLE. IN FACT 850 MB TEMPS DROP BETWEEN -6 TO -9C RESULTING IN
HIGH TEMPS TO BE BE IN THE MID 40S TO LOW 50S. WITH COASTAL LOW WAY
OUT IN THE MARITIMES AND CANADIAN HIGH BUILDING ACROSS THE NORTH
COUNTRY...DUE NORTH WINDS ARE ANTICIPATED. THESE NORTHERLY WINDS
WILL ALLOW FOR SOME POSSIBLE OCEAN EFFECT SHOWERS TO DEVELOP AND
MOVE ALONG THE EAST COAST LINE AND ACROSS THE CAPE AND ISLANDS. HAVE
KEPT A SLIGHT CHANCE MENTIONED FOR NOW. THESE SHOWERS WILL BE VERY
ISOLATED IN NATURE. ALTHOUGH TEMPS ALOFT ARE DROPPING
QUICKLY...BELIEVE LIQUID PRECIP WILL HOLD OUT AS SURFACE AND BL
TEMPS WILL STILL STAY ABOVE FREEZING.
SUNDAY NIGHT INTO WEDNESDAY....
CANADIAN HIGH PRESSURE WILL BEGIN TO MOVE INTO THE REGION LATE
SUNDAY NIGHT INTO MONDAY...AND BUILD OVER THE NORTHEAST THROUGH AT
LEAST WEDNESDAY. THIS HIGH PRESSURE WILL ALLOW FOR LIGHT WINDS AND
CLEAR SKIES ESP DURING THE OVERNIGHT HOURS. THIS WILL ALLOW FOR
RADIATIONAL COOLING ON SUNDAY NIGHT AND ON MONDAY NIGHT. SUNDAY
NIGHT APPEARS TO BE THE COLDEST WITH TEMPS DROPPING INTO THE MID
TEENS TO MID 20S. MONDAY WILL BE THE COOLEST THE REGION HAS SEEN
IN AWHILE WITH HIGHS BELOW AVERAGE...LOW TO MID 40S.
AN UPPER LEVEL RIDGE WILL BEGIN TO BUILD ACROSS THE EASTERN SEABOARD
RESULTING IN DRY WEATHER AND A WARMING TREND. IN FACT MID 60S RETURN
TO THE FORECAST BY WEDNESDAY AND POSSIBLY ON THURSDAY.
THURSDAY AND BEYOND...
MODELS BEGIN TO DRIVE THE WESTERN TROUGH TOWARDS THE EAST COAST BY
THURSDAY. APPEARS THAT THIS LOW PRESSURE SYSTEM WILL BRING HEAVY
RAIN AS WELL AS STRONG WINDS TO THE REGION BY THURSDAY MORNING
LASTING INTO FRIDAY MORNING. BECAUSE THIS SYSTEM IS SEVERAL DAYS
AWAY...A LOT CAN CHANGE SO STAY TUNED TO THE LATEST FORECAST.
&&
.AVIATION /11Z FRIDAY THROUGH TUESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
TODAY...IFR-MVFR WITH A BAND OF LOCALLY HEAVY SHOWERS MOVING
ACROSS THE REGION...EXITING 18-21Z FROM WEST TO EAST WITH
IMPROVING CONDITIONS TO VFR. STRONG S/SW WINDS GUSTING UP TO
40-45 KT RI AND EASTERN MA IN THE MORNING...THEN SHIFTING TO WSW
IN THE AFTERNOON WITH GUSTS 30-40 KT. HIGH CONFIDENCE ON TRENDS.
TONIGHT...LINGERING MVFR/IFR IN OCCASIONAL SHOWERS AT
ACK...POSSIBLY AS FAR N AS CAPE COD. OTHERWISE VFR WITH
DIMINISHING WIND. MODERATE CONFIDENCE.
KBOS TAF...HIGH CONFIDENCE IN TRENDS...LOWER IN EXACT TIMING.
KBDL TAF...HIGH CONFIDENCE IN TRENDS...LOWER IN EXACT TIMING.
OUTLOOK...SATURDAY THROUGH TUESDAY...
SATURDAY...MVFR/IFR CONDITIONS TO START WILL IMPROVE TO VFR FROM
WEST TO EAST.
SUNDAY...VFR. NNW WINDS COULD GUST TO 25 KTS.
MONDAY AND TUESDAY...VFR.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
TODAY...SW GALE FORCE WINDS TO 35-40 KT. SCATTERED HEAVY SHOWERS
EXIT OFFSHORE DURING THE AFTERNOON...HOWEVER MAY LINGER OVER
SOUTHEAST WATERS. HIGH CONFIDENCE.
TONIGHT...DIMINISHING WIND AND SEAS. OCCASIONAL SHOWERS WILL
CONTINUE ACROSS SE WATERS...OTHERWISE MAINLY DRY. MODERATE
CONFIDENCE ON NW EXTENT OF SHOWERS.
OUTLOOK...SATURDAY THROUGH TUESDAY...HIGH CONFIDENCE.
SATURDAY AND SUNDAY...SMALL CRAFT ADVISORIES WILL LIKELY BE
NECESSARY FOR SEAS OVER 5 FEET AND NORTHWESTERLY WINDS GUSTING TO 30
KTS. THERE IS A LOW PROBABILITY THAT NORTH GALES WILL OCCUR ACROSS
THE EASTERN OUTER WATERS ON SUNDAY. VISIBILITIES MAY BE LIMITED IN
INTERMITTENT SHOWERS.
MONDAY AND TUESDAY...WINDS AND SEAS DIMINISH AS HIGH PRESSURE MOVES
OVER SOUTHERN NEW ENGLAND AND OVER THE WATERS. LIGHT NORTHERLY
WINDS SHIFT TO THE EAST AND THEN SOUTH THROUGH THIS TIME PERIOD.
&&
.TIDES/COASTAL FLOODING...
COASTAL FLOODING CONCERNS ALONG THE SOUTH COAST ARE MINIMAL. NOT
MUCH OF A SURGE GIVEN SURFACE LOW AND PRESSURE FALLS ARE TRACKING
SO FAR NORTHWEST OF NEW ENGLAND. WILL HAVE MODEST TO LARGE WAVE
ACTION ON THE SOUTH COAST BUT TIDES WILL NOT BE HIGH ENOUGH TO
WARRANT ANY FLOODING.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WIND ADVISORY UNTIL 6 PM EDT THIS EVENING FOR CTZ002>004.
MA...WIND ADVISORY UNTIL 6 PM EDT THIS EVENING FOR MAZ002>024-026.
NH...WIND ADVISORY UNTIL 6 PM EDT THIS EVENING FOR NHZ011-012-015.
RI...WIND ADVISORY UNTIL 6 PM EDT THIS EVENING FOR RIZ001>008.
MARINE...GALE WARNING UNTIL 6 PM EDT THIS EVENING FOR ANZ230>237-250-
251-254>256.
&&
$$
SYNOPSIS...KJC/DUNTEN
NEAR TERM...KJC/DUNTEN
SHORT TERM...KJC/DUNTEN
LONG TERM...DUNTEN
AVIATION...KJC/DUNTEN
MARINE...KJC/DUNTEN
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1203 PM EDT FRI NOV 1 2013
.SYNOPSIS...
DEEP SOUTHWEST FLOW AHEAD OF AN APPROACHING COLD FRONT WILL RESULT
IN SHOWERS THIS AFTERNOON INTO THE EVENING. IT WILL BE BREEZY
AHEAD OF THE FRONT. DRYING WILL OCCUR BEHIND THE COLD FRONT
OVERNIGHT. HIGH PRESSURE BEHIND THE FRONT WILL DOMINATE SATURDAY
INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
MOISTURE WILL CONTINUE TO INCREASE THIS AFTERNOON AHEAD OF THE
APPROACHING COLD FRONT. SHOWER COVERAGE WAS SCATTERED AT MIDDAY.
THE HRRR INDICATES COVERAGE WILL BECOME WIDESPREAD BETWEEN 300 PM
AND 500 PM POSSIBLY IN RESPONSE TO A MID-LEVEL SHORTWAVE TROUGH.
WE PLAN TO CONTINUE THE CATEGORICAL POPS. CLOUDINESS AND
WIDESPREAD SHOWERS WILL LIMIT INSTABILITY BUT DAMAGING WIND GUSTS
COULD POSSIBLY OCCUR BECAUSE OF STRONG WIND SHEAR. THE KCAE VAD
WIND PROFILE INDICATED WINDS OF 40 KNOTS AT 2000 FEET AND 50 KNOTS
AT 3000 FEET. SOME OF THIS WIND COULD POSSIBLY MIX DOWN IN HEAVIER
SHOWERS. CLOUDINESS AND SHOWERS SHOULD HELP HOLD DOWN
TEMPERATURES. WE USED THE COOLER TEMPERATURE GUIDANCE.
IT WILL BE BREEZY TODAY BUT WITH LIMITED INSTABILITY BELIEVE
WINDS WILL BE GENERALLY JUST BELOW THE LAKE WIND ADVISORY
CRITERIA.
CONVERGENCE ASSOCIATED WITH THE FRONT WILL LIKELY RESULT IN
WIDESPREAD SHOWER COVERAGE THIS EVENING. THE HRRR INDICATES
WIDESPREAD COVERAGE AT 800 PM WITH SHOWERS SHIFTING MAINLY EAST OF
THE AREA BY 1000 PM. STRONG WIND SHEAR WILL SUPPORT A CONTINUED
THREAT OF DAMAGING WIND BUT THE THREAT WILL BE LIMITED BY A LACK
OF SIGNIFICANT INSTABILITY. THE COLD FRONT WILL PUSH EAST OF THE
FORECAST AREA AROUND MIDNIGHT. DRIER AND COOLER AIR WILL FOLLOW
THE FRONT. USED THE GUIDANCE CONSENSUS FOR THE LOW TEMPERATURE
FORECAST.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
THE COLD FRONT WILL BE OFF THE COAST BY SUNRISE SATURDAY. SURFACE
HIGH PRESSURE OVER THE CENTRAL CONUS SATURDAY WILL BUILD EASTWARD
ACROSS THE AREA THROUGH EARLY NEXT WEEK. DRY WEATHER IS IN STORE
FOR THE WEEKEND INTO EARLY NEXT WEEK. AN UPPER-LEVEL TROUGH
CROSSING THE EASTERN STATES WILL BRING COOLER TEMPERATURES. NEAR
NORMAL TEMPERATURES IN THE LOWER TO MIDDLE 70S SATURDAY WILL COOL
INTO THE 60S SUNDAY AND MONDAY. OVERNIGHT LOWS WILL BE IN THE
UPPER 30S AND 40S.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
UPPER-LEVEL RIDGING WILL TAKE HOLD ACROSS THE REGION BY THE
MIDDLE OF NEXT WEEK...BRINGING MILDER TEMPERATURES. SURFACE HIGH
PRESSURE ANCHORED OFF THE NEW ENGLAND COAST WILL RIDGE INTO THE
CAROLINAS AND GEORGIA...PROVIDING AN ONSHORE FLOW. THIS FLOW WILL
BRING INCREASING MOISTURE WEDNESDAY. THE MOISTURE MAY BECOME DEEP
AHEAD OF A COLD FRONT THURSDAY. THE ECMWF WAS CLOSER WITH THE
FRONTAL TIMING LATE IN THE PERIOD. WE LEANED TOWARD THE ECMWF AND
EKD MOS POPS WHICH WERE CLOSE TO THE GFS ENSEMBLE MEANS.
&&
.AVIATION /16Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS CONTINUE ACROSS THE AREA THIS MORNING WITH THE
REGIONAL SATELLITE SHOWING MAINLY MID/HIGH LEVEL CLOUDS. INCREASING
LOW LEVEL MOISTURE AND A DEVELOPING LOW LEVEL JET THIS MORNING WILL
BEGIN BRINGING SOME LOWER LEVEL MOISTURE BACK INTO THE REGION AHEAD
OF THE APPROACHING COLD FRONT. GUIDANCE INDICATING THE ONSET OF THE
LOWER MVFR/IFR CEILINGS TOWARD LATE MORNING AND INTO THE EARLY
AFTERNOON. MODERATE CONFIDENCE REGARDING THE DEVELOPMENT OF LOWER
CIGS. REGIONAL 88D COMPOSITE SHOWS SOME LIGHT SHOWERS/SPRINKLES
MOVING ACROSS THE CWA THIS MORNING WITH A BAND OF HEAVIER SHOWERS
BACK NEAR THE FRONT ACROSS NW GA INTO ERN TN.
THE MODELS ARE IN PRETTY GOOD AGREEMENT WITH THE PROGRESS OF THE
COLD FRONT TODAY. AS THE FRONT APPROACHES...SHOWER ACTIVITY WILL BE
THE PRIMARY RAIN FEATURE. CAN NOT RULE OUT AN ISOLATED
THUNDERSTORM...BUT WITH LOW CONFIDENCE IN TS WILL NOT INCLUDED
MENTION IN THE TAFS AT THIS TIME. THE TIMING OF THE RAIN LOOKS TO
BE AROUND 14-16Z ACROSS THE WESTERN MIDLANDS/CSRA THEN MOVING
EASTWARD TO CENTRAL MIDLANDS NEAR 18Z AND THE EASTERN MIDLANDS/PEE
DEE AROUND 22-24Z. EXPECT A PERIOD OF MVFR CONDITIONS WITH PASSAGE
OF PRECIPITATION. WINDS WILL BE FROM THE SOUTH TODAY FROM 10 TO 15
KTS WITH GUSTS UP TO 20 TO 25 KTS. AFTER THAT TIME...THINK RISK OF
STORMS WILL GREATLY DIMINISH WITH SHOWERS ENDING FROM WEST TO EAST
FROM 22Z THROUGH 02Z. EXPECT SOME CLEARING ACROSS THE AREA AFTER
MIDNIGHT AS MUCH DRIER AIR MOVES INTO THE REGION AND SURFACE WINDS
BECOME WEST/WEST NORTHWEST.
EXTENDED AVIATION OUTLOOK...BREEZY CONDITIONS POSSIBLE SATURDAY.
OTHERWISE...VFR CONDITIONS EXPECTED THROUGH TUESDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1038 AM EDT FRI NOV 1 2013
.SYNOPSIS...
DEEP SOUTHWEST FLOW AHEAD OF AN APPROACHING COLD FRONT WILL RESULT
IN SHOWERS THIS AFTERNOON INTO THE EVENING. IT WILL BE BREEZY
AHEAD OF THE FRONT. DRYING WILL OCCUR BEHIND THE COLD FRONT
OVERNIGHT. HIGH PRESSURE BEHIND THE FRONT WILL DOMINATE SATURDAY
INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
MOISTURE WILL CONTINUE TO INCREASE TODAY AHEAD OF THE APPROACHING
COLD FRONT. SHOWER COVERAGE WAS SCATTERED LATE THIS MORNING. THE
HRRR INDICATES COVERAGE WILL BECOME WIDESPREAD BETWEEN 300 PM AND
500 PM POSSIBLY IN RESPONSE TO A MID-LEVEL SHORTWAVE TROUGH. WE
PLAN TO CONTINUE THE CATEGORICAL POPS. CLOUDINESS AND WIDESPREAD
SHOWERS WILL LIMIT INSTABILITY BUT DAMAGING WIND GUSTS COULD
POSSIBLY OCCUR BECAUSE OF STRONG WIND SHEAR. THE KCAE VAD WIND
PROFILE INDICATED WINDS OF 40 KNOTS AT 2000 FEET AND 50 KNOTS AT
3000 FEET. SOME OF THIS WIND COULD POSSIBLY MIX DOWN IN HEAVIER
SHOWERS. CLOUDINESS AND SHOWERS SHOULD HELP HOLD DOWN
TEMPERATURES. WE USED THE COOLER TEMPERATURE GUIDANCE.
IT WILL BE BREEZY TODAY BUT WITH LIMITED INSTABILITY BELIEVE
WINDS WILL BE GENERALLY JUST BELOW THE LAKE WIND ADVISORY
CRITERIA.
CONVERGENCE ASSOCIATED WITH THE FRONT WILL LIKELY RESULT IN
WIDESPREAD SHOWER COVERAGE THIS EVENING. THE HRRR INDICATES
WIDESPREAD COVERAGE AT 800 PM WITH SHOWERS SHIFTING MAINLY EAST OF
THE AREA BY 1000 PM. STRONG WIND SHEAR WILL SUPPORT A CONTINUED
THREAT OF DAMAGING WIND BUT THE THREAT WILL BE LIMITED BY A LACK
OF SIGNIFICANT INSTABILITY. THE COLD FRONT WILL PUSH EAST OF THE
FORECAST AREA AROUND MIDNIGHT. DRIER AND COOLER AIR WILL FOLLOW
THE FRONT. USED THE GUIDANCE CONSENSUS FOR THE LOW TEMPERATURE
FORECAST.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
THE COLD FRONT WILL BE OFF THE COAST BY SUNRISE SATURDAY. SURFACE
HIGH PRESSURE OVER THE CENTRAL CONUS SATURDAY WILL BUILD EASTWARD
ACROSS THE AREA THROUGH EARLY NEXT WEEK. DRY WEATHER IS IN STORE
FOR THE WEEKEND INTO EARLY NEXT WEEK. AN UPPER-LEVEL TROUGH
CROSSING THE EASTERN STATES WILL BRING COOLER TEMPERATURES. NEAR
NORMAL TEMPERATURES IN THE LOWER TO MIDDLE 70S SATURDAY WILL COOL
INTO THE 60S SUNDAY AND MONDAY. OVERNIGHT LOWS WILL BE IN THE
UPPER 30S AND 40S.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
UPPER-LEVEL RIDGING WILL TAKE HOLD ACROSS THE REGION BY THE
MIDDLE OF NEXT WEEK...BRINGING MILDER TEMPERATURES. SURFACE HIGH
PRESSURE ANCHORED OFF THE NEW ENGLAND COAST WILL RIDGE INTO THE
CAROLINAS AND GEORGIA...PROVIDING AN ONSHORE FLOW. THIS FLOW WILL
BRING INCREASING MOISTURE WEDNESDAY. THE MOISTURE MAY BECOME DEEP
AHEAD OF A COLD FRONT THURSDAY. THE ECMWF WAS CLOSER WITH THE
FRONTAL TIMING LATE IN THE PERIOD. WE LEANED TOWARD THE ECMWF AND
EKD MOS POPS WHICH WERE CLOSE TO THE GFS ENSEMBLE MEANS.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS CONTINUE ACROSS THE AREA THIS MORNING WITH THE
REGIONAL SATELLITE SHOWING MAINLY MID/HIGH LEVEL CLOUDS. INCREASING
LOW LEVEL MOISTURE AND A DEVELOPING LOW LEVEL JET THIS MORNING WILL
BEGIN BRINGING SOME LOWER LEVEL MOISTURE BACK INTO THE REGION AHEAD
OF THE APPROACHING COLD FRONT. GUIDANCE INDICATING THE ONSET OF THE
LOWER MVFR/IFR CEILINGS TOWARD LATE MORNING AND INTO THE EARLY
AFTERNOON. MODERATE CONFIDENCE REGARDING THE DEVELOPMENT OF LOWER
CIGS. REGIONAL 88D COMPOSITE SHOWS SOME LIGHT SHOWERS/SPRINKLES
MOVING ACROSS THE CWA THIS MORNING WITH A BAND OF HEAVIER SHOWERS
BACK NEAR THE FRONT ACROSS NW GA INTO ERN TN.
THE MODELS ARE IN PRETTY GOOD AGREEMENT WITH THE PROGRESS OF THE
COLD FRONT TODAY. AS THE FRONT APPROACHES...SHOWER ACTIVITY WILL BE
THE PRIMARY RAIN FEATURE. CAN NOT RULE OUT AN ISOLATED
THUNDERSTORM...BUT WITH LOW CONFIDENCE IN TS WILL NOT INCLUDED
MENTION IN THE TAFS AT THIS TIME. THE TIMING OF THE RAIN LOOKS TO
BE AROUND 14-16Z ACROSS THE WESTERN MIDLANDS/CSRA THEN MOVING
EASTWARD TO CENTRAL MIDLANDS NEAR 18Z AND THE EASTERN MIDLANDS/PEE
DEE AROUND 22-24Z. EXPECT A PERIOD OF MVFR CONDITIONS WITH PASSAGE
OF PRECIPITATION. WINDS WILL BE FROM THE SOUTH TODAY FROM 10 TO 15
KTS WITH GUSTS UP TO 20 TO 25 KTS. AFTER THAT TIME...THINK RISK OF
STORMS WILL GREATLY DIMINISH WITH SHOWERS ENDING FROM WEST TO EAST
FROM 22Z THROUGH 02Z. EXPECT SOME CLEARING ACROSS THE AREA AFTER
MIDNIGHT AS MUCH DRIER AIR MOVES INTO THE REGION AND SURFACE WINDS
BECOME WEST/WEST NORTHWEST.
EXTENDED AVIATION OUTLOOK...BREEZY CONDITIONS POSSIBLE SATURDAY.
OTHERWISE...VFR CONDITIONS EXPECTED THROUGH TUESDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
956 AM EDT FRI NOV 1 2013
.SYNOPSIS...
DEEP SOUTHWEST FLOW AHEAD OF AN APPROACHING COLD FRONT WILL SPREAD
SHOWERS AND BREEZY CONDITIONS ACROSS THE AREA TODAY. THE FRONT
WILL CROSS THE AREA TONIGHT. DRY HIGH PRESSURE RETURNS FOR SATURDAY
INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
A COLD FRONT WAS APPROACHING THE FORECAST AREA FROM THE WEST THIS
MORNING. MOISTURE CONTINUES TO INCREASE IN DEEP SOUTHWEST FLOW
AHEAD OF THE FRONT. PRE-FRONTAL SHOWERS OVER THE PIEDMONT ARE
EXPECTED TO SPREAD EAST INTO THE MIDLANDS AND CSRA THIS MORNING
OR EARLY THIS AFTERNOON. THE HRRR SHOWS SHOWER COVERAGE INCREASING
ESPECIALLY TOWARD 5 PM.
A 120-KNOT UPPER-LEVEL JETLET WILL PROVIDE UPPER DIVERGENCE AHEAD
OF THE ADVANCING COLD FRONT. THE DIVERGENCE COMBINED WITH 2+
INCHES OF PWAT AND A 50-KNOT H85 JET PROVIDE HIGH CONFIDENCE FOR
SHOWERS TODAY INTO THIS EVENING. CLOUDINESS AND RAIN SHOULD LIMIT
INSTABILITY. THE NAM INDICATES SURFACE-BASED LI/S LOWERING TO
AROUND -2 MAINLY ACROSS THE EASTERN MIDLANDS. SHEAR WILL BE HIGH.
ANY THUNDERSTORMS COULD CONTAIN DAMAGING WIND BECAUSE OF THE SHEAR
ALTHOUGH A LACK OF SIGNIFICANT INSTABILITY SHOULD BE A LIMITING
FACTOR. THE DEEPEST MOISTURE AND STRONGEST INSTABILITY APPEARS TO
OCCUR DURING THE 16Z TO 00Z TIME FRAME. THE NAM...GFS...AND SREF
MEAN INDICATE RAIN AMOUNTS AROUND 1 INCH AND THIS APPEARS
POSSIBLE BASED ON THE STRONG H85 JET AND PRECIPITABLE WATER PLUS
THE HRRR DISPLAY OF SHOWER COVERAGE INCREASING LATER TODAY.
THE COLD FRONT WILL PUSH EAST OF THE MIDLANDS AND CSRA AFTER
MIDNIGHT...WITH DRIER AND COOL AIR FILTERING IN FROM THE WEST.
CLOUDS AND SHOWERS SHOULD LIMIT HIGH TEMPERATURES TO THE LOWER OR
MIDDLE 70S WEST TO AROUND 80 EAST. WE USED THE COOLER TEMPERATURE
GUIDANCE. USED THE GUIDANCE CONSENSUS FOR TONIGHT/S TEMPERATURE
FORECAST.
IT WILL BE BREEZY BUT WITH LIMITED INSTABILITY BELIEVE WINDS WILL BE
GENERALLY JUST BELOW THE LAKE WIND ADVISORY CRITERIA.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
THE COLD FRONT WILL BE OFF THE COAST BY SUNRISE SATURDAY. SURFACE
HIGH PRESSURE OVER THE CENTRAL CONUS SATURDAY WILL BUILD EASTWARD
ACROSS THE AREA THROUGH EARLY NEXT WEEK. DRY WEATHER IS IN STORE
FOR THE WEEKEND INTO EARLY NEXT WEEK. AN UPPER-LEVEL TROUGH
CROSSING THE EASTERN STATES WILL BRING COOLER TEMPERATURES. NEAR
NORMAL TEMPERATURES IN THE LOWER TO MIDDLE 70S SATURDAY WILL COOL
INTO THE 60S SUNDAY AND MONDAY. OVERNIGHT LOWS WILL BE IN THE
UPPER 30S AND 40S.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
UPPER-LEVEL RIDGING WILL TAKE HOLD ACROSS THE REGION BY THE
MIDDLE OF NEXT WEEK...BRINGING MILDER TEMPERATURES. SURFACE HIGH
PRESSURE ANCHORED OFF THE NEW ENGLAND COAST WILL RIDGE INTO THE
CAROLINAS AND GEORGIA...PROVIDING AN ONSHORE FLOW. THIS FLOW WILL
BRING INCREASING MOISTURE WEDNESDAY. THE MOISTURE MAY BECOME DEEP
AHEAD OF A COLD FRONT THURSDAY. THE ECMWF WAS CLOSER WITH THE
FRONTAL TIMING LATE IN THE PERIOD. WE LEANED TOWARD THE ECMWF AND
EKD MOS POPS WHICH WERE CLOSE TO THE GFS ENSEMBLE MEANS.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS CONTINUE ACROSS THE AREA THIS MORNING WITH THE
REGIONAL SATELLITE SHOWING MAINLY MID/HIGH LEVEL CLOUDS. INCREASING
LOW LEVEL MOISTURE AND A DEVELOPING LOW LEVEL JET THIS MORNING WILL
BEGIN BRINGING SOME LOWER LEVEL MOISTURE BACK INTO THE REGION AHEAD
OF THE APPROACHING COLD FRONT. GUIDANCE INDICATING THE ONSET OF THE
LOWER MVFR/IFR CEILINGS TOWARD LATE MORNING AND INTO THE EARLY
AFTERNOON. MODERATE CONFIDENCE REGARDING THE DEVELOPMENT OF LOWER
CIGS. REGIONAL 88D COMPOSITE SHOWS SOME LIGHT SHOWERS/SPRINKLES
MOVING ACROSS THE CWA THIS MORNING WITH A BAND OF HEAVIER SHOWERS
BACK NEAR THE FRONT ACROSS NW GA INTO ERN TN.
THE MODELS ARE IN PRETTY GOOD AGREEMENT WITH THE PROGRESS OF THE
COLD FRONT TODAY. AS THE FRONT APPROACHES...SHOWER ACTIVITY WILL BE
THE PRIMARY RAIN FEATURE. CAN NOT RULE OUT AN ISOLATED
THUNDERSTORM...BUT WITH LOW CONFIDENCE IN TS WILL NOT INCLUDED
MENTION IN THE TAFS AT THIS TIME. THE TIMING OF THE RAIN LOOKS TO
BE AROUND 14-16Z ACROSS THE WESTERN MIDLANDS/CSRA THEN MOVING
EASTWARD TO CENTRAL MIDLANDS NEAR 18Z AND THE EASTERN MIDLANDS/PEE
DEE AROUND 22-24Z. EXPECT A PERIOD OF MVFR CONDITIONS WITH PASSAGE
OF PRECIPITATION. WINDS WILL BE FROM THE SOUTH TODAY FROM 10 TO 15
KTS WITH GUSTS UP TO 20 TO 25 KTS. AFTER THAT TIME...THINK RISK OF
STORMS WILL GREATLY DIMINISH WITH SHOWERS ENDING FROM WEST TO EAST
FROM 22Z THROUGH 02Z. EXPECT SOME CLEARING ACROSS THE AREA AFTER
MIDNIGHT AS MUCH DRIER AIR MOVES INTO THE REGION AND SURFACE WINDS
BECOME WEST/WEST NORTHWEST.
EXTENDED AVIATION OUTLOOK...BREEZY CONDITIONS POSSIBLE SATURDAY.
OTHERWISE...VFR CONDITIONS EXPECTED THROUGH TUESDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
852 AM EDT FRI NOV 1 2013
.SYNOPSIS...
DEEP SOUTHWEST FLOW AHEAD OF AN APPROACHING COLD FRONT WILL SPREAD
SHOWERS AND BREEZY CONDITIONS ACROSS THE AREA TODAY. THE FRONT
WILL CROSS THE AREA TONIGHT. DRY HIGH PRESSURE RETURNS FOR THE
SATURDAY INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
A COLD FRONT WAS APPROACHING THE FORECAST AREA FROM THE WEST THIS
MORNING. MOISTURE CONTINUES TO INCREASE IN DEEP SOUTHWEST FLOW
AHEAD OF THE FRONT. PRE-FRONTAL SHOWERS OVER THE PIEDMONT ARE
EXPECTED TO SPREAD EAST INTO THE MIDLANDS AND CSRA THIS MORNING
OR EARLY THIS AFTERNOON. THE HRRR SHOWS SHOWER COVERAGE INCREASING
ESPECIALLY TOWARD 5 PM.
A 120-KNOT UPPER-LEVEL JETLET WILL PROVIDE UPPER DIVERGENCE AHEAD
OF THE ADVANCING COLD FRONT. THE DIVERGENCE COMBINED WITH 2+
INCHES OF PWAT AND A 50-KNOT H85 JET PROVIDE HIGH CONFIDENCE FOR
SHOWERS TODAY INTO THIS EVENING. CLOUDINESS AND RAIN SHOULD LIMIT
INSTABILITY. THE NAM INDICATES SURFACE-BASED LI/S LOWERING TO
AROUND -2 MAINLY ACROSS THE EASTERN MIDLANDS. SHEAR WILL BE HIGH.
ANY THUNDERSTORMS COULD CONTAIN DAMAGING WIND BECAUSE OF THE SHEAR
ALTHOUGH A LACK OF SIGNIFICANT INSTABILITY SHOULD BE A LIMITING
FACTOR. THE DEEPEST MOISTURE AND STRONGEST INSTABILITY APPEARS TO
OCCUR DURING THE 16Z TO 00Z TIME FRAME. THE NAM...GFS...AND SREF
MEAN INDICATE RAIN AMOUNTS AROUND 1 INCH AND THIS APPEARS
POSSIBLE BASED ON THE STRONG H85 JET AND PRECIPITABLE WATER PLUS
THE HRRR DISPLAY OF SHOWER COVERAGE INCREASING LATER TODAY.
THE COLD FRONT WILL PUSH EAST OF THE MIDLANDS AND CSRA AFTER
MIDNIGHT...WITH DRIER AND COOL AIR FILTERING IN FROM THE WEST.
CLOUDS AND SHOWERS SHOULD LIMIT HIGH TEMPERATURES TO THE LOWER OR
MIDDLE 70S WEST TO AROUND 80 EAST. WE USED THE COOLER TEMPERATURE
GUIDANCE. USED THE GUIDANCE CONSENSUS FOR TONIGHT/S TEMPERATURE
FORECAST.
IT WILL BE BREEZY BUT WITH LIMITED INSTABILITY BELIEVE WINDS WILL BE
GENERALLY JUST BELOW THE LAKE WIND ADVISORY CRITERIA.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
THE COLD FRONT WILL BE OFF THE COAST BY SUNRISE SATURDAY. SURFACE
HIGH PRESSURE OVER THE CENTRAL CONUS SATURDAY WILL BUILD EASTWARD
ACROSS THE AREA THROUGH EARLY NEXT WEEK. DRY WEATHER IS IN STORE
FOR THE WEEKEND INTO EARLY NEXT WEEK. AN UPPER-LEVEL TROUGH
CROSSING THE EASTERN STATES WILL BRING COOLER TEMPERATURES. NEAR
NORMAL TEMPERATURES IN THE LOWER TO MIDDLE 70S SATURDAY WILL COOL
INTO THE 60S SUNDAY AND MONDAY. OVERNIGHT LOWS WILL BE IN THE
UPPER 30S AND 40S.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
UPPER-LEVEL RIDGING WILL TAKE HOLD ACROSS THE REGION BY THE
MIDDLE OF NEXT WEEK...BRINGING MILDER TEMPERATURES. SURFACE HIGH
PRESSURE ANCHORED OFF THE NEW ENGLAND COAST WILL RIDGE INTO THE
CAROLINAS AND GEORGIA...PROVIDING AN ONSHORE FLOW. THIS FLOW WILL
BRING INCREASING MOISTURE WEDNESDAY. THE MOISTURE MAY BECOME DEEP
AHEAD OF A COLD FRONT THURSDAY. THE ECMWF WAS CLOSER WITH THE
FRONTAL TIMING LATE IN THE PERIOD. WE LEANED TOWARD THE ECMWF AND
EKD MOS POPS WHICH WERE CLOSE TO THE GFS ENSEMBLE MEANS.
&&
.AVIATION /13Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS CONTINUE ACROSS THE AREA THIS MORNING WITH THE
REGIONAL SATELLITE SHOWING MAINLY MID/HIGH LEVEL CLOUDS. INCREASING
LOW LEVEL MOISTURE AND A DEVELOPING LOW LEVEL JET THIS MORNING WILL
BEGIN BRINGING SOME LOWER LEVEL MOISTURE BACK INTO THE REGION AHEAD
OF THE APPROACHING COLD FRONT. GUIDANCE INDICATING THE ONSET OF THE
LOWER MVFR/IFR CEILINGS TOWARD LATE MORNING AND INTO THE EARLY
AFTERNOON. MODERATE CONFIDENCE REGARDING THE DEVELOPMENT OF LOWER
CIGS. REGIONAL 88D COMPOSITE SHOWS SOME LIGHT SHOWERS/SPRINKLES
MOVING ACROSS THE CWA THIS MORNING WITH A BAND OF HEAVIER SHOWERS
BACK NEAR THE FRONT ACROSS NW GA INTO ERN TN.
THE MODELS ARE IN PRETTY GOOD AGREEMENT WITH THE PROGRESS OF THE
COLD FRONT TODAY. AS THE FRONT APPROACHES...SHOWER ACTIVITY WILL BE
THE PRIMARY RAIN FEATURE. CAN NOT RULE OUT AN ISOLATED
THUNDERSTORM...BUT WITH LOW CONFIDENCE IN TS WILL NOT INCLUDED
MENTION IN THE TAFS AT THIS TIME. THE TIMING OF THE RAIN LOOKS TO
BE AROUND 14-16Z ACROSS THE WESTERN MIDLANDS/CSRA THEN MOVING
EASTWARD TO CENTRAL MIDLANDS NEAR 18Z AND THE EASTERN MIDLANDS/PEE
DEE AROUND 22-24Z. EXPECT A PERIOD OF MVFR CONDITIONS WITH PASSAGE
OF PRECIPITATION. WINDS WILL BE FROM THE SOUTH TODAY FROM 10 TO 15
KTS WITH GUSTS UP TO 20 TO 25 KTS. AFTER THAT TIME...THINK RISK OF
STORMS WILL GREATLY DIMINISH WITH SHOWERS ENDING FROM WEST TO EAST
FROM 22Z THROUGH 02Z. EXPECT SOME CLEARING ACROSS THE AREA AFTER
MIDNIGHT AS MUCH DRIER AIR MOVES INTO THE REGION AND SURFACE WINDS
BECOME WEST/WEST NORTHWEST.
EXTENDED AVIATION OUTLOOK...BREEZY CONDITIONS POSSIBLE SATURDAY.
OTHERWISE...VFR CONDITIONS EXPECTED THROUGH TUESDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
Area Forecast Discussion
National Weather Service Lincoln IL
1020 AM CDT Fri Nov 1 2013
.DISCUSSION...
ISSUED 1020 AM CDT Fri Nov 1 2013
Southern edge of stratocumulus roughly along a Macomb to Paris
line late this morning. This has not made a lot of southward
progress over the last few hours, but morning model guidance
continues to show a southern nudge through the afternoon as a
weak trough drops southward through Wisconsin. Updated zones/grids
were sent to make some adjustments for the cloud trends for
today. Temperatures and winds were largely on track and only
required minor tweaks.
Geelhart
&&
.AVIATION...
ISSUED 659 AM CDT Fri Nov 1 2013
West to northwest flow will persist across the central Illinois
terminals today in the wake of yesterday`s cold front. A period of
gusty winds is expected for much of the daytime hours today due to
a moderately strong pressure gradient lingering in the area, as
will as enhanced diurnal mixing.
Wrap around moisture will produce cigs across much of the area
today, with period of MVFR or even IFR likely this morning though
most of the terminals. Cigs will rise with time today, with VFR
cigs expected to develop area wide by tonight.
Bak
&&
.PREV DISCUSSION...
ISSUED 303 AM CDT Fri Nov 1 2013
SHORT TERM...Today through Sunday
Northwesterly upper flow pattern will keep plenty of cloud cover
in place across at least the northern half of the KILX CWA today.
07z/2am satellite imagery shows overcast conditions upstream over
much of Iowa, with satellite timing tools generally keeping the
clouds along/north of the I-74 corridor as they work eastward this
morning. Further south, mostly clear skies will be noted along and
south of a Springfield to Paris line initially: however, cooling
aloft will create fairly steep lapse rates and additional diurnal
cloud development. CU rule remains most negative across the
northern CWA, but still suggests SCT-BKN cloud cover even across
the south. End result will be mostly cloudy skies north and partly
sunny conditions far south. Short-wave trough currently evident on
water vapor imagery over eastern Montana will drop southeastward
later today into tonight. Weak lift ahead of this feature may
trigger a few sprinkles late this afternoon, particularly across
the northern CWA. Based on latest HRRR and 4km WRF-NMM, have
included scattered sprinkles for locations north of Peoria late
this afternoon. Despite weak lift ahead of the approaching wave,
forecast soundings remain too dry to support measurable precip
through tonight.
Cool/dry weather will be the rule through the weekend, as high
pressure builds into the region. High temperatures will only be in
the 50s both Saturday and Sunday, while lows dip into the lower to
middle 30s by Sunday morning.
LONG TERM...Monday through Thursday
Challenges in the extended continue to focus on strength of
building upper ridge over the southeast CONUS and timing of
approaching short-wave next week. Previous runs of the ECMWF had
featured an unseasonably strong 594dm 500mb high developing over
the Carolinas by Monday/Tuesday. This strong ridge essentially
slowed the eastward progress of an upper short-wave over the
Plains, resulting in an extended period of rain chances across
central Illinois from Tuesday through Thursday. Meanwhile, both
the GFS and GEM were slightly weaker with the high and thus
brought the Plains wave and associated cold front eastward a bit
faster. 00z Nov 1 run of the ECMWF has now come into much better
agreement with the GFS/GEM, leading to increased confidence in a
more progressive pattern next week. As such, will continue to
focus highest PoPs during the Tuesday night/Wednesday time frame
when strongest lift and deepest moisture will be present. Have
opted to go with a dry forecast for Thursday, as all model
guidance pushes front east of the region.
Barnes
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
712 AM CDT FRI NOV 1 2013
.DISCUSSION...
312 AM CDT
PRIMARY FORECAST CHALLENGES THIS MORNING INCLUDE CLOUD COVER AND ITS
EFFECT ON TEMPS THE NEXT COUPLE DAYS...SHOWER CHANCES LATER THIS
AFTERNOON AND EVENING...FOLLOWED BY WHAT LOOKS TO BE A POSSIBLE
REPEAT OF THIS WEEK`S EVENTS NEXT WEEK!
AFTER DEEPENING 15MB IN THE PAST 12 HOURS THE POWERHOUSE AUTUMN
STORM CONTINUES TO SLOWLY DEEPEN AS IT LIFTS NORTHEAST OUT OF THE
REGION. RAIN HAS ENDED BUT GUSTY WEST WINDS ARE USHERING IN A
STARKLY DIFFERENT AIR MASS COMPARED WITH 24 HOURS AGO WITH 24
TEMP/TD CHANGES OF 20-25F. COMBINATION OF COLD AIR STRATOCUMULUS
WRAPPING AROUND THE SYSTEM INTO THE AREA AND CONTINUATION OF WEAK
COLD AIR ADVECTION THROUGH THE DAY SHOULD ALLOW VERY LITTLE TEMP
RECOVERY AND HAVE UNDERCUT GUIDANCE FOR HIGHS TODAY...MAINLY
NORTHERN CWA WHERE PROSPECTS FOR SUNSHINE ARE DIMMER (PARDON THE
PUN).
WATER VAPOR IMAGERY SHOWS A PAIR OF WELL DEFINED SHORTWAVE TROUGHS
OVER EASTERN NEBRASKA AND WESTERN NEBRASKA EARLY THIS MORNING.
MODELS BRING BOTH OF THESE WAVES EASTWARD INTO OUR AREA THIS
AFTERNOON AND EVENING. WHILE CLOUD COVER WILL LIMIT SFC HEATING
TODAY...MUCH COLDER MID LEVEL TEMPS WILL ADVECT INTO THE AREA WITH
THESE SECONDARY WAVES WHICH WILL STEEPEN THE LOW AND MID LEVEL LAPSE
RATES. THE STEEP LAPSE RATES AND LARGE SCALE ASCENT WITH THE
APPROACHING WAVES SHOULD ALLOW FOR SCATTERED SHOWERS TO MOVE ACROSS
THE CWA LATER THIS AFTERNOON INTO THE EVENING...ESPECIALLY NORTHERN
HALF OF THE CWA. FREEZING LEVELS DROP TO JUST OVER 3K FT AGL AND
GIVEN THE CONVECTIVE NATURE OF THE SHOWERS IT WOULDNT BE SURPRISED
TO SEE A FEW GRAUPEL REPORTS LATER TODAY INTO EARLY THIS EVENING
BEFORE SHORTWAVE RIDGING RESULTS IN DECREASING SHOWER CHANCES
OVERNIGHT.
CYCLONIC LOW LEVEL FLOW AND FRONTAL INVERSION LIKELY TO RESULT IN
STRATUS HANGING AROUND TONIGHT INTO SATURDAY AND POSSIBLY INTO PART
OF SATURDAY NIGHT BEFORE FLOW BECOMES MORE ANTICYCLONIC AS WAA
BEGINS. THE EXTENSIVE CLOUD COVER TODAY THROUGH SATURDAY SHOULD
RESULT IN SMALL DIURNAL TEMP SWING AND HAVE GONE BELOW GUIDANCE FOR
HIGHS TODAY AND SATURDAY AND ABOVE GUIDANCE FOR LOW TEMPS TONIGHT.
ASSUMING STRATUS FINALLY CLEARS SAT NIGHT HAVE ALLOWED FOR A HEALTHY
DROP IN TEMPS WITH CLEARING SKIES AND LIGHT WINDS.
SUNDAY INTO MONDAY WILL MARK A TRANSITION PERIOD AS LONG WAVE TROUGH
MOVES OUT OF THE AREA AND IS REPLACED BY LONGWAVE RIDGING IN ADVANCE
OF THE NEXT SIGNIFICANT TROUGH DIGGING INTO THE WEST. INITIALLY WARM
AIR ADVECTION WILL BE MOST PRONOUNCED ALOFT SUNDAY BUT SOUTHEAST
WINDS AND MORE SUNSHINE SHOULD STILL ALLOW TEMPS TO WARM A
COUPLE/FEW DEGREES OVER SATURDAY. FURTHER WARMING IS EXPECTED MONDAY
AS SOUTHERLY WINDS RAMP UP...THOUGH INCREASING MID-HIGH LEVEL CLOUDS
COULD FILTER SUNSHINE AND TEMPER THE WARM UP A BIT.
NEXT SIGNIFICANT LONG WAVE TROUGH WILL BEGIN TO AFFECT THE REGION
TUESDAY AND ESPECIALLY TUESDAY NIGHT INTO WEDNESDAY. SUSPECT THE
SYSTEM COULD SLOW SOMEWHAT FROM WHAT CURRENT GUIDANCE IS
SHOWING...MUCH LIKE HAPPENED WITH THIS WEEK`S SYSTEM. STILL LOOK FOR
GRADUALLY INCREASING RAIN CHANCES TUESDAY...BUT THE BEST RAIN BET
APPEARS TO BE TUESDAY NIGHT INTO WEDNESDAY MORNING. PWATS ONCE AGAIN
ARE PROGGED TO CLIMB TO WELL OVER AN INCH...OR OVER 200% OF NORMAL
WITH SOME GUIDANCE EVEN SUGGESTING THAT SOME OF THE MID-UPPER LEVEL
MOISTURE FROM 18E OVER THE TROPICAL EASTERN PACIFIC POSSIBLY GETTING
ENTANGLED INTO THIS SYSTEM...SO ONCE AGAIN WE WILL NEED TO WATCH OUT
FOR A POSSIBILITY OF A HEALTHY RAIN EVENT.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* CEILING HEIGHTS.
* WIND GUSTS.
* PERIOD OF LIGHT SHOWERS LATE AFTERNOON INTO EARLY EVENING.
TRS
//DISCUSSION...UPDATED 12Z...
THE UPPER LOW CONTINUES TO PULL AWAY TO THE NE FROM THE UPPER
GREAT LAKES THOUGH A STRONG JET DROPPING SE FROM B.C. AND
SOUTHERN ALBERTA OVER THE NORTHERN HIGH PLAINS AND TO THE CENTRAL
PLAINS WILL SHARPEN THE UPPER TROUGH OVER THE CENTRAL U.S. WITHIN
THIS NW FLOW ARE MULTIPLE SHORT WAVES THE FIRST OF WHICH IS
TURNING MORE TO THE E OVER IA AND NORTHERN MO AS IT NEARS THE
BASE OF THE UPPER TROUGH.
THIS SHORT WAVE IS PROGGED TO ZIP ACROSS THE LOCAL AREA MIDDAY.
THERE SHOULD NOT BE ANY PRECIP OF NOTE FROM THIS DISTURBANCE AS
FORECAST SOUNDINGS SOME MOISTENING OF MID LEVELS THERE IS STILL A
SIGNIFICANT LAYER OF DRY AIR FROM AROUND 6K FT AGL UP.
MODELS BRING THE NEXT SHORT WAVE ACROSS THE AREA DURING THE LATE
AFTERNOON AND EARLY EVENING WITH THE INITIALLY DRY MID LEVELS
NEARING SATURATION 22Z-00Z. MODELS ALSO GENERATE SOME PRECIP
AMOUNTS WITH THIS DISTURBANCE. EXPECT WETTING SHOWERS DURING THE
LATE AFTERNOON INTO EARLY EVENING BUT COVERAGE EXPECTED TO BE
SOMEWHAT LIMITED SO HAVE ONLY WENT FROM PROB30 TO VCSH FOR 12Z
SET OF TAFS.
WITH THE UPPER LOW AND ITS ASSOCIATED SURFACE LOW MOVING FURTHER
AWAY FROM THE AREA WITH TIME THOUGH STRONG HIGH PRESSURE WILL BE
GRADUALLY BUILDING INTO THE HIGH PLAINS SO A MODERATE FLOW SHOULD
PERSIST TODAY. WIND DIRECTION IS EXPECTED TO REMAIN BASICALLY W
THOUGH SUSPECT THERE WILL BE A LITTLE BACKING AS EACH SHORT WAVE
APPROACHES FOLLOWED BY A LITTLE VEERING AS EACH PASSES BY.
OVERALL...WINDS WILL BE BETWEEN WSW AND WNW.
ALTHOUGH THERE ARE AREAS OF MVFR CEILINGS OVER PARTS OF THE
REGION HIGH RESOLUTION ARW MODEL SHOWS A GRADUAL LIFTING OF THE
CLOUD BASES SO HAVE LEFT PREVAILING VFR IN THE FORECAST UNTIL THE
SHOWERS MOVE INTO THE AREA LATE AFTERNOON WHEN EXPECT CEILINGS TO
LOWER BACK INTO MVFR RANGE.
TRS
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* HIGH CONFIDENCE WINDS...MEDIUM CONFIDENCE ALL OTHER ELEMENTS.
TRS
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT...VF
SUNDAY...VFR
MONDAY...VFR
TUESDAY...CHANCE OF SHOWERS.
WEDNESDAY...MVFR. RAIN LIKELY.
THURSDAY...VFR.
&&
.MARINE...
344 AM CDT
GALES ON LAKE MI WILL QUICKLY DIMINISH TODAY AS LOW PRESSURE MOVES
RAPIDLY FROM THE NORTH CHANNEL OF LAKE SUPERIOR TO QUEBEC BY THIS
AFTERNOON. W PRESSURE OF 28.9 INCHES OVER THE NORTH CHANNEL OF
LAKE SUPERIOR WILL MOVE QUICKLY NORTHEAST TO LABRADOR BY THIS
EVENING. WINDS WILL DIMINISH FURTHER DURING LATER SAT THROUGH EARLY
SUN MORNING AS A RIDGE OF HIGH PRESSURE MOVES E ACROSS THE LAKE.
WINDS WILL BE FRESHENING OUT THE SE LATE SUN AND SUN NIGHT AS THE
HIGH STRENGTHENS AS IT MOVES OFF TO THE E AND LOW PRESSURE MOVES E
INTO THE PLAINS.
THE GALE WARNING HAS BEEN ALLOWED TO CONTINUE UNTIL 9AM CDT THIS
A.M. THOUGH SUSTAINED SPEEDS ON THE N PORTION OF LAKE MI SHOULD BE
BELOW GALES WITH ONLY SOME LOW END GALE FORCE GUSTS THROUGH THE
EARLY MORNING.
SMALL CRAFT ADVISORIES FOR THE IL AND IN NEARSHORE WATERS WILL
LIKELY NEED TO CONTINUE FOR A FEW HOURS INTO THE LATER MORNING
UNTIL WINDS DROP OFF. WITH W WINDS BEHIND LAST NIGHT/S COLD FRONT
WAVES DID NOT BUILD GREATLY IN THE NEARSHORE WATERS...ESPECIALLY
ALONG THE IL SHORE
TRS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 9 AM FRIDAY.
SMALL CRAFT ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN UNTIL NOON FRIDAY.
SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO GARY IN UNTIL 9 AM
FRIDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
National Weather Service Lincoln IL
700 AM CDT Fri Nov 1 2013
.DISCUSSION...
ISSUED 303 AM CDT Fri Nov 1 2013
SHORT TERM...Today through Sunday
Northwesterly upper flow pattern will keep plenty of cloud cover
in place across at least the northern half of the KILX CWA today.
07z/2am satellite imagery shows overcast conditions upstream over
much of Iowa, with satellite timing tools generally keeping the
clouds along/north of the I-74 corridor as they work eastward this
morning. Further south, mostly clear skies will be noted along and
south of a Springfield to Paris line initially: however, cooling
aloft will create fairly steep lapse rates and additional diurnal
cloud development. CU rule remains most negative across the
northern CWA, but still suggests SCT-BKN cloud cover even across
the south. End result will be mostly cloudy skies north and partly
sunny conditions far south. Short-wave trough currently evident on
water vapor imagery over eastern Montana will drop southeastward
later today into tonight. Weak lift ahead of this feature may
trigger a few sprinkles late this afternoon, particularly across
the northern CWA. Based on latest HRRR and 4km WRF-NMM, have
included scattered sprinkles for locations north of Peoria late
this afternoon. Despite weak lift ahead of the approaching wave,
forecast soundings remain too dry to support measurable precip
through tonight.
Cool/dry weather will be the rule through the weekend, as high
pressure builds into the region. High temperatures will only be in
the 50s both Saturday and Sunday, while lows dip into the lower to
middle 30s by Sunday morning.
LONG TERM...Monday through Thursday
Challenges in the extended continue to focus on strength of
building upper ridge over the southeast CONUS and timing of
approaching short-wave next week. Previous runs of the ECMWF had
featured an unseasonably strong 594dm 500mb high developing over
the Carolinas by Monday/Tuesday. This strong ridge essentially
slowed the eastward progress of an upper short-wave over the
Plains, resulting in an extended period of rain chances across
central Illinois from Tuesday through Thursday. Meanwhile, both
the GFS and GEM were slightly weaker with the high and thus
brought the Plains wave and associated cold front eastward a bit
faster. 00z Nov 1 run of the ECMWF has now come into much better
agreement with the GFS/GEM, leading to increased confidence in a
more progressive pattern next week. As such, will continue to
focus highest POPs during the Tuesday night/Wednesday time frame
when strongest lift and deepest moisture will be present. Have
opted to go with a dry forecast for Thursday, as all model
guidance pushes front east of the region.
Barnes
&&
.AVIATION...
ISSUED 659 AM CDT Fri Nov 1 2013
West to northwest flow will persist across the central Illinois
terminals today in the wake of yesterday`s cold front. A period of
gusty winds is expected for much of the daytime hours today due to
a moderately strong pressure gradient lingering in the area, as
will as enhanced diurnal mixing.
Wrap around moisture will produce cigs across much of the area
today, with period of MVFR or even IFR likely this morning though
most of the terminals. Cigs will rise with time today, with VFR
cigs expected to develop areawide by tonight.
Bak
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
613 AM CDT FRI NOV 1 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 349 AM CDT FRI NOV 1 2013
DEPARTING STORM SYSTEM THAT AFFECTED THE MIDWEST OVER THE PAST TWO
DAYS WILL KEEP RESIDUAL MOISTURE IN WC WI THRU NOON ALONG WITH
OCCASIONAL SPRINKLES/DRIZZLE. ELSEWHERE...A SHRTWV MOVING SE ACROSS
THE WESTERN DAKOTAS WILL ENHANCE THE OVERALL LIFT ACROSS WC/SW/SC MN
DURING THE DAY. HOWEVER...THE MAIN ENERGY WILL HOLD IN THE EASTERN
DAKOTAS AND KEPT THE BULK OF THE MEASURABLE PRECIPITATION IN THIS
REGION. CHC POPS REMAIN REASONABLE IN THE FAR SW 1/3 OF THE CWA DUE
TO SOME UNCERTAINTY WITH LIFT. ELSEWHERE...MEASURABLE PRECIPITATION
IS NOT LIKELY BUT AN OCCASIONAL SPRINKLES OR LIGHT SHOWER IS
POSSIBLE. THIS SYSTEM WILL DEPART THE REGION BY LATE
TONIGHT...ENDING ANY CHC/S OF PRECIPITATION UNTIL MONDAY.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 349 AM CDT FRI NOV 1 2013
RIDGING WILL EXPAND EASTWARD ACROSS THE PLAINS SATURDAY AND INTO
THE UPPER MISSISSIPPI VALLEY SUNDAY. NORTHWEST WINDS WON/T
CONTRIBUTE TO TOO MUCH WARMING SATURDAY...BUT AS LOW PRESSURE
DEVELOPS OVER THE NORTHERN PLAINS WINDS WILL BECOME SOUTHEASTERLY
AND STRENGTHEN MARKEDLY. IT WON/T BE UNTIL ABOUT MIDDAY WHEN THE
BOUNDARY LAYER BECOMES FULLY MIXED AND GUSTS OF 30 TO 40 MPH ARE
POSSIBLE ACROSS MN. MIXING SHOULD EXTEND UP TO 850 MB WHERE TEMPS
SHOULD BE +4 OR +5C BRINGING HIGHS WELL INTO THE 50S AND POSSIBLY
LOWER 60S IN THE MN RIVER VALLEY. AFTER SOME STABILIZING OF THE
BOUNDARY LAYER OCCURS FOLLOWING SUNSET...WINDS OF 50 TO 60 KT
WILL DEVELOP BETWEEN 2-3KFT. THUS...30-40 MPH GUSTS COULD EXTEND
INTO THE EVENING. MODELS APPEAR TOO COOL SUNDAY NIGHT WITH SUCH A
WIND REGIME. MOST AREAS SHOULD STAY IN THE LOW OR MID 40S.
THE PLAINS LOW WILL LIFT NORTH INTO MANITOBA MONDAY WITH A
TRAILING COLD FRONT BRINGING A FEW SHOWERS TO THE REGION. OVERALL
NOT TOO IMPRESSED WITH THIS FIRST ROUND SO KEPT POPS LOW. ANOTHER
DISTURBANCE DIGGING INTO THE SOUTHWESTERN U.S. IS WHAT WILL BRING
THE BIGGEST LONG TERM HEADACHE...SNOW POTENTIAL ON TUESDAY AND
TUESDAY NIGHT. MODELS APPEAR TO BE MUCH MORE IN LINE WITH ONE
ANOTHER WITH THE EVOLUTION OF THIS SYSTEM...BUT KEY QUESTIONS
REMAIN. LOW PRESSURE DEVELOPING OVER NORTHEAST NEW MEXICO OR THE
TEXAS PANHANDLE WILL LIFT NORTHEAST INTO THE MID MISSOURI VALLEY
TUESDAY AFTERNOON AND TO WISCONSIN BY EARLY WEDNESDAY MORNING.
DEEP MOISTURE WILL SURGE NORTH FROM THE EASTERN PACIFIC AND THE
GULF OF MEXICO. PW VALUES BETWEEN 200-250 PERCENT OF NORMAL
PUSH INTO MISSOURI AND IOWA TUESDAY AFTERNOON. WITH 50-60 KT
UPGLIDE WINDS ON THE 295K ISENTROPIC SURFACE...THINK MDT-HVY
PRECIPITATION WILL RAPIDLY DEVELOP EARLY TUESDAY ON THE CENTRAL
PLAINS AND RACE NORTHWARD INTO THE MISSOURI AND MISSISSIPPI
VALLEYS BY AFTERNOON. AS THIS PRECIPITATION ENCOUNTERS DRIER AIR
IN OUR NECK OF THE WOODS...SOME DYNAMICAL COOLING CAN BE EXPECTED
BUT WET BULB TEMPERATURES ABOVE FREEZING MAY KEEP MUCH OF IT RAIN.
RAW MODEL 2M TEMPS FALL INTO THE MID 30S DURING THE AFTERNOON AND
I CANNOT REALLY ARGUE AGAINST THIS. AS THE LOW TRACKS SOUTHEAST OF
THE AREA...STRONGER CAA WILL BEGIN AND PRECIP WILL GRADUALLY TURN
TO SNOW TUESDAY EVENING FROM WEST TO EAST. HOW MUCH PRECIP
REMAINS AFTER THIS TRANSITION IS THE BIGGEST QUESTION AND THE
LARGEST DRIVER OF POTENTIAL ACCUMULATIONS. THE BEST POTENTIAL FOR
ACCUMULATING SNOW CURRENTLY LIES ALONG AN AXIS FROM SOUTHWEST MN
THROUGH CENTRAL AND NORTHEAST MN. WILL HIGHLIGHT THIS POTENTIAL IN
THE HWO.
NORTHWEST FLOW FOLLOWS FOR THE REST OF THE WEEK WITH ANOTHER
TROUGH DIGGING DOWN THE WEST COAST. TEMPS LOOK SEASONAL WITH DRY
CONDITIONS EXPECTED.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 558 AM CDT FRI NOV 1 2013
RESIDUAL MOISTURE BLW 2K ACROSS WC WI WILL SLOWLY MOVE SE OUT OF
THIS REGION BY MID/LATE MORNING. CIGS SHOULD BEGIN TO LIFT TO MVFR
AT KEAU BY 14-16Z...THEN VFR AFT 18Z. KRNH REMAINS PROBLEMATIC...BUT
CIGS SHOULD LIFT TO VFR BY 12-1230Z.
UPSTREAM MVFR/IFR CIGS ACROSS N/NE MN SHOULD MOVE NE OF MPX TAF
SITES IN WI TODAY...BUT CONFIDENCE REMAINS LOW. THE NEXT SHRTWV
DIVING SE ACROSS NORTHERN ND WILL EXPAND AN AREA OF LOW END VFR OR
HIGH END MVFR CIGS ACROSS THE EASTERN DAKOTAS THIS MORNING...AND
POSSIBLY AFFECTING KAXN/KRWF BY 18Z. STILL BELIEVE THE BULK OF THE
MOISTURE BLW 3K WILL HOLD IN EASTERN SD. LATEST RAP DOES SUPPORT
THIS AREA OF LOWER CIGS EXPANDING EASTWARD ACROSS WESTERN MN AFT
18Z. ELSEWHERE...CIGS SHOULD REMAIN VFR THRU THE TAF PERIOD. ONLY
ISOLD SHRA WILL BE POSSIBLE...AND NOTHING TOO HEAVY TO LOWER
VSBYS. WINDS WILL REMAIN FROM THE WNW/NW TODAY AND TONIGHT...WITH
A FEW GUSTS IN THE UPPER TEENS/LOWER 20S THIS AFTN.
KMSP...
VFR CIGS SHOULD PREVAIL DURING THIS TAF PERIOD. HAVE SOME CONCERNS
WITH LOWER CIGS ACROSS N/NE MN MOVING SOUTHWARD THIS MORNING...BUT
AS THE MAIN LOW MOVES NE INTO SOUTHEAST CANADA...THE BULK OF THIS
MOISTURE SHOULD HOLD OFF TO THE NE. CONFIDENCE REMAINS HIGH FOR
VFR CIGS TODAY. THE SHRTWV ACROSS ND SHOULD NOT AFFECT KMSP TAF
SITE AS IT MOVES SW OF THE REGION. WINDS WILL BE GENERALLY FROM
THE WNW EARLY THIS MORNING...BECOMING MORE NW/NNW THIS
AFTN/TONIGHT. A FEW GUSTS UP TO 20 KTS IS POSSIBLE THIS AFTN.
/OUTLOOK FOR KMSP/
SAT...VFR. WINDS NW 10-15 KT.
SUN...VFR. WINDS SE 10-20 KT.
MON...VFR. MVFR CIGS IN -SHRA. WINDS S 15-20G30 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...JLT
LONG TERM...BORGHOFF
AVIATION...JLT
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1030 AM EDT FRI NOV 1 2013
.SYNOPSIS...
A STRONG COLD FRONT APPROACHING FROM THE WEST WILL MOVE ACROSS THE
AREA SATURDAY MORNING. IT WILL BECOME WINDY AHEAD OF THIS FRONT WITH
A HIGH RISK FOR SHOWERS AND POSSIBLY A THUNDERSTORM. SIGNIFICANT
RAINFALL IS POSSIBLE. HIGH PRESSURE WILL FOLLOW LATE SATURDAY
THROUGH SUNDAY BRINGING WITH IT COLDER AND DRIER CONDITIONS. HIGH
PRESSURE WILL PERSIST THROUGH THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM FRIDAY...FORECAST STILL APPEARS TO BE IN GOOD SHAPE.
STILL AWAITING SOME OF THE HIGHER RES HRRR AND RUC FOR ANY POSSIBLE
TWEAKS IN TIMING...BUT THEY SHOULD BE MINOR...IF ANY. 12Z RAOBS FROM
CHS AND MHX STILL SHOW A FAIR AMOUNT OF SUBSIDENCE IN THE 850-700MB
LAYER. THIS WILL ACT TO INHIBIT ANYTHING OTHER THAN FAIRLY
INSIGNIFICANT RADAR ECHOES UNTIL THIS EVENINGS STRONG FORCING
ARRIVES. CONCUR WITH SWODY1 THAT A SLIGHT RISK-WORTHY AREA OF
ORGANIZED SEVERE IS POSSIBLE SOMEWHERE SOUTHEAST/MIDATLANTIC AND
SOME TIME WILL TELL WHAT PARTS OF THE CWA WILL QUALIFY. INITIAL
SUSPICION IS THAT MOST OF THE AREA MAY SEE HIGHER WIND AND TOR
PROBS LATER ON WITH COASTAL AREAS SLIGHTLY MORE FAVORABLE FOR
SEVERE. ROUGHLY 40 OF THE 60 KNOTS OF DEEP LAYER SHEAR CURRENTLY
OBSERVED ACROSS THE REGION LIES IN THE LOWEST 1KM. SETUP APPEARS
FAVORABLE FOR A SLOWLY EASTWARD PROPAGATING SQUALL LINE READILY
CAPABLE OF WIND DAMAGE DUE TO THE STRENGTH OF THE LOW LEVEL WIND
FIELDS. QUICK TORNADO SPINUPS ALSO SEEM POSSIBLE ALONG ANY
BOUNDARIES OR STORM SCALE INTERACTIONS. PREVIOUS FOLLOWS...
AS OF 700 AM FRIDAY...STRONG SURFACE LOW PRESSURE IN THE GREAT LAKES
IS ASSOCIATED WITH AN ENERGETIC UPPER LEVEL SYSTEM LIFTING NORTHEAST
ACROSS INTO SOUTHERN ONTARIO. A SURFACE COLD FRONT EXTENDING SOUTH
OF THE LOW IS NOW ENTERING THE SOUTHERN AND CENTRAL APPALACHIANS.
TROPICAL MOISTURE IS PRESENT WITH PRECIPITABLE WATER VALUES EXPECTED
TO EXCEED 2.0 INCHES BY THIS EVENING JUST AHEAD OF THE FRONT. TO PUT
THAT IN PERSPECTIVE...2.0 INCHES IS THE 99TH PERCENTILE FOR NOVEMBER
PRECIP WATER AT CHS...AND COULD BE A RECORD NOVEMBER PW VALUE AT MHX.
THE FRONT WILL MAKE STEADY EASTWARD PROGRESS...AND THE BAND OF
SHOWERS AND EMBEDDED T-STORMS SHOULD SLIDE INTO THE CENTRAL
CAROLINAS THIS AFTERNOON. MY FORECAST POPS ALONG AND WEST OF
INTERSTATE 95 ARE IN THE 60-90 PERCENT RANGE BY LATE AFTERNOON...
WITH THE MOST SUBSTANTIAL COVERAGE OF PRECIPITATION EXPECTED ALONG
THE COAST AFTER DARK WHERE MY POPS ARE 80-90 PERCENT. STORM TOTAL
RAINFALL COULD EXCEED 1 INCH...WITH HEAVIER AMOUNTS POSSIBLE
IF/WHERE CONVECTIVE TRAINING OCCURS. COMPARED TO MY THOUGHTS BASED
ON THE 00Z MODELS...THE 06Z MODELS PLUS THE LATEST SREF SLOWS THE
WHOLE SYSTEM DOWN BY A FEW HOURS.
RADAR VERTICAL WIND PROFILES ARE CONFIRMING MODEL FORECASTS OF A
HEALTHY LOW LEVEL JET BLOWING OVERHEAD CURRENTLY. WINDS AT 1000 FT
AGL ARE AROUND 30 KNOTS WITH 40 KNOTS MEASURED AT 2000 FT. AS THE
BOUNDARY LAYER DEEPENS LATER THIS MORNING WITH RISING
TEMPERATURES...EXPECT STRONGER WINDS TO MIX DOWN WITH 30-35 MPH
GUSTS EXPECTED BY 10-11 AM. HELICITY (0-1 KM) SHOULD RANGE FROM
150-200 WITH 0-6 KM BULK SHEAR 40-50 KT. THESE VALUES ARE ALSO
SUPPORTIVE OF A SEVERE WEATHER THREAT. THE LIMITING FACTOR COULD END
UP BEING INSTABILITY: FORECAST CAPE VALUES ONLY RANGE FROM 200-400
J/KG WITH PERHAPS SOME 700 J/KG NUMBERS SHOWING UP THIS EVENING
ALONG THE COAST IF DEWPOINTS CAN HOLD IN THE UPPER 60S TO NEAR 70.
THE STORM PREDICTION CENTER CURRENTLY HAS A "SEE TEXT" 5 PERCENT
PROBABILITY FOR DAMAGING WIND GUSTS AND 2 PERCENT TORNADO RISK IN
THE CAROLINAS.
TEMPERATURES TODAY SHOULD BE VERY WARM BY NOVEMBER STANDARDS...
COURTESY OF TROPICAL AIR ADVECTED NORTHWARD AHEAD OF THE FRONT. 850
MB TEMPS EXPECTED TO RISE TO +15C ARE IN THE 95-98TH PERCENTILE FOR
NOVEMBER. TEMPERATURES SHOULD LEAP WITH THE FIRST TOUCH OF SUNLIGHT
THIS MORNING...AND HIGHS SHOULD REACH 80-82 DEGREES FOR AREAS EAST
OF INTERSTATE 95 AND A FEW MILES INLAND FROM THE BEACHES. THE FRONT
WILL MOVE ACROSS THE AREA LATE TONIGHT WITH COLD ADVECTION NOT
REACHING THE COAST UNTIL JUST A FEW HOURS BEFORE DAYBREAK. THERE IS
SOME UNCERTAINTY WITH TONIGHT`S LOW TEMPERATURES SINCE WEAKER WINDS
BEHIND THE FRONT COULD ALLOW FOR BOUNDARY LAYER DECOUPLING JUST
BEFORE SUNRISE...BUT IT APPEARS LOWS SHOULD RANGE FROM THE MID 60S
ON THE COAST TO THE UPPER 50S INLAND.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 330 AM FRIDAY...COLD FRONT WILL BE MAKING ITS WAY OFF SHORE
SAT MORNING. DRY AND COOLER AIR WILL BEGIN TO FEED INTO AREA
BEHIND THE FRONT BUT DEEP NW FLOW WITH GREATEST CAA WILL COME LATER
ON SAT AS MID TO UPPER TROUGH FINALLY SWINGS THROUGH. MAY SEE SOME
CLOUDS WITH ITS PASSAGE BUT THINK MOST CLOUDS AND ANY CHC OF A
SPRINKLE WILL REMAIN TO THE NORTH WHERE BETTER SHORTWAVE ENERGY
WILL BE.
AFTER A WARM START TO THE DAY ON SAT...TEMPS WILL REACH INTO THE 70S
AS SKIES CLEAR FROM WEST TO EAST THROUGH THE DAY. 850 TEMPS
PLUMMET THROUGH SAT INTO SUNDAY MORNING DROPPING DOWN TO 2 TO 3C
BY SUN. DEWPOINT TEMPS WILL DROP OUT AS WELL WITH READING IN THE
LOWER 30S BY MON MORNING. EXPECT TEMPS TO DROP A GOOD 10 DEGREES
SAT NIGHT FROM PREVIOUS MIN TEMPS AND THEN AN ADDITIONAL DROP SUN
NIGHT IN BETTER RADIATIONAL COOLING WITH READINGS RIGHT AROUND 40
MOST PLACES.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 3 PM THURSDAY...STRONG HIGH PRESSURE WILL RIDGE DOWN INTO
THE SOUTHEAST AS IT SHIFTS EAST THROUGH THE WEEK. AFTER A COLD
START MONDAY TEMPS WILL ONLY RECOVER TO AROUND 60 DEGREES IN COOL
NORTHERLY FLOW. AS THE HIGH SHIFTS EAST FURTHER OFF THE NEW
ENGLAND COAST THROUGH MID WEEK...A MOIST ON SHORE FLOW WILL
DEVELOP. A WEDGE LIKE PATTERN WILL SET UP WITH POTENTIAL FOR LOW
CLOUDS AND SPOTTY DRIZZLE OR SPRINKLES AS EARLY AS MONDAY NIGHT
AND POSSIBLY LASTING FOR A FEW DAYS BEFORE A COLD FRONT MAKES ITS
WAY ACROSS THE CAROLINAS BY THURS. EXPECT INCREASED CHC OF PCP ON
THURS AHEAD OF THIS COLD FRONT.
MONDAY WILL BE THE COOLEST DAY BUT WILL MODIFY SLOWLY THROUGH
MID WEEK. BUILDING RIDGE ALOFT WITH RISING H5 HEIGHTS WILL HELP TO
BRING TEMPS BACK UP ABOVE NORMAL BY WEDNESDAY. HIGHS WILL MAINLY
BE IN THE 60S THROUGH TUES AND WILL REACH BACK INTO THE 70S ON
WED. A WARMER AND MORE HUMID SOUTHERLY RETURN FLOW SHOULD SET UP
BRIEFLY BY THURS AHEAD OF NEXT FRONT. THIS WILL HELP BRING TEMPS
BACK ABOVE NORMAL REACHING WELL INTO THE 70S.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
AS OF 12Z...LOTS OF MID AND HIGH CLOUDS ACROSS THE REGION THIS
MORNING IN ADVANCE OF A COLD FRONT THAT WILL MOVE IN THIS EVENING.
AHEAD OF THE FRONT...EXPECT GUSTY SOUTH SOUTHWEST FLOW WITH
CONTINUED CLOUDY CONDITIONS...PREDOMINATELY VFR. JUST AHEAD OF THE
FRONT THIS EVENING...LIGHT CAPE...HIGH PRECIPITABLE WATER...AND
MODERATE BULK SHEER WILL PRODUCE CONVECTION. WINDS SHOULD MIX DOWN
OCCASIONALLY FROM 4K FEET...WITH ISOLATED WIND GUSTS TO 40 KTS
POSSIBLE. ONLY A TWO OR THREE HOUR WINDOW FOR THIS SCENARIO THIS
EVENING. AFTER INITIAL CONVECTION EXPECT LIGHT TO MODERATE SHOWERS
FOR ANOTHER FEW HOURS...FOLLOWED BY A WIND SHIFT TO THE WEST WELL
AFTER MIDNIGHT. CONVECTION WILL END FROM WEST TO EAST TOWARD
MORNING. IFR CEILINGS MAY LINGER UNTIL MID MORNING SATURDAY.
EXTENDED OUTLOOK...MVFR/IFR CIGS POSSIBLE ON TUESDAY. OTHERWISE VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM FRIDAY...7 FT SEAS ALREADY AT MAIN BUOYS 41013 AND
41036 IN ADDITION TO 41004 FARTHER SOUTH. CURRENT CWF FCST OF 5 TO 7
FT STILL HOLDING JUST FINE AND THE TWEAKS MADE TO WAVE GRIDS WILL BE
TO BRING A LITTLE MORE OF THE 6FT SEAS INTO THE 20NM ZONES.
LLJ/925MB FLOW PROGGED TO INCREASE ALONG THE COAST AND OVER WATER
TONIGHT INTO THE 40KT REALM. WILL EXAMINE FCST SOUNDINGS TO SEE IF
FUTURE FORECASTS SHOULD INCLUDE 40KT IN GUSTS...SEEMINGLY MAINLY
HINGING UPON LAPSE RATES AND THE EXTENT OF VERTICAL MIXING. PREVIOUS
FOLLOWS...
AS OF 700 AM FRIDAY...A STRONG COLD FRONT NOW ENTERING THE SOUTHERN
APPALACHIANS SHOULD SWEEP EAST AND ACROSS THE CAROLINA COASTAL
WATERS AFTER MIDNIGHT. AHEAD OF THE FRONT STRONG SOUTH WINDS SHOULD
AVERAGE 20-25 KNOTS THROUGH TONIGHT. MODELS ARE IN EXCELLENT
AGREEMENT WITH THE MAGNITUDE OF THIS MILD SOUTHERLY FLOW. A COUPLE
WAVES OF SHOWERS HAVE AFFECTED THE COASTAL WATERS THIS MORNING...
AND ADDITIONAL ISOLATED TO SCATTERED SHOWERS COULD OCCUR DURING THE
DAY. THE HEAVIER SHOWERS AND EMBEDDED THUNDERSTORMS WITH THE ACTUAL
COLD FRONT SHOULD NOT ARRIVE UNTIL TONIGHT BUT COULD POSE A SAFETY
RISK FOR MARINERS WITH STRONG GUSTY WINDS...LIGHTNING... AND REDUCED
VISIBILITY IN HEAVY RAIN. WINDS WILL SHIFT WESTERLY BEHIND THE FRONT
AND DECREASE LATE.
SEAS ARE CURRENTLY 5 FEET AT THE FRYING PAN SHOALS BUOY AND 4 FT AT
THE BUOY SEVERAL MILES SOUTH OF BALD HEAD ISLAND. WITH CONTINUED
SOUTH WINDS SEAS SHOULD BUILD TO AS HIGH AS 6-7 FEET 10-20 MILES OFF
THE SOUTH CAROLINA COAST...AND AS HIGH AS 7-8 FEET OFF THE NORTH
CAROLINA COAST. SEAS SHOULD BEGIN TO SUBSIDE LATE TONIGHT AS WINDS
SHIFT WESTERLY.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 330 AM FRIDAY...WINDS WILL VEER TO THE W TO NW ON SATURDAY
AS COLD FRONT PROGRESSES FURTHER OFF SHORE. DEEPER LAYER NORTHERLY
FLOW WILL DEVELOP SAT NIGHT AS MID TO UPPER TROUGH CROSSES THE
WATERS. WINDS WILL DIMINISH THROUGH SATURDAY DOWN TO 15 KTS BUT
WILL SPIKE UP AGAIN WITH DEEP COLD AND DRY ADVECTION THROUGH SAT
NIGHT. SEAS WILL SUBSIDE AS WINDS SUBSIDE ON SATURDAY DROPPING
BELOW SCA THRESHOLDS THROUGH SAT MORNING. AS WINDS BECOME
OFFSHORE IN DIRECTION SAT AND SAT NIGHT...SIGNIFICANT SEAS WILL
SUBSIDE TO 2 TO 5 FT...BUT WILL BUILD AGAIN OVERNIGHT SUNDAY AS
STRONG HIGH PRESSURE BUILDS DOWN INTO THE WATERS.
LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 330 AM FRIDAY...NORTHERLY WINDS WILL PERSIST AND VEER SLOWLY
AS STRONG HIGH PRESSURE REACHING DOWN FROM CANADA SHIFTS EAST OFF
THE NEW ENGLAND COAST BY TUES MORNING. WINDS WILL BE UP TO 15 TO
25 KTS ON MONDAY AS HIGH CONTINUES TO RIDGE INTO WATERS FROM THE
NORTH. GRADIENT WILL BECOME MORE PINCHED MON INTO TUES AS WEDGE
LIKE PATTERN SETS UP...KEEPING A PERSISTENT N-NE FLOW OVER THE
WATERS. THIS WILL PRODUCE AN INCREASE IN SEAS POSSIBLY REACHING
SCA THRESHOLDS.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EDT SATURDAY FOR AMZ250-252-
254-256.
&&
$$
NEAR TERM...MBB/TRA
SHORT TERM...RGZ
LONG TERM...RGZ
AVIATION...43
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
651 AM EDT FRI NOV 1 2013
.SYNOPSIS...
A STRONG COLD FRONT APPROACHING FROM THE WEST WILL MOVE ACROSS THE
AREA SATURDAY MORNING. IT WILL BECOME WINDY AHEAD OF THIS FRONT WITH
A HIGH RISK FOR SHOWERS AND POSSIBLY A THUNDERSTORM. SIGNIFICANT
RAINFALL IS POSSIBLE. HIGH PRESSURE WILL FOLLOW LATE SATURDAY
THROUGH SUNDAY BRINGING WITH IT COLDER AND DRIER CONDITIONS. HIGH
PRESSURE WILL PERSIST THROUGH THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 700 AM FRIDAY...STRONG SURFACE LOW PRESSURE IN THE GREAT LAKES
IS ASSOCIATED WITH AN ENERGETIC UPPER LEVEL SYSTEM LIFTING NORTHEAST
ACROSS INTO SOUTHERN ONTARIO. A SURFACE COLD FRONT EXTENDING SOUTH
OF THE LOW IS NOW ENTERING THE SOUTHERN AND CENTRAL APPALACHIANS.
TROPICAL MOISTURE IS PRESENT WITH PRECIPITABLE WATER VALUES EXPECTED
TO EXCEED 2.0 INCHES BY THIS EVENING JUST AHEAD OF THE FRONT. TO PUT
THAT IN PERSPECTIVE...2.0 INCHES IS THE 99TH PERCENTILE FOR NOVEMBER
PRECIP WATER AT CHS...AND COULD BE A RECORD NOVEMBER PW VALUE AT MHX.
THE FRONT WILL MAKE STEADY EASTWARD PROGRESS...AND THE BAND OF
SHOWERS AND EMBEDDED T-STORMS SHOULD SLIDE INTO THE CENTRAL
CAROLINAS THIS AFTERNOON. MY FORECAST POPS ALONG AND WEST OF
INTERSTATE 95 ARE IN THE 60-90 PERCENT RANGE BY LATE AFTERNOON...
WITH THE MOST SUBSTANTIAL COVERAGE OF PRECIPITATION EXPECTED ALONG
THE COAST AFTER DARK WHERE MY POPS ARE 80-90 PERCENT. STORM TOTAL
RAINFALL COULD EXCEED 1 INCH...WITH HEAVIER AMOUNTS POSSIBLE
IF/WHERE CONVECTIVE TRAINING OCCURS. COMPARED TO MY THOUGHTS BASED
ON THE 00Z MODELS...THE 06Z MODELS PLUS THE LATEST SREF SLOWS THE
WHOLE SYSTEM DOWN BY A FEW HOURS.
RADAR VERTICAL WIND PROFILES ARE CONFIRMING MODEL FORECASTS OF A
HEALTHY LOW LEVEL JET BLOWING OVERHEAD CURRENTLY. WINDS AT 1000 FT
AGL ARE AROUND 30 KNOTS WITH 40 KNOTS MEASURED AT 2000 FT. AS THE
BOUNDARY LAYER DEEPENS LATER THIS MORNING WITH RISING
TEMPERATURES...EXPECT STRONGER WINDS TO MIX DOWN WITH 30-35 MPH
GUSTS EXPECTED BY 10-11 AM. HELICITY (0-1 KM) SHOULD RANGE FROM
150-200 WITH 0-6 KM BULK SHEAR 40-50 KT. THESE VALUES ARE ALSO
SUPPORTIVE OF A SEVERE WEATHER THREAT. THE LIMITING FACTOR COULD END
UP BEING INSTABILITY: FORECAST CAPE VALUES ONLY RANGE FROM 200-400
J/KG WITH PERHAPS SOME 700 J/KG NUMBERS SHOWING UP THIS EVENING
ALONG THE COAST IF DEWPOINTS CAN HOLD IN THE UPPER 60S TO NEAR 70.
THE STORM PREDICTION CENTER CURRENTLY HAS A "SEE TEXT" 5 PERCENT
PROBABILITY FOR DAMAGING WIND GUSTS AND 2 PERCENT TORNADO RISK IN
THE CAROLINAS.
TEMPERATURES TODAY SHOULD BE VERY WARM BY NOVEMBER STANDARDS...
COURTESY OF TROPICAL AIR ADVECTED NORTHWARD AHEAD OF THE FRONT. 850
MB TEMPS EXPECTED TO RISE TO +15C ARE IN THE 95-98TH PERCENTILE FOR
NOVEMBER. TEMPERATURES SHOULD LEAP WITH THE FIRST TOUCH OF SUNLIGHT
THIS MORNING...AND HIGHS SHOULD REACH 80-82 DEGREES FOR AREAS EAST
OF INTERSTATE 95 AND A FEW MILES INLAND FROM THE BEACHES. THE FRONT
WILL MOVE ACROSS THE AREA LATE TONIGHT WITH COLD ADVECTION NOT
REACHING THE COAST UNTIL JUST A FEW HOURS BEFORE DAYBREAK. THERE IS
SOME UNCERTAINTY WITH TONIGHT`S LOW TEMPERATURES SINCE WEAKER WINDS
BEHIND THE FRONT COULD ALLOW FOR BOUNDARY LAYER DECOUPLING JUST
BEFORE SUNRISE...BUT IT APPEARS LOWS SHOULD RANGE FROM THE MID 60S
ON THE COAST TO THE UPPER 50S INLAND.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 330 AM FRIDAY...COLD FRONT WILL BE MAKING ITS WAY OFF SHORE
SAT MORNING. DRY AND COOLER AIR WILL BEGIN TO FEED INTO AREA
BEHIND THE FRONT BUT DEEP NW FLOW WITH GREATEST CAA WILL COME LATER
ON SAT AS MID TO UPPER TROUGH FINALLY SWINGS THROUGH. MAY SEE SOME
CLOUDS WITH ITS PASSAGE BUT THINK MOST CLOUDS AND ANY CHC OF A
SPRINKLE WILL REMAIN TO THE NORTH WHERE BETTER SHORTWAVE ENERGY
WILL BE.
AFTER A WARM START TO THE DAY ON SAT...TEMPS WILL REACH INTO THE 70S
AS SKIES CLEAR FROM WEST TO EAST THROUGH THE DAY. 850 TEMPS
PLUMMET THROUGH SAT INTO SUNDAY MORNING DROPPING DOWN TO 2 TO 3C
BY SUN. DEWPOINT TEMPS WILL DROP OUT AS WELL WITH READING IN THE
LOWER 30S BY MON MORNING. EXPECT TEMPS TO DROP A GOOD 10 DEGREES
SAT NIGHT FROM PREVIOUS MIN TEMPS AND THEN AN ADDITIONAL DROP SUN
NIGHT IN BETTER RADIATIONAL COOLING WITH READINGS RIGHT AROUND 40
MOST PLACES.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 3 PM THURSDAY...STRONG HIGH PRESSURE WILL RIDGE DOWN INTO
THE SOUTHEAST AS IT SHIFTS EAST THROUGH THE WEEK. AFTER A COLD
START MONDAY TEMPS WILL ONLY RECOVER TO AROUND 60 DEGREES IN COOL
NORTHERLY FLOW. AS THE HIGH SHIFTS EAST FURTHER OFF THE NEW
ENGLAND COAST THROUGH MID WEEK...A MOIST ON SHORE FLOW WILL
DEVELOP. A WEDGE LIKE PATTERN WILL SET UP WITH POTENTIAL FOR LOW
CLOUDS AND SPOTTY DRIZZLE OR SPRINKLES AS EARLY AS MONDAY NIGHT
AND POSSIBLY LASTING FOR A FEW DAYS BEFORE A COLD FRONT MAKES ITS
WAY ACROSS THE CAROLINAS BY THURS. EXPECT INCREASED CHC OF PCP ON
THURS AHEAD OF THIS COLD FRONT.
MONDAY WILL BE THE COOLEST DAY BUT WILL MODIFY SLOWLY THROUGH
MID WEEK. BUILDING RIDGE ALOFT WITH RISING H5 HEIGHTS WILL HELP TO
BRING TEMPS BACK UP ABOVE NORMAL BY WEDNESDAY. HIGHS WILL MAINLY
BE IN THE 60S THROUGH TUES AND WILL REACH BACK INTO THE 70S ON
WED. A WARMER AND MORE HUMID SOUTHERLY RETURN FLOW SHOULD SET UP
BRIEFLY BY THURS AHEAD OF NEXT FRONT. THIS WILL HELP BRING TEMPS
BACK ABOVE NORMAL REACHING WELL INTO THE 70S.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 06Z...EXPECT MAINLY VFR TONIGHT WITH PERHAPS SOME MVFR STRATUS
IN THE 09-12Z RANGE AND THE LOWEST CIGS INLAND. IFR CIGS CANNOT BE
RULED OUT FOR KFLO/KLBT...BUT CONFIDENCE IS FAIRLY LOW...AND ANY
CIGS BELOW 1KFT WOULD LIKELY BE VERY TEMPO IN NATURE. HRRR STILL
SHOWS SOME LIGHT -SHRA ALONG THE COAST BEFORE 12Z...WHICH SEEMS
REASONABLE BASED ON CURRENT RADAR TRENDS. AN APPROACHING COLD FRONT
WILL BRING PLENTY OF RAIN TO OUR CWA LATER TODAY. THE BEST PCPN
CHANCES FOR OUR AREA WILL BE AFTER 18Z...BEGINNING AT KFLO/KLBT
FOLLOWED BY THE COASTAL SITES A FEW HOURS LATER. ISOLATED TSTMS ARE
POSSIBLE...BUT WITH THE LIMITED INSTABILITY CHOSE NOT TO MENTION
TSTMS WITH THIS ISSUANCE. HEAVIER SHOWERS COULD RESULT IN PERIODS OF
MVFR CIGS/VSBYS...ESPECIALLY AFTER 00Z SATURDAY. EXPECT GUSTY
SOUTHWEST WINDS 10-20 KTS DURING THE DAY AS THE GRADIENT TIGHTENS
AHEAD OF THE FRONT.
EXTENDED OUTLOOK...MVFR/IFR CIGS POSSIBLE ON TUESDAY. OTHERWISE VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 700 AM FRIDAY...A STRONG COLD FRONT NOW ENTERING THE SOUTHERN
APPALACHIANS SHOULD SWEEP EAST AND ACROSS THE CAROLINA COASTAL
WATERS AFTER MIDNIGHT. AHEAD OF THE FRONT STRONG SOUTH WINDS SHOULD
AVERAGE 20-25 KNOTS THROUGH TONIGHT. MODELS ARE IN EXCELLENT
AGREEMENT WITH THE MAGNITUDE OF THIS MILD SOUTHERLY FLOW. A COUPLE
WAVES OF SHOWERS HAVE AFFECTED THE COASTAL WATERS THIS MORNING...
AND ADDITIONAL ISOLATED TO SCATTERED SHOWERS COULD OCCUR DURING THE
DAY. THE HEAVIER SHOWERS AND EMBEDDED THUNDERSTORMS WITH THE ACTUAL
COLD FRONT SHOULD NOT ARRIVE UNTIL TONIGHT BUT COULD POSE A SAFETY
RISK FOR MARINERS WITH STRONG GUSTY WINDS...LIGHTNING... AND REDUCED
VISIBILITY IN HEAVY RAIN. WINDS WILL SHIFT WESTERLY BEHIND THE FRONT
AND DECREASE LATE.
SEAS ARE CURRENTLY 5 FEET AT THE FRYING PAN SHOALS BUOY AND 4 FT AT
THE BUOY SEVERAL MILES SOUTH OF BALD HEAD ISLAND. WITH CONTINUED
SOUTH WINDS SEAS SHOULD BUILD TO AS HIGH AS 6-7 FEET 10-20 MILES OFF
THE SOUTH CAROLINA COAST...AND AS HIGH AS 7-8 FEET OFF THE NORTH
CAROLINA COAST. SEAS SHOULD BEGIN TO SUBSIDE LATE TONIGHT AS WINDS
SHIFT WESTERLY.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 330 AM FRIDAY...WINDS WILL VEER TO THE W TO NW ON SATURDAY
AS COLD FRONT PROGRESSES FURTHER OFF SHORE. DEEPER LAYER NORTHERLY
FLOW WILL DEVELOP SAT NIGHT AS MID TO UPPER TROUGH CROSSES THE
WATERS. WINDS WILL DIMINISH THROUGH SATURDAY DOWN TO 15 KTS BUT
WILL SPIKE UP AGAIN WITH DEEP COLD AND DRY ADVECTION THROUGH SAT
NIGHT. SEAS WILL SUBSIDE AS WINDS SUBSIDE ON SATURDAY DROPPING
BELOW SCA THRESHOLDS THROUGH SAT MORNING. AS WINDS BECOME
OFFSHORE IN DIRECTION SAT AND SAT NIGHT...SIGNIFICANT SEAS WILL
SUBSIDE TO 2 TO 5 FT...BUT WILL BUILD AGAIN OVERNIGHT SUNDAY AS
STRONG HIGH PRESSURE BUILDS DOWN INTO THE WATERS.
LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 330 AM FRIDAY...NORTHERLY WINDS WILL PERSIST AND VEER SLOWLY
AS STRONG HIGH PRESSURE REACHING DOWN FROM CANADA SHIFTS EAST OFF
THE NEW ENGLAND COAST BY TUES MORNING. WINDS WILL BE UP TO 15 TO
25 KTS ON MONDAY AS HIGH CONTINUES TO RIDGE INTO WATERS FROM THE
NORTH. GRADIENT WILL BECOME MORE PINCHED MON INTO TUES AS WEDGE
LIKE PATTERN SETS UP...KEEPING A PERSISTENT N-NE FLOW OVER THE
WATERS. THIS WILL PRODUCE AN INCREASE IN SEAS POSSIBLY REACHING
SCA THRESHOLDS.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EDT SATURDAY FOR AMZ250-252-
254-256.
&&
$$
NEAR TERM...TRA
SHORT TERM...RGZ
LONG TERM...RGZ
AVIATION...BJR
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
646 AM CDT FRI NOV 1 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 221 AM CDT FRI NOV 1 2013
MAIN FORECAST CONCERNS ARE ON SHOWER/DRIZZLE POTENTIAL THROUGH
THIS EVENING.
CURRENTLY AS OF 07Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED RIDGING ALONG THE WEST COAST OF THE U.S. WHILE TROUGHING
ENCOMPASSED AN AREA FROM HUDSON BAY SOUTHWESTWARD INTO THE CENTRAL
PLAINS. ONE POTENT SHORTWAVE MOVING THROUGH THE TROUGH WAS OVER
LOWER MICHIGAN. COLD AIR ADVECTION IN THE WAKE OF THIS SHORTWAVE
ALONG WITH LINGERING LOW LEVEL MOISTURE HAS RESULTED IN PERSISTENT
STRATUS ACROSS THE WESTERN GREAT LAKES. THIS STRATUS WAS EVIDENT IN
00Z MPX AND GRB SOUNDINGS WITH PLENTIFUL MOISTURE BELOW 700MB. OTHER
WEAK SHORTWAVES MOVING THROUGH THE UPPER TROUGH ACROSS THE FORECAST
AREA...COMBINED WITH WEAK SURFACE TROUGHS ALSO MOVING THROUGH AND
TURBULENCE IN THE STRATUS DECK HAS PRODUCED POCKETS OF SHOWERS AND
DRIZZLE. THERE IS SOME CLEARING OF THE STRATUS DECK UPSTREAM OVER
THE DAKOTAS WITH DRIER AIR PRESENT ON THE 00Z BIS/ABR SOUNDINGS.
HOWEVER...ANOTHER SHORTWAVE MOVING THROUGH THE TROUGHING COMING INTO
WESTERN NORTH DAKOTA WAS BRINGING MORE LIGHT SHOWER ACTIVITY THERE.
REGARDING THE AFOREMENTIONED COLD ADVECTION...AT MPX...925MB AND
850MB TEMPS DROPPED ABOUT 4C BETWEEN 12Z YESTERDAY AND 00Z...WITH
READINGS OF 2C AND -1C RESPECTIVELY. THESE READINGS ARE ABOUT 0.5
STANDARD DEVIATION BELOW NORMAL.
MODELS ARE IN GOOD AGREEMENT MAINTAINING UPPER TROUGHING OVER THE
FORECAST AREA THROUGH TONIGHT. HOWEVER...THE OVERALL TROUGHING WILL
START TO PROGRESS EAST TONIGHT AS THE RIDGING ALONG THE WEST COAST
OF THE U.S. GETS PUSHED FURTHER INLAND. THE MAIN SHORTWAVE FOCUS FOR
THE SHORT TERM IS THE ONE APPROACHING WESTERN NORTH DAKOTA. MODELS
TAKE THIS SHORTWAVE INTO WESTERN IOWA BY 00Z AND SOUTHERN ILLINOIS
BY 12Z SAT. LIGHT RAIN SHOWERS ACCOMPANYING THIS SHORTWAVE COULD
IMPACT FAR WESTERN PORTIONS OF THE FORECAST AREA LATE THIS AFTERNOON
INTO THIS EVENING...THOUGH MODEL CONSENSUS WOULD SUGGEST THE BEST
DYNAMICAL FORCING AND BULK OF THE PRECIPITATION STAYS SOUTH AND WEST
OF THE AREA.
OTHERWISE THE MAIN FOCUS FOR THE SHORT TERM PERIOD IS ON THE CURRENT
STRATUS DECK AND POCKETS OF DRIZZLE/SHOWERS. WEAK TROUGHS AS WELL AS
TURBULENCE IN THE STRATUS DECK LOOKS TO CONTINUE THROUGH THIS
EVENING...THUS POCKETS OF DRIZZLE AND SHOWERS ARE LIKELY TO PERSIST
UNTIL THE DECK CLEARS. REGARDING CLEARING...NORTHWEST WINDS OF 10-20
KT BELOW 800MB WILL HELP TO ADVECT THE DRIER AIR OVER THE DAKOTAS
TOWARDS THE FORECAST AREA. RAP/NAM 950-900MB RH PROGS SUGGEST
LOCATIONS WEST OF THE MISSISSIPPI RIVER SHOULD CLEAR OUT OF THE
STRATUS THIS AFTERNOON...WHILE LOCATIONS EAST OF THE MISSISSIPPI
RIVER CLEAR OUT DURING THE EVENING. THERE COULD STILL BE SOME
LINGERING CLOUDS OVERNIGHT...BUT THESE WOULD BE MORE OF THE
ALTOSTRATUS VARIETY AND LESS OF A CONCERN FOR PRECIP.
EXPECT ANOTHER COOL DAY TODAY DUE TO 925MB TEMPS ONLY CLIMBING TO
2-5C...CLOUDS...PRECIP AND WIND. COOL CONDITIONS CONTINUE INTO
TONIGHT AS 925MB TEMPS FALL TO AROUND 0C.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 221 AM CDT FRI NOV 1 2013
MAIN FORECAST CONCERNS ARE ON WINDS SUNDAY AND PRECIPITATION
CHANCES SUNDAY NIGHT THROUGH TUESDAY NIGHT.
THE UPPER LEVEL PATTERN IS FORECAST TO UNDERGO MAJOR CHANGES DURING
THE LONG TERM PERIOD...MUCH OF WHICH OCCURS DURING THE WEEKEND.
BETWEEN 12Z SATURDAY AND 00Z MONDAY...THE WESTERN U.S. GOES FROM
RIDGING TO A FAIRLY DEEP TROUGH. THE NET RESULT IS FOR 500MB HEIGHTS
TO RISE DRAMATICALLY DOWNSTREAM OVER THE EASTERN U.S....INCLUDING
THE FORECAST AREA...ALONG WITH DEEPENING LOW PRESSURE ALONG THE LEE
OF THE ROCKIES. THERE IS STRONG MODEL CONSENSUS FOR THE WESTERN
TROUGH TO GRADUALLY EJECT EAST-NORTHEAST THROUGH THE MIDDLE OF NEXT
WEEK...AND THIS EJECTION TIMING WILL BE CRITICAL ON HOW THE WEATHER
PANS OUT.
FOR THE WEEKEND...ONE MORE SURFACE TROUGH IS PROGGED TO DROP THROUGH
WISCONSIN ON SATURDAY WHICH COULD BRING SOME LIGHT PRECIP TO
LOCATIONS NORTHEAST OF I-94. OTHERWISE...DRY CONDITIONS WILL PREVAIL
AS A RIDGE OF HIGH PRESSURE MAKES ITS WAY ACROSS THE FORECAST AREA.
TEMPERATURES LOOK TO REMAIN ON THE COOL SIDE SATURDAY AS 925MB TEMPS
ARE HELD DOWN TO NO MORE THAN 2C. HOWEVER...AS THE RIDGE PASSES OFF
TO THE EAST ON SUNDAY...WINDS REALLY START TO CRANK UP OUT OF THE
SOUTHEAST. 925MB SPEEDS ARE PROGGED AT 25-40 KT BY 00Z MONDAY...
STRONGEST OUT WEST. THESE WINDS HELP TO BRING THE 925MB TEMPS UP TO
3-5C...AND WITH SUNSHINE SHOULD HELP TO PROPEL HIGH TEMPS INTO THE
MID 40S TO LOW 50S. RIGHT NOW IT APPEARS A STRONG ENOUGH SURFACE
INVERSION WILL BE IN PLACE TO PREVENT A WIND ADVISORY SITUATION
SUNDAY OR SUNDAY NIGHT. STILL...EXPECT WINDY CONDITIONS...ESPECIALLY
OVER THE HIGHER TERRAIN OF SOUTHEAST MN AND NORTHEAST IA.
AS WE HEAD FROM SUNDAY NIGHT THROUGH THE MIDDLE OF NEXT WEEK...DEEP
LAYER MOISTURE WILL INCREASE AHEAD OF THE GRADUALLY EJECTING WESTERN
TROUGH. PRECIPITABLE WATER VALUES CLIMB FROM NEAR 0.5 INCH SUNDAY
NIGHT TO AROUND 1 INCH BY LATE TUESDAY PER THE 01.00Z GFS. THE
INCREASING MOISTURE BRINGS UP CONCERNS FOR PRECIPITATION GIVEN ITS
ALSO A WARM ADVECTION PATTERN. THE 01.00Z CANADIAN ALREADY DEVELOPS
PRECIPITATION OVER THE NORTHWEST HALF OF THE AREA SUNDAY NIGHT...
ASSOCIATED WITH A SHORTWAVE TROUGH ALL MODELS SHOW...THOUGH IT IS
THE ONLY MODEL TO DO SO. THEN ON MONDAY...THE 01.00Z ECMWF BECOMES
THE ONLY MODEL TO OVERSPREAD PRECIP ACROSS MUCH OF THE FORECAST
AREA. THIS IS ASSOCIATED WITH A WARM CONVEYOR BELT AHEAD OF A POTENT
SHORTWAVE LIFTING NORTHEAST THROUGH THE DAKOTAS. GIVEN GOOD
CONTINUITY IN THE ECMWF...SOME LOW END PRECIPITATION CHANCES ARE
REQUIRED. CHANCES FOR PRECIPITATION LOOK INCREASINGLY LIKELY FOR
TUESDAY AND TUESDAY NIGHT AS THE POTENT SHORTWAVE AT THE BASE OF THE
TROUGH APPROACHES. HAVE RAISED CHANCES ABOUT 10 PERCENT WITH FURTHER
INCREASES LIKELY NEEDED IN LATER FORECASTS. VERY LITTLE INSTABILITY
SUGGESTED THUS NO MENTION OF THUNDER AT THIS TIME. PRECIPITATION
CHANCES THEN DECLINE WEDNESDAY INTO WEDNESDAY NIGHT AS THAT POTENT
SHORTWAVE LIFTS OFF TO THE NORTHEAST OF THE AREA. HIGH PRESSURE
LOOKS TO BUILD IN FOR THURSDAY TO DRY THINGS OUT ENTIRELY.
TEMPERATURES FOR MONDAY AND TUESDAY SHOULD BE NEAR OR SLIGHTLY ABOVE
NORMAL IN THE WARM ADVECTION AHEAD OF EJECTING WESTERN TROUGH...
AIDED TOO BY BREEZY SOUTHERLY WINDS AND HIGHER MOISTURE. CONDITIONS
COOL BACK DOWN TO BELOW NORMAL FOR WEDNESDAY AND THURSDAY AS COLD
AIR FLOWS IN THE WAKE OF THE POTENT SHORTWAVE. OVERALL MUCH OF THE
AFOREMENTIONED PRECIPITATION THAT FALLS LOOKS TO OCCUR WHEN THE
BOUNDARY LAYER IS WARM ENOUGH FOR RAIN.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 646 AM CDT FRI NOV 1 2013
MVFR AND SOME IFR CIGS WILL PREVAIL THROUGH THE MORNING HOURS AS
LOWER LEVEL MOISTURE WRAPPED AROUND THE LOW OVER EASTERN ONTARIO
ROTATES OVER THE AREA. ISOLATED TO SCT -SHRA ARE ALSO EXPECTED
DURING EARLY THIS MORNING. AS THE LOW CONTINUES TO PULL AWAY...
DRIER AIR FROM THE WEST WILL FILTER INTO THE AREA WITH CIGS RISING
TO VFR THRU THE AFTERNOON AND FOR TONIGHT. ANOTHER UPPER LEVEL
DISTURBANCE WILL TRACK SOUTHEAST ACROSS THE REGION THIS AFTERNOON
AND EVENING. COMBINED WITH SOME DIURNAL WARMING...WIDELY SCT -SHRA
ARE AGAIN POSSIBLE THIS AFTERNOON AND EVENING. ONCE THIS FEATURE
PASSES...CLOUDS ARE EXPECTED TO START DECREASING LATE TONIGHT AND
FOR SATURDAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM....AJ
AVIATION.....RRS
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
511 PM EDT FRI NOV 1 2013
.SYNOPSIS...
A COLD FRONT MOVING INTO THE FORECAST AREA WILL RESULT IN SHOWERS
THROUGH THE EVENING. DRYING WILL OCCUR BEHIND THE COLD FRONT
LATE TONIGHT. HIGH PRESSURE BEHIND THE FRONT WILL DOMINATE
SATURDAY INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
INTO EARLY THIS EVENING...SHOWERS WILL CONTINUE ACROSS THE AREA
AHEAD OF AN APPROACHING COLD FRONT. NO STORM CELLS ARE CURRENTLY
BEING DETECTED BY LOCAL AND REGIONAL RADAR. HRRR MODEL INDICATING
SHOWERS TO CONTINUE INTO THE MID-EVENING...AND THEN TAPER OFF FROM
THE WEST FOR THE REMAINDER OF THE EVENING. THINK ANY STORM
DEVELOPMENT WILL BE VERY ISOLATED DUE TO THE LACK OF SIGNIFICANT
INSTABILITY. LATER THIS EVENING...SHOWERS SHOULD DIMINISH FROM WEST TO EAST
LATE AS DRIER AIR MOVING INTO THE AREA BEHIND THE COLD FRONT. USED
THE GUIDANCE CONSENSUS FOR THE LOW TEMPERATURE FORECAST.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY NIGHT/...
THE COLD FRONT WILL BE OFF THE COAST BY SUNRISE SATURDAY. SURFACE
HIGH PRESSURE OVER THE CENTRAL CONUS SATURDAY WILL BUILD EASTWARD
ACROSS THE AREA THROUGH EARLY NEXT WEEK. DRY WEATHER IS IN STORE
FOR SATURDAY INTO EARLY NEXT WEEK. THE TEMPERATURE GUIDANCE WAS
CONSISTENT. NEAR NORMAL TEMPERATURES IN THE LOWER TO MIDDLE 70S
SATURDAY WILL COOL INTO THE 60S SUNDAY AND MONDAY. OVERNIGHT LOWS
WILL BE IN THE UPPER 30S AND LOWER 40S.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
UPPER-LEVEL RIDGING WILL TAKE HOLD ACROSS THE REGION BY THE
MIDDLE OF NEXT WEEK...BRINGING MILDER TEMPERATURES. SURFACE HIGH
PRESSURE ANCHORED OFF THE NEW ENGLAND COAST WILL RIDGE INTO THE
CAROLINAS AND GEORGIA...PROVIDING AN ONSHORE FLOW. THIS FLOW WILL
BRING INCREASING MOISTURE WEDNESDAY. THE MOISTURE MAY BECOME DEEP
AHEAD OF A COLD FRONT THURSDAY. THE ECMWF AND GFS WERE CLOSE WITH
THE TIMING OF THIS FRONT. THE GFS...ECMWF AND EKD MOS SUPPORT
CHANCE POPS OF 30 TO 40 PERCENT THURSDAY.
&&
.AVIATION /21Z FRIDAY THROUGH WEDNESDAY/...
THE MAIN BATCH OF RAINFALL ASSOCIATED WITH THE SLOW MOVING COLD
FRONT HAS MOVED INTO THE CSRA AND WESTERN MIDLANDS. THIS WILL
CONTINUE TO MOVE SLOWLY EASTWARD THROUGH THE EARLY EVENING HOURS. THIS
ACTIVITY WILL IMPACT BOTH CEILINGS AND VISIBILITIES INTO THE
EVENING HOURS. MVFR CEILINGS WILL DEVELOP...ALONG WITH MVFR
VISIBILITIES IN -RA AND BR AT ALL SITES. IN THE HEAVIEST
RAINFALL...IFR CEILINGS AND VISIBILITIES WILL BE POSSIBLE IN RA
AND BR.
THE MODELS SEEM TO INDICATE THAT THE MAIN BATCH OF RAINFALL AND
MOISTURE WILL BE PUSHING EAST OF THE TAF SITES BY 23Z...WITH
CEILINGS AND VISIBILITIES IMPROVING ONCE AGAIN TO VFR. WITH DRIER
AIR MOVING IN BEHIND THE FRONT IN LOW AND MID LEVELS...CLOUDS ARE
FORECAST TO LIFT AND CLEAR OUT BY 06Z. VFR CONDITIONS FOR
SATURDAY.
WINDS WILL CONTINUE TO BE FROM THE SOUTH TO SOUTHWEST FROM 10 TO 15
KTS WITH GUSTS UP TO 20 KTS AHEAD OF THE FRONT. BEHIND THE FRONT
THE WILDS SHIFT TO A SOUTHWEST TO WEST DIRECTION. WIND SHOULD
REMAIN STRONG ENOUGH ALL NIGHT TO INHIBIT ANY FOG FORMATION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
509 PM EDT FRI NOV 1 2013
.SYNOPSIS...
A COLD FRONT MOVING INTO THE FORECAST AREA WILL RESULT IN SHOWERS
THROUGH THE EVENING. DRYING WILL OCCUR BEHIND THE COLD FRONT
LATE TONIGHT. HIGH PRESSURE BEHIND THE FRONT WILL DOMINATE
SATURDAY INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
INTO EARLY THIS EVENING....
SHOWERS WILL CONTINUE ACROSS THE AREA AHEAD OF AN APPROACHING COLD
FRONT. NO STORM CELLS ARE CURRENTLY BEING DETECTED BY LOCAL AND
REGIONAL RADAR. HRRR MODEL INDICATING SHOWERS TO CONTINUE INTO THE
MID-EVENING...AND THEN TAPER OFF FROM THE WEST FOR THE REMAINDER
OF THE EVENING. THINK ANY STORM DEVELOPMENT WILL BE VERY ISOLATED
DUE TO THE LACK OF SIGNIFICANT INSTABILITY. SHOWERS SHOULD
DIMINISH FROM WEST TO EAST LATE AS DRIER AIR MOVING INTO THE AREA
BEHIND THE COLD FRONT. USED THE GUIDANCE CONSENSUS FOR THE LOW
TEMPERATURE FORECAST.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY NIGHT/...
THE COLD FRONT WILL BE OFF THE COAST BY SUNRISE SATURDAY. SURFACE
HIGH PRESSURE OVER THE CENTRAL CONUS SATURDAY WILL BUILD EASTWARD
ACROSS THE AREA THROUGH EARLY NEXT WEEK. DRY WEATHER IS IN STORE
FOR SATURDAY INTO EARLY NEXT WEEK. THE TEMPERATURE GUIDANCE WAS
CONSISTENT. NEAR NORMAL TEMPERATURES IN THE LOWER TO MIDDLE 70S
SATURDAY WILL COOL INTO THE 60S SUNDAY AND MONDAY. OVERNIGHT LOWS
WILL BE IN THE UPPER 30S AND LOWER 40S.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
UPPER-LEVEL RIDGING WILL TAKE HOLD ACROSS THE REGION BY THE
MIDDLE OF NEXT WEEK...BRINGING MILDER TEMPERATURES. SURFACE HIGH
PRESSURE ANCHORED OFF THE NEW ENGLAND COAST WILL RIDGE INTO THE
CAROLINAS AND GEORGIA...PROVIDING AN ONSHORE FLOW. THIS FLOW WILL
BRING INCREASING MOISTURE WEDNESDAY. THE MOISTURE MAY BECOME DEEP
AHEAD OF A COLD FRONT THURSDAY. THE ECMWF AND GFS WERE CLOSE WITH
THE TIMING OF THIS FRONT. THE GFS...ECMWF AND EKD MOS SUPPORT
CHANCE POPS OF 30 TO 40 PERCENT THURSDAY.
&&
.AVIATION /21Z FRIDAY THROUGH WEDNESDAY/...
THE MAIN BATCH OF RAINFALL ASSOCIATED WITH THE SLOW MOVING COLD
FRONT HAS MOVED INTO THE CSRA AND WESTERN MIDLANDS. THIS WILL
CONTINUE TO MOVE SLOWLY EASTWARD THROUGH THE EARLY EVENING HOURS. THIS
ACTIVITY WILL IMPACT BOTH CEILINGS AND VISIBILITIES INTO THE
EVENING HOURS. MVFR CEILINGS WILL DEVELOP...ALONG WITH MVFR
VISIBILITIES IN -RA AND BR AT ALL SITES. IN THE HEAVIEST
RAINFALL...IFR CEILINGS AND VISIBILITIES WILL BE POSSIBLE IN RA
AND BR.
THE MODELS SEEM TO INDICATE THAT THE MAIN BATCH OF RAINFALL AND
MOISTURE WILL BE PUSHING EAST OF THE TAF SITES BY 23Z...WITH
CEILINGS AND VISIBILITIES IMPROVING ONCE AGAIN TO VFR. WITH DRIER
AIR MOVING IN BEHIND THE FRONT IN LOW AND MID LEVELS...CLOUDS ARE
FORECAST TO LIFT AND CLEAR OUT BY 06Z. VFR CONDITIONS FOR
SATURDAY.
WINDS WILL CONTINUE TO BE FROM THE SOUTH TO SOUTHWEST FROM 10 TO 15
KTS WITH GUSTS UP TO 20 KTS AHEAD OF THE FRONT. BEHIND THE FRONT
THE WILDS SHIFT TO A SOUTHWEST TO WEST DIRECTION. WIND SHOULD
REMAIN STRONG ENOUGH ALL NIGHT TO INHIBIT ANY FOG FORMATION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
145 PM EDT FRI NOV 1 2013
.SYNOPSIS...
DEEP SOUTHWEST FLOW AHEAD OF AN APPROACHING COLD FRONT WILL RESULT
IN SHOWERS THIS AFTERNOON INTO THE EVENING. IT WILL BE BREEZY
AHEAD OF THE FRONT. DRYING WILL OCCUR BEHIND THE COLD FRONT
OVERNIGHT. HIGH PRESSURE BEHIND THE FRONT WILL DOMINATE SATURDAY
INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
MOISTURE WILL CONTINUE TO INCREASE THIS AFTERNOON AHEAD OF THE
APPROACHING COLD FRONT. SHOWER COVERAGE WAS SCATTERED AT MIDDAY.
THE HRRR INDICATES COVERAGE WILL BECOME WIDESPREAD BETWEEN 300 PM
AND 500 PM POSSIBLY IN RESPONSE TO A MID-LEVEL SHORTWAVE TROUGH.
WE PLAN TO CONTINUE THE CATEGORICAL POPS. CLOUDINESS AND
WIDESPREAD SHOWERS WILL LIMIT INSTABILITY BUT DAMAGING WIND GUSTS
COULD POSSIBLY OCCUR BECAUSE OF STRONG WIND SHEAR. THE KCAE VAD
WIND PROFILE INDICATED WINDS OF 40 KNOTS AT 2000 FEET AND 50 KNOTS
AT 3000 FEET. SOME OF THIS WIND COULD POSSIBLY MIX DOWN IN HEAVIER
SHOWERS. CLOUDINESS AND SHOWERS SHOULD HELP HOLD DOWN
TEMPERATURES. WE USED THE COOLER TEMPERATURE GUIDANCE.
IT WILL BE BREEZY TODAY BUT WITH LIMITED INSTABILITY BELIEVE
WINDS WILL BE GENERALLY JUST BELOW THE LAKE WIND ADVISORY
CRITERIA.
CONVERGENCE ASSOCIATED WITH THE FRONT WILL LIKELY RESULT IN
WIDESPREAD SHOWER COVERAGE THIS EVENING. THE HRRR INDICATES
WIDESPREAD COVERAGE AT 800 PM WITH SHOWERS SHIFTING MAINLY EAST OF
THE AREA BY 1000 PM. STRONG WIND SHEAR WILL SUPPORT A CONTINUED
THREAT OF DAMAGING WIND BUT THE THREAT WILL BE LIMITED BY A LACK
OF SIGNIFICANT INSTABILITY. THE COLD FRONT WILL PUSH EAST OF THE
FORECAST AREA AROUND MIDNIGHT. DRIER AND COOLER AIR WILL FOLLOW
THE FRONT. USED THE GUIDANCE CONSENSUS FOR THE LOW TEMPERATURE
FORECAST.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
THE COLD FRONT WILL BE OFF THE COAST BY SUNRISE SATURDAY. SURFACE
HIGH PRESSURE OVER THE CENTRAL CONUS SATURDAY WILL BUILD EASTWARD
ACROSS THE AREA THROUGH EARLY NEXT WEEK. DRY WEATHER IS IN STORE
FOR THE WEEKEND INTO EARLY NEXT WEEK. AN UPPER-LEVEL TROUGH
CROSSING THE EASTERN STATES WILL BRING COOLER TEMPERATURES. NEAR
NORMAL TEMPERATURES IN THE LOWER TO MIDDLE 70S SATURDAY WILL COOL
INTO THE 60S SUNDAY AND MONDAY. OVERNIGHT LOWS WILL BE IN THE
UPPER 30S AND 40S.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
UPPER-LEVEL RIDGING WILL TAKE HOLD ACROSS THE REGION BY THE
MIDDLE OF NEXT WEEK...BRINGING MILDER TEMPERATURES. SURFACE HIGH
PRESSURE ANCHORED OFF THE NEW ENGLAND COAST WILL RIDGE INTO THE
CAROLINAS AND GEORGIA...PROVIDING AN ONSHORE FLOW. THIS FLOW WILL
BRING INCREASING MOISTURE WEDNESDAY. THE MOISTURE MAY BECOME DEEP
AHEAD OF A COLD FRONT THURSDAY. THE ECMWF WAS CLOSER WITH THE
FRONTAL TIMING LATE IN THE PERIOD. WE LEANED TOWARD THE ECMWF AND
EKD MOS POPS WHICH WERE CLOSE TO THE GFS ENSEMBLE MEANS.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
THE MAIN BATCH OF RAINFALL ASSOCIATED WITH THE SLOW MOVING COLD
FRONT HAS MOVED INTO THE CSRA AND WESTERN MIDLANDS. THIS WILL
CONTINUE TO MOVE SLOWLY EASTWARD THROUGH THE LATE AFTERNOON HOURS.
THIS ACTIVITY WILL IMPACT BOTH CEILINGS AND VISIBILITIES THROUGHOUT
THE AFTERNOON HOURS. AS THE RAINFALL MOVES IN...MVFR CEILINGS WILL
DEVELOP...ALONG WITH MVFR VISIBILITIES IN -RA AND BR AT ALL SITES. IN
THE HEAVIEST RAINFALL...IFR CEILINGS AND VISIBILITIES WILL BE
POSSIBLE IN RA AND BR.
THE MODELS SEEM TO INDICATE THAT THE MAIN BATCH OF RAINFALL AND
MOISTURE WILL BE PUSHING EAST OF THE TAF SITES BY 22Z...WITH
CEILINGS AND VISIBILITIES IMPROVING ONCE AGAIN TO VFR. WITH DRIER
AIR MOVING IN BEHIND THE FRONT IN LOW AND MID LEVELS...CLOUDS ARE
FORECAST TO LIFT AND CLEAR OUT BY 06Z. VFR CONDITIONS FOR SATURDAY.
WINDS WILL CONTINUE TO BE FROM THE SOUTH TO SOUTHWEST FROM 10 TO 15
KTS WITH GUSTS UP TO 20 KTS AHEAD OF THE FRONT. BEHIND THE FRONT
THE WILDS SHIFT TO A SOUTHWEST TO WEST DIRECTION. WIND SHOULD
REMAIN STRONG ENOUGH ALL NIGHT TO INHIBIT ANY FOG FORMATION.
EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1248 PM CDT FRI NOV 1 2013
.DISCUSSION...
312 AM CDT
PRIMARY FORECAST CHALLENGES THIS MORNING INCLUDE CLOUD COVER AND ITS
EFFECT ON TEMPS THE NEXT COUPLE DAYS...SHOWER CHANCES LATER THIS
AFTERNOON AND EVENING...FOLLOWED BY WHAT LOOKS TO BE A POSSIBLE
REPEAT OF THIS WEEK`S EVENTS NEXT WEEK!
AFTER DEEPENING 15MB IN THE PAST 12 HOURS THE POWERHOUSE AUTUMN
STORM CONTINUES TO SLOWLY DEEPEN AS IT LIFTS NORTHEAST OUT OF THE
REGION. RAIN HAS ENDED BUT GUSTY WEST WINDS ARE USHERING IN A
STARKLY DIFFERENT AIR MASS COMPARED WITH 24 HOURS AGO WITH 24
TEMP/TD CHANGES OF 20-25F. COMBINATION OF COLD AIR STRATOCUMULUS
WRAPPING AROUND THE SYSTEM INTO THE AREA AND CONTINUATION OF WEAK
COLD AIR ADVECTION THROUGH THE DAY SHOULD ALLOW VERY LITTLE TEMP
RECOVERY AND HAVE UNDERCUT GUIDANCE FOR HIGHS TODAY...MAINLY
NORTHERN CWA WHERE PROSPECTS FOR SUNSHINE ARE DIMMER (PARDON THE
PUN).
WATER VAPOR IMAGERY SHOWS A PAIR OF WELL DEFINED SHORTWAVE TROUGHS
OVER EASTERN NEBRASKA AND WESTERN NEBRASKA EARLY THIS MORNING.
MODELS BRING BOTH OF THESE WAVES EASTWARD INTO OUR AREA THIS
AFTERNOON AND EVENING. WHILE CLOUD COVER WILL LIMIT SFC HEATING
TODAY...MUCH COLDER MID LEVEL TEMPS WILL ADVECT INTO THE AREA WITH
THESE SECONDARY WAVES WHICH WILL STEEPEN THE LOW AND MID LEVEL LAPSE
RATES. THE STEEP LAPSE RATES AND LARGE SCALE ASCENT WITH THE
APPROACHING WAVES SHOULD ALLOW FOR SCATTERED SHOWERS TO MOVE ACROSS
THE CWA LATER THIS AFTERNOON INTO THE EVENING...ESPECIALLY NORTHERN
HALF OF THE CWA. FREEZING LEVELS DROP TO JUST OVER 3K FT AGL AND
GIVEN THE CONVECTIVE NATURE OF THE SHOWERS IT WOULDNT BE SURPRISED
TO SEE A FEW GRAUPEL REPORTS LATER TODAY INTO EARLY THIS EVENING
BEFORE SHORTWAVE RIDGING RESULTS IN DECREASING SHOWER CHANCES
OVERNIGHT.
CYCLONIC LOW LEVEL FLOW AND FRONTAL INVERSION LIKELY TO RESULT IN
STRATUS HANGING AROUND TONIGHT INTO SATURDAY AND POSSIBLY INTO PART
OF SATURDAY NIGHT BEFORE FLOW BECOMES MORE ANTICYCLONIC AS WAA
BEGINS. THE EXTENSIVE CLOUD COVER TODAY THROUGH SATURDAY SHOULD
RESULT IN SMALL DIURNAL TEMP SWING AND HAVE GONE BELOW GUIDANCE FOR
HIGHS TODAY AND SATURDAY AND ABOVE GUIDANCE FOR LOW TEMPS TONIGHT.
ASSUMING STRATUS FINALLY CLEARS SAT NIGHT HAVE ALLOWED FOR A HEALTHY
DROP IN TEMPS WITH CLEARING SKIES AND LIGHT WINDS.
SUNDAY INTO MONDAY WILL MARK A TRANSITION PERIOD AS LONG WAVE TROUGH
MOVES OUT OF THE AREA AND IS REPLACED BY LONGWAVE RIDGING IN ADVANCE
OF THE NEXT SIGNIFICANT TROUGH DIGGING INTO THE WEST. INITIALLY WARM
AIR ADVECTION WILL BE MOST PRONOUNCED ALOFT SUNDAY BUT SOUTHEAST
WINDS AND MORE SUNSHINE SHOULD STILL ALLOW TEMPS TO WARM A
COUPLE/FEW DEGREES OVER SATURDAY. FURTHER WARMING IS EXPECTED MONDAY
AS SOUTHERLY WINDS RAMP UP...THOUGH INCREASING MID-HIGH LEVEL CLOUDS
COULD FILTER SUNSHINE AND TEMPER THE WARM UP A BIT.
NEXT SIGNIFICANT LONG WAVE TROUGH WILL BEGIN TO AFFECT THE REGION
TUESDAY AND ESPECIALLY TUESDAY NIGHT INTO WEDNESDAY. SUSPECT THE
SYSTEM COULD SLOW SOMEWHAT FROM WHAT CURRENT GUIDANCE IS
SHOWING...MUCH LIKE HAPPENED WITH THIS WEEK`S SYSTEM. STILL LOOK FOR
GRADUALLY INCREASING RAIN CHANCES TUESDAY...BUT THE BEST RAIN BET
APPEARS TO BE TUESDAY NIGHT INTO WEDNESDAY MORNING. PWATS ONCE AGAIN
ARE PROGGED TO CLIMB TO WELL OVER AN INCH...OR OVER 200% OF NORMAL
WITH SOME GUIDANCE EVEN SUGGESTING THAT SOME OF THE MID-UPPER LEVEL
MOISTURE FROM 18E OVER THE TROPICAL EASTERN PACIFIC POSSIBLY GETTING
ENTANGLED INTO THIS SYSTEM...SO ONCE AGAIN WE WILL NEED TO WATCH OUT
FOR A POSSIBILITY OF A HEALTHY RAIN EVENT.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* MVFR CIGS ARND 1800-2000FT AGL WILL PERSIST THRU THE OVERNIGHT.
* WEST WINDS ARND 10-14KT WITH GUSTS TO 20KT THRU 21-22Z...THEN
SPEEDS ARND 10-13KT THRU THIS EVENING.
* A FEW SPRINKLES TO LIGHT RAIN WILL DEVELOP LATER TODAY MAINLY
BETWEEN 23-02Z.
BEACHLER
//DISCUSSION...UPDATED 18Z...
UPPER LEVEL TROUGH CONTINUES TO KEEP CLOUDY SKIES ACROSS THE
REGION THIS AFTERNOON...AND LOOKING AT CURRENT VISIBLE IMAGERY ANY
IMPROVEMENT DOES NOT LOOK LIKELY IN THE NEAR TERM. WINDS REMAIN
WESTERLY...HOWEVER A WEAK ELEVATED WAVE WILL SLIDE ACROSS THE
REGION THIS AFTN AND BRING WINDS TO THE NORTHWEST. OCCASIONAL
GUSTS CONTINUE TO BE NOTED AT VARIOUS POINTS THIS AFTN...HOWEVER
EXPECT WITH THE WAVE SLIDING OVERHEAD LATER TODAY AND WINDS
TURNING NW THAT THE GUSTS WILL DISSIPATE WITH SPEEDS GENERALLY
ARND 10-13KT. IN ADDITION TO THE OVERHEAD WAVE THAT IS SLIDING
OVERHEAD THIS AFTN WILL BE THE POTENTIAL FOR SPOTTY SHOWERS TO
DEVELOP. TIMING FOR ANY PRECIP DOES LOOK TO BE FAVORED BETWEEN 23Z
AND 02Z...SO HAVE REFLECTED THIS IN THE CURRENT TAF.
GUIDANCE CONTINUES TO BE SLUGGISH WITH LIFTING CIGS BEYOND 2KFT
AGL OVERNIGHT...AND IN MANY INSTANCES WILL HOLD DOWN ARND
1700-1800FT AGL. GIVEN THE TREND HAS BEEN TO HOLD ONTO LOW
CIGS...HAVE OPTED TO KEEP CIGS DOWN GIVEN THE ABUNDANCE OF CLOUDS
UPSTREAM EXPECTED TO ARRIVE ACROSS THE REGION TONIGHT.
MORE DRY AIR ALOFT WILL BEGIN TO ARRIVE ACROSS THE AIRFIELDS LATE
SAT MORNING...AND EXPECT BETTER MIXING TO EVENTUALLY PRODUCE A SCT
CLOUD DECK ARND 3000-4000FT AGL BY 17-18Z SAT.
BEACHLER
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN WIND DIR/SPEED/GUSTS...HIGH CONFIDENCE IN
GUSTS DISSIPATING BY 23Z.
* HIGH CONFIDENCE IN CIGS HOLDING AT MVFR CONDS THRU DAYBREAK SAT.
* MEDIUM CONFIDENCE IN COVERAGE/TIMING OF PRECIP AFT 22Z THRU 02Z.
BEACHLER
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT...VF
SUNDAY...VFR
MONDAY...VFR
TUESDAY...CHANCE OF SHOWERS.
WEDNESDAY...MVFR. RAIN LIKELY.
THURSDAY...VFR.
&&
.MARINE...
344 AM CDT
GALES ON LAKE MI WILL QUICKLY DIMINISH TODAY AS LOW PRESSURE MOVES
RAPIDLY FROM THE NORTH CHANNEL OF LAKE SUPERIOR TO QUEBEC BY THIS
AFTERNOON. W PRESSURE OF 28.9 INCHES OVER THE NORTH CHANNEL OF
LAKE SUPERIOR WILL MOVE QUICKLY NORTHEAST TO LABRADOR BY THIS
EVENING. WINDS WILL DIMINISH FURTHER DURING LATER SAT THROUGH EARLY
SUN MORNING AS A RIDGE OF HIGH PRESSURE MOVES E ACROSS THE LAKE.
WINDS WILL BE FRESHENING OUT THE SE LATE SUN AND SUN NIGHT AS THE
HIGH STRENGTHENS AS IT MOVES OFF TO THE E AND LOW PRESSURE MOVES E
INTO THE PLAINS.
THE GALE WARNING HAS BEEN ALLOWED TO CONTINUE UNTIL 9AM CDT THIS
A.M. THOUGH SUSTAINED SPEEDS ON THE N PORTION OF LAKE MI SHOULD BE
BELOW GALES WITH ONLY SOME LOW END GALE FORCE GUSTS THROUGH THE
EARLY MORNING.
SMALL CRAFT ADVISORIES FOR THE IL AND IN NEARSHORE WATERS WILL
LIKELY NEED TO CONTINUE FOR A FEW HOURS INTO THE LATER MORNING
UNTIL WINDS DROP OFF. WITH W WINDS BEHIND LAST NIGHT/S COLD FRONT
WAVES DID NOT BUILD GREATLY IN THE NEARSHORE WATERS...ESPECIALLY
ALONG THE IL SHORE
TRS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN UNTIL 4 PM FRIDAY.
&&
$$
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FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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Area Forecast Discussion
National Weather Service Lincoln IL
1230 PM CDT Fri Nov 1 2013
.DISCUSSION...
ISSUED 1020 AM CDT Fri Nov 1 2013
Southern edge of stratocumulus roughly along a Macomb to Paris
line late this morning. This has not made a lot of southward
progress over the last few hours, but morning model guidance
continues to show a southern nudge through the afternoon as a
weak trough drops southward through Wisconsin. Updated zones/grids
were sent to make some adjustments for the cloud trends for
today. Temperatures and winds were largely on track and only
required minor tweaks.
Geelhart
&&
.AVIATION...
ISSUED 1230 PM CDT Fri Nov 1 2013
Persistent area of stratocumulus from KPIA-KBMI-KCMI to persist
for several more hours and slowly sink southward. Still seeing a
fair amount of MVFR ceilings further north as a weak trough drops
southward, which will likely affect these sites at times. Around
KSPI/KDEC, diurnal clouds have been increasing and mostly should
be VFR. Will see much of the lower clouds pull out shortly after
00Z, but another area of stratocumulus associated with an upper
disturbance over the Dakotas may move in again later on.
Geelhart
&&
.PREV DISCUSSION...
ISSUED 303 AM CDT Fri Nov 1 2013
SHORT TERM...Today through Sunday
Northwesterly upper flow pattern will keep plenty of cloud cover
in place across at least the northern half of the KILX CWA today.
07z/2am satellite imagery shows overcast conditions upstream over
much of Iowa, with satellite timing tools generally keeping the
clouds along/north of the I-74 corridor as they work eastward this
morning. Further south, mostly clear skies will be noted along and
south of a Springfield to Paris line initially: however, cooling
aloft will create fairly steep lapse rates and additional diurnal
cloud development. CU rule remains most negative across the
northern CWA, but still suggests SCT-BKN cloud cover even across
the south. End result will be mostly cloudy skies north and partly
sunny conditions far south. Short-wave trough currently evident on
water vapor imagery over eastern Montana will drop southeastward
later today into tonight. Weak lift ahead of this feature may
trigger a few sprinkles late this afternoon, particularly across
the northern CWA. Based on latest HRRR and 4km WRF-NMM, have
included scattered sprinkles for locations north of Peoria late
this afternoon. Despite weak lift ahead of the approaching wave,
forecast soundings remain too dry to support measurable precip
through tonight.
Cool/dry weather will be the rule through the weekend, as high
pressure builds into the region. High temperatures will only be in
the 50s both Saturday and Sunday, while lows dip into the lower to
middle 30s by Sunday morning.
LONG TERM...Monday through Thursday
Challenges in the extended continue to focus on strength of
building upper ridge over the southeast CONUS and timing of
approaching short-wave next week. Previous runs of the ECMWF had
featured an unseasonably strong 594dm 500mb high developing over
the Carolinas by Monday/Tuesday. This strong ridge essentially
slowed the eastward progress of an upper short-wave over the
Plains, resulting in an extended period of rain chances across
central Illinois from Tuesday through Thursday. Meanwhile, both
the GFS and GEM were slightly weaker with the high and thus
brought the Plains wave and associated cold front eastward a bit
faster. 00z Nov 1 run of the ECMWF has now come into much better
agreement with the GFS/GEM, leading to increased confidence in a
more progressive pattern next week. As such, will continue to
focus highest PoPs during the Tuesday night/Wednesday time frame
when strongest lift and deepest moisture will be present. Have
opted to go with a dry forecast for Thursday, as all model
guidance pushes front east of the region.
Barnes
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1117 AM CDT FRI NOV 1 2013
.DISCUSSION...
312 AM CDT
PRIMARY FORECAST CHALLENGES THIS MORNING INCLUDE CLOUD COVER AND ITS
EFFECT ON TEMPS THE NEXT COUPLE DAYS...SHOWER CHANCES LATER THIS
AFTERNOON AND EVENING...FOLLOWED BY WHAT LOOKS TO BE A POSSIBLE
REPEAT OF THIS WEEK`S EVENTS NEXT WEEK!
AFTER DEEPENING 15MB IN THE PAST 12 HOURS THE POWERHOUSE AUTUMN
STORM CONTINUES TO SLOWLY DEEPEN AS IT LIFTS NORTHEAST OUT OF THE
REGION. RAIN HAS ENDED BUT GUSTY WEST WINDS ARE USHERING IN A
STARKLY DIFFERENT AIR MASS COMPARED WITH 24 HOURS AGO WITH 24
TEMP/TD CHANGES OF 20-25F. COMBINATION OF COLD AIR STRATOCUMULUS
WRAPPING AROUND THE SYSTEM INTO THE AREA AND CONTINUATION OF WEAK
COLD AIR ADVECTION THROUGH THE DAY SHOULD ALLOW VERY LITTLE TEMP
RECOVERY AND HAVE UNDERCUT GUIDANCE FOR HIGHS TODAY...MAINLY
NORTHERN CWA WHERE PROSPECTS FOR SUNSHINE ARE DIMMER (PARDON THE
PUN).
WATER VAPOR IMAGERY SHOWS A PAIR OF WELL DEFINED SHORTWAVE TROUGHS
OVER EASTERN NEBRASKA AND WESTERN NEBRASKA EARLY THIS MORNING.
MODELS BRING BOTH OF THESE WAVES EASTWARD INTO OUR AREA THIS
AFTERNOON AND EVENING. WHILE CLOUD COVER WILL LIMIT SFC HEATING
TODAY...MUCH COLDER MID LEVEL TEMPS WILL ADVECT INTO THE AREA WITH
THESE SECONDARY WAVES WHICH WILL STEEPEN THE LOW AND MID LEVEL LAPSE
RATES. THE STEEP LAPSE RATES AND LARGE SCALE ASCENT WITH THE
APPROACHING WAVES SHOULD ALLOW FOR SCATTERED SHOWERS TO MOVE ACROSS
THE CWA LATER THIS AFTERNOON INTO THE EVENING...ESPECIALLY NORTHERN
HALF OF THE CWA. FREEZING LEVELS DROP TO JUST OVER 3K FT AGL AND
GIVEN THE CONVECTIVE NATURE OF THE SHOWERS IT WOULDNT BE SURPRISED
TO SEE A FEW GRAUPEL REPORTS LATER TODAY INTO EARLY THIS EVENING
BEFORE SHORTWAVE RIDGING RESULTS IN DECREASING SHOWER CHANCES
OVERNIGHT.
CYCLONIC LOW LEVEL FLOW AND FRONTAL INVERSION LIKELY TO RESULT IN
STRATUS HANGING AROUND TONIGHT INTO SATURDAY AND POSSIBLY INTO PART
OF SATURDAY NIGHT BEFORE FLOW BECOMES MORE ANTICYCLONIC AS WAA
BEGINS. THE EXTENSIVE CLOUD COVER TODAY THROUGH SATURDAY SHOULD
RESULT IN SMALL DIURNAL TEMP SWING AND HAVE GONE BELOW GUIDANCE FOR
HIGHS TODAY AND SATURDAY AND ABOVE GUIDANCE FOR LOW TEMPS TONIGHT.
ASSUMING STRATUS FINALLY CLEARS SAT NIGHT HAVE ALLOWED FOR A HEALTHY
DROP IN TEMPS WITH CLEARING SKIES AND LIGHT WINDS.
SUNDAY INTO MONDAY WILL MARK A TRANSITION PERIOD AS LONG WAVE TROUGH
MOVES OUT OF THE AREA AND IS REPLACED BY LONGWAVE RIDGING IN ADVANCE
OF THE NEXT SIGNIFICANT TROUGH DIGGING INTO THE WEST. INITIALLY WARM
AIR ADVECTION WILL BE MOST PRONOUNCED ALOFT SUNDAY BUT SOUTHEAST
WINDS AND MORE SUNSHINE SHOULD STILL ALLOW TEMPS TO WARM A
COUPLE/FEW DEGREES OVER SATURDAY. FURTHER WARMING IS EXPECTED MONDAY
AS SOUTHERLY WINDS RAMP UP...THOUGH INCREASING MID-HIGH LEVEL CLOUDS
COULD FILTER SUNSHINE AND TEMPER THE WARM UP A BIT.
NEXT SIGNIFICANT LONG WAVE TROUGH WILL BEGIN TO AFFECT THE REGION
TUESDAY AND ESPECIALLY TUESDAY NIGHT INTO WEDNESDAY. SUSPECT THE
SYSTEM COULD SLOW SOMEWHAT FROM WHAT CURRENT GUIDANCE IS
SHOWING...MUCH LIKE HAPPENED WITH THIS WEEK`S SYSTEM. STILL LOOK FOR
GRADUALLY INCREASING RAIN CHANCES TUESDAY...BUT THE BEST RAIN BET
APPEARS TO BE TUESDAY NIGHT INTO WEDNESDAY MORNING. PWATS ONCE AGAIN
ARE PROGGED TO CLIMB TO WELL OVER AN INCH...OR OVER 200% OF NORMAL
WITH SOME GUIDANCE EVEN SUGGESTING THAT SOME OF THE MID-UPPER LEVEL
MOISTURE FROM 18E OVER THE TROPICAL EASTERN PACIFIC POSSIBLY GETTING
ENTANGLED INTO THIS SYSTEM...SO ONCE AGAIN WE WILL NEED TO WATCH OUT
FOR A POSSIBILITY OF A HEALTHY RAIN EVENT.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* CEILING HEIGHTS ARND 2KFT AGL THRU LATE AFTN.
* WIND GUSTS TO 20KT THRU THIS AFTN.
* PERIOD OF LIGHT SHOWERS LATE AFTERNOON INTO EARLY EVENING.
BEACHLER
//DISCUSSION...UPDATED 14Z...
CIGS CONTINUE TO LOWER TO THE NORTHWEST OF THE TAF SITES...AND
THIS APPEARS TO BE POISED TO PUSH ACROSS NORTHERN IL/NORTHWEST IN
AIRFIELDS LATER THIS MORNING AND CONTINUE THRU THE AFTN. IT DOES
APPEAR THAT WITH SOME PRECIP CHANCES ARRIVING EARLY THIS
AFTN...THAT CIGS MAY COME UP A BIT ALTHOUGH THE CONFIDENCE REMAINS
LOW. SO ADDITIONAL ADJUSTMENTS MAY BE NEEDED FOR AFTN CIGS.
PREVIOUS DISCUSSION UPDATED 12Z...
THE UPPER LOW CONTINUES TO PULL AWAY TO THE NE FROM THE UPPER
GREAT LAKES THOUGH A STRONG JET DROPPING SE FROM B.C. AND
SOUTHERN ALBERTA OVER THE NORTHERN HIGH PLAINS AND TO THE CENTRAL
PLAINS WILL SHARPEN THE UPPER TROUGH OVER THE CENTRAL U.S. WITHIN
THIS NW FLOW ARE MULTIPLE SHORT WAVES THE FIRST OF WHICH IS
TURNING MORE TO THE E OVER IA AND NORTHERN MO AS IT NEARS THE
BASE OF THE UPPER TROUGH.
THIS SHORT WAVE IS PROGGED TO ZIP ACROSS THE LOCAL AREA MIDDAY.
THERE SHOULD NOT BE ANY PRECIP OF NOTE FROM THIS DISTURBANCE AS
FORECAST SOUNDINGS SOME MOISTENING OF MID LEVELS THERE IS STILL A
SIGNIFICANT LAYER OF DRY AIR FROM AROUND 6K FT AGL UP.
MODELS BRING THE NEXT SHORT WAVE ACROSS THE AREA DURING THE LATE
AFTERNOON AND EARLY EVENING WITH THE INITIALLY DRY MID LEVELS
NEARING SATURATION 22Z-00Z. MODELS ALSO GENERATE SOME PRECIP
AMOUNTS WITH THIS DISTURBANCE. EXPECT WETTING SHOWERS DURING THE
LATE AFTERNOON INTO EARLY EVENING BUT COVERAGE EXPECTED TO BE
SOMEWHAT LIMITED SO HAVE ONLY WENT FROM PROB30 TO VCSH FOR 12Z
SET OF TAFS.
WITH THE UPPER LOW AND ITS ASSOCIATED SURFACE LOW MOVING FURTHER
AWAY FROM THE AREA WITH TIME THOUGH STRONG HIGH PRESSURE WILL BE
GRADUALLY BUILDING INTO THE HIGH PLAINS SO A MODERATE FLOW SHOULD
PERSIST TODAY. WIND DIRECTION IS EXPECTED TO REMAIN BASICALLY W
THOUGH SUSPECT THERE WILL BE A LITTLE BACKING AS EACH SHORT WAVE
APPROACHES FOLLOWED BY A LITTLE VEERING AS EACH PASSES BY.
OVERALL...WINDS WILL BE BETWEEN WSW AND WNW.
ALTHOUGH THERE ARE AREAS OF MVFR CEILINGS OVER PARTS OF THE
REGION HIGH RESOLUTION ARW MODEL SHOWS A GRADUAL LIFTING OF THE
CLOUD BASES SO HAVE LEFT PREVAILING VFR IN THE FORECAST UNTIL THE
SHOWERS MOVE INTO THE AREA LATE AFTERNOON WHEN EXPECT CEILINGS TO
LOWER BACK INTO MVFR RANGE.
TRS
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* HIGH CONFIDENCE WINDS...MEDIUM CONFIDENCE ALL OTHER ELEMENTS.
BEACHLER
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT...VF
SUNDAY...VFR
MONDAY...VFR
TUESDAY...CHANCE OF SHOWERS.
WEDNESDAY...MVFR. RAIN LIKELY.
THURSDAY...VFR.
&&
.MARINE...
344 AM CDT
GALES ON LAKE MI WILL QUICKLY DIMINISH TODAY AS LOW PRESSURE MOVES
RAPIDLY FROM THE NORTH CHANNEL OF LAKE SUPERIOR TO QUEBEC BY THIS
AFTERNOON. W PRESSURE OF 28.9 INCHES OVER THE NORTH CHANNEL OF
LAKE SUPERIOR WILL MOVE QUICKLY NORTHEAST TO LABRADOR BY THIS
EVENING. WINDS WILL DIMINISH FURTHER DURING LATER SAT THROUGH EARLY
SUN MORNING AS A RIDGE OF HIGH PRESSURE MOVES E ACROSS THE LAKE.
WINDS WILL BE FRESHENING OUT THE SE LATE SUN AND SUN NIGHT AS THE
HIGH STRENGTHENS AS IT MOVES OFF TO THE E AND LOW PRESSURE MOVES E
INTO THE PLAINS.
THE GALE WARNING HAS BEEN ALLOWED TO CONTINUE UNTIL 9AM CDT THIS
A.M. THOUGH SUSTAINED SPEEDS ON THE N PORTION OF LAKE MI SHOULD BE
BELOW GALES WITH ONLY SOME LOW END GALE FORCE GUSTS THROUGH THE
EARLY MORNING.
SMALL CRAFT ADVISORIES FOR THE IL AND IN NEARSHORE WATERS WILL
LIKELY NEED TO CONTINUE FOR A FEW HOURS INTO THE LATER MORNING
UNTIL WINDS DROP OFF. WITH W WINDS BEHIND LAST NIGHT/S COLD FRONT
WAVES DID NOT BUILD GREATLY IN THE NEARSHORE WATERS...ESPECIALLY
ALONG THE IL SHORE
TRS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN UNTIL 4 PM FRIDAY.
&&
$$
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FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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Area Forecast Discussion
National Weather Service Lincoln IL
1020 AM CDT Fri Nov 1 2013
.DISCUSSION...
ISSUED 1020 AM CDT Fri Nov 1 2013
Southern edge of stratocumulus roughly along a Macomb to Paris
line late this morning. This has not made a lot of southward
progress over the last few hours, but morning model guidance
continues to show a southern nudge through the afternoon as a
weak trough drops southward through Wisconsin. Updated zones/grids
were sent to make some adjustments for the cloud trends for
today. Temperatures and winds were largely on track and only
required minor tweaks.
Geelhart
&&
.AVIATION...
ISSUED 659 AM CDT Fri Nov 1 2013
West to northwest flow will persist across the central Illinois
terminals today in the wake of yesterday`s cold front. A period of
gusty winds is expected for much of the daytime hours today due to
a moderately strong pressure gradient lingering in the area, as
will as enhanced diurnal mixing.
Wrap around moisture will produce cigs across much of the area
today, with period of MVFR or even IFR likely this morning though
most of the terminals. Cigs will rise with time today, with VFR
cigs expected to develop area wide by tonight.
Bak
&&
.PREV DISCUSSION...
ISSUED 303 AM CDT Fri Nov 1 2013
SHORT TERM...Today through Sunday
Northwesterly upper flow pattern will keep plenty of cloud cover
in place across at least the northern half of the KILX CWA today.
07z/2am satellite imagery shows overcast conditions upstream over
much of Iowa, with satellite timing tools generally keeping the
clouds along/north of the I-74 corridor as they work eastward this
morning. Further south, mostly clear skies will be noted along and
south of a Springfield to Paris line initially: however, cooling
aloft will create fairly steep lapse rates and additional diurnal
cloud development. CU rule remains most negative across the
northern CWA, but still suggests SCT-BKN cloud cover even across
the south. End result will be mostly cloudy skies north and partly
sunny conditions far south. Short-wave trough currently evident on
water vapor imagery over eastern Montana will drop southeastward
later today into tonight. Weak lift ahead of this feature may
trigger a few sprinkles late this afternoon, particularly across
the northern CWA. Based on latest HRRR and 4km WRF-NMM, have
included scattered sprinkles for locations north of Peoria late
this afternoon. Despite weak lift ahead of the approaching wave,
forecast soundings remain too dry to support measurable precip
through tonight.
Cool/dry weather will be the rule through the weekend, as high
pressure builds into the region. High temperatures will only be in
the 50s both Saturday and Sunday, while lows dip into the lower to
middle 30s by Sunday morning.
LONG TERM...Monday through Thursday
Challenges in the extended continue to focus on strength of
building upper ridge over the southeast CONUS and timing of
approaching short-wave next week. Previous runs of the ECMWF had
featured an unseasonably strong 594dm 500mb high developing over
the Carolinas by Monday/Tuesday. This strong ridge essentially
slowed the eastward progress of an upper short-wave over the
Plains, resulting in an extended period of rain chances across
central Illinois from Tuesday through Thursday. Meanwhile, both
the GFS and GEM were slightly weaker with the high and thus
brought the Plains wave and associated cold front eastward a bit
faster. 00z Nov 1 run of the ECMWF has now come into much better
agreement with the GFS/GEM, leading to increased confidence in a
more progressive pattern next week. As such, will continue to
focus highest PoPs during the Tuesday night/Wednesday time frame
when strongest lift and deepest moisture will be present. Have
opted to go with a dry forecast for Thursday, as all model
guidance pushes front east of the region.
Barnes
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
159 PM MDT FRI NOV 1 2013
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 122 PM MDT FRI NOV 1 2013
LATEST WV IMAGERY AND RAP ANALYSIS SHOW LARGE SCALE H5 TROUGH
EXTENDING FROM THE GREAT LAKES REGION INTO THE SOUTHERN PLAINS. AN
AMPLIFIED H5 RIDGE HAS BUILT INTO THE WESTERN CONUS EXTENDING INTO
THE NORTHERN ROCKIES. EMBEDDED SHORTWAVE TROUGHS ARE PROGRESSING
THROUGH THE ROCKIES/NORTHERN PLAINS WITHIN THE NW FLOW BETWEEN THESE
FEATURES.
REGARDING WIND ADVISORY...SO FAR WINDS HAVE INCREASED TO WITHIN
3-5KT OF GUST CRITERIA...AND SEVERAL LOCATIONS HAVE HAD SUSTAINED
WINDS WITHIN CRITERIA. WITH PEAK MIXING UNDERWAY I WOULD EXPECT
WINDS TO CONTINUE TO TREND UP THROUGH THE REST OF THE AFTERNOON
BEFORE DIMINISHING ON TIME AROUND SUNSET.
A SHALLOW CU FIELD HAS DEVELOPED WITH MID LEVEL COLD POOL OVER CWA
AND WEAK SHORTWAVE TROUGH PASSAGE OVER NEBRASKA. WHILE THERE
CONTINUES TO BE LIGHT RETURNS ON RADAR IN THE WEST...THIS IS LIKELY
VIRGA CONSIDERING THE DRY AIR MASS IN PLACE BELOW 700MB. WHILE I
COULDNT RULE OUT A SPRINKLE OR TWO BEFORE SUNSET...I DECIDED TO
LEAVE MENTION OUT THIS AFTERNOON WITH RADAR RETURNS GENERALLY
DIMINISHING. AS THE SUN SETS I EXPECT CLOUD COVER TO CLEAR...WITH
CLEARING SKIES AIDED BY SUBSIDENCE BUILDING IN WITH H5 RIDGE IN THE
WEST. WITH DECREASING WINDS AND CLEARING SKIES...COUPLED WITH TD
VALUES IN THE TEENS TO LOW 20S IT LOOKS LIKE WE WILL HAVE IDEAL
CONDITIONS FOR RADIATIONAL COOLING TONIGHT. MOS GUIDANCE CONTINUES
TO SHOW LOW TO MID 20S ACROSS THE CWA...AND THIS SEEMS
REASONABLE...WITH COLD SPOTS IN THE WEST POSSIBLY DROPPING INTO THE
TEENS.
AS H5 RIDGE BUILDS WEST AND LEE TROUGH DEVELOPS AT THE SURFACE WINDS
WILL SHIFT TO THE SOUTH AND INCREASE SATURDAY. WINDS SHOULD REMAIN
BELOW ADVISORY CRITERIA...THOUGH THEY WILL REMAIN BREEZY ACROSS MUCH
OF THE CWA WITH GUSTS TO 30-35 MPH RANGE DURING THE AFTERNOON.
STABLE/DRY AIR MASS WILL SUPPORT SUNNY SKIES AND DRY CONDITIONS. WAA
ASSOCIATED WITH DEEP SOUTHERLY FLOW WILL HELP TEMPS RECOVER INTO THE
60S BY MIDDAY.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 158 PM MDT FRI NOV 1 2013
SATURDAY NIGHT THROUGH SUNDAY...THERE IS DECENT AGREEMENT BETWEEN
THE SHORT RANGE MODELS THAT A 500 MB RIDGE WILL EXTEND FROM THE
TEXAS PANHANDLE TO THE DAKOTAS THROUGH SUNDAY MORNING. RIDGE AXIS
WILL MOVE EAST QUICKLY AS A SHORT WAVE TROUGH MOVES INTO THE HIGH
PLAINS BY SUNDAY AFTERNOON. EXPECT MOISTURE TO BE LIMITED WITH THIS
FEATURE...SO WILL CONTINUE WITH A DRY FORECAST. LEE SIDE SURFACE
TROUGH WILL PRODUCE AN INCREASING SURFACE PRESSURE GRADIENT. WITH
GOOD MIXING...EXPECT SOUTHWEST WINDS 20-30 KNOTS...ESPECIALLY EAST
OF HIGHWAY 25. LOW LEVEL THERMAL RIDGE WITH 850 MB TEMPERATURES
AROUND 18 DEGREES CELSIUS WILL ADVECT OVER THE FORECAST AREA SUNDAY
AFTERNOON...SO EXPECT MAXIMUM TEMPERATURES TO BE AROUND 70 DEGREES.
SUNDAY NIGHT THROUGH MONDAY...CYCLONIC FLOW WILL DEVELOP OVER THE
HIGH PLAINS AS MID LEVEL SHORT WAVE TROUGH MOVES ACROSS THE NORTHERN
ROCKIES. A COLD FRONT WILL MOVE THROUGH THE FORECAST AREA LATE
SUNDAY NIGHT/EARLY MONDAY MORNING. MODEL SOUNDINGS KEEP THE AIR MASS
UNSATURATED...THOUGH LOW LEVEL WINDS WILL BE UPSLOPE. COLD AIR
ADVECTION WILL DROP MAXIMUM TEMPERATURES ABOUT 10-15 DEGREES.
MONDAY NIGHT THROUGH WEDNESDAY... THIS IS THE CHALLENGING PART OF
THE FORECAST AS A TROUGH DEEPENS OVER THE INTER MOUNTAIN WEST.
GFS/ECMWF AGREE THAT PRECIPITATION WILL BE A GOOD BET LATE MONDAY
NIGHT THROUGH TUESDAY. HOWEVER...MODELS ARE VERY DIFFERENT WITH THE
TEMPERATURE PROFILES. GFS IS WARM THROUGH 21Z TUESDAY...EVEN ACROSS
THE WESTERN HALF OF THE AREA. GFS TEMPERATURE PROFILES KEEP
PRECIPITATION TYPE AS RAIN...WITH A CHANGE TO SNOW AROUND 00Z
WEDNESDAY. FURTHER EAST...GFS KEEPS PRECIPITATION TYPE AS ALL
RAIN. THE ECMWF IS COLDER WITH TEMPERATURE PROFILES INDICATING
SNOW AS THE PRECIPITATION TYPE. PROGGED 500 MB HEIGHT ANOMALIES
ARE AROUND 2.5 STANDARD DEVIATIONS FROM NORMAL...SO THE FEATURE
HAS THE POTENTIAL FOR BEING POTENT. FOR NOW...WILL INDICATE SNOW
OVER THE FAR WESTERN COUNTIES...A MIX OF RAIN/NOW OVER THE
CENTRAL...AND ALL RAIN FURTHER EAST. SNOW POTENTIAL NOW IS 2-4
INCHES ACROSS THE EASTERN COLORADO COUNTIES...BUT CONFIDENCE IS NOT
HIGH DUE TO CONFLICTING MODEL SIGNALS. TROUGH WILL BEGIN TO MOVE
EAST WEDNESDAY RESULTING IN DECREASING PRECIPITATION CHANCES.
WEDNESDAY NIGHT THROUGH FRIDAY...500 MB TROUGH WILL MOVE EAST OF THE
FORECAST AREA WEDNESDAY NIGHT AS A RIDGE REBUILDS OVER THE WESTERN
UNITED STATES. AS THE NEXT SYSTEM MOVES OVER THE PACIFIC NORTHWEST
THURSDAY NIGHT...RIDGE WILL AMPLIFY OVER THE PLAINS. SO DRY WEATHER
AND WARMER TEMPERATURES WILL OCCUR THE LAST PART OF THE WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1115 AM MDT FRI NOV 1 2013
VFR CONDITIONS WILL PERSIST AT BOTH KGLD AND KMCK TERMINALS
THROUGH THE TAF PERIOD. I COULDNT RULE OUT VIRGA OR ISOLATED
SPRINKLES AT KGLD EARLY IN THE TAF PERIOD...HOWEVER
RADAR/SATELLITE TRENDS WOULD INDICATE THIS ACTIVITY SHOULD REMAIN
IN EASTERN COLORADO. WITH DEEP UNIDIRECTIONAL GRADIENT IN
PLACE...NORTHWEST WINDS WILL CONTINUE TO INCREASE WITH PEAK
GUSTS AROUND 40KT THIS AFTERNOON. WINDS WILL DIMINISH EARLY THIS
EVENING WITH LOSS OF DAYTIME HEATING...AND THEN SHIFT TO THE
SOUTHWEST AROUND 8KT AS SURFACE HIGH PRESSURE BUILDS IN THE SOUTH
OVERNIGHT.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...WIND ADVISORY UNTIL 6 PM MDT /7 PM CDT/ THIS EVENING FOR
KSZ001>004-013>016-027>029.
CO...WIND ADVISORY UNTIL 6 PM MDT THIS EVENING FOR COZ090>092.
NE...WIND ADVISORY UNTIL 6 PM MDT /7 PM CDT/ THIS EVENING FOR
NEZ079>081.
&&
$$
SHORT TERM...DR
LONG TERM...MENTZER
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
124 PM MDT FRI NOV 1 2013
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 122 PM MDT FRI NOV 1 2013
LATEST WV IMAGERY AND RAP ANALYSIS SHOW LARGE SCALE H5 TROUGH
EXTENDING FROM THE GREAT LAKES REGION INTO THE SOUTHERN PLAINS. AN
AMPLIFIED H5 RIDGE HAS BUILT INTO THE WESTERN CONUS EXTENDING INTO
THE NORTHERN ROCKIES. EMBEDDED SHORTWAVE TROUGHS ARE PROGRESSING
THROUGH THE ROCKIES/NORTHERN PLAINS WITHIN THE NW FLOW BETWEEN THESE
FEATURES.
REGARDING WIND ADVISORY...SO FAR WINDS HAVE INCREASED TO WITHIN
3-5KT OF GUST CRITERIA...AND SEVERAL LOCATIONS HAVE HAD SUSTAINED
WINDS WITHIN CRITERIA. WITH PEAK MIXING UNDERWAY I WOULD EXPECT
WINDS TO CONTINUE TO TREND UP THROUGH THE REST OF THE AFTERNOON
BEFORE DIMINISHING ON TIME AROUND SUNSET.
A SHALLOW CU FIELD HAS DEVELOPED WITH MID LEVEL COLD POOL OVER CWA
AND WEAK SHORTWAVE TROUGH PASSAGE OVER NEBRASKA. WHILE THERE
CONTINUES TO BE LIGHT RETURNS ON RADAR IN THE WEST...THIS IS LIKELY
VIRGA CONSIDERING THE DRY AIR MASS IN PLACE BELOW 700MB. WHILE I
COULDNT RULE OUT A SPRINKLE OR TWO BEFORE SUNSET...I DECIDED TO
LEAVE MENTION OUT THIS AFTERNOON WITH RADAR RETURNS GENERALLY
DIMINISHING. AS THE SUN SETS I EXPECT CLOUD COVER TO CLEAR...WITH
CLEARING SKIES AIDED BY SUBSIDENCE BUILDING IN WITH H5 RIDGE IN THE
WEST. WITH DECREASING WINDS AND CLEARING SKIES...COUPLED WITH TD
VALUES IN THE TEENS TO LOW 20S IT LOOKS LIKE WE WILL HAVE IDEAL
CONDITIONS FOR RADIATIONAL COOLING TONIGHT. MOS GUIDANCE CONTINUES
TO SHOW LOW TO MID 20S ACROSS THE CWA...AND THIS SEEMS
REASONABLE...WITH COLD SPOTS IN THE WEST POSSIBLY DROPPING INTO THE
TEENS.
AS H5 RIDGE BUILDS WEST AND LEE TROUGH DEVELOPS AT THE SURFACE WINDS
WILL SHIFT TO THE SOUTH AND INCREASE SATURDAY. WINDS SHOULD REMAIN
BELOW ADVISORY CRITERIA...THOUGH THEY WILL REMAIN BREEZY ACROSS MUCH
OF THE CWA WITH GUSTS TO 30-35 MPH RANGE DURING THE AFTERNOON.
STABLE/DRY AIR MASS WILL SUPPORT SUNNY SKIES AND DRY CONDITIONS. WAA
ASSOCIATED WITH DEEP SOUTHERLY FLOW WILL HELP TEMPS RECOVER INTO THE
60S BY MIDDAY.
.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 321 AM MDT FRI NOV 1 2013
THE MAIN CONCERN FOR THE EXTENDED FORECAST WILL BE THE POTENTIAL FOR
ACCUMULATING SNOW FROM MONDAY NIGHT THROUGH TUESDAY NIGHT.
CONFIDENCE FOR THIS PARTICULAR WEATHER SYSTEM IS GROWING AS ALL
MODELS AGREE ON THE SAME UPPER LEVEL PATTERN...HOWEVER...THERE
REMAINS A LARGE SPREAD IN TEMPERATURES BETWEEN THE WARM GFS AND THE
MUCH COLDER EUROPEAN AND CANADIAN MODELS.
AS STATED ABOVE...MODEL AGREEMENT WITH RESPECT TO THE LOCATION AND
MOVEMENT OF THE POSITIVELY TITLED TROUGH AND TIMING IS FAIRLY GOOD.
MONDAY SHOULD BE PRECIPITATION FREE AS THE BEST DYNAMICS FOR THIS
SYSTEM ARE STILL WELL TO THE SOUTHWEST OF THE FORECAST AREA. THE
BRUNT OF THE SYSTEM SHOULD MOVE THROUGH FROM MONDAY NIGHT THROUGH
TUESDAY NIGHT. THE CANADIAN AND EUROPEAN MODELS ARE ALMOST IDENTICAL
FOR TIMING WHILE THE GFS SEEMS TO LAG BY 6 HOURS OR SO. THIS IS
BECAUSE THE GFS IS SLIGHTLY SLOWER TO SATURATE THE COLUMN. BOTH THE
GFS AND EUROPEAN MODELS DEPICT A STRONG PV ANOMALY WITH TROPOPAUSE
HEIGHTS DROPPING TO 400-500 MB. IN ADDITION...BOTH MODELS SUGGEST A
PROLONGED PERIOD OF FRONTOGENESIS WITHIN THE 00Z TUESDAY THROUGH 00Z
WEDNESDAY TIME FRAME...OR MONDAY EVENING THROUGH TUESDAY EVENING.
MODEL SOUNDINGS AND 850 MB TEMPS SHOW A PRONOUNCED COOLING OVER THE
REGION WITH THE CANADIAN AND EUROPEAN MODELS AS THE COOLEST
SOLUTIONS. IT IS HARD TO BELIEVE THE WARM GFS WITH ANTICIPATED CLOUD
COVER AND COLD AIR ADVECTION OVER THE REGION SO FOR THIS
PACKAGE...HAVE WEIGHTED THE FORECAST TOWARDS THE CANADIAN AND
EUROPEAN MODELS. THIS IS RELATIVELY CLOSE TO THE PREVIOUS FORECAST
WITH A SLIGHT COOLING OF A DEGREE OR TWO...ESPECIALLY FOR HIGH
TEMPERATURES ON TUESDAY. TAKING INTO ACCOUNT ALL OF THIS...IT SEEMS
THE MOST LIKELY SCENARIO WILL BE A DECENT BAND OF PRECIPITATION
DEVELOPING OVER THE REGION AND SLOWLY MOVING THROUGH TUESDAY AND
EXITING THE AREA SOMETIME THURSDAY EVENING. AT THIS POINT...THE
MAJORITY OF THE PRECIPITATION IN THIS BAND COULD BE SNOW BASED ON
MODEL INDICATIONS AND ACCUMULATING SNOW COULD BECOME A PROBLEM. THE
NORTHWEST HALF OF THE REGION...A LINE FROM OBERLIN KANSAS TO
CHEYENNE WELLS KANSAS...IS ADVERTISED TO HAVE THE BEST CHANCE FOR
ACCUMULATING SNOW. HAVE CONTINUED ADVERTISING RAIN/SNOW MIX FOR MOST
OF THE DAY TUESDAY DUE TO THE TEMPERATURE CONCERNS. IT IS POSSIBLE
SNOWFALL AMOUNTS ARE UNDERDONE WITH THE POTENTIAL FOR A HEAVIER BAND
OF PRECIP AND POSSIBLE CONVECTIVE ELEMENTS. THIS SYSTEM WILL NEED TO
BE MONITORED BUT CONFIDENCE IS GROWING IN A COOLER SOLUTION WITH
ACCUMULATING SNOW POSSIBLE.
ONCE THIS SYSTEM MOVES OUT TUESDAY NIGHT...A DRY FORECAST HAS BEEN
PRODUCED AS A RIDGE OF HIGH PRESSURE AND SURFACE HIGH PRESSURE MOVE
IN BEHIND THE UPPER LEVEL TROUGH. A SLOW WARMING TREND IS EXPECTED
AS 850 MB TEMPERATURES WARM UNDER SOUTH TO SOUTHWEST WINDS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1115 AM MDT FRI NOV 1 2013
VFR CONDITIONS WILL PERSIST AT BOTH KGLD AND KMCK TERMINALS
THROUGH THE TAF PERIOD. I COULDNT RULE OUT VIRGA OR ISOLATED
SPRINKLES AT KGLD EARLY IN THE TAF PERIOD...HOWEVER
RADAR/SATELLITE TRENDS WOULD INDICATE THIS ACTIVITY SHOULD REMAIN
IN EASTERN COLORADO. WITH DEEP UNIDIRECTIONAL GRADIENT IN
PLACE...NORTHWEST WINDS WILL CONTINUE TO INCREASE WITH PEAK
GUSTS AROUND 40KT THIS AFTERNOON. WINDS WILL DIMINISH EARLY THIS
EVENING WITH LOSS OF DAYTIME HEATING...AND THEN SHIFT TO THE
SOUTHWEST AROUND 8KT AS SURFACE HIGH PRESSURE BUILDS IN THE SOUTH
OVERNIGHT.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...WIND ADVISORY UNTIL 6 PM MDT /7 PM CDT/ THIS EVENING FOR
KSZ001>004-013>016-027>029.
CO...WIND ADVISORY UNTIL 6 PM MDT THIS EVENING FOR COZ090>092.
NE...WIND ADVISORY UNTIL 6 PM MDT /7 PM CDT/ THIS EVENING FOR
NEZ079>081.
&&
$$
SHORT TERM...DR
LONG TERM...RRH
AVIATION...DR
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
325 PM CDT FRI NOV 1 2013
.SHORT TERM...TONIGHT THROUGH MONDAY.
...A NICE AUTUMN WEEKEND AS WE FALL BACK TO STANDARD TIME...ALTHOUGH
IT WILL BE QUITE WINDY ON SUNDAY...
A 140KT JET OVER ALBERTA WAS DIVING SOUTHEAST WITH AN H5 TROF OVER
MUCH OF THE CENTRAL U.S. AND THE GREAT LAKES AT 12Z. SHORTWAVE
TROF ENERGY WAS NOTED OVER NEBRASKA AND A STRONGER WAVE OVER NORTH
DAKOTA. THE 12Z OAX SOUNDING SHOWED SOME SATURATION AROUND 750MB
AND THERE WERE A FEW SPRINKLES AROUND THIS MORNING.
THE RH PROGS THROUGH TONIGHT DO BRING CONTINUED MID LEVEL
MOISTURE SOUTHWARD AND ALSO INCREASE THE LOW LEVEL MOISTURE IN
THE NORTHWEST FLOW...ESPECIALLY FOR EASTERN NEBRASKA INTO IOWA.
WITH THE H3 JET TRANSLATING QUICKLY SOUTHEAST...THE SHOWERS SHOULD
MOVE THROUGH AT A QUICK SPEED AS WELL. BY 12Z SATURDAY...THE
TREND IS FOR THE MOISTURE IS TO HAVE SHIFTED OUT OF EASTERN
NEBRASKA AND IS EXITING OUR WESTERN IOWA COUNTIES. THE LATEST WSR-
88D SHOWED SOME OF THESE SHOWERS IN THE DAKOTAS AND A POCKET OF
STEEPER MID LEVEL LAPSE RATES AT 18Z AND BY 20Z THERE WAS A NICE
ARC OF SHOWERS OVER THE MIDLANDS. THE SHORT-TERM MODELS KEEP THE
BULK OF THE ISOLATED SHOWER ACTIVITY NORTH OR EAST OF OUR FORECAST
AREA...HOWEVER THE HRRR AND THE RAP BOTH HAVE SOME MINOR PRECIP
SWINGING THROUGH AND THEY HAVE A BETTER HANDLE ON WHAT IS GOING
ON. WILL TAKE A LOOK AT THE RADAR BEFORE FORECAST ISSUANCE DUE TO
THE FAST NORTHWEST FLOW...BUT FOR NOW...WILL PLAN ON A MENTION
FOR ISOLATED SHOWERS OR SPRINKLES FOR PARTS OF THE FORECAST AREA
INTO EARLY THIS EVENING.
MID LEVEL RIDGING BUILDS IN FOR SATURDAY AND OUR NORTHWEST WINDS
ALOFT WILL BECOME MORE WESTERLY LATE SATURDAY AFTERNOON AND
SATURDAY NIGHT. STRONG WARM ADVECTION ENSUES SATURDAY NIGHT THRU
SUNDAY SUNDAY NIGHT. MEANWHILE...SURFACE LOW PRESSURE OVER EASTERN
COLORADO MOVES INTO WESTERN KANSAS AND A COLD FRONT OVER WESTERN
NEBRASKA SLIDES INTO CENTRAL AND EASTERN NEBRASKA. THERE IS GOOD
LIFT AND UPPER SUPPORT SUNDAY...HOWEVER THE ATMOSPHERE STILL
APPEARS TOO DRY FOR PRECIP TO DEVELOP. HIGHS SATURDAY SHOULD BE IN
THE 50S WITH 50S TO LOWER 60S SUNDAY. H85 WINDS OF 45 TO 55KTS
WILL RESULT IN STRONG SOUTHEAST TO SOUTH WINDS SUNDAY. FOR NOW
HAVE SURFACE WINDS INCREASING TO 25 TO 30MPH SUSTAINED...THUS
HITTING WIND ADVISORY CRITERIA.
RH IS STILL LACKING SUNDAY NIGHT INTO MONDAY AND THE SURFACE FRONT
SLOWLY SHIFTS FROM CENTRAL NEBRASKA INTO EASTERN NEBRASKA. CANNOT
RULE OUT ISOLATED SHOWERS SUNDAY NIGHT OR MONDAY WITH THE FRONT IN
THE AREA AND FRONTOGENESIS INCREASING...SO HAVE SO LOW POPS
MENTIONED.
.LONG TERM...MONDAY NIGHT THROUGH FRIDAY.
LARGE-SCALE POSITIVELY TILTED OPEN UPPER LEVEL TROUGH WILL BE
MOVING THROUGH THE CENTRAL PLAINS DURING THE FIRST HALF OF THE
PERIOD. ALTHOUGH SOME TIMING DIFFERENCES STILL EXIST...THE MAIN
FORCING FOR LARGE-SCALE ASCENT WILL ARRIVE LATE MONDAY NIGHT AND
THROUGH THE DAY ON TUESDAY BEFORE THE LIFT WEAKENS LATE TUESDAY
AND TUESDAY NIGHT. THE MOST SIGNIFICANT DIFFERENCES CURRENTLY ARE
IN REGARDS TO THE LOW- LEVEL TEMPERATURE PROFILE AS THE GFS WOULD
INITIALLY TAKE THE COLD FRONT SOUTH OF I80 MONDAY NIGHT AND THEN
LIFT THIS BACK TO THE NORTH ON TUESDAY AS A WARM FRONT BEFORE
SWEEPING IT SOUTH AS A COLD FRONT ON WEDNESDAY NIGHT. THIS IS IN
ODDS TO THE EC AND FOR MOST PART GEM THAT FOR THE MOST PART KEEPS
THE FRONT STATIONARY ON TUESDAY BEFORE IS SWEEPS SOUTH ON TUESDAY
NIGHT ONCE IT MOVES SOUTH OF I80 ON MONDAY NIGHT...AND GIVEN THE
POSITIVE NATURE TO THE UPPER LEVEL TROUGH AND ASSOCIATED ENSEMBLE
SUPPORT THIS IS OUR FAVORED SOLUTION AS WELL. THIS RESULTED IN THE
LOWERING OF HIGHS TEMPERATURES ON TUESDAY OVER THE NORTHWESTERN
2/3RD OF THE FA WHERE CLOUDS...PRECIP AND LOW-LEVEL CAA WILL KEEP
TMPS BELOW GOING HIGHS AND CURRENT MOS GUIDANCE. WE WILL KEEP THE
FAR MAJORITY OF THE CWA WITH JUST RAIN DURING THE DAY ON
TUESDAY...EXCEPT THE FAR NORTHWEST CORNER /I.E.
BOONE...ANTELOPE...KNOX COUNTIES/ WHERE WE WILL CONTINUE A MIX OF
RAIN OR SNOW. WITH THE POSITIVE TILT AND OPEN NATURE OF THE UPPER
LEVEL TROUGH WE EXPECT A FAIRLY SHARP GRADIENT TO THE ENDING OF
PRECIP ON TUESDAY NIGHT BUT WILL CONT WITH THE LIKELY POPS AND
BRING THE MIX OF RA/SN A BIT FARTHER SOUTHEAST. THE PERIOD FROM
WEDNESDAY THROUGH FRIDAY LOOK DRY BUT WITH MUCH BELOW NORMAL
TEMPERATURES. WE HAVE COOLED HIGHS FOR WEDNESDAY A GOOD 5 TO 7
DEGREES BELOW GOING MOS GUIDANCE AND MAY NOT BE COOL ENOUGH YET. A
SLIGHT WARMING TREND IS THE EXPECTED TO END THE WORK WEEK BUT
STILL BELOW NORMAL.
&&
.AVIATION...
18Z TAFS FOR KOMA...KLNK...AND KOFK.
VFR CONDITIONS ARE EXPECTED THROUGH THE TAF CYCLE...WITH
INTERMITTENT SCATTERED TO BROKEN CEILINGS AT 5-10KFT. GUSTY
NORTHWEST WINDS WILL GET JUST A LITTLE GUSTIER YET THIS
AFTERNOON...THEN BEGIN TO SLACKEN SHORTLY AFTER SUNSET...WITH
SPEEDS DECREASING BELOW 10KT BY AROUND MIDNIGHT.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
ZAPOTOCNY/BOUSTEAD/MAYES
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
130 PM EDT FRI NOV 1 2013
.SYNOPSIS...
A STRONG COLD FRONT APPROACHING FROM THE WEST WILL MOVE ACROSS THE
AREA SATURDAY MORNING. IT WILL BECOME WINDY AHEAD OF THIS FRONT WITH
A HIGH RISK FOR SHOWERS AND POSSIBLY A THUNDERSTORM. SIGNIFICANT
RAINFALL IS POSSIBLE. HIGH PRESSURE WILL FOLLOW LATE SATURDAY
THROUGH SUNDAY BRINGING WITH IT COLDER AND DRIER CONDITIONS. HIGH
PRESSURE WILL PERSIST THROUGH THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM FRIDAY...FORECAST STILL APPEARS TO BE IN GOOD SHAPE.
STILL AWAITING SOME OF THE HIGHER RES HRRR AND RUC FOR ANY POSSIBLE
TWEAKS IN TIMING...BUT THEY SHOULD BE MINOR...IF ANY. 12Z RAOBS FROM
CHS AND MHX STILL SHOW A FAIR AMOUNT OF SUBSIDENCE IN THE 850-700MB
LAYER. THIS WILL ACT TO INHIBIT ANYTHING OTHER THAN FAIRLY
INSIGNIFICANT RADAR ECHOES UNTIL THIS EVENINGS STRONG FORCING
ARRIVES. CONCUR WITH SWODY1 THAT A SLIGHT RISK-WORTHY AREA OF
ORGANIZED SEVERE IS POSSIBLE SOMEWHERE SOUTHEAST/MIDATLANTIC AND
SOME TIME WILL TELL WHAT PARTS OF THE CWA WILL QUALIFY. INITIAL
SUSPICION IS THAT MOST OF THE AREA MAY SEE HIGHER WIND AND TOR
PROBS LATER ON WITH COASTAL AREAS SLIGHTLY MORE FAVORABLE FOR
SEVERE. ROUGHLY 40 OF THE 60 KNOTS OF DEEP LAYER SHEAR CURRENTLY
OBSERVED ACROSS THE REGION LIES IN THE LOWEST 1KM. SETUP APPEARS
FAVORABLE FOR A SLOWLY EASTWARD PROPAGATING SQUALL LINE READILY
CAPABLE OF WIND DAMAGE DUE TO THE STRENGTH OF THE LOW LEVEL WIND
FIELDS. QUICK TORNADO SPINUPS ALSO SEEM POSSIBLE ALONG ANY
BOUNDARIES OR STORM SCALE INTERACTIONS. PREVIOUS FOLLOWS...
AS OF 700 AM FRIDAY...STRONG SURFACE LOW PRESSURE IN THE GREAT LAKES
IS ASSOCIATED WITH AN ENERGETIC UPPER LEVEL SYSTEM LIFTING NORTHEAST
ACROSS INTO SOUTHERN ONTARIO. A SURFACE COLD FRONT EXTENDING SOUTH
OF THE LOW IS NOW ENTERING THE SOUTHERN AND CENTRAL APPALACHIANS.
TROPICAL MOISTURE IS PRESENT WITH PRECIPITABLE WATER VALUES EXPECTED
TO EXCEED 2.0 INCHES BY THIS EVENING JUST AHEAD OF THE FRONT. TO PUT
THAT IN PERSPECTIVE...2.0 INCHES IS THE 99TH PERCENTILE FOR NOVEMBER
PRECIP WATER AT CHS...AND COULD BE A RECORD NOVEMBER PW VALUE AT MHX.
THE FRONT WILL MAKE STEADY EASTWARD PROGRESS...AND THE BAND OF
SHOWERS AND EMBEDDED T-STORMS SHOULD SLIDE INTO THE CENTRAL
CAROLINAS THIS AFTERNOON. MY FORECAST POPS ALONG AND WEST OF
INTERSTATE 95 ARE IN THE 60-90 PERCENT RANGE BY LATE AFTERNOON...
WITH THE MOST SUBSTANTIAL COVERAGE OF PRECIPITATION EXPECTED ALONG
THE COAST AFTER DARK WHERE MY POPS ARE 80-90 PERCENT. STORM TOTAL
RAINFALL COULD EXCEED 1 INCH...WITH HEAVIER AMOUNTS POSSIBLE
IF/WHERE CONVECTIVE TRAINING OCCURS. COMPARED TO MY THOUGHTS BASED
ON THE 00Z MODELS...THE 06Z MODELS PLUS THE LATEST SREF SLOWS THE
WHOLE SYSTEM DOWN BY A FEW HOURS.
RADAR VERTICAL WIND PROFILES ARE CONFIRMING MODEL FORECASTS OF A
HEALTHY LOW LEVEL JET BLOWING OVERHEAD CURRENTLY. WINDS AT 1000 FT
AGL ARE AROUND 30 KNOTS WITH 40 KNOTS MEASURED AT 2000 FT. AS THE
BOUNDARY LAYER DEEPENS LATER THIS MORNING WITH RISING
TEMPERATURES...EXPECT STRONGER WINDS TO MIX DOWN WITH 30-35 MPH
GUSTS EXPECTED BY 10-11 AM. HELICITY (0-1 KM) SHOULD RANGE FROM
150-200 WITH 0-6 KM BULK SHEAR 40-50 KT. THESE VALUES ARE ALSO
SUPPORTIVE OF A SEVERE WEATHER THREAT. THE LIMITING FACTOR COULD END
UP BEING INSTABILITY: FORECAST CAPE VALUES ONLY RANGE FROM 200-400
J/KG WITH PERHAPS SOME 700 J/KG NUMBERS SHOWING UP THIS EVENING
ALONG THE COAST IF DEWPOINTS CAN HOLD IN THE UPPER 60S TO NEAR 70.
THE STORM PREDICTION CENTER CURRENTLY HAS A "SEE TEXT" 5 PERCENT
PROBABILITY FOR DAMAGING WIND GUSTS AND 2 PERCENT TORNADO RISK IN
THE CAROLINAS.
TEMPERATURES TODAY SHOULD BE VERY WARM BY NOVEMBER STANDARDS...
COURTESY OF TROPICAL AIR ADVECTED NORTHWARD AHEAD OF THE FRONT. 850
MB TEMPS EXPECTED TO RISE TO +15C ARE IN THE 95-98TH PERCENTILE FOR
NOVEMBER. TEMPERATURES SHOULD LEAP WITH THE FIRST TOUCH OF SUNLIGHT
THIS MORNING...AND HIGHS SHOULD REACH 80-82 DEGREES FOR AREAS EAST
OF INTERSTATE 95 AND A FEW MILES INLAND FROM THE BEACHES. THE FRONT
WILL MOVE ACROSS THE AREA LATE TONIGHT WITH COLD ADVECTION NOT
REACHING THE COAST UNTIL JUST A FEW HOURS BEFORE DAYBREAK. THERE IS
SOME UNCERTAINTY WITH TONIGHT`S LOW TEMPERATURES SINCE WEAKER WINDS
BEHIND THE FRONT COULD ALLOW FOR BOUNDARY LAYER DECOUPLING JUST
BEFORE SUNRISE...BUT IT APPEARS LOWS SHOULD RANGE FROM THE MID 60S
ON THE COAST TO THE UPPER 50S INLAND.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 330 AM FRIDAY...COLD FRONT WILL BE MAKING ITS WAY OFF SHORE
SAT MORNING. DRY AND COOLER AIR WILL BEGIN TO FEED INTO AREA
BEHIND THE FRONT BUT DEEP NW FLOW WITH GREATEST CAA WILL COME LATER
ON SAT AS MID TO UPPER TROUGH FINALLY SWINGS THROUGH. MAY SEE SOME
CLOUDS WITH ITS PASSAGE BUT THINK MOST CLOUDS AND ANY CHC OF A
SPRINKLE WILL REMAIN TO THE NORTH WHERE BETTER SHORTWAVE ENERGY
WILL BE.
AFTER A WARM START TO THE DAY ON SAT...TEMPS WILL REACH INTO THE 70S
AS SKIES CLEAR FROM WEST TO EAST THROUGH THE DAY. 850 TEMPS
PLUMMET THROUGH SAT INTO SUNDAY MORNING DROPPING DOWN TO 2 TO 3C
BY SUN. DEWPOINT TEMPS WILL DROP OUT AS WELL WITH READING IN THE
LOWER 30S BY MON MORNING. EXPECT TEMPS TO DROP A GOOD 10 DEGREES
SAT NIGHT FROM PREVIOUS MIN TEMPS AND THEN AN ADDITIONAL DROP SUN
NIGHT IN BETTER RADIATIONAL COOLING WITH READINGS RIGHT AROUND 40
MOST PLACES.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 3 AM FRIDAY...STRONG HIGH PRESSURE WILL RIDGE DOWN INTO
THE SOUTHEAST AS IT SHIFTS EAST THROUGH THE WEEK. AFTER A COLD
START MONDAY TEMPS WILL ONLY RECOVER TO AROUND 60 DEGREES IN COOL
NORTHERLY FLOW. AS THE HIGH SHIFTS EAST FURTHER OFF THE NEW
ENGLAND COAST THROUGH MID WEEK...A MOIST ON SHORE FLOW WILL
DEVELOP. A WEDGE LIKE PATTERN WILL SET UP WITH POTENTIAL FOR LOW
CLOUDS AND SPOTTY DRIZZLE OR SPRINKLES AS EARLY AS MONDAY NIGHT
AND POSSIBLY LASTING FOR A FEW DAYS BEFORE A COLD FRONT MAKES ITS
WAY ACROSS THE CAROLINAS BY THURS. EXPECT INCREASED CHC OF PCP ON
THURS AHEAD OF THIS COLD FRONT.
MONDAY WILL BE THE COOLEST DAY BUT WILL MODIFY SLOWLY THROUGH
MID WEEK. BUILDING RIDGE ALOFT WITH RISING H5 HEIGHTS WILL HELP TO
BRING TEMPS BACK UP ABOVE NORMAL BY WEDNESDAY. HIGHS WILL MAINLY
BE IN THE 60S THROUGH TUES AND WILL REACH BACK INTO THE 70S ON
WED. A WARMER AND MORE HUMID SOUTHERLY RETURN FLOW SHOULD SET UP
BRIEFLY BY THURS AHEAD OF NEXT FRONT. THIS WILL HELP BRING TEMPS
BACK ABOVE NORMAL REACHING WELL INTO THE 70S.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 18Z...ONLY A FEW MINOR TWEAKS ON THE TIMING TODAY. AHEAD OF
THE FRONT...EXPECT GUSTY SOUTH SOUTHWEST FLOW WITH CONTINUED CLOUDY
CONDITIONS...PREDOMINATELY VFR. JUST AHEAD OF THE FRONT THIS
EVENING...LIGHT CAPE...HIGH PRECIPITABLE WATER...AND MODERATE BULK
SHEAR IN PLACE FAVORING DEEP CONVECTION AS STRONG LIFTING ALONG COLD
FRONT ARRIVES. WINDS SHOULD MIX DOWN OCCASIONALLY FROM 4K
FEET...WITH ISOLATED WIND GUSTS TO 40 KTS POSSIBLE MAINLY AT ILM
WHERE INSTABILITY AND/OR LIFT MAY BE GREATEST. ONLY A TWO OR THREE
HOUR WINDOW FOR THIS SCENARIO THIS EVENING...STILL UNCERTAIN AS MAIN
CONVECTIVE BAND HAS NOT YET FORMED TO OUR WEST. ADDING TO TIMING
DIFFICULTY IS THE FACT THAT SQUALL LINE WILL BE DECELERATING AS IT
HEADS EAST INTO THE COASTAL PLAIN. AFTER INITIAL CONVECTION EXPECT
LIGHT TO MODERATE SHOWERS FOR ANOTHER FEW HOURS...FOLLOWED BY A WIND
SHIFT TO THE WEST WELL AFTER MIDNIGHT. CONVECTION WILL END FROM WEST
TO EAST TOWARD MORNING. IFR CEILINGS MAY LINGER UNTIL MID MORNING
SATURDAY...MAINLY INLAND.
EXTENDED OUTLOOK...MVFR/IFR CIGS POSSIBLE ON TUESDAY. OTHERWISE VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM FRIDAY...7 FT SEAS ALREADY AT MAIN BUOYS 41013 AND
41036 IN ADDITION TO 41004 FARTHER SOUTH. CURRENT CWF FCST OF 5 TO 7
FT STILL HOLDING JUST FINE AND THE TWEAKS MADE TO WAVE GRIDS WILL BE
TO BRING A LITTLE MORE OF THE 6FT SEAS INTO THE 20NM ZONES.
LLJ/925MB FLOW PROGGED TO INCREASE ALONG THE COAST AND OVER WATER
TONIGHT INTO THE 40KT REALM. WILL EXAMINE FCST SOUNDINGS TO SEE IF
FUTURE FORECASTS SHOULD INCLUDE 40KT IN GUSTS...SEEMINGLY MAINLY
HINGING UPON LAPSE RATES AND THE EXTENT OF VERTICAL MIXING. PREVIOUS
FOLLOWS...
AS OF 700 AM FRIDAY...A STRONG COLD FRONT NOW ENTERING THE SOUTHERN
APPALACHIANS SHOULD SWEEP EAST AND ACROSS THE CAROLINA COASTAL
WATERS AFTER MIDNIGHT. AHEAD OF THE FRONT STRONG SOUTH WINDS SHOULD
AVERAGE 20-25 KNOTS THROUGH TONIGHT. MODELS ARE IN EXCELLENT
AGREEMENT WITH THE MAGNITUDE OF THIS MILD SOUTHERLY FLOW. A COUPLE
WAVES OF SHOWERS HAVE AFFECTED THE COASTAL WATERS THIS MORNING...
AND ADDITIONAL ISOLATED TO SCATTERED SHOWERS COULD OCCUR DURING THE
DAY. THE HEAVIER SHOWERS AND EMBEDDED THUNDERSTORMS WITH THE ACTUAL
COLD FRONT SHOULD NOT ARRIVE UNTIL TONIGHT BUT COULD POSE A SAFETY
RISK FOR MARINERS WITH STRONG GUSTY WINDS...LIGHTNING... AND REDUCED
VISIBILITY IN HEAVY RAIN. WINDS WILL SHIFT WESTERLY BEHIND THE FRONT
AND DECREASE LATE.
SEAS ARE CURRENTLY 5 FEET AT THE FRYING PAN SHOALS BUOY AND 4 FT AT
THE BUOY SEVERAL MILES SOUTH OF BALD HEAD ISLAND. WITH CONTINUED
SOUTH WINDS SEAS SHOULD BUILD TO AS HIGH AS 6-7 FEET 10-20 MILES OFF
THE SOUTH CAROLINA COAST...AND AS HIGH AS 7-8 FEET OFF THE NORTH
CAROLINA COAST. SEAS SHOULD BEGIN TO SUBSIDE LATE TONIGHT AS WINDS
SHIFT WESTERLY.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 330 AM FRIDAY...WINDS WILL VEER TO THE W TO NW ON SATURDAY
AS COLD FRONT PROGRESSES FURTHER OFF SHORE. DEEPER LAYER NORTHERLY
FLOW WILL DEVELOP SAT NIGHT AS MID TO UPPER TROUGH CROSSES THE
WATERS. WINDS WILL DIMINISH THROUGH SATURDAY DOWN TO 15 KTS BUT
WILL SPIKE UP AGAIN WITH DEEP COLD AND DRY ADVECTION THROUGH SAT
NIGHT. SEAS WILL SUBSIDE AS WINDS SUBSIDE ON SATURDAY DROPPING
BELOW SCA THRESHOLDS THROUGH SAT MORNING. AS WINDS BECOME
OFFSHORE IN DIRECTION SAT AND SAT NIGHT...SIGNIFICANT SEAS WILL
SUBSIDE TO 2 TO 5 FT...BUT WILL BUILD AGAIN OVERNIGHT SUNDAY AS
STRONG HIGH PRESSURE BUILDS DOWN INTO THE WATERS.
LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 330 AM FRIDAY...NORTHERLY WINDS WILL PERSIST AND VEER SLOWLY
AS STRONG HIGH PRESSURE REACHING DOWN FROM CANADA SHIFTS EAST OFF
THE NEW ENGLAND COAST BY TUES MORNING. WINDS WILL BE UP TO 15 TO
25 KTS ON MONDAY AS HIGH CONTINUES TO RIDGE INTO WATERS FROM THE
NORTH. GRADIENT WILL BECOME MORE PINCHED MON INTO TUES AS WEDGE
LIKE PATTERN SETS UP...KEEPING A PERSISTENT N-NE FLOW OVER THE
WATERS. THIS WILL PRODUCE AN INCREASE IN SEAS POSSIBLY REACHING
SCA THRESHOLDS.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EDT SATURDAY FOR AMZ250-252-
254-256.
&&
$$
NEAR TERM...MBB/TRA
SHORT TERM...RGZ
LONG TERM...RGZ
AVIATION...43/MBB
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
331 PM CDT FRI NOV 1 2013
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 331 PM CDT FRI NOV 1 2013
MAIN FORECAST CONCERNS ARE ON RAIN CHANCES SUNDAY NIGHT THROUGH THE
MIDDLE OF NEXT WEEK.
3 PM WATER VAPOR IMAGERY SHOWED AND 500 MB RAP ANALYSIS SHOWED A
SHORTWAVE TROUGH MOVING ACROSS SOUTHWEST MINNESOTA/SOUTHEAST SOUTH
DAKOTA AND WAS MOVING SOUTHEAST. ANOTHER WAVE WAS NOTED OVER SOUTHERN
WISCONSIN/NORTHERN ILLINOIS MOVING EAST. SHOWERS WERE OCCURING
OVER NORTHWEST IOWA/SOUTHWEST MINNESOTA IN RESPONSE TO THE
SHORTWAVE. ANOTHER BAND OF SHOWERS WAS NOTED OVER SOUTHEAST
WISCONSIN. THE FORECAST AREA WAS LOCATED IN BETWEEN THESE TWO
FEATURES LATE THIS AFTERNOON.
MOSTLY TO PARTLY SUNNY SKIES WERE SEEN OVER MUCH OF SOUTHEAST
MINNESOTA AND NORTHEAST IOWA THIS AFTERNOON WITH WESTERN WISCONSIN
STAYING CLOUDY THROUGH MUCH OF THE DAY. THE BREAK IN CLOUD COVER
SHOULD ADVANCE EAST BUT WILL GRADUALLY FILL BACK IN AS THE WESTERN
WAVE MOVES INTO IOWA. A FEW SHOWERS MAY OCCUR OVER PORTIONS OF
SOUTHEAST MINNESOTA AND NORTHEAST IOWA THIS EVENING AS THE WAVE
MOVES THROUGH. THE MAIN PV ADVECTION IN THE 500-300 MB LAYER PASSES
ACROSS THESE AREAS SO THIS SHOULD PROVIDE THE SUPPORT FOR A FEW
SHOWERS. THE WAVE EXITS THE REGION TONIGHT AS SURFACE HIGH PRESSURE
STARTS TO BUILD IN FROM THE WEST. WEAK SHORTWAVES IN NORTHWEST FLOW
ALOFT WILL BRING PARTLY TO MOSTLY CLOUDY SKIES TO REGION. PLAN ON
OVERNIGHT LOWS RANGING FROM THE LOWER 30S OVER NORTH CENTRAL
WISCONSIN TO THE MID TO UPPER 30S ACROSS NORTHEAST IOWA. CLOUDS
SHOULD DECREASE FROM WEST TO EAST ACROSS THE AREA ON SATURDAY AS THE
SURFACE HIGH MOVES IN AND UPPER RIDGING PUSHES ACROSS THE PLAINS.
HIGHS ON SATURDAY WILL RANGE FROM THE LOWER 40S OVER NORTH CENTRAL
WISCONSIN TO THE UPPER 40S ACROSS NORTHEAST IOWA.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 331 PM CDT FRI NOV 1 2013
QUIET CONDITIONS AND COOL TEMPERATURES WILL BE THE RULE ACROSS THE
UPPER MISSISSIPPI RIVER VALLEY SATURDAY NIGHT WITH THE HIGH IN
CONTROL. THE HIGH IS EXPECTED TO SLIDE EAST OF THE REGION ON SUNDAY
AS A BROAD UPPER TROUGH DIGS INTO THE WESTERN CONUS. A SURFACE
TROUGH WILL DEEPEN OVER THE PLAINS ON SUNDAY AS THE HIGH SLIDES OFF
TO THE EAST. THIS WILL PRODUCE A TIGHT PRESSURE GRADIENT ACROSS THE
REGION WITH INCREASING SOUTH/SOUTHEAST WINDS THROUGH THE DAY.
SOUTHEAST WINDS OF 15 TO 25 MPH ARE EXPECTED WITH GUSTS TO AROUND 35
MPH POSSIBLE ACROSS THE OPEN AREAS OF SOUTHEAST MINNESOTA AND
NORTHEAST IOWA. THE TROUGH PUSHES INTO THE DAKOTAS SUNDAY NIGHT AS A
60 KT LOW LEVEL JET DEVELOPS OVER SOUTHERN MINNESOTA/WESTERN IOWA AND
SHIFTS EAST. THIS WILL PRODUCE BREEZY SOUTH WINDS THROUGH THE LATE
AFTERNOON AND EVENING HOURS. IN FACT...IF THE BOUNDARY LAYER STAYS
MIXED WE COULD SEE GUSTS AT THE SURFACE APPROACHING 40 MPH. HAVE
INCREASED WINDS SLIGHTLY DURING THE EVENING HOURS TO ACCOUNT FOR
THIS POTENTIAL. HAVE ALSO LOWERED DEWPOINTS A COUPLE OF DEGREES ON
SUNDAY TO ACCOUNT FOR MIXING TO AROUND 925 MB. 850-700MB MOISTURE
TRANSPORT INCREASES ACROSS THE WESTERN HALF OF THE FORECAST AREA
LATE SUNDAY NIGHT INTO EARLY MONDAY MORNING AS A WEAK SHORTWAVE
MOVES THROUGH THE UPPER MISSISSIPPI RIVER VALLEY. THIS MAY BE
ENOUGH SUPPORT TO TRIGGER A FEW SHOWERS SO HAVE ADDED A SLIGHT
CHANCES OF SHOWERS OVER SOUTHEAST MINNESOTA...NORTHEAST IOWA...AND
WEST CENTRAL WISCONSIN. A STRONG UPPER TROUGH EJECTS OUT OF THE
SOUTHWEST CONUS INTO THE CENTRAL PLAINS AND INTO THE UPPER
MISSISSIPPI RIVER VALLEY LATE MONDAY NIGHT INTO TUESDAY NIGHT.
THIS WILL BRING WIDESPREAD RAIN TO THE REGION ESPECIALLY TUESDAY
INTO TUESDAY NIGHT. WARM AIR WILL BE ADVECTED NORTHWARD AHEAD OF
THIS FEATURE WITH HIGHS ON MONDAY CLIMBING INTO THE MID TO UPPER
50S. THE TROUGH FINALLY SWINGS THROUGH WEDNESDAY INTO WEDNESDAY
NIGHT AND DRIVES A COLD FRONT ACROSS THE AREA. PRECIPITATION WILL
TAPER OFF FROM WEST TO EAST. SOME SNOW MAY MIX IN LATE WEDNESDAY
NIGHT BEFORE THE PRECIPITATION ENDS AND COLDER AIR MOVES IN.
THURSDAY AND FRIDAY WILL BE COOLER AND QUIET IN THE WAKE OF THE
FRONT. PLAN ON HIGHS FALLING BACK INTO THE 40S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1233 PM CDT FRI NOV 1 2013
AS THE MEAN TROUGH CONTINUES TO DRIVE SHORT WAVE TROUGHS THROUGH THE
NORTHERN PLAINS AND GREAT LAKES REGION...AREAS OF LOW CLOUDS AND
RELATED LIGHT PRECIPITATION STILL IMPACTING AVIATION.
FIRST AREA OF IFR TO MVFR CEILINGS SHIFTING EAST OF MISSISSIPPI
RIVER TODAY BUT WILL LIKELY SLOW WITH ABUNDANT LOW LEVEL MOISTURE
LOCKED UPSTREAM. CLEARING CONDITIONS OVER PARTS OF MINNESOTA AND
IOWA A NICE BREAK ALLOW VFR CONDITIONS BUT NEXT SHORT WAVE TROUGH
MOVING THROUGH THE DAKOTAS LIKELY TO BRING CEILINGS BACK INTO THE
AREA BY EVENING. MOST AREAS WILL LIKELY BE IN VFR RANGE THOUGH SO
OVERALL IMPROVEMENT IN CONDITIONS EXPECTED. COULD SEE SOME MVFR AT
TIMES OVERNIGHT AS LOW LEVEL MOISTURE DEVELOPS MORE CEILINGS AND
LIGHT FOG BUT TREND TOWARDS MIDDAY SATURDAY SHOULD BE ANOTHER STEP
IN THE IMPROVEMENT DIRECTION AS DRIER AIR MIXES IN FROM THE WEST.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM...WETENKAMP
AVIATION.....SHEA
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1233 PM CDT FRI NOV 1 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 221 AM CDT FRI NOV 1 2013
MAIN FORECAST CONCERNS ARE ON SHOWER/DRIZZLE POTENTIAL THROUGH
THIS EVENING.
CURRENTLY AS OF 07Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED RIDGING ALONG THE WEST COAST OF THE U.S. WHILE TROUGHING
ENCOMPASSED AN AREA FROM HUDSON BAY SOUTHWESTWARD INTO THE CENTRAL
PLAINS. ONE POTENT SHORTWAVE MOVING THROUGH THE TROUGH WAS OVER
LOWER MICHIGAN. COLD AIR ADVECTION IN THE WAKE OF THIS SHORTWAVE
ALONG WITH LINGERING LOW LEVEL MOISTURE HAS RESULTED IN PERSISTENT
STRATUS ACROSS THE WESTERN GREAT LAKES. THIS STRATUS WAS EVIDENT IN
00Z MPX AND GRB SOUNDINGS WITH PLENTIFUL MOISTURE BELOW 700MB. OTHER
WEAK SHORTWAVES MOVING THROUGH THE UPPER TROUGH ACROSS THE FORECAST
AREA...COMBINED WITH WEAK SURFACE TROUGHS ALSO MOVING THROUGH AND
TURBULENCE IN THE STRATUS DECK HAS PRODUCED POCKETS OF SHOWERS AND
DRIZZLE. THERE IS SOME CLEARING OF THE STRATUS DECK UPSTREAM OVER
THE DAKOTAS WITH DRIER AIR PRESENT ON THE 00Z BIS/ABR SOUNDINGS.
HOWEVER...ANOTHER SHORTWAVE MOVING THROUGH THE TROUGHING COMING INTO
WESTERN NORTH DAKOTA WAS BRINGING MORE LIGHT SHOWER ACTIVITY THERE.
REGARDING THE AFOREMENTIONED COLD ADVECTION...AT MPX...925MB AND
850MB TEMPS DROPPED ABOUT 4C BETWEEN 12Z YESTERDAY AND 00Z...WITH
READINGS OF 2C AND -1C RESPECTIVELY. THESE READINGS ARE ABOUT 0.5
STANDARD DEVIATION BELOW NORMAL.
MODELS ARE IN GOOD AGREEMENT MAINTAINING UPPER TROUGHING OVER THE
FORECAST AREA THROUGH TONIGHT. HOWEVER...THE OVERALL TROUGHING WILL
START TO PROGRESS EAST TONIGHT AS THE RIDGING ALONG THE WEST COAST
OF THE U.S. GETS PUSHED FURTHER INLAND. THE MAIN SHORTWAVE FOCUS FOR
THE SHORT TERM IS THE ONE APPROACHING WESTERN NORTH DAKOTA. MODELS
TAKE THIS SHORTWAVE INTO WESTERN IOWA BY 00Z AND SOUTHERN ILLINOIS
BY 12Z SAT. LIGHT RAIN SHOWERS ACCOMPANYING THIS SHORTWAVE COULD
IMPACT FAR WESTERN PORTIONS OF THE FORECAST AREA LATE THIS AFTERNOON
INTO THIS EVENING...THOUGH MODEL CONSENSUS WOULD SUGGEST THE BEST
DYNAMICAL FORCING AND BULK OF THE PRECIPITATION STAYS SOUTH AND WEST
OF THE AREA.
OTHERWISE THE MAIN FOCUS FOR THE SHORT TERM PERIOD IS ON THE CURRENT
STRATUS DECK AND POCKETS OF DRIZZLE/SHOWERS. WEAK TROUGHS AS WELL AS
TURBULENCE IN THE STRATUS DECK LOOKS TO CONTINUE THROUGH THIS
EVENING...THUS POCKETS OF DRIZZLE AND SHOWERS ARE LIKELY TO PERSIST
UNTIL THE DECK CLEARS. REGARDING CLEARING...NORTHWEST WINDS OF 10-20
KT BELOW 800MB WILL HELP TO ADVECT THE DRIER AIR OVER THE DAKOTAS
TOWARDS THE FORECAST AREA. RAP/NAM 950-900MB RH PROGS SUGGEST
LOCATIONS WEST OF THE MISSISSIPPI RIVER SHOULD CLEAR OUT OF THE
STRATUS THIS AFTERNOON...WHILE LOCATIONS EAST OF THE MISSISSIPPI
RIVER CLEAR OUT DURING THE EVENING. THERE COULD STILL BE SOME
LINGERING CLOUDS OVERNIGHT...BUT THESE WOULD BE MORE OF THE
ALTOSTRATUS VARIETY AND LESS OF A CONCERN FOR PRECIP.
EXPECT ANOTHER COOL DAY TODAY DUE TO 925MB TEMPS ONLY CLIMBING TO
2-5C...CLOUDS...PRECIP AND WIND. COOL CONDITIONS CONTINUE INTO
TONIGHT AS 925MB TEMPS FALL TO AROUND 0C.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 221 AM CDT FRI NOV 1 2013
MAIN FORECAST CONCERNS ARE ON WINDS SUNDAY AND PRECIPITATION
CHANCES SUNDAY NIGHT THROUGH TUESDAY NIGHT.
THE UPPER LEVEL PATTERN IS FORECAST TO UNDERGO MAJOR CHANGES DURING
THE LONG TERM PERIOD...MUCH OF WHICH OCCURS DURING THE WEEKEND.
BETWEEN 12Z SATURDAY AND 00Z MONDAY...THE WESTERN U.S. GOES FROM
RIDGING TO A FAIRLY DEEP TROUGH. THE NET RESULT IS FOR 500MB HEIGHTS
TO RISE DRAMATICALLY DOWNSTREAM OVER THE EASTERN U.S....INCLUDING
THE FORECAST AREA...ALONG WITH DEEPENING LOW PRESSURE ALONG THE LEE
OF THE ROCKIES. THERE IS STRONG MODEL CONSENSUS FOR THE WESTERN
TROUGH TO GRADUALLY EJECT EAST-NORTHEAST THROUGH THE MIDDLE OF NEXT
WEEK...AND THIS EJECTION TIMING WILL BE CRITICAL ON HOW THE WEATHER
PANS OUT.
FOR THE WEEKEND...ONE MORE SURFACE TROUGH IS PROGGED TO DROP THROUGH
WISCONSIN ON SATURDAY WHICH COULD BRING SOME LIGHT PRECIP TO
LOCATIONS NORTHEAST OF I-94. OTHERWISE...DRY CONDITIONS WILL PREVAIL
AS A RIDGE OF HIGH PRESSURE MAKES ITS WAY ACROSS THE FORECAST AREA.
TEMPERATURES LOOK TO REMAIN ON THE COOL SIDE SATURDAY AS 925MB TEMPS
ARE HELD DOWN TO NO MORE THAN 2C. HOWEVER...AS THE RIDGE PASSES OFF
TO THE EAST ON SUNDAY...WINDS REALLY START TO CRANK UP OUT OF THE
SOUTHEAST. 925MB SPEEDS ARE PROGGED AT 25-40 KT BY 00Z MONDAY...
STRONGEST OUT WEST. THESE WINDS HELP TO BRING THE 925MB TEMPS UP TO
3-5C...AND WITH SUNSHINE SHOULD HELP TO PROPEL HIGH TEMPS INTO THE
MID 40S TO LOW 50S. RIGHT NOW IT APPEARS A STRONG ENOUGH SURFACE
INVERSION WILL BE IN PLACE TO PREVENT A WIND ADVISORY SITUATION
SUNDAY OR SUNDAY NIGHT. STILL...EXPECT WINDY CONDITIONS...ESPECIALLY
OVER THE HIGHER TERRAIN OF SOUTHEAST MN AND NORTHEAST IA.
AS WE HEAD FROM SUNDAY NIGHT THROUGH THE MIDDLE OF NEXT WEEK...DEEP
LAYER MOISTURE WILL INCREASE AHEAD OF THE GRADUALLY EJECTING WESTERN
TROUGH. PRECIPITABLE WATER VALUES CLIMB FROM NEAR 0.5 INCH SUNDAY
NIGHT TO AROUND 1 INCH BY LATE TUESDAY PER THE 01.00Z GFS. THE
INCREASING MOISTURE BRINGS UP CONCERNS FOR PRECIPITATION GIVEN ITS
ALSO A WARM ADVECTION PATTERN. THE 01.00Z CANADIAN ALREADY DEVELOPS
PRECIPITATION OVER THE NORTHWEST HALF OF THE AREA SUNDAY NIGHT...
ASSOCIATED WITH A SHORTWAVE TROUGH ALL MODELS SHOW...THOUGH IT IS
THE ONLY MODEL TO DO SO. THEN ON MONDAY...THE 01.00Z ECMWF BECOMES
THE ONLY MODEL TO OVERSPREAD PRECIP ACROSS MUCH OF THE FORECAST
AREA. THIS IS ASSOCIATED WITH A WARM CONVEYOR BELT AHEAD OF A POTENT
SHORTWAVE LIFTING NORTHEAST THROUGH THE DAKOTAS. GIVEN GOOD
CONTINUITY IN THE ECMWF...SOME LOW END PRECIPITATION CHANCES ARE
REQUIRED. CHANCES FOR PRECIPITATION LOOK INCREASINGLY LIKELY FOR
TUESDAY AND TUESDAY NIGHT AS THE POTENT SHORTWAVE AT THE BASE OF THE
TROUGH APPROACHES. HAVE RAISED CHANCES ABOUT 10 PERCENT WITH FURTHER
INCREASES LIKELY NEEDED IN LATER FORECASTS. VERY LITTLE INSTABILITY
SUGGESTED THUS NO MENTION OF THUNDER AT THIS TIME. PRECIPITATION
CHANCES THEN DECLINE WEDNESDAY INTO WEDNESDAY NIGHT AS THAT POTENT
SHORTWAVE LIFTS OFF TO THE NORTHEAST OF THE AREA. HIGH PRESSURE
LOOKS TO BUILD IN FOR THURSDAY TO DRY THINGS OUT ENTIRELY.
TEMPERATURES FOR MONDAY AND TUESDAY SHOULD BE NEAR OR SLIGHTLY ABOVE
NORMAL IN THE WARM ADVECTION AHEAD OF EJECTING WESTERN TROUGH...
AIDED TOO BY BREEZY SOUTHERLY WINDS AND HIGHER MOISTURE. CONDITIONS
COOL BACK DOWN TO BELOW NORMAL FOR WEDNESDAY AND THURSDAY AS COLD
AIR FLOWS IN THE WAKE OF THE POTENT SHORTWAVE. OVERALL MUCH OF THE
AFOREMENTIONED PRECIPITATION THAT FALLS LOOKS TO OCCUR WHEN THE
BOUNDARY LAYER IS WARM ENOUGH FOR RAIN.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1233 PM CDT FRI NOV 1 2013
AS THE MEAN TROUGH CONTINUES TO DRIVE SHORT WAVE TROUGHS THROUGH THE
NORTHERN PLAINS AND GREAT LAKES REGION...AREAS OF LOW CLOUDS AND
RELATED LIGHT PRECIPITATION STILL IMPACTING AVIATION.
FIRST AREA OF IFR TO MVFR CEILINGS SHIFTING EAST OF MISSISSIPPI
RIVER TODAY BUT WILL LIKELY SLOW WITH ABUNDANT LOW LEVEL MOISTURE
LOCKED UPSTREAM. CLEARING CONDITIONS OVER PARTS OF MINNESOTA AND
IOWA A NICE BREAK ALLOW VFR CONDITIONS BUT NEXT SHORT WAVE TROUGH
MOVING THROUGH THE DAKOTAS LIKELY TO BRING CEILINGS BACK INTO THE
AREA BY EVENING. MOST AREAS WILL LIKELY BE IN VFR RANGE THOUGH SO
OVERALL IMPROVEMENT IN CONDITIONS EXPECTED. COULD SEE SOME MVFR AT
TIMES OVERNIGHT AS LOW LEVEL MOISTURE DEVELOPS MORE CEILINGS AND
LIGHT FOG BUT TREND TOWARDS MIDDAY SATURDAY SHOULD BE ANOTHER STEP
IN THE IMPROVEMENT DIRECTION AS DRIER AIR MIXES IN FROM THE WEST.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM....AJ
AVIATION.....SHEA