Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 10/05/13
AREA FORECAST DISCUSSION
NWS TAUNTON MA
731 PM EDT FRI OCT 4 2013
.SYNOPSIS...
A STALLED FRONT WILL REMAIN NEAR THE NEW ENGLAND SOUTH COAST
THROUGH SATURDAY. A WEAK WAVES OF LOW PRESSURE WILL MOVE ALONG
THE FRONT TONIGHT INTO SATURDAY...WHICH MAY BRING ANOTHER ROUND
OF SHOWERS. THE FRONT WILL THEN WILL LIFT SLOWLY NORTH DURING
SUNDAY...BRINGING WARMER TEMPERATURES MONDAY. THERE WILL A BETTER
CHANCE OF WIDESPREAD SHOWERS EARLY NEXT WEEK AS A COLD FRONT
SLOWLY MOVES ACROSS NEW ENGLAND.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
715 PM UPDATE...COVERAGE OF SHOWERS ACROSS SOUTHERN NEW ENGLAND
CONTINUES TO DIMINISH THIS EVENING. LATEST NEAR-TERM MODEL
GUIDANCE...INCLUDING THE LAST FEW RUNS OF BOTH THE HRRR AND RAP...
APPEAR TO HAVE A VERY GOOD HANDLE ON CONVECTION MOVING ACROSS
EASTERN NY STATE. WILL USE THOSE MODELS TO TWEAK RAINFALL CHANCES
FOR THE NEXT FEW HOURS.
OTHERWISE...PLENTY OF CLOUDS AND LIGHT WINDS WILL LIKELY MEAN
TEMPERATURES WILL NOT CHANGE MUCH. ADJUSTED TEMPERATURES BASED ON
OBSERVED TRENDS FOR THIS EVENING.
PREVIOUS DISCUSSION...
MAIN AREA OF SHOWERS CONTINUING TO MOVE E OF CAPE COD AT 20Z. MAY
SEE SOME BRIEF HEAVY DOWNPOURS OVER THE NEXT COUPLE OF HOURS
ACROSS THE CAPE. INTERESTING TO NOTE THAT WFO BOX RECEIVED 1.5
INCHES OF RAIN AS A COUPLE OF HEAVY SHOWERS PASS OVER THE STATION
TODAY...WHILE ABOUT 8 MILES SE...KTAN AIRPORT ONLY 0.36 INCHES WAS
REPORTED.
NOTING BREAK IN CLOUD DECK ON VISIBLE SATELLITE...WITH SOME
CLEARING ACROSS S CT AND S RI. NE RADAR MOSAIC SHOWING SCT
SHOWERS/ISOLD TSTMS ACROSS CENTRAL AND SE NY/N NJ INTO SW CT NEAR
AND S OF A STALLED FRONT AS AIRMASS DESTABILIZES. SOME MAY MOVE
INTO CT VALLEY AND NE CT/W RI THROUGH THIS EVENING. CAN NOT RULE
OUT ISOLD THUNDER...THOUGH NOT MENTIONED IN THE FORECAST FOR NOW.
WEAK LOW PRES WILL ALSO MOVE ALONG THE STALLED FRONT LATER ON...SO
HAVE KEPT CHANCE POPS GOING THROUGH THE NIGHT...WHICH WILL SHIFT
TO THE S COAST AFTER MIDNIGHT.
WILL CONTINUE TO SEE WIDE RANGE IN TEMPS INTO THIS EVENING AS E-NE
WINDS BRING COOLER AIR OFF THE OCEAN N OF THE FRONT. CASE IN
POINT...TEMP AT KFMH WAS 59 DEGREES WITH NE WINDS AT 19Z...WHILE
75 DEGREES WITH LIGHT/VRBL WINDS AT KMVY. AFTER SUNSET...TEMPS
WILL DROP BACK TO THE 50S...POSSIBLY A FEW UPPER 40S ACROSS
NORTHERN CHESHIRE AND HILLSBOROUGH COUNTIES. WILL ALSO SEE SOME
PATCHY FOG DEVELOP IN THE NORMALLY PRONE VALLEY AREAS OF INTERIOR
E MA AND THE CT VALLEY INTO NE CT.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
SATURDAY...
UPPER LEVEL RIDGING STARTS TO BUILD IN WITH THE STALLED FRONT
RUNNING PARALLEL TO IT. WEAK FRONTAL WAVE WILL SHIFT OFFSHORE AS
SURFACE RIDGE BUILDS OVER NORTHERN NEW ENGLAND. SHORT RANGE MODELS
ALL SIGNAL DRYING WORKING IN FROM THE N DURING THE DAY...THOUGH
THE FRONT DOES REMAIN STALLED NOT TOO FAR AWAY. WENT WITH ONLY
SLIGHT CHANCE POPS EARLY IN THE DAY WHICH SHOULD DRY OUT. CLOUDS
WILL LINGER INTO THE AFTERNOON...THEN SHOULD BREAK UP. WILL BE
RATHER MUGGY ALONG THE S COAST...CAPE AND ISLANDS AS DEWPTS HOVER
CLOSE TO 60 NEAR THE FRONT. TEMPS SHOULD REACH AROUND 70 ACROSS
MOST OF THE REGION.
SATURDAY NIGHT...
MODELS INDICATING THAT THE FRONT MAY TRY TO MAKE A RUN DURING THIS
TIMEFRAME...THOUGH SHOULD REMAIN S OF THE REGION THROUGH THE
NIGHT. NOT MUCH IN THE WAY OF PRECIP WITH THIS. ANOTHER WEAK LOW
MAY MOVE ALONG THE FRONT AFTER MIDNIGHT...WITH ANOTHER SHOT FOR
PRECIP TOWARD DAYBREAK. KEPT DRY FOR MOST OF THE NIGHT...THOUGH
WILL LIKELY SEE ANOTHER ROUND OF FOG DEVELOPING LATE AT NIGHT.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
HIGHLIGHTS...
* TEMPERATURES AT OR WARMER THAN NORMAL
* UNSETTLED BUT NOT A WASHOUT SUNDAY
* WIDESPREAD SHOWERS WITH LOCALLY HEAVY RAIN POSSIBLE MON/TUE
SYNOPTIC OVERVIEW...
A WARM FRONT WILL BE LIFTING NORTH THROUGH THE REGION SUNDAY AS ITS
PARENT LOW EXITS THE GREAT LAKES INTO ONTARIO. THE ATTENDING COLD
FRONT WILL BE PROGRESSIVE AND SWEEP ACROSS NEW ENGLAND SOMETIME
MON/TUE. THIS FRONT WILL MOVE OFFSHORE LATER TUE WITH CONFLUENT FLOW
ALOFT AND HIGH PRESSURE AT THE SURFACE BUILDING INTO NEW ENGLAND
LATER TUE INTO WED/THU. THIS MAY LEAVE THE REMNANTS OF TROPICAL
STORM KAREN MEANDERING SOMEWHERE OVER THE SOUTHEAST STATES NEXT WEEK.
MODELS/GUIDANCE...
WITH THE EXCEPTION OF THE 12Z CMC...THERE IS GOOD AGREEMENT WITH THE
OVERALL SYNOPTIC PATTERN AMONG THE MEMBERS OF THE 12Z GUIDANCE
SUITE. MODELS ARE STARTING TO SLOW THE PASSAGE OF A COLD FRONT FROM
EARLY TUESDAY...TO SOMETIME TUESDAY NIGHT INTO WEDNESDAY. CONFIDENCE
WITH THIS TIMING IS BELOW AVERAGE...GIVEN THE RUN-TO-RUN
INCONSISTENCIES.
THE SLOWER TIMING OF A COLD FRONT WOULD MEAN LESS PHASING OF THE
MOISTURE FROM REMNANTS OF KAREN WITH THE FORCING OF THIS FRONT.
THUS DESPITE THE POTENTIAL FOR 1-2 INCHES OF RAIN SOMEWHERE...THERE
IS NOT MUCH CONFIDENCE TO SAY EXACTLY WHERE AND WHEN JUST YET. THE
TREND CONTINUES WHERE IT WOULD BE LESS LIKELY TO BE SOMEWHERE IN
SOUTHERN NEW ENGLAND.
SENSIBLE WEATHER...
SUNDAY...A WARM FRONT LIFTS ACROSS AND NORTH OF OUR REGION. DEEP
LAYER MOISTURE AND LIFT ARE LACKING...SO THINKING ANY SHOWER
ACTIVITY WILL BE SPOTTY AND NOT WIDESPREAD. HENCE MANY HOURS OF DRY
WEATHER. COOLER AS WARM SECTOR MAY NOT OVERSPREAD THE REGION UNTIL
SUNDAY NIGHT OR MONDAY.
MONDAY/TUESDAY...A PERIOD OF SHOWERS WITH LOCALLY HEAVY RAIN APPEARS
LIKELY. DEPARTURE TIME OF SHOWERS STILL SOMEWHAT UNCERTAIN. MILD TO
WARM WITH A COLD FRONT LIKELY NOT CROSSING OUR REGION UNTIL LATE
TUESDAY OR TUESDAY NIGHT.
WEDNESDAY/THURSDAY...MODEL CONSENSUS CONTINUES WITH A DRYING TREND
AS A HIGH PRESSURE IS EXPECTED TO BUILD TOWARD NEW ENGLAND FROM THE
GREAT LAKES. THIS WOULD MEAN THE REMNANTS OF KAREN WOULD REMAIN WELL
SOUTH OF NEW ENGLAND. COOLER BUT PROBABLY STILL NEAR OR SLIGHTLY
WARMER THAN NORMAL.
FRIDAY...HIGH PRESSURE SHOULD BE IN CONTROL WITH DRY WEATHER AND
NEAR NORMAL TEMPERATURES.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH SATURDAY NIGHT/...MODERATE TO HIGH
CONFIDENCE.
TONIGHT...GENERALLY VFR CONDITIONS. SCT SHOWERS MAY PRODUCE LOCAL
MVFR-IFR CONDITIONS ACROSS CENTRAL AND SOUTHERN AREAS EARLY
TONIGHT...WHICH SHOULD DIMINISH AFTER MIDNIGHT. MAY ALSO SEE
PATCHY FOG AFTER MIDNIGHT WITH IFR-LIFR CIGS/VSBYS IN NORMALLY
PRONE AREAS.
SATURDAY...ANY LEFTOVER SHOWERS WILL DIMINISH BY MIDDAY. MAINLY
VFR. EARLY MORNING PATCHY FOG WILL DISSIPATE BY MID MORNING.
SATURDAY NIGHT...MAINLY VFR CIGS. LOCAL MVFR-IFR CIGS/VSBYS AFTER
MIDNIGHT IN PATCHY FOG IN NORMALLY PRONE AREAS.
KBOS TERMINAL...HIGH CONFIDENCE VFR. LIGHT/VRBL WINDS BECOME E-NE
TONIGHT AND SAT. LOW PROB OF MVFR CIGS/VSBYS TONIGHT/EARLY SAT WITH
ONSHORE WINDS.
KBDL TERMINAL...MAINLY VFR. MVFR CIGS POSSIBLE LATE TONIGHT INTO
EARLY SAT.
OUTLOOK...SUNDAY THROUGH WEDNESDAY...
MODERATE CONFIDENCE.
SUNDAY...VFR LIKELY WITH SPOTTY SHOWERS POSSIBLE...MAINLY DURING THE
AFTERNOON ACROSS THE WESTERN HALF OF THE REGION.
MONDAY/TUESDAY...A PERIOD OF MVFR/IFR POSSIBLE IN SHOWERS AHEAD OF
AN APPROACHING COLD FRONT.
WEDNESDAY...VFR LIKELY ACROSS THE INTERIOR...WITH A LOW PROBABILITY
OF MVFR CONDITIONS TOWARD THE CAPE AND ISLANDS...ESPECIALLY EARLY.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH SATURDAY NIGHT/...HIGH CONFIDENCE.
EXPECT WINDS AND SEAS TO REMAIN BELOW SMALL CRAFT CRITERIA. SCT
SHOWERS THROUGH THIS EVENING ACROSS THE EASTERN WATERS. PATCHY FOG
POSSIBLE LATE TONIGHT AND SAT NIGHT WITH LOCAL VSBY RESTRICTIONS.
OUTLOOK...SUNDAY THROUGH WEDNESDAY...
SUNDAY...LIGHT SE WINDS WITH HIGH PRES OVER THE MARITIMES.
SUNDAY NIGHT/MONDAY...INCREASING SSW WINDS WITH APPROACHING COLD
FRONT. VSBY LIMITED IN SHOWERS AND FOG. ROUGH SEAS LIKELY DEVELOPING
ACROSS THE OUTER COASTAL WATERS.
MONDAY NIGHT/TUESDAY...COLD FRONTAL PASSAGE WITH REMNANTS OF
TROPICAL STORM KAREN LIKELY REMAINING WELL SOUTH OF NEW ENGLAND.
WEDNESDAY...WINDS DIMINISH SOME...WITH LINGERING ROUGH SEAS ACROSS
THE OUTER COASTAL WATERS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...EVT/BELK
NEAR TERM...BELK/EVT
SHORT TERM...EVT
LONG TERM...BELK
AVIATION...EVT/BELK
MARINE...EVT/BELK
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1014 PM CDT FRI OCT 4 2013
.DISCUSSION...
804 PM CDT
THIS EVENING...WARM FRONT STRETCHES FROM NEAR DBQ ESE TO JOT...THEN
EAST TO VPZ. TEMPERATURES CONTINUE TO RUN IN THE MID TO UPPER 70S
SOUTH OF THE FRONT...WITH DEWPOINTS INTO THE MID TO UPPER 60S. NORTH
OF THE BOUNDARY...TEMPERATURES QUICKLY TAPER INTO THE MID 60S...WITH
LOW DEW POINT DEPRESSIONS. FOG/LOW STRATUS ALREADY STARTING TO
DEVELOP ACROSS THESE AREAS...AND SHOULD CONTINUE TO EXPAND OVERNIGHT.
REMOVED PRECIP MENTION OVERNIGHT FOR ALL BUT THE NORTHERN TIER OF
COUNTIES. LAST VISIBLE SATELLITE IMAGES BEFORE SUNSET SHOWED CU
FIELD QUICKLY DISSIPATING...AND THE MAIN IMPETUS FOR ANY PRECIP
OVERNIGHT IS NEAR THE IL/WI STATE LINE WHERE THE BEST FOCUSED
ISENTROPIC ASCENT IS NOTED. FORECAST OTHERWISE ON TRACK WITH ONLY
MINOR TWEAKS TO THE HOURLY TRENDS.
DEUBELBEISS
//PREV DISCUSSION...
240 PM
FOR THE REMAINDER OF THE AFTERNOON THROUGH SATURDAY...THE MAIN
CONCERN WILL BE SEVERE WEATHER POTENTIAL...WITH A SECONDARY CONCERN
FOR TEMPERATURES.
EARLY THIS AFTERNOON...CONVECTIVE ACTIVITY IS FOCUSING ON THE NOSE
OF A STRONG LOW LEVEL JET POINTING INTO NRN IL...WHICH IS ENHANCING
THE ISENTROPIC LIFT ALREADY IN PLACE AS WARM MOIST AIR CONTINUES TO
STREAM INTO THE REGION. A SECONDARY FOCUS OF CONVECTIVE ACTIVITY IS
A SFC TROUGH/SECONDARY WARM FRONT EXTENDING FROM NRN MO...THROUGH
NRN IL AND NRN INDIANA. LATEST RADAR IMAGERY SHOWS THE WARM
ADVECTION CONVECTION ALREADY INTO NWRN IL AND WITH COPIOUS AMOUNTS
OF HEAT...TEMPS IN THE UPPERS 70S-LOW 80S...MOISTURE...DEWPOINTS IN
THE UPPER 60S TO LOWERS 70S...AND INSTABILITY...MIXED LAYER CAPE OF
1500-2000 J/KG...EXPLOSIVE CONVECTION IS QUITE POSSIBLE WHERE ALL
ELEMENTS LINE UP JUST RIGHT. WITH THE LOW LEVEL JET OF 30KT+ OVER
THE AREA...STRONGER WINDS CAN CERTAINLY MIX DOWN TO THE SURFACE.
THE ONE QUESTION MARK AT THIS TIME IS THE CLOUD COVER. LATEST
SATELLITE IMAGERY SHOWS DENSE OVC OVER NRN IL...WITH MORE
CONVECTIVELY DRIVEN CU/TOWERING CU SOUTH OF THE I-80 CORRIDOR. OF
PARTICULAR CONCERN IS THE SECONDARY WARM FRONT...WHICH LIES IN THE
AREA OF GREATER SFC INSOLATION SOUTH OF I-80. THE 12Z ILX SOUNDING
INDICATES AT LEAST SOME VEERING OF WINDS THROUGH THE LOWER LEVELS
WHICH WOULD HELP ADD SOME ROTATIONAL ASPECT TO STORMS...WHICH IN
TURN COULD ADD A LARGE HAIL OR TORNADIC POTENTIAL TO THE STRONG WIND
THREAT. ON TOP OF ALL OF THIS WILL BE A HEAVY RAINFALL POTENTIAL.
THE 12Z KDVN SOUNDING INDICATES PWAT OF 1.4 INCHES...SO DEEP LAYER
MOISTURE IS ALREADY IN PLACE. THE VARIOUS MODEL FORECAST PWATS
INDICATE THAT A CORRIDOR OF EXTREME DEEP LAYER MOISTURE POOLING IN A
CORRIDOR FROM SWRN WISCONSIN TO NERN KANSAS. WITH TIME AND
PROGRESSION OF THE PATTERN...EXPECT THAT PWATS WILL ONLY INCREASE
OVER THE LOCAL AREA THROUGH THE NEXT 36HRS. THE KDVN PWAT
CLIMATOLOGY INDICATES THAT FOR OCTOBER...2 STANDARD DEVIATIONS FROM
NORMAL IS 1.6 INCHES AND THE 99TH PERCENTILE PWAT IS 1.9 INCHES.
THE LATEST MODEL RUNS SHOW PWAT INCREASING TO IN EXCESS OF 1.5
INCHES IN THE ENVIRONMENT AHEAD OF THE APPROACHING COLD FRONT.
SO...FOR THE SEVERE WEATHER THREAT...TIMING AND COVERAGE ARE THE BIG
QUESTIONS. ANTICIPATE THAT THE GREATEST SEVERE WEATHER THREAT WILL
BE WITH THE COLD FRONT DUE TO THE GREATER SFC FORCING WHICH WILL
LINE UP WITH THE FAVORABLE UPPER DYNAMICS WITH THE UPPER TROUGH.
HOWEVER...THERE WILL STILL BE A MORE ISOLATED SEVERE WEATHER THREAT
ACROSS THE LOCAL AREA SIMPLY DUE TO THE UNSEASONABLY STRONG LOWER
LEVEL THERMODYNAMICS AND EXTREME DEEP LAYER MOISTURE. ALONG WITH
THE SEVERE WEATHER THREAT...HEAVY RAINFALL AND LOCALIZED FLOODING
WILL BE A CONCERN. THE PRIMARY LOCATION FOR POSSIBLE FLOODING WILL
BE ALONG THE SECONDARY WARM FRONT AS RADAR TRENDS INDICATE THAT THE
BOUNDARY ITSELF IS QUASISTATIONARY WHILE INDIVIDUAL CELLS TRACK TO
THE EAST. THE CURRENT CONVECTIVE ACTIVITY ALONG THIS BOUNDARY IS
CURRENTLY OVER NRN INDIANA...BUT RADAR SHOWS A FINE-LINE WEST INTO
NERN IL. IF CONVECTION FILLS IN ALONG THE BOUNDARY AND IT REMAINS
QUASISTATIONARY OR AT LEAST SLOWLY PROGRESSIVE...LOCALIZED FLOODING
WILL BECOME AN INCREASING CONCERN.
FOR TIMING OF THE PROGRESSION OF THE COLD FRONT...THE VARIOUS MODELS
HAVE CONVERGED INTO GOOD AGREEMENT ON THE PROGRESSION...CROSSING THE
RIVER INTO NWRN IL BY ARND 12Z SATURDAY AND STEADILY PROGRESSING EWD
TO NRN INDIANA BY LATE AFTERNOON OR EARLY EVENING. THE THUNDERSTORM
THREAT SHOULD BE CONFINED TO A ZONE ALONG AND AHEAD OF THE FRONT.
FOLLOWING THE FRONTAL PASSAGE...CONDITIONS SHOULD QUICKLY
IMPROVE...FOR A TIME...WITH TEMPERATURES DROPPING OFF QUICKLY.
TEMPERATURES WILL DROP OFF FROM HIGHS IN THE LOW TO MIDDLE 80S TODAY
AND SATURDAY TO LOWS IN THE UPPER 40S TO MIDDLE 50S SUNDAY MORNING
AND LOWS IN THE MIDDLE 40S BY MONDAY MORNING. HIGHS FOR SUNDAY AND
MONDAY SHOULD BE IN THE LOWER TO MIDDLE 60S. THERE WILL STILL BE
SOME CHANCE FOR SOME PCPN SUNDAY AND MONDAY AS THE CENTER OF THE
UPPER LOW TRACKS RIGHT OVER NRN IL/IN...BUT ANY PCPN SHOULD
GENERALLY BE SCT SHOWERS AND PCPN AMOUNTS GENERALLY LIGHT.
FOR THE EXTENDED FORECAST PERIOD...FROM TUESDAY THROUGH
FRIDAY...EXPECT A PERIOD OF SLOWLY MODERATING TEMPERATURES WITH
LITTLE TO NO CHANCE OF PCPN. FOLLOWING THE PASSAGE OF THE UPPER
LOW...A BUILDING UPPER LEVEL RIDGE WILL SLOWLY MOVE OUT OVER THE
PLAINS AND MISSISSIPPI VALLEY AS ANOTHER DEEP UPPER LOW DROPS DOWN
THE WEST COAST INTO THE DESERT SOUTHWEST. THE AMPLIFYING...BUT
SLOWLY PROGRESSIVE PATTERN ALOFT WILL KEEP CONDITIONS DRY WITH ABOVE
NORMAL TEMPS OVER THE LOCAL WITH HIGHS IN THE LOWER TO MIDDLE 70S
AND LOWS IN THE UPPER 40S TO MIDDLE 50S.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 03Z...
* LOWERING VISIBILITY AND CIGS INTO IFR CATEGORY INTO OVERNIGHT.
* NORTHEAST WINDS BECOMING EAST THEN SOUTHEAST TONIGHT WITH SPEEDS
MOST OF TIME BELOW 10 KT.
* SMALL CHANCE OF TSRA SAT MORNING GRADUALLY INCREASING INTO MID-
AFTERNOON.
* THUNDERSTORMS LIKELY 21Z-02Z SOME OF WHICH COULD BE STRONG.
//DISCUSSION...UPDATED 00Z...
COMPLEX AVIATION FORECAST AS STATIONARY BOUNDARY IS IN PLACE FROM
JUST NORTH OF QUAD CITIES EASTWARD NEAR I-80. WITH TERMINALS BEING
NORTH OF THIS...WIND FLOW OF NE TO E IS EXPECTED MUCH OF THIS EVE
THOUGH SPEEDS SHOULD REMAIN MAINLY BELOW 10 KT. THIS LOCATION
NORTH OF THE FRONT ALONG WITH ANOMALOUSLY HIGH LOW-LEVEL MOISTURE
WILL SET THE STAGE FOR CONTINUING DECREASING VISIBILITY AND CIGS
TONIGHT. THE LATEST SATELLITE IMAGERY AND OBSERVATIONS ARE
INDICATING THE CIGS BECOMING MORE WIDESPREAD AND EXPECT THAT TAFS
WILL HAVE TO ACCOUNT FOR THESE MORE IN TIME. EITHER WAY...IFR
CONDITIONS ARE EXPECTED TO DEVELOP FROM NORTH TO SOUTH THIS EVE.
THE BOUNDARY SHOULD MOVE GRADUALLY NORTH INTO SATURDAY MORNING
ALLOWING FOR THE FOG AND STRATUS TO DIMINISH DURING THAT TIME.
ATTENTION THEN TURNS TO THUNDER LIKELIHOOD BY EARLY AFTERNOON IN
ROCKFORD AND MID AFTERNOON INTO EARLY EVE AT CHICAGO SITES. THIS
WILL AHEAD OF A POTENT COLD FRONT WORKING EASTWARD. SOME OF THE
STORMS WILL PROBABLY BE GUSTY...POSSIBLY WITH SEVERE GUSTS...AND
THAT MOST FAVORED TIMING WILL BE AT THE LEADING EDGE OF THE
STORMS. SOUTH SOUTHWEST WINDS WILL BE GUSTY AT TIMES AND THEN TURN
WESTERLY BEHIND THE FRONT SATURDAY EVE.
//ORD AND MDW CONFIDENCE...UPDATED 03Z...
* HIGH CONFIDENCE IN STABLE/SLIGHTLY LOWERING TREND OF
CIG...MEDIUM CONFIDENCE ON VISIBILITY. MEDIUM CONFIDENCE ON HOW
LOW CIG AND VISIBILITY WILL FALL.
* MEDIUM-HIGH CONFIDENCE IN WIND FORECAST.
* MEDIUM CONFIDENCE ON TSRA TIMING OF 21Z-02Z.
//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...
SUNDAY...VFR DURING THE DAY WITH MVFR CIGS AND CHC SHRA DURING THE
NIGHT.
MONDAY...CHC OF MVFR AND SLT CHC OF SHRA DURING THE MORNING.
TUESDAY-THURSDAY...MAINLY VFR.
MTF
&&
.MARINE...
341 PM CDT
A TROUGH OF LOW PRESSURE AND ASSOCIATED FRONTAL BOUNDARY ARE
SITUATED ACROSS THE UPPER MISSISSIPPI VALLEY EAST ACROSS TO THE
SOUTHERN GREAT LAKES REGION...WITH THESE FEATURES STEMMING FROM AN
AREA OF LOW PRESSURE SITUATED OVER THE CENTRAL PLAINS. ITS THESE
FEATURES THAT ARE PROVIDING...AND WILL CONTINUE TO PROVIDE
DRASTICALLY VARYING CONDITIONS ACROSS THE ENTIRE LAKE. A LIGHTER
WIND FIELD IS CURRENTLY PRESENT OVER THE SOUTHERN PORTIONS OF THE
LAKE WHERE THE PRESSURE GRADIENT IS RELAXED...BUT WITH SPEEDS
INCREASING TO 15 TO 25 KT FOR THE FAR NORTHERN PORTIONS OF THE
LAKE. THIS BOUNDARY WILL LIFT BACK NORTH ACROSS THE LAKE TONIGHT
INTO SATURDAY WHILE THIS LOW PRESSURE SYSTEM SLOWLY TRACKS
NORTHEAST TOWARDS THE MISSISSIPPI VALLEY. AS THIS OCCURS...EXPECT
A GRADUAL TRANSITION TO THE EAST SOUTHEAST WITH SPEEDS INCREASING
ACROSS THE ENTIRE LAKE. EXPECT THE HIGHEST SPEEDS OF 30KT TO BE
OBSERVED ACROSS THE NORTH...WITH THESE EASTERLY WINDS/SPEEDS
LIKELY PERSISTING INTO EARLY SATURDAY NIGHT. EXPECT THIS LOW TO
THEN CONTINUE NORTHEAST AND REACH THE CENTRAL GREAT LAKES LATE
SATURDAY NIGHT INTO SUNDAY...AND THEN CONTINUE EAST TOWARDS THE
EASTERN GREAT LAKES SUNDAY NIGHT INTO MONDAY. AS THIS
OCCURS...EXPECT SPEEDS TO DIMINISH WHILE BECOMING MORE SOUTHERLY
ON SUNDAY AND THEN WEST/NORTHWEST INTO MONDAY.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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[top]
Area Forecast Discussion
National Weather Service Lincoln IL
851 PM CDT Fri Oct 4 2013
.DISCUSSION...
ISSUED 850 PM CDT Fri Oct 4 2013
Updated the forecast for tonight to increase the PoPs early in
southeast IL for the isolated showers and few rumbles of thunder.
Also dropped the PoPs a bit in areas west of the IL River. Radar
trends with the convection in Iowa and western Missouri, along
with high res model solutions from the HRRR and RAP, indicate that
the showers and t-storms may not impact west central IL until
close to daybreak.
Otherwise, the forecast low temperatures, sky cover and wind are
all on track for the rest of tonight.
Miller
&&
.AVIATION...
ISSUED 650 PM CDT Fri Oct 4 2013
Main aviation weather concerns for the next 24 hours will be the
potential for MVFR, and at times IFR, ceilings and visibility
early in the morning, and then the timing of the convection and
associated cold front.
Similar to the past few nights, warm and moist air in the lower
atmosphere will eventually yield areas of light fog/mist and the
potential for IFR ceilings after 09Z. Once again, a south wind of
6 to 10 knots should keep the fog from becoming thicker.
Remnants of the convection that is currently ongoing in the Plains
is expected in central IL during the late morning. There is the
potential for scattered showers and t-storms to develop ahead of
this convection toward daybreak. However, confidence is not very
high with only one operational model - the GFS - indicating this
potential.
The big issue for Saturday will be the approaching cold front and
t-storms that are expected with it. Model consensus is that
convection is expected to develop/intensify between the IL River
and I-55 from very late in the morning into early afternoon, with
the frontal passage around 20-22Z. The instability is expected to
be modest, but increasing unidirectional vertical wind shear could
produce some fairly strong to severe wind gusts with the t-storms.
Picking any particular TAF site where this may happen is difficult
this far out, so will stick with a predominant TSRA group for now
and make adjustments with future forecasts.
Eastern IL may see scattered showers and t-storms from late
morning into the afternoon. The best potential for widespread
thunderstorms is expected late in the afternoon with the frontal
passage after dark.
Miller
&&
.PREV DISCUSSION...
ISSUED 300 PM CDT Fri Oct 4 2013
The current heat and humidity will be displaced by a chilly
Canadian airmass after a strong cold front moves through on
Saturday. Severe weather potential will increase as we head into
Saturday afternoon, especially if sunshine is able to help
destabilized the boundary layer for any portion of the day. A
slight risk for severe storms has been outlined by SPC for nearly
all of Illinois. The timing of the front remains in question, with
a compromise used between the faster NAM/Canadian and the slower
GFS/ECMWF. That basically allowed for some consistency with the
going forecast. Dry air will be wrapping into the back side of the
cold front, but as the occlusion process occurs, bands of moisture
will trail the front and allow for a few post frontal showers to
linger into Sunday and possibly even Monday.
SHORT TERM...Tonight through Sunday night.
A Pacific moisture connection will continue to feed into the warm
sector across the nations heartland over the next 24-36 hours...as
the warm front lingers in N Iowa and S Wisconsin. Localized
pockets of energy will tap into that moisture to fuel isolated
showers in our SE counties as well as our far NW counties into
this evening. Most areas should remain dry this evening, and even
overnight. We left a wide area of slight chance pops across the
area after midnight, with chance PoPs in the far NW closer to the
expected storm track.
Tonight and early Saturday, low pressure in the western plains will
lift north into eastern South Dakota before stalling during
occlusion. It`s eastward progression will pick up speed as a
kicker trough enters the northwest coast. The timing of the front
will be key in where severe potential is maximized, mainly from
the amount of sunshine for low level heating. There may be some
isolated severe storms overnight west of our area as the nocturnal
jet intensifies ahead of the cold front. The cold front is
projected to reach the I-55 corridor by Noon or 1 pm, then slow
down and reach the Indiana border mid- evening.
Instability params and hodographs are pointing toward damaging
winds as the main hazard in our area, with better directional
shear and rotating storms farther north near the warm front and
track of the low. Hail potential will increase closer to the cold
front and moisture pooling and updraft strength intensify. Severe
chances will linger into the evening east of I-57, but should
become more isolated as the front slows down.
We kept likely PoPs east of I-57 Sat eve, and near the Indiana
border after midnight. Coverage of storms will likely diminish Sat
night as will intensity. Some clearing behind the cold front will
low temps drop into the 40s by Sunday morning west of I-55.
The cold air will limit highs on Sunday to the upper 50s near GBG
and mid 60s near LWV. Scattered rain will be possible across
the east and north associated with cold pool-instability
showers...as the upper trough lingers just west of IL.
Sunday night will be coldest night of the next week, with lows in
the low to mid 40s everywhere.
LONG TERM...Monday through Friday.
The upper vortex may still be over IL on Monday if the GFS and
ECMWF verify, which would put showers across IL during the day. We
left Mon dry for now, but at least sprinkles may be needed if the
next couple of model runs show the slower progression.
A warming trend will begin on Tue and continue through Friday.
Highs should reach above normal into the mid 70s Thur/Fri. Dry
conditions are expected to prevail all week, with comfortable
humidity levels. The next chance of rain may hold off until the
Sunday Oct 13.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
943 PM CDT Fri Oct 4 2013
.UPDATE...
Issued at 931 PM CDT FRI OCT 4 2013
Weak elevated lift occurring behind the cold front across portions
of northeast and north central Kansas has triggered a few isolated
showers. Observations and latest runs of the HRRR suggest these
benign showers to linger through the overnight period before
clearing skies bring an end to the precipitation.
&&
.SHORT TERM...(This Evening through Saturday)
Issued at 318 PM CDT FRI OCT 4 2013
Latest surface analysis at 19Z had the cold front extending from
east of Concordia through Salina and into northwest Oklahoma. Dew
points and temperatures have dropped back into the 40s and 50s
behind the front. Visible satellite loop shows cu field along the
front which had developed since 18Z.
Surface based CAPE is in the 2500 to 4000 J/kg range. 18Z TOP
sounding still showed a Cap in place, but is expected to erode by
21Z.
0-6 km shear is forecast to be in the 30 to 40 kt range. Low level
helicity is highest near the Nebraska border in far northeast
Kansas. Across the rest of the area values are lower and low level
winds from VAD and profilers should little turning with height in
the low levels with the best low level shear in Nebraska. As the
front continues to move through have adjusted where convective
initiation is expected to occur which is from near Abilene through
Marysville, so have lowered or eliminated chances of thunderstorms
across north central Kansas. Shear and instability are favorable for
severe storms late this afternoon and evening with damaging winds
and hail the main hazards, but an isolated tornado cannot be ruled
out. Initial cells forming along the front will become linear in
nature as they move east across the cwa with bowing segments owning
to the wind threat.
Precipitation should come to an end by sunrise Saturday with skies
clearing out during the morning hours. Cold advection tonight and
Saturday will bring an abrupt drop in temperatures with lows in the
40s tonight and highs in the 50s to lower 60s Saturday.
.LONG TERM...(Saturday Night through Friday)
Issued at 318 PM CDT FRI OCT 4 2013
Upper low will progress eastward through the mid MO and MS valleys
Sat night through Sunday night. As it does...the cyclonic
circulation around it will likely clip the northern cwa with
stratocu deck. However it remains a challenge this far out to
determine how extensive the cloud cover and period of time the
clouds will linger. Either way...decent mixing should persist
through the night into Sunday morning...which along with any clouds
should help to keep overnight lows up a bit. Will keep lows in the
upper 30s to around 40 degrees for now...but if clouds are more
extensive than current fcst...then lows may need to be increased
slightly. Clouds on Sunday should be most extensive across the
northeast corner in better proximity to exiting upper low and will
keep highs in the upper 50s in that with low to mid 60s elsewhere
with more sunshine.
Upper level ridging will develop across the central plains as the
first trough exits to the east and a second upper trough digs into
the western coast. Will slowly but steadily increase high temps
through the 70s next week while warming lows from the lower 40s
Monday...to the middle and upper 50s by Thursday. Will include low
chances for showers and thunderstorms west to east across the cwa
Thursday night into Friday as the western trough begins to eject
out into the plains.
&&
.AVIATION...(For the 00Z TAFs through 00Z Saturday Evening)
Issued at 650 PM CDT FRI OCT 4 2013
Line of thunderstorms will move through TOP and FOE terminals
through 02Z. Winds may gust to 45 kts with the stronger cells.
Behind the front expect winds to shift to the west with gust front
then become southwest around 12 kts. After 03Z west to northwest
winds of 12 mph will prevail along with VFR conditions. Winds will
increase after 15Z to around 14 kts with gusts up to 25 kts
possible.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Bowen
SHORT TERM...53
LONG TERM...63
AVIATION...53
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
1039 PM EDT FRI OCT 4 2013
.SYNOPSIS...
WEAK HIGH PRESSURE WILL REMAIN OVER NEW ENGLAND THROUGH SATURDAY
WHILE A STATIONARY FRONT REMAINS OVER SOUTHERN NEW ENGLAND AND
EASTERN NEW YORK STATE. LOW PRESSURE WILL PULL A WARM FRONT NORTH
ACROSS THE AREA LATE SUNDAY OR SUNDAY NIGHT...WITH A TRAILING
COLD FRONT TO CROSS THE REGION TUESDAY. SOME OF THE MOISTURE FROM
THE REMAINS OF TROPICAL STORM KAREN MAY MOVE UP ALONG THIS FRONT.
&&
.NEAR TERM /THROUGH SATURDAY/...
UPDATE...A FEW CHANGES TO THE CURRENT FORECAST BASED ON LATEST
GUIDANCE/TRENDS. HAVE SHARPENED THE TEMP GRADIENT ACROSS THE CWFA.
BREAKS IN OR THIN CLOUDS ACROSS THE FAR NE WILL ALLOW TEMPS TO
APPROACH THE UPPER 30S TONIGHT...WHILE THICKENING CLOUD COVER WILL
KEEP THINGS MILDER ACROSS THE S. EXPECT A MOSTLY DRY NIGHT...SO
HAVE TRENDED POP DOWN FROM PREVIOUS FORECAST. A FEW ISOLD SHRA MAY
BE POSSIBLE ACROSS SRN ZONES...CLOSER TO THE WARM FNT.
PREVIOUS DISCUSSION...CLOUD SHIELD HAS FINALLY REACHED EASTERN
PORTIONS OF THE FORECAST AREA...DESPITE DRY AIR ASSOCIATED WITH
SURFACE HIGH PRESSURE OVER NORTHERN NEW ENGLAND. AN AREA OF
SHOWERS HAS JUST EXITED THE NH SEACOAST...MUCH IN LINE WITH THE
TIMING OF THE LATEST HRRR MODEL. MORE SHOWERS CONTINUE TO DEVELOP
OVER QUEBEC PROVINCE AND SLIDE TO THE SOUTH AND EAST. THERE IS
STILL A GOOD AMOUNT OF DRY AIR IN THE SOUNDING...HOWEVER A FEW OF
THESE SHOWERS MAY SURVIVE THE TRIP THROUGH THE REGION.
PLACED A SMALL AREA OF PATCHY LATE NIGHT FOG INTO THE CT RIVER
VALLEY TONIGHT. DESPITE CLOUD COVER...SOME FOG MAY DEVELOP IN THE
LEBANON AND ADJACENT VALLEY AREAS.
&&
.SHORT TERM /SATURDAY NIGHT/...
THE BATTLE BETWEEN THE RIDGE TO OUR NORTH AND EAST...AND A
STATIONARY FRONT TO OUR SOUTH AND WEST WILL CONTINUE ON SATURDAY
AND SATURDAY NIGHT. BY LATE SATURDAY NIGHT...THIS FRONT ADVANCES
TOWARDS NORTHERN NEW ENGLAND AS A WARM FRONT. LIMITED MOISTURE
MOVING INTO THE RIDGE UNDER A WARM AIR ADVECTION PATTERN MAY BRING
A FEW LIGHT SHOWERS TO THE REGION. THE PROBABILITY OF
PRECIPITATION WILL INCREASE LATE SATURDAY NIGHT AS THE FRONT APPROACHES.
USED A BLEND OF MET/MAV MOS FOR TEMPS THIS PERIOD.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
A DIRTY UPPER RIDGE AXIS WILL EXTEND ACROSS NEW ENGLAND BUT A
SHORT WAVE MOVES THROUGH ON SUNDAY AS A VERY MOIST ONSHORE SSELY
FLOW DEVELOPS ALLOWING OVERRUNNING RAINS TO DEVELOP FROM S-N DURING
THE DAY SUNDAY AND CONTINUE SUNDAY NIGHT INTO MON NIGHT AND PSBLY
TUE. OVERNIGHT LOWS WILL REMAIN MILD BUT DAYTIME HIGHS WILL REMAIN
COOL DUE TO THE ONSHORE FLOW EVEN THO H85 TEMPS WILL BE +12 TO
+14C. THE MOISTURE THAT WILL BE ASSOCIATED FROM THE REMNANTS OF
KAREN WILL ALSO GET ENTRAINED EARLY NEXT WEEK INTO THE SOUTHERLY
FLOW ALOFT SO SOME HEAVY RAINS EXPECTED. BY WED AND THU THE GT
LAKES UPR LOW DRIFTS EWD OVER NEW ENGL WITH A COOL CYCLONIC FLOW
ALOFT SO A FEW INSTBLTY MAINLY AFTN SHWRS CAN`T BE RULED OUT EACH
DAY BUT MAINLY IN THE MTNS. TEMPS TO REMAIN COOL THRU THE END OF
THE WEEK DUE TO THE CYCLONIC UPR LOW OVER THE REGION.
USED A BLEND OF THE EURO/MAV/MET/MEX GUID FOR THIS PCKG.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
SHORT TERM...CHALLENGING FORECAST FOR TONIGHT IN TERMS OF CLOUD
COVER AND POSSIBLE FOG. PLAN ON KEEPING ANY FOG LIMITED TO THE CT
RIVER VALLEY...AND ONLY BRIEFLY FOR LATE TONIGHT.
LONG TERM...SUN THRU LATE MON MVFR TO IFR CONDS EXPECTED IN
RN/SHWRS/PATCHY DRZL. AREAS OF FOG ALG THE COAST WILL DEVELOP SUN
NIGHT INTO MON REDUCING CONDS TO LIFR AT KPWM/KPSM/KRKD. IPVG
CONDS EXPECTED TO MOSTLY VFR BY MIDWEEK.
&&
.MARINE...
SHORT TERM...WINDS AND SEAS WILL REMAIN BELOW SMALL CRAFT ADVISORY
CRITERIA.
LONG TERM...WINDS AND SEAS WILL INCREASE BUT SHOULD REMAIN JUST
BELOW SCA CRITERIA THROUGH MIDWEEK.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...LEGRO
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
1003 PM CDT Fri Oct 4 2013
.UPDATE:
Issued at 950 PM CDT Fri Oct 4 2013
Inherited forecast still looks on track...so made no major
changes. Warm advection SHRAS have moved out of SW IL. SHRA/TSTMS
along and ahead of the front across ern KS/wrn MO timed to reach
the wrn CWA around 9-10Z...if it holds together. Several
solutions have moisture convergence along the front weakening
significantly overnight across nthrn MO. Going fcst reflects the
assumption that precip in one form or another will reach our CWA
prior to daybreak. Besides massaging other grids to reflect
ongoing trends...existing fcst looks good.
2%
&&
.SHORT TERM: (Through Late Tonight)
Issued at 330 PM CDT Fri Oct 4 2013
Diurnal heating of the unseasonably warm and moist air mass has
resulted in weak instability across the region this afternoon.
However with little impetus, attempts for convective development
thus far across far southeast Missouri and southern Illinois have
been short-lived. The HRRR continues to indicate potential for
spot storms through sunset within the southern CWA so will
continue with some slight chance pops until then. Otherwise
attention for tonight turns to the strong storm system currently
across the Plains region. Anticipating that a squall line will
evolve ahead of the attendant cold front from Nebraska into
Oklahoma this evening and this will move eastward as the whole
system progresses, with a swath of precipitation also developing
overnight in the wake of the front in response to frontogenetical
forcing and large scale ascent as a short-wave rotates through the
base of the progressive upper trof. The main question then is just
how far eastward all of this precipitation will get before
daybreak Saturday. The consensus of the model guidance is that it
may be after 12z before entering the CWA. At this time I didn`t
deviate dramatically from the previous forecast with the leading
edge just making it into the western CWA, but reduced pops further
east. Areas to the east of the main line will still be under the
threat of spotty warm advection activity overnight.
Glass
.LONG TERM: (Saturday through Next Friday)
Issued at 300 PM CDT Fri Oct 4 2013
By Saturday morning, surface cold front to be just west of St. Louis
metro area. As the occluded surface low, over southeastern SD,
associated with it slowly lifts out to the northeast, front to
slowly slide through rest of forecast area. Expect activity that
initially forms tonight to diminish by mid morning. Then trying to
determine when and where activity will refire as atmosphere becomes
more unstable by early afternoon is hard to pin down. With front
extending from Quincy to just west of St. Louis to near Monett by
18z Saturday, best chances of storms refiring and some severe
weather will be over southeast MO and southern IL. This matches well
with the day 2 outlook with this area in a slight risk. Another
forecast issue will be temperatures on Saturday. Will see a
non-diurnal trend as high temps will be reached early in the day
then either remain steady or fall during the afternoon hours.
Showers and isolated thunderstorms will taper off Saturday evening
before coming to an end. However, could see some scattered showers
on Sunday, especially during the afternoon hours as wrap around
clouds on back side of system moves through with an upper level
shortwave. So have added low chance pops over northeast MO/west
central IL with silent slight chance pops further south for now as
well as increase cloud cover through this period. Lows Saturday
night will be in the low 40s to low 50s with highs only rising
into the mid 50s to mid 60s on Sunday.
Sunday night could be our coldest night depending on how fast the
clouds clear out. For now will err on side of caution and keep more
clouds over the region with lows in the low to mid 40s. If clouds
completely clear out and winds remain light, could see even cooler
temps.
Beyond that, surface ridge moves off to the east with a slow warming
trend through the week. Temperatures to warm back up into the mid to
upper 70s by Thursday.
Byrd
&&
.AVIATION: (For the 00z TAFs through 00z Saturday Evening)
Issued at 632 PM CDT Fri Oct 4 2013
High pressure along the eastern seaboard combined with a deep
surface low over northeast Nebraska and cold front extending south
into eastern Kansas and then into west central Texas. Cold front
from the west is expected to move eastward into east central
Missouri by late Saturday morning. Scattered rainshowers and a few
thunderstorms are expected along the cold front. Then post frontal
rain can be expected behind the cold front through early Saturday
evening hours.
Specifics for KSTL: Southerly winds of 5 to 8 kts will increase to
10 kts from the southwest by mid Saturday morning. Cold front will
move through STL area between 1700-1800 UTC on Saturday. Scattered
showers and thunderstorms will move across the area from late
Saturday morning through early afternoon. Low clouds around 015Kft
and light rain..fog will continue through late afternoon hours.
Przybylinski
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
740 PM CDT Fri Oct 4 2013
.MESOSCALE DISCUSSION...
Issued at 726 PM CDT FRI OCT 4 2013
Last several hours of radar imagery have shown an interesting trend
with a rapid initial upscale growth into a squall line, followed by
a subsequent weakening. 18Z KTOP sounding showed the dry EML and
high LFC combination that ultimately led to the rapid gusting out of
the initial convection. Nevertheless, I believe that this weakening
is short-lived. Despite having lost daytime heating, the gust
front/cold front, now arcing from Omaha to Topeka to Emporia, is
entering a very warm and substantially more moist airmass. Slow
nocturnal cooling will actually aid in the low level buoyancy by
offsetting the high LFC heights, and thus muting the effects of cold
down drafts/evaporation. Additionally, the backing of the warm
sector flow should enhance frontal convergence in the next 1-2
hours, with a developing low level jet further aiding in large scale
ascent.
Thus, it seems to reason that a temporary upswing in thunderstorms
is likely as the gust front advances towards the I-35 corridor from
Emporia through Kansas City. Deep layer shear vectors initially
suggested that convective mode would be solely linear, but a recent
analysis of RAP data overlayed against the surface front orientation
captures enough cross angle to support more discrete development
(supported by ICT radar imagery). Although small bowing segments
would largely support wind damage, any discrete development and
storm scale rotation could also support large hail and possible a
tornado or two as 0-1km storm relative helicity is maximized between
01 and 03Z.
Linear extrapolation of this activity places it across the Kansas
City Metro between 8:30 and 10PM.
Bookbinder
&&
.UPDATE...
Issued at 731 PM CDT FRI OCT 4 2013
Updated forecast to refine the evolution of precipitation tonight.
Solid line of storms across central Kansas is no longer as solid as
it was earlier today. Discreet bowing segments of the line keep trying
to push out from the front, but then they fade as the gust front from
the storm pushes out ahead, thus forcing the storm to reform back along
the advancing front. So while the storms, and the timing for these storms,
remains relatively unchanged the widespread severe weather expected
will likely be more discrete but could still contain damaging winds.
Otherwise...trimmed down POPs in the post frontal environment as
latest model runs have backed off on the rain behind the front, which
looks reasonable as the parent low driving this activity looks to be
occluding to our north, thus possibly limiting the elevated frontogenic
forcing lagging behind the front.
&&
.SHORT TERM...(This Evening through Saturday Afternoon)
Issued at 339 PM CDT FRI OCT 4 2013
Focus for todays forecast is squarely on the remainder of the
afternoon and overnight hours as a cold front and associated
thunderstorms sweep through. A large upper level trough is exiting
the Rocky Mountains this afternoon. As this occurs copious amounts
of warm air and moisture for this time of year are being advected
north ahead of the cold front, which is associated with this trough
and currently moving east through central Kansas. Early afternoon
analysis shows the elevated mix layer that advected in aloft late
this morning, putting the kibosh on this mornings convection, has
begun to erode. Storms currently forming in extreme northeast Kansas
--well in advance of the front-- will likely help keep the effective
frontal boundary across northern Missouri in northern Missouri
through the afternoon and evening hours as the storms quickly
transit the front and reinforce the cold air across the Iowa border.
Looking at visible satellite imagery, a thin line of clouds have
begun to erupt along the cold front in central Kansas, and it is
this line of developing storms which is expected to grow through the
remainder of the afternoon bringing potential severe weather to
eastern Kansas and western Missouri this evening.
For this afternoon...storms bubbling up across extreme northeast
Kansas and sweeping into northwest Missouri may be strong at times
as elevated instability values of 3000 to 3500 J/KG pushes in above
the cap. However, despite the abundant instability these storms are
not based at the surface at this time as the effective warm front
put down early this morning in northern Missouri is only slowly
retreating north towards a secondary warm front along I-80 in Iowa.
This should limit mid to late afternoon severe threats as the cloud
cover and rain cooled air form the storms slow the retreat even
more. As a result, still expect the main show for tonight to develop
from the fine line of clouds forming along the front in central
Kansas.
Models persist in displaying good agreement on this evenings
expected activity. Current forecast has the front entering our
section of northeastern and east central Kansas between 6PM and 7PM.
This will be late enough in the day for instability to have trended
down, but there should be more than enough available energy still
there to fuel strong to severe storms as they move into Missouri
this evening. 0-6KM Shear vectors will be running near parallel to
the front as it moves in this evening across areas of west central
Missouri, but those areas in far northwest Missouri --near the Iowa
border-- will still have slightly more backed winds at the surface,
which might enhance the threat for supercell thunderstorms north of
St Joseph. As the front pushes in this evening the upper level low
within the trough will only slowly shift northeast, and is expected
to allow the front to occlude later tonight which will likely force
the severe threat south along the cold front in southeast Kansas and
Oklahoma, thus limiting the time period and location for strong to
severe thunderstorms to areas near and west of I-35. Timing for the
strongest storms is expected between 7PM and 10PM. Primary threats
are thought to be from large hail and damaging straighting winds,
though torrential rain and abundant lightning will also be present.
With all of the fall outdoor activities this evening folks are
encouraged to pay close attention to the weather.
After the main line of storms sweep through tonight, stratiform rain
with embedded thunder will remain likely well through the overnight
hours behind the front as frontogenic forcing from the cold air
sweeping in and goes to work on the moisture wrapping around the
low. Some lingering activity from the storms could still effect
areas from central to northeast Missouri through noon Saturday.
Additionally, behind the cold front cold air will spread across the
region with gusty west to northwest winds dominating the day. This
will likely leave temperatures Saturday struggling to reach 60
degrees.
.LONG TERM...(Saturday Evening through Friday)
Issued at 339 PM CDT FRI OCT 4 2013
A rather quiet extended forecast period expected behind a large
upper level trough currently moving into the Plains. Once this
system exits the local region, much cooler air will linger across
the area and only allow highs to climb into the upper 50s and low
60s by Sunday afternoon. Current models have slowed this upper level
low a bit, allowing for a few scattered rain showers to be possible
on the backside of this system. This precipitation will primarily be
across the northern portion of MO, and will be dependent on the
final speed and placement of the upper low as it begins to move out
of the mid-MO region. Once this system moves out of the region,
northwest flow will briefly return as shortwave ridging builds into
the the central US. Southwest flow will develop across the Plains as
a deepening trough across the western Cascades aides in building the
ridge eastward. As a result, the cooler early week temperatures will
undergo a gradual warming trend with highs in the 70s by the end of
the week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday Evening)
Issued at 652 PM CDT FRI OCT 4 2013
Main focus for the 00Z TAFs is the line of storms advancing across
eastern Kansas this evening. Current timing for storms would have
them reach KSTJ near 01Z with the Kansas City terminals around 02Z.
Given the limited width of the current line of storms, expectations
are that they will only impact the terminals for a few hours this
evening...though they will likely have strong and gusty winds which
could be widely variable in direction near the storms. Questions still
exists with how low clouds will be behind the front, so have left in
a combination of MVFR to VFR ceilings for the morning hours of
Saturday. Gusty winds will spread in behind the front Saturday, with
gusty west winds onsetting around noon Saturday.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
MESOSCALE...Bookbinder
UPDATE...Cutter
SHORT TERM...Cutter
LONG TERM...PMM
AVIATION...Cutter
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
726 PM CDT FRI OCT 4 2013
.MESOSCALE DISCUSSION...
Issued at 726 PM CDT FRI OCT 4 2013
Last several hours of radar imagery have shown an interesting trend
with a rapid initial upscale growth into a squall line, followed by
a subsequent weakening. 18Z KTOP sounding showed the dry EML and
high LFC combination that ultimately led to the rapid gusting out of
the initial convection. Nevertheless, I believe that this weakening
is short-lived. Despite having lost daytime heating, the gust
front/cold front, now arcing from Omaha to Topeka to Emporia, is
entering a very warm and substantially more moist airmass. Slow
nocturnal cooling will actually aid in the low level buoyancy by
offsetting the high LFC heights, and thus muting the effects of cold
down drafts/evaporation. Additionally, the backing of the warm
sector flow should enhance frontal convergence in the next 1-2
hours, with a developing low level jet further aiding in large scale
ascent.
Thus, it seems to reason that a temporary upswing in thunderstorms
is likely as the gust front advances towards the I-35 corridor from
Emporia through Kansas City. Deep layer shear vectors initially
suggested that convective mode would be solely linear, but a recent
analysis of RAP data overlayed against the surface front orientation
captures enough cross angle to support more discrete development
(supported by ICT radar imagery). Although small bowing segments
would largely support wind damage, any discrete development and
storm scale rotation could also support large hail and possible a
tornado or two as 0-1km storm relative helicity is maximized between
01 and 03Z.
Linear extrapolation of this activity places it across the Kansas
City Metro between 8:30 and 10PM.
Bookbinder
.SHORT TERM...(This Evening through Saturday Afternoon)
Issued at 339 PM CDT FRI OCT 4 2013
Focus for todays forecast is squarely on the remainder of the
afternoon and overnight hours as a cold front and associated
thunderstorms sweep through. A large upper level trough is exiting
the Rocky Mountains this afternoon. As this occurs copious amounts
of warm air and moisture for this time of year are being advected
north ahead of the cold front, which is associated with this trough
and currently moving east through central Kansas. Early afternoon
analysis shows the elevated mix layer that advected in aloft late
this morning, putting the kibosh on this mornings convection, has
begun to erode. Storms currently forming in extreme northeast Kansas
--well in advance of the front-- will likely help keep the effective
frontal boundary across northern Missouri in northern Missouri
through the afternoon and evening hours as the storms quickly
transit the front and reinforce the cold air across the Iowa border.
Looking at visible satellite imagery, a thin line of clouds have
begun to erupt along the cold front in central Kansas, and it is
this line of developing storms which is expected to grow through the
remainder of the afternoon bringing potential severe weather to
eastern Kansas and western Missouri this evening.
For this afternoon...storms bubbling up across extreme northeast
Kansas and sweeping into northwest Missouri may be strong at times
as elevated instability values of 3000 to 3500 J/KG pushes in above
the cap. However, despite the abundant instability these storms are
not based at the surface at this time as the effective warm front
put down early this morning in northern Missouri is only slowly
retreating north towards a secondary warm front along I-80 in Iowa.
This should limit mid to late afternoon severe threats as the cloud
cover and rain cooled air form the storms slow the retreat even
more. As a result, still expect the main show for tonight to develop
from the fine line of clouds forming along the front in central
Kansas.
Models persist in displaying good agreement on this evenings
expected activity. Current forecast has the front entering our
section of northeastern and east central Kansas between 6PM and 7PM.
This will be late enough in the day for instability to have trended
down, but there should be more than enough available energy still
there to fuel strong to severe storms as they move into Missouri
this evening. 0-6KM Shear vectors will be running near parallel to
the front as it moves in this evening across areas of west central
Missouri, but those areas in far northwest Missouri --near the Iowa
border-- will still have slightly more backed winds at the surface,
which might enhance the threat for supercell thunderstorms north of
St Joseph. As the front pushes in this evening the upper level low
within the trough will only slowly shift northeast, and is expected
to allow the front to occlude later tonight which will likely force
the severe threat south along the cold front in southeast Kansas and
Oklahoma, thus limiting the time period and location for strong to
severe thunderstorms to areas near and west of I-35. Timing for the
strongest storms is expected between 7PM and 10PM. Primary threats
are thought to be from large hail and damaging straighting winds,
though torrential rain and abundant lightning will also be present.
With all of the fall outdoor activities this evening folks are
encouraged to pay close attention to the weather.
After the main line of storms sweep through tonight, stratiform rain
with embedded thunder will remain likely well through the overnight
hours behind the front as frontogenic forcing from the cold air
sweeping in and goes to work on the moisture wrapping around the
low. Some lingering activity from the storms could still effect
areas from central to northeast Missouri through noon Saturday.
Additionally, behind the cold front cold air will spread across the
region with gusty west to northwest winds dominating the day. This
will likely leave temperatures Saturday struggling to reach 60
degrees.
.LONG TERM...(Saturday Evening through Friday)
Issued at 339 PM CDT FRI OCT 4 2013
A rather quiet extended forecast period expected behind a large
upper level trough currently moving into the Plains. Once this
system exits the local region, much cooler air will linger across
the area and only allow highs to climb into the upper 50s and low
60s by Sunday afternoon. Current models have slowed this upper level
low a bit, allowing for a few scattered rain showers to be possible
on the backside of this system. This precipitation will primarily be
across the northern portion of MO, and will be dependent on the
final speed and placement of the upper low as it begins to move out
of the mid-MO region. Once this system moves out of the region,
northwest flow will briefly return as shortwave ridging builds into
the the central US. Southwest flow will develop across the Plains as
a deepening trough across the western Cascades aides in building the
ridge eastward. As a result, the cooler early week temperatures will
undergo a gradual warming trend with highs in the 70s by the end of
the week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday Evening)
Issued at 652 PM CDT FRI OCT 4 2013
Main focus for the 00Z TAFs is the line of storms advancing across
eastern Kansas this evening. Current timing for storms would have
them reach KSTJ near 01Z with the Kansas City terminals around 02Z.
Given the limited width of the current line of storms, expectations
are that they will only impact the terminals for a few hours this
evening...though they will likely have strong and gusty winds which
could be widely variable in direction near the storms. Questions
still exists with how low clouds will be behind the front, so have
left in a combination of MVFR to VFR ceilings for the morning hours
of Saturday. Gusty winds will spread in behind the front Saturday,
with gusty west winds onsetting around noon Saturday.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
MESOSCALE...Bookbinder
SHORT TERM...Cutter
LONG TERM...PMM
AVIATION...Cutter
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
702 PM CDT Fri Oct 4 2013
.SHORT TERM: (Through Late Tonight)
Issued at 330 PM CDT Fri Oct 4 2013
Diurnal heating of the unseasonably warm and moist air mass has
resulted in weak instability across the region this afternoon.
However with little impetus, attempts for convective development
thus far across far southeast Missouri and southern Illinois have
been short-lived. The HRRR continues to indicate potential for
spot storms through sunset within the southern CWA so will
continue with some slight chance pops until then. Otherwise
attention for tonight turns to the strong storm system currently
across the Plains region. Anticipating that a squall line will
evolve ahead of the attendant cold front from Nebraska into
Oklahoma this evening and this will move eastward as the whole
system progresses, with a swath of precipitation also developing
overnight in the wake of the front in response to frontogenetical
forcing and large scale ascent as a short-wave rotates through the
base of the progressive upper trof. The main question then is just
how far eastward all of this precipitation will get before
daybreak Saturday. The consensus of the model guidance is that it
may be after 12z before entering the CWA. At this time I didn`t
deviate dramatically from the previous forecast with the leading
edge just making it into the western CWA, but reduced pops further
east. Areas to the east of the main line will still be under the
threat of spotty warm advection activity overnight.
Glass
.LONG TERM: (Saturday through Next Friday)
Issued at 300 PM CDT Fri Oct 4 2013
By Saturday morning, surface cold front to be just west of St. Louis
metro area. As the occluded surface low, over southeastern SD,
associated with it slowly lifts out to the northeast, front to
slowly slide through rest of forecast area. Expect activity that
initially forms tonight to diminish by mid morning. Then trying to
determine when and where activity will refire as atmosphere becomes
more unstable by early afternoon is hard to pin down. With front
extending from Quincy to just west of St. Louis to near Monett by
18z Saturday, best chances of storms refiring and some severe
weather will be over southeast MO and southern IL. This matches well
with the day 2 outlook with this area in a slight risk. Another
forecast issue will be temperatures on Saturday. Will see a
non-diurnal trend as high temps will be reached early in the day
then either remain steady or fall during the afternoon hours.
Showers and isolated thunderstorms will taper off Saturday evening
before coming to an end. However, could see some scattered showers
on Sunday, especially during the afternoon hours as wrap around
clouds on back side of system moves through with an upper level
shortwave. So have added low chance pops over northeast MO/west
central IL with silent slight chance pops further south for now as
well as increase cloud cover through this period. Lows Saturday
night will be in the low 40s to low 50s with highs only rising
into the mid 50s to mid 60s on Sunday.
Sunday night could be our coldest night depending on how fast the
clouds clear out. For now will err on side of caution and keep more
clouds over the region with lows in the low to mid 40s. If clouds
completely clear out and winds remain light, could see even cooler
temps.
Beyond that, surface ridge moves off to the east with a slow warming
trend through the week. Temperatures to warm back up into the mid to
upper 70s by Thursday.
Byrd
&&
.AVIATION: (For the 00z TAFs through 00z Saturday Evening)
Issued at 632 PM CDT Fri Oct 4 2013
High pressure along the eastern seaboard combined with a deep
surface low over northeast Nebraska and cold front extending south
into eastern Kansas and then into west central Texas. Cold front
from the west is expected to move eastward into east central
Missouri by late Saturday morning. Scattered rainshowers and a few
thunderstorms are expected along the cold front. Then post frontal
rain can be expected behind the cold front through early Saturday
evening hours.
Specifics for KSTL: Southerly winds of 5 to 8 kts will increase to
10 kts from the southwest by mid Saturday morning. Cold front will
move through STL area between 1700-1800 UTC on Saturday. Scattered
showers and thunderstorms will move across the area from late
Saturday morning through early afternoon. Low clouds around 015Kft
and light rain..fog will continue through late afternoon hours.
Przybylinski
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
833 PM MDT FRI OCT 4 2013
.UPDATE...
NEAR-BLIZZARD CONDITIONS ARE ONGOING IN SOUTHERN CARTER COUNTY PER
RECENT SPOTTER REPORTS...AND RADAR TRENDS SUGGEST SNOW SHOULD KEEP
FALLING IN THE DEFORMATION ZONE FOR SEVERAL MORE HOURS. WE DO HAVE
SOME QUESTION ABOUT HOW LONG SNOW WILL CONTINUE AFTER 06 UTC...BUT
FORECAST SOUNDINGS FROM THE RAP SHOW 30 KT WINDS IN THE WELL-MIXED
NEAR-SURFACE LAYER CONTINUE THROUGH THE NIGHT. THUS...IF SNOW DOES
CONTINUE PAST MIDNIGHT VISIBILITY RESTRICTIONS WILL ALSO CONTINUE.
WE THUS CHOSE TO EXTEND THE WINTER STORM WARNING FOR CARTER COUNTY
UNTIL 12 UTC. WE RECEIVED REPORTS OF A FOOT OF SNOW IN ALZADA NEAR
0045 UTC...SO WHEN ALL IS SAID AND DONE STORM TOTALS WILL PROBABLY
BE IN THE 13 TO 16 INCH RANGE IN SOUTHERN CARTER COUNTY.
ELSEWHERE...OBSERVATIONS SUGGEST CONDITIONS ARE IMPROVING LIKE THE
18 UTC GFS/NAM AND RECENT RAP RUNS SUGGESTED...SO WE CANCELLED ALL
OF THE WINTER STORM WARNINGS SAVE FOR CARTER COUNTY. NO OTHER REAL
CHANGES OF NOTE APPEAR WARRANTED TO THE OVERNIGHT FORECAST AT THIS
TIME...WITH THE FIRST FREEZE OF THE FALL SEASON ACROSS MUCH OF THE
PLAINS EXPECTED TONIGHT. SCHULTZ
&&
.SHORT TERM...VALID FOR SAT AND SUN...
UPPER LOW WAS SEEN ON WATER VAPOR SPINNING INTO W NE THIS
AFTERNOON. STORM SYSTEM HAS BEEN A PROLIFIC SNOW PRODUCER WITH 1
TO 2 FEET OF SNOW IN THE MOUNTAINS AND FOOTHILLS AND OVER SHERIDAN
COUNTY. MANY LOCATIONS REPORTED DOWNED TREES AND POWER LINES WITH
SUBSEQUENT POWER OUTAGES. THE SNOW CONTINUED TO FALL OVER SOUTHERN
BIG HORN AND SHERIDAN COUNTIES...AS WELL AS SE MT THIS AFTERNOON.
WILL LEAVE THE WARNING IN PLACE UNTIL 06Z TONIGHT WHEN LIFT
DRAMATICALLY DECREASES DUE TO WEAKENING FRONTOGENESIS AND THE
TROWAL SHIFTING TO THE E. ACCUMULATIONS SHOULD BECOME LIGHTER WITH
TIME AS THE LIFT WEAKENS OVER THE AREA.
WILL KEEP THE NEAR RECORD LOW MENTIONED FOR KSHR WITH ALL THE SNOW
ON THE GROUND. ONLY ISSUES THAT MIGHT PREVENT RECORD FROM BEING
REACHED WOULD BE CLOUD COVER AND WINDS STAYING UP. LOWERED
TONIGHT/S MINS IN A FEW AREAS DUE TO THE SNOW COVER. FOG SHOULD
NOT BE AN ISSUE AS DEWPOINTS WERE EXPECTED TO FALL OVERNIGHT.
UPPER RIDGING AND DRY WEATHER WILL BUILD OVER THE AREA SAT THROUGH
SUN NIGHT. SOME GAP FLOW CONDITIONS WILL SET UP FOR THE KLVM...BIG
TIMBER AND HARLOWTON AREAS BUT PATTERN DID NOT SUPPORT OVERLY
STRONG WINDS. MIXING BETWEEN 850 AND 700 MB WILL SUPPORT
TEMPERATURES IN THE 50S ON SAT...BUT SOME READINGS WILL BE
TEMPERED BY THE SNOW COVER. WARMER AIRMASS ON SUN WILL PUSH
TEMPERATURES INTO THE 60S WITH A FEW 70S POSSIBLE. ARTHUR
.LONG TERM...VALID FOR MON...TUE...WED...THU...FRI...
A RIDGE OF HIGH PRESSURE WILL BRING DRY AND MILD CONDITIONS OVER
THE AREA MONDAY. THIS RIDGE WILL SHIFT QUICKLY EASTWARD DURING THE
DAY AS A LONG WAVE TROUGH OF LOW PRESSURE DEEPENS ALONG THE WEST
COAST. FLOW WILL BEGIN BACKING TO THE SOUTHWEST WITH DIFFLUENT
FLOW INCREASING ACROSS SC/SE MT. PIECES OF VORTICITY WILL BE
EJECTING OUT AHEAD OF THE MAIN TROUGH AND THIS WILL BRING THE
CHANCE OF A FEW RAIN SHOWERS TO OUR WESTERN ZONES TUESDAY
AFTERNOON AND NIGHT WITH SNOW SHOWERS OVER THE MOUNTAINS.
PRECIPITATION CHANCES WILL INCREASE WEDNESDAY THROUGH THURSDAY AS
THE UPPER TROUGH MOVES INTO THE ROCKIES. GFS/ECMWF ARE CONSISTENT
IN SHOWING THE DEVELOPMENT OF A CLOSED UPPER LOW OVER SOUTHERN
NEVADA ON THURSDAY. THE LOW IS PROGGED TO LIFT NORTHEAST INTO
SOUTHEASTERN WYOMING THURSDAY NIGHT. MODELS INDICATING THAT THIS
LOW WILL BRING A POTENTIAL FOR ANOTHER STRONG FALL STORM TO IMPACT
THE AREA. GFS IS THE STRONGEST OF THE TWO MODELS AND INDICATES THE
CLOSED 500 MB LOW WILL MOVE INTO EXTREME SOUTHEAST MONTANA ON
FRIDAY WITH THE 700 AND 850 MB LOWS STACKED UNDERNEATH IT. THIS
WOULD CAUSE THE STORM SYSTEM TO MOVE SLOWER AND THUS BRING A
LONGER PERIOD OF STRONG UPSLOPE FLOW TO MUCH OF THE FORECAST AREA.
HAVE RAISED POPS THURSDAY NIGHT AND FRIDAY.
TEMPERATURES STARTING OUT WELL ABOVE NORMAL FOR MONDAY WITH HIGHS
RUNNING 15 TO 20 DEGREES ABOVE NORMAL. UPPER TROUGH MOVING IN ON
TUESDAY WILL BRING FALLING HEIGHTS WHICH WILL ALLOW FOR
TEMPERATURES FALLING TO THE LOWER 60S. WEDNESDAY THROUGH FRIDAY
WILL SEE NEAR SEASONAL TEMPERATURES. RICHMOND
&&
.AVIATION...
VERY HAZARDOUS WEATHER WILL CONTINUE THROUGH ABOUT 09Z OVER THE
SE CORNER OF MONTANA AND THE NEARBY AREAS INTO NE WYOMING.
OTHERWISE...CONDITIONS WILL CONTINUE TO IMPROVE OVERNIGHT ACROSS
THE REST OF THE FORECAST AREA. VFR IS EXPECTED TO PREVAIL AT
ALL FORECAST TERMINALS...ALTHOUGH MOUNTAIN PEAKS MAY REMAIN
OBSCURED UNTIL 12Z. BT
&&
.PRELIMINARY POINT TEMP/POPS...
SAT SUN MON TUE WED THU FRI
-----------------------------------------------------------
BIL 028/056 042/069 043/070 043/062 039/057 037/053 040/052
00/N 00/N 00/U 02/W 22/W 23/W 33/W
LVM 023/054 038/066 041/068 039/061 036/053 033/049 034/050
00/N 00/N 00/N 02/W 22/W 23/W 33/W
HDN 027/058 038/070 040/070 041/065 039/059 038/054 040/053
10/U 00/U 00/U 01/B 22/W 22/W 33/W
MLS 029/057 037/070 042/068 043/067 043/061 038/057 042/057
10/U 00/U 00/U 01/B 22/W 22/W 34/W
4BQ 026/050 033/065 038/066 040/064 039/059 036/055 038/054
51/U 00/U 00/U 01/B 12/W 22/W 35/W
BHK 025/049 031/066 040/063 040/065 041/060 036/055 039/054
30/U 00/U 00/U 01/B 11/B 22/W 36/W
SHR 019/048 032/063 039/068 040/065 038/059 034/054 036/053
20/U 00/U 00/U 01/B 22/W 22/W 34/W
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...WINTER STORM WARNING IN EFFECT UNTIL 6 AM MDT SATURDAY FOR
ZONE 37.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
525 PM MDT FRI OCT 4 2013
.AVIATION...
00Z TAF CYCLE
VFR CIGS AND VIZ NEXT 24 HRS. WEATHER SYSTEM OVER NEBRASKA
PANHANDLE MAINTAINING GUSTY SOUTHWEST FLOW ACROSS NM...WITH COLD
FRONT FROM THE TX PANHANDLE SWEEPING SOUTH AND WEST TO A ROW TO
DMN LINE. WIND SPEEDS DECREASING GRADUALLY AFTER 01Z...WITH COLD
FRONT REACHING THE MEXICO BORDER BY 12Z SAT MORNING. WINDS
SHIFTING NORTHERLY AS FRONT SLIDES BY. REDUCED WIND SPEEDS FOR
SATURDAY AS WEATHER SYSTEM SHIFTS TO MISSOURI RIVER VALLEY IN
SD...NORTHERLY FLOW ALOFT OVER NM WEAKENS IN TURN...AND DOME OF
HIGH PRESSURE BUILDS OUT OF WESTERN COLORADO INTO NORTHERN NM BY
00Z SAT EVENING.
SHY
&&
.PREV DISCUSSION...315 PM MDT FRI OCT 4 2013...
FRONT HAS BEEN HUNG UP JUST NORTH OF THE UNION COUNTY BORDER ALL
DAY...ALTHOUGH THE LOW CLOUDS ASSOCIATED WITH IT LAST NIGHT HAVE
DISSIPATED OVER SOUTHEAST AND EAST CENTRAL CO. RUC INDICATES THE
BOUNDARY TO PLUNGE SWD WITHIN THE NEXT 3 HOURS. IT ALSO INDICATES A
LITTLE MORE MOISTURE OVER PARTS OF THE NORTHEAST...AND RESULT HAS
BEEN TO UPGRADE SKY COVER TO PARTLY CLOUDY RATHER THAN CLEAR. STILL
MODELS NOT SUGGESTING A HUGE UPTICK IN DEW POINTS THERE OVERNIGHT.
NORTHERLY WINDS ASSOCIATED WITH THE FRONT AS IT TRACKS THROUGH THE
PLAINS TO BE GUSTY BUT NOT QUITE AS STRONG AS INDICATED 24 HOURS
AGO.
AS FOR FREEZE HIGHLIGHTS...STILL SOME MARGINAL TEMPERATURES FOR
PORTIONS OF THE EAST CENTRAL AND RGV AS WELL AS THE SOUTH CENTRAL
HIGHLANDS. AND SATURDAY NIGHT TEMPERATURE GUIDANCE IS STILL LEANING
TOWARDS SOME WARMING. FORECAST BOUNDARY LAYER WINDS TONIGHT
NORTHEAST OVER THE PLAINS BUT FOR SATURDAY NIGHT THE GFS FORECASTS A
MORE WLY WIND FLOW IN THE LOWER LEVELS...AS OPPOSED TO THE NAM/S
LIGHT AND VRBL TO WEAK NW WINDS. FORECAST SOUNDINGS INDICATE
SOME STEEP INVERSIONS OFF THE DECK AT SELECTED POINTS SATURDAY NIGHT
BUT OVERALL THE SOUNDINGS EXHIBIT A WARMING TREND. THINK THERE
MAY BE SOME POINTS IN SHELTERED AREAS UNAFFECTED BY WIND THAT COULD
REACH THE MAGIC 32 OR SLIGHTLY BELOW OUTSIDE OF OUR FORECAST POINTS
TONIGHT...SO WENT AHEAD AND UPGRADED REMAINING EAST CENTRAL ZONES IN
THE WATCH. ALSO ADDED THE SOUTH CENTRAL HIGHLANDS TO THE WARNING
TONIGHT WITH FORECAST LOWS AGAIN HOVERING NEAR THE FREEZING MARK.
BASED ON THE ABOVE MODEL DISCUSSION...HAVE HELD OFF ON ISSUING
FURTHER FREEZE HIGHLIGHTS FOR SATURDAY NIGHT. WILL WAIT TO SEE WHAT
THE GUIDANCE DOES AS WELL AS WHAT MINS TONIGHT DO.
WINDS STILL TO TAPER OFF SATURDAY WITH A WARMING TREND SUNDAY
THROUGH TUESDAY. MODELS CONTINUE TO FOCUS ON AN UPPER LOW DIGGING
INTO THE SW US AROUND THE MID TO LATE WEEK PERIOD NEXT WEEK. WINDS
LOOK TO INCREASE TUESDAY AND MORE SO WEDNESDAY WITH TEMPERATURES
FALLING THURSDAY/FRIDAY. WE NOW HAVE SOME MEAGER POPS FOR THE NORTH
AND WEST DURING THIS PERIOD...BUT MODELS NOT EXACTLY IN AGREEMENT
HOW THIS WILL PLAY OUT.
.FIRE WEATHER...
CURRENT FIRE WEATHER HIGHLIGHTS ARE MARGINAL BUT WILL KEEP THEM
RUNNING THROUGH EVENT EXPIRATION. TUCUMCARI IS SHOWING NEAR RED FLAG
CONDITIONS WITH GUSTY WINDS AND TEEN HUMIDITY.
THE UPPER LOW WHICH IS CURRENTLY OVER THE CENTRAL ROCKIES AND GREAT
PLAINS WILL GRADUALLY SHIFT EASTWARD THE REST OF TODAY...TONIGHT
INTO SATURDAY. THE SURFACE WIND FLOW WILL GENERALLY RELAX AS A
RESULT ALTHOUGH A BACK DOOR COLD FRONT WILL PUSH ACROSS THE EASTERN
PLAINS TONIGHT AND INCREASE WINDS FOR A TIME. A CHILLY NIGHT IS IN
STORE WITH FREEZING TO NEAR FREEZING TEMPERATURES EXPECTED ACROSS
THE MAJORITY OF THE FIRE WEATHER FORECAST AREA. A HARD FREEZE WILL
BE FELT ACROSS THE NORTHERN AND WESTERN MOUNTAINS AND INCLUDE SOME
LOWLAND SITES AS WELL.
HIGH PRESSURE WILL BE IN CONTROL DURING THE WEEKEND. THE SURFACE
WIND FLOW WILL BE MUCH MORE RELAXED ALTHOUGH LOOK FOR SOME NORTHERLY
BREEZES ACROSS SOME WESTERN AND CENTRAL AREAS SATURDAY AFTERNOON.
THE FLOW ALOFT WILL BE MUCH WEAKER SO MAINLY SURFACE DRIVEN. FAIRLY
LIGHT WINDS FOR SUNDAY WITH JUST A FEW BREEZES ALONG INTERSTATE 25
BETWEEN LAS VEGAS TO RATON. MIXING HEIGHTS WILL BE ON THE LOWER SIDE
THANKS TO POST COLD FRONTAL INVERSION EFFECTS. THUS VENTILATION
RATES WILL BE LOWER. VENTILATION WILL BE THE POOREST ON SUNDAY.
EXPECTING A STRONG LOW LEVEL RADIATION INVERSION TO DEVELOP SATURDAY
NIGHT. THIS WILL BE ACCOMPANIED BY ADDITIONAL FREEZING TEMPERATURES
WITHIN BASINS AND VALLEYS. HIGH TEMPERATURES WILL BE WELL BELOW
NORMAL SATURDAY AND BE AROUND 5 TO 10 DEGREES BELOW NORMAL SUNDAY
AFTERNOON. HUMIDITY VALUES WILL BE NEAR SEASONABLE LEVELS ON
SATURDAY BUT LOWER ON SUNDAY WITH LOTS OF MINIMUM VALUES IN THE
TEENS. A MID LEVEL DRY INTRUSION PLUS A WARM UP WILL BE THE CATALYST
FOR LOWER HUMIDITY VALUES SUNDAY.
WEATHER MODELS REMAIN PERSISTENT WITH DEPICTING RIDGING ON MONDAY
AND THEN BREAKING DOWN OR SHIFTING EASTWARD ON TUESDAY. TEMPERATURES
WOULD CONTINUE TO WARM WHILE THE UPPER FLOW TURNS MORE SOUTHWESTERLY
ON TUESDAY. DRY CONDITIONS WOULD CONTINUE. VENTILATION RATES WILL
REMAIN ON THE LOWER SIDE MONDAY ALTHOUGH IMPROVE IN A FEW AREAS
COMPARED TO SUNDAY/S READINGS. TRANSPORT WINDS WILL INCREASE TUESDAY
SO THE VENTILATION WILL IMPROVE SIGNIFICANTLY THEN. NEAR TO ABOVE
NORMAL TEMPERATURES EXPECTED EARLY NEXT WEEK AND SURFACE HUMIDITY
WILL REMAIN ON THE LOWER SIDE. CURRENTLY HAVE SOME LOCALIZED
CRITICAL FIRE WEATHER GROWTH CONDITIONS DEPICTED WITHIN OUR GRIDDED
FORECAST TUESDAY AFTERNOON ACROSS THE NORTHEAST SO WILL BE
MONITORING THAT TREND.
THE LATEST LONG RANGE MODELS CONTINUE TO SHOW A BREEZY TO WINDY
PATTERN WEDNESDAY THROUGH FRIDAY AS ANOTHER PACIFIC TROUGH CROSSES
OVER THE INTERMOUNTAIN WEST. IT STILL APPEARS TO BE A DRY TROUGH
PASSAGE FOR THE FORECAST AREA. THUS...CANT RULE OUT SOME CRITICAL
FIRE WEATHER AREAS...MOST LIKELY FAVORING THE EAST...WHERE
TEMPERATURES WOULD BE ABOVE NORMAL FOR THE LONGEST. COOLING EXPECTED
ACROSS THE WEST ON THURSDAY AND SPREAD ACROSS THE ENTIRE AREA ON
FRIDAY. THIS AIR MASS APPEARS TO BE LESS CHILLY COMPARED TO THE
CURRENT ONE. VENTILATION WOULD BE QUITE HIGH WEDNESDAY AND THURSDAY
AND PROBABLY LOWER SOME ON FRIDAY. CONFIDENCE IS AT LEAST MODERATE
FOR THIS SCENARIO.
50
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 7 PM MDT THIS EVENING FOR THE FOLLOWING
ZONES...NMZ103-104-108.
FREEZE WARNING FROM 1 AM TO 9 AM MDT SATURDAY FOR THE FOLLOWING
ZONES...NMZ518-519-524-530>534.
&&
$$
AREA FORECAST DISCUSSION
NWS RALEIGH NC
940 PM EDT FRI OCT 4 2013
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO RESIDE OVER THE REGION THROUGH
SUNDAY. INCREASING MOISTURE AHEAD OF BOTH A COLD FRONT...AND
TROPICAL STORM KAREN...WILL SPREAD INTO THE REGION FOR THE START OF
THE NEXT WORK WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 940 PM FRIDAY...
LITTLE CHANGE TO THE OVERNIGHT FORECAST NEEDED AS HIGH PRESSURE
REMAINS PERSISTENT OVER THE CAROLINAS. SKIES HAVE CLEARED AND
WINDS. DEWPOINTS HAVE RECOVERED ANOTHER 2 TO 4 DEGREES SINCE 24
HOURS AGO...MAINLY ACROSS THE SOUTH... AND DEWPOINT DEPRESSIONS ARE
ALREADY LESS THAN 5 DEGREES AT MANY OBSERVING SITES. RH CROSS
SECTIONS FAVOR SOUTHERN AREAS FOR FOG...AND THE RECENT HRRR RUNS
SUPPORT THIS. LOWS MOSTLY IN THE 60-63 RANGE.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
AS OF 255 PM FRIDAY...
SATURDAY AND SATURDAY NIGHT...HIGH PRESSURE PERSISTS...WITH
MID-LEVEL HEIGHTS ACTUALLY RISING FOR A TIME SATURDAY BEFORE
BEGINNING TO FALL AGAIN SATURDAY NIGHT. BUFR SOUNDINGS FROM BOTH THE
NAM AND THE GFS SUGGEST A COUPLE OF DEGREES OR SO OF WARMING ALOFT
AROUND 500MB SATURDAY...WITH SOME 850MB MOISTURE AVAILABLE ONCE
AGAIN SUGGESTIVE OF SOME DIURNAL CUMULUS WITH MIXING SATURDAY
MORNING INTO THE AFTERNOON. SUBSIDENCE CONTINUES TO DOMINATE...AND K
INDICES ACTUALLY FALL SOMEWHAT ON THE GFS DURING THE DAY SATURDAY.
ANOTHER DRY DAY ANTICIPATED WITH LIGHT WINDS EARLY INCREASING A
TOUCH...UNDER 10KT...AND SHOWING A SOUTHERLY COMPONENT BEFORE AGAIN
DIMINISHING TO FAIRLY LIGHT SOUTHERLY SATURDAY NIGHT. 1000-850MB
THICKNESSES SUPPORT HIGHS AROUND THE MOS GUIDANCE...MANY UPPER 80S
AND A FEW READINGS AT 90. AVAILABLE LOW-LEVEL MOISTURE SUPPORTS A
GREATER PROBABILITY OF AREAS OF FOG ACROSS CENTRAL NORTH CAROLINA
LATE SATURDAY NIGHT INTO SUNDAY MORNING...AND HAVE AGAIN CONTINUED
THIS IN THE GRIDDED AND WORDED FORECASTS. OVERNIGHT LOWS SATURDAY
NIGHT MAINLY LOWER 60S. -DJF
SUNDAY...WINDS ALOFT WILL BACK TO SOUTHWESTERLY AS THE MID-UPPER
RIDGE AXIS SHIFTS EAST AND OFFSHORE...WHICH WILL PROMOTE A GRADUAL
INCREASE IN MID TO ESPECIALLY HIGH LEVEL MOISTURE THROUGHOUT THE DAY
SUNDAY. THE COMBINATION OF THE INCREASING CLOUDS AND THE EASTWARD
DEPARTURE OF THE RIDGE ALOFT WILL LIKELY RESULT IN TEMPERATURES UP
TO A FEW DEGREES COOLER THAN THOSE OF SAT - OR WITHIN A COUPLE OF
DEGREES EITHER SIDE OF 85. THE TIGHTENING MSL PRESSURE GRADIENT IN
RETURN FLOW WILL ALSO PROMOTE THE DEVELOPMENT OF A SOUTHERLY BREEZE
THAT WILL PEAK IN THE 10-15 KT RANGE OVER THE WESTERN PIEDMONT
ACCORDING TO MIXED LAYER WINDS DEPICTED BY BUFR FORECAST SOUNDINGS.
DESPITE THE INCREASING MAINLY HIGH CLOUDS...PRECIPITATION CHANCES
WILL REMAIN RELATIVELY LOW. WILL ACCORDINGLY TRIM INHERITED
PRECIPITATION CHANCES AND CONFINE A SLIGHT CHANCE TO ROUGHLY THE
SOUTHERN HALF OF THE CWFA...TO ACCOUNT FOR THE PROPAGATION OF
SHOWERS THAT FORM OWING TO ONSHORE FLOW/FRICTIONAL CONVERGENCE AND
WEAK HEIGHT FALLS ALOFT...IN A WEAKLY INHIBITED AND UNSTABLE
ENVIRONMENT ALONG AND INVOF COASTAL AREAS. -MWS
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
AS OF 255 PM FRIDAY...
SUN NIGHT THROUGH MON NIGHT...CONFIDENCE IS HIGH THAT THE REMNANTS
OF T.S. KAREN WILL INTERACT WITH A POWERFUL UPPER TROUGH AND
ATTENDING FRONTAL ZONE AND CONSEQUENTLY AFFECT CENTRAL NC EARLY NEXT
WEEK. HOWEVER...STILL-LARGE MODEL SPREAD YIELDS BELOW AVERAGE
FORECAST CONFIDENCE OF THE ASSOCIATED SENSIBLE WEATHER IMPACTS AND
TIMING THEREOF. INTERPOLATION OF THE LATEST NHC AND WPC FORECAST
TRACKS DEPICT A NORTHEASTWARD PATH DIRECTLY THROUGH THE NC PIEDMONT
MON-EARLY MON NIGHT...WITH FRONTAL PASSAGE AND DRY CONDITIONS BY
EARLY TUE.
PATTERN RECOGNITION/CONCEPTUAL MODELS SUGGEST THE ASSOCIATED
PRECIPITATION SHIELD WILL SHIFT WEST OF TRACK AS THE REMNANT LOW IS
INFLUENCED BY THE POWERFUL UPPER TROUGH/LOW FORECAST TO MIGRATE FROM
THE ROCKIES TODAY TO THE UPPER MIDWEST MON MORNING. SO WHILE IT
APPEARS THAT MOST OF OUR REGION WILL RECEIVE AT LEAST A BENEFICIAL
SOAKING RAIN...SOME AREAS - IMMEDIATELY LEFT OF THE EVENTUAL LOW
TRACK - WILL LIKELY EXPERIENCE A MULTI-INCH RAIN EVENT. THE
ASSOCIATED LOW-DEEP LAYER SHEAR AND AT LEAST POCKETS OF MARGINAL
INSTABILITY WILL ALSO SUPPORT A THREAT OF SEVERE WEATHER WITH THE
PASSAGE OF THE LOW...MON AFTERNOON. A SEPARATE BAND OF CONVECTION...
THOUGH LIKELY SUB-SEVERE WITH GUSTY WINDS...MAY ALSO ACCOMPANY THE
FRONT MON NIGHT.
TEMPERATURES THROUGH THE PERIOD ARE EXPECTED TO RANGE FROM THE
MIDDLE TO UPPER 60S IN A MIXED AND MOIST BOUNDARY LAYER SUN
NIGHT...TO 70S (WITH POCKETS OF LOWER 80S WHERE ANY BINOVC OCCUR)
MON...TO UPPER 50S TO MIDDLE 60S IN POST-FRONTAL CAA MON NIGHT.
TUE THROUGH FRI...MEDIUM RANGE DETERMINISTIC AND ENSEMBLE MODEL
SPREAD INCREASES FURTHER DURING THE MIDDLE AND END OF THE WEEK WITH
RESPECT TO HOW QUICKLY THE PARENT UPPER LOW LIFTS FROM THE UPPER
MIDWEST TO SE CANADA...AS WELL AS HOW MUCH POSITIVELY-TILTED
TROUGHING ALOFT IS LEFT BEHIND OVER THE SE US. DESPITE THESE
DIFFERENCES...THE ASSOCIATED SENSIBLE WEATHER IMPACTS FOR OUR REGION
ARE SIMILAR. THAT IS...THE EXPANSION INTO THE EASTERN US OF PACIFIC
HIGH PRESSURE AND ASSOCIATED MILD AND DRY CONDITIONS...WITH ANY
UNSETTLED WEATHER RESULTING FROM LINGERING POSITIVELY-TILTED
TROUGHING ALOFT HOLDING TO OUR SOUTH - OVER THE SW NORTH ATLANTIC
AND CARIBBEAN.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
AS OF 745 PM FRIDAY...
AREAS OF FOG ARE EXPECTED DEVELOP LATE TONIGHT BETWEEN 06 TO
12Z......WITH THE HIGHEST PROBABILITY AND CORRESPONDINGLY LOWER
VISIBILITIES EXPECTED IN THE EAST AT KRWI AND KFAY.
BEYOND THE 18Z VALID TAF PERIOD...AREAS OF FOG WILL BE POSSIBLE
AGAIN EARLY SUNDAY MORNING...OTHERWISE EXPECT PREDOMINATELY VFR
CONDITIONS THROUGH THE WEEKEND. MOISTURE ASSOCIATED WITH REMNANTS
OF TS KAREN WILL SPREAD INTO THE AREA LATE SUNDAY NIGHT AND INTO
MONDAY. SUB-VFR CONDITIONS WILL BE POSSIBLE AGAIN LATE SUNDAY NIGHT
AND MONDAY MORNING WITH WIDESPREAD SHOWERS AND STORMS MONDAY
AFTERNOON THROUGH MONDAY NIGHT WITH CORRESPONDING AREAS OF SUB-VFR
CONDITIONS. WIDESPREAD VFR CONDITIONS ARE LIKELY TO RETURN BY
TUESDAY AFTERNOON AS A COLD FRONT PUSHES EAST AND OFFSHORE.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DJF
NEAR TERM...SMITH
SHORT TERM...DJF/MWS
LONG TERM...MWS
AVIATION...CBL
AREA FORECAST DISCUSSION
NWS TULSA OK
910 PM CDT FRI OCT 4 2013
...UPDATE...
.DISCUSSION...
THUNDERSTORMS CONTINUED TO RIDE ALONG THE INITIAL WIND SHIFT OF
THE COLD FRONT THIS EVENING FROM SOUTHWEST OKLAHOMA TO JUST WEST OF
OSAGE COUNTY AS OF 9 PM THIS EVENING. THE DRIER AIR REMAINED
FURTHER WEST ACROSS NORTHWEST OKLAHOMA. THESE THUNDERSTORMS WILL
PUSH INTO THE CWA OVER THE NEXT HOUR AS THE FRONT CONTINUES TO
PUSH EAST SOUTHEASTWARD. WITH THE LOSS OF DAYTIME HEATING THE CAP
HAS BEGUN TO STRENGHTEN ACROSS THE CWA...HOWEVER DEEP LAYER SHEAR
NEAR AND JUST BEHIND THE FRONT WILL ALLOW FOR THE POTENTIAL FOR
SOME STORMS TO BECOME STRONG TO SEVERE. LARGE HAIL AND STRONG
WINDS CONTINUE TO BE THE MAIN THREATS WITH THIS ACTIVITY. GREATEST
POTENTIAL FOR ANY SEVERE STORMS LOOKS TO BE MAINLY NORTHWEST OF
INTERSTATE 44 OVER THE NEXT FEW HOURS. THE SEVERE THUNDERSTORM
WATCH FOR OSAGE AND PAWNEE COUNTIES REMAINS IN EFFECT UNTIL 3Z.
LATEST RUNS OF THE HRRR AND THE LOCAL IN-HOUSE MODEL INDICATE THAT
THUNDERSTORMS COULD BE NEAR EAST CENTRAL OKLAHOMA BY 06Z AND INTO
SOUTHEAST OKLAHOMA AND NORTHWEST ARKANSAS BY 9Z. INSTABILITY
ACROSS THE REST OF THE CWA SHOULD WEAKEN OVERNIGHT AS THE CAP
CONTINUES TO STRENGHTEN...THOUGH AN ISOLATED STRONG TO SEVERE
STORM COULD BE POSSIBLE.
GUSTY NORTHWESTERLY WINDS IN THE 20 TO 30 MPH RANGE HAVE BEEN
OBSERVED BEHIND THE FRONT WITHIN THE DRIER/COOLER AIR AND WILL
CONTINUE TO FILTER INTO THE REGION OVERNIGHT. TEMPERATURES BY
EARLY SATURDAY MORNING LOOK BE AROUND 50 TO LOWER 50S NEAR THE
KANSAS BORDER TO THE 60S FOR FAR SOUTHEAST OKLAHOMA AND WEST
CENTRAL ARKANSAS. EVENING UPDATE WILL BE TO ADJUST POPS/WX/SKY
GRIDS BASED ON LATEST TRENDS AND TIMING...WHILE THE REST OF THE
FORECAST SEEMS TO BE HANDLING WELL AT THIS TIME.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 53 64 47 68 / 90 20 10 0
FSM 66 73 46 68 / 80 70 10 0
MLC 56 60 44 70 / 90 60 10 0
BVO 51 65 43 66 / 80 20 10 0
FYV 60 65 42 63 / 80 80 10 10
BYV 63 68 44 62 / 80 80 10 10
MKO 56 59 45 68 / 90 60 10 0
MIO 53 61 43 64 / 90 50 10 10
F10 53 60 46 69 / 90 40 10 0
HHW 66 73 46 72 / 80 50 10 0
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
SHORT TERM...20
LONG TERM....99
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
608 PM CDT FRI OCT 4 2013
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 330 PM CDT FRI OCT 4 2013
FORECAST CONCERNS ARE ON SEVERE THUNDERSTORM POTENTIAL TONIGHT AND
THE POSSIBILITY OF A FEW SEVERE STORMS IN CENTRAL WISCONSIN LATE
SATURDAY MORNING INTO EARLY SATURDAY AFTERNOON.
LATEST SURFACE OBSERVATIONS SHOWED SURFACE LOW PRESSURE OVER
CENTRAL NEBRASKA...LIFTING NORTHEAST. A WARM FRONT EXTENDED
SOUTHEAST THROUGH SOUTHWEST AND CENTRAL IOWA. THE FRONT WILL LIFT
NORTH LATE THIS AFTERNOON INTO THIS EVENING AND BE THE FOCUS FOR
STRONG TO SEVERE THUNDERSTORM DEVELOPMENT AS A POTENT UPPER LOW
PUSHES EAST ACROSS THE NEBRASKA PANHANDLE.
THE WARM FRONT IS EXPECTED TO LIFT NORTH INTO NORTHERN IOWA AND
PERHAPS EXTREME SOUTHWEST WISCONSIN THIS EVENING. STRONG 850 MB
MOISTURE TRANSPORT FOCUSES INTO THE FRONT THIS EVENING...LEADING TO
SHOWERS AND THUNDERSTORMS DEVELOPING OVER NORTHEAST IOWA...SOUTHEAST
MINNESOTA AND PORTIONS OF SOUTHWEST WISCONSIN. MEANWHILE THE SURFACE
LOW WILL LIFT NORTH INTO SOUTHEAST SOUTH DAKOTA AS THE LOW OCCLUDES.
A TRIPLE POINT LIFTS NORTHEAST FROM NORTHEAST IOWA INTO SOUTH
CENTRAL MINNESOTA LATE IN THE EVENING. THE 04.17 HRRR SHOWS ISOLATED
STRONG STORMS DEVELOPING ALONG THE FRONT. STORMS ALSO DEVELOP OVER
WESTERN IOWA EARLY THIS EVENING CLOSER TO THE OCCLUSION. THESE STORMS
WILL LIKELY BE SUPERCELLS...CAPABLE OF PRODUCING LARGE
HAIL...DAMAGING WINDS AND ISOLATED TORNADOES. THE STORMS FURTHER TO
THE NORTH OVER THE FORECAST AREA...SHOULD BE NORTH OF THE WARM
FRONT AND ELEVATED IN NATURE. 1-7 KM BULK SHEAR VALUES HOVER RIGHT
AROUND 30 KTS DURING THE EVENING HOURS SO CANNOT RULE OUT ISOLATED
SEVERE STORMS CAPABLE OF PRODUCING LARGE HAIL...HEAVY
RAINFALL...AND POSSIBLY DAMAGING WINDS. THE HIGHEST CHANCES FOR
SEVERE WEATHER WILL BE OVER NORTHEAST IOWA AND SOUTHEAST
MINNESOTA...WEST OF HIGHWAY 52. A FEW OF THESE STRONGER STORMS
COULD MAINTAIN INTENSITY INTO PORTIONS OF WESTERN WISCONSIN BUT
SHOULD THEN WEAKEN AS THEY MOVE EAST...BUT STILL CAPABLE OF
PRODUCING HEAVY RAINFALL. THE 850 MB MOISTURE TRANSPORT GRADUALLY
SHIFTS EAST INTO WESTERN WISCONSIN OVERNIGHT WITH WIDESPREAD
SHOWERS AND STORMS PERSISTING. THE MAIN THREAT FROM THE STORMS
SHOULD GRADUALLY SHIFT TOWARDS HEAVY RAIN LATE IN THE NIGHT. A
COLD FRONT THEN PUSHES EAST ACROSS THE REGION EARLY SATURDAY
MORNING AND SHOULD BE POSITIONED RIGHT ALONG THE MISSISSIPPI RIVER
BY THE MID TO LATE MORNING HOURS. IF ENOUGH INSTABILITY CAN BUILD
AHEAD OF THE FRONT...THERE IS THE POSSIBILITY OF SEEING A FEW
STRONG TO SEVERE STORMS OVER CENTRAL WISCONSIN. THE MAIN HAZARDS
FROM THESE STORMS WOULD BE DAMAGING WINDS. SHOWERS AND STORMS WILL
END FROM WEST TO EAST SATURDAY AFTERNOON AS A DRY SLOT PUSHES INTO
THE REGION. TEMPERATURES SHOULD FALL ACROSS THE AREA SATURDAY
AFTERNOON IN THE WAKE OF THE COLD FRONT.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 330 PM CDT FRI OCT 4 2013
MOST OF THE FORECAST AREA WILL REMAIN IN THE DRY SLOT SATURDAY
NIGHT...WITH THE EXCEPTION OF NORTH CENTRAL WISCONSIN WHERE A FEW
SHOWERS MAY LINGER. PLAN ON A COOLER NIGHT WITH LOWS FALLING INTO
THE 40S. A FEW 30S CANNOT BE RULED OUT OVER CENTRAL WISCONSIN. THE
UPPER LOW MOVES INTO INTO WESTERN IOWA ON SUNDAY AND EVENTUALLY
INTO WESTERN ILLINOIS SUNDAY NIGHT. SHOWERS WRAPPING AROUND THE
LOW LOOK TO MOVE INTO THE REGION SUNDAY AND WILL LIKELY CONTINUE
INTO SUNDAY NIGHT AS THE LOW PROGRESSES EAST. THE LOW THEN LOOKS
TO MOVE INTO THE EASTERN GREAT LAKES LATE ON TUESDAY WITH HIGH
PRESSURE BUILDING INTO THE AREA IN ITS WAKE. HIGH PRESSURE THEN
BUILDS OVER THE AREA WEDNESDAY INTO THURSDAY WITH DRY AND QUIET
WEATHER EXPECTED...OUTSIDE OF THE POSSIBILITY OF OF SOME EARLY
MORNING VALLEY FOG. A TROUGH IS EXPECTED TO DIG INTO THE SOUTHWEST
CONUS LATE IN THE WEEK. SOUTHWEST FLOW LOOKS TO DEVELOP OVER THE
UPPER MISSISSIPPI RIVER VALLEY LATE FRIDAY INTO SATURDAY. FORECAST
MODELS SHOWS THE TROUGH EJECTING INTO THE CENTRAL AND NORTHERN
PLAINS...WILL HAVE TO KEEP A VERY CLOSE EYE ON THIS SYSTEM OVER
THE NEXT SEVERAL MODEL RUNS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 608 PM CDT FRI OCT 4 2013
SOME CONVECTION DEVELOPING ALONG A WEAK BOUNDARY ACROSS NORTHERN
IOWA. ACTIVITY IS MOVING PRIMARILY TO THE NORTH/NORTHEAST AND
SHOULD THE GREATEST POTENTIAL TO IMPACT KRST IF IT HOLDS TOGETHER
AS IT MOVES NORTH. AROUND 500 J/KG OF MU CAPE EXITS AS FAR NORTH
AS THE I90 CORRIDOR SO WILL SHOW A VCTS AT KRST FOR THIS ACTIVITY.
THE FOCUS THEN SHIFTS TO HOW FAST THE CONVECTION NEAR THE MISSOURI
RIVER WILL TRANSLATE INTO THE AREA. THE 04.21Z HRRR SEEMS TO BE
HANDLING THIS WELL AND INDICATES IT COULD START COMING IN BY MID
EVENING AND THEN MOVE OFF TO THE EAST BETWEEN 06 AND 08Z. BRIEF
BREAK IN THE ACTION BEFORE THE COLD FRONT COMES IN EARLY SATURDAY
MORNING WITH ANOTHER ROUND OF CONVECTION. THIS ACTIVITY COULD
POTENTIALLY STICK AROUND INTO THE MIDDLE OF THE AFTERNOON...EVEN
FOR A FEW HOURS AFTER THE FRONT GOES THROUGH WITH THE UPPER LEVEL
SYSTEM HANGING BACK WELL TO THE WEST. THE WINDS SHOULD GO AROUND
TO SOUTHWEST DURING THE AFTERNOON BEHIND THE PASSAGE OF THE FRONT.
CEILINGS LOOK TO REMAIN IFR AT BOTH SITES FOR MUCH OF THE PERIOD
WITH VISIBILITIES PRIMARILY MVFR.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM...WETENKAMP
AVIATION...04
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
322 AM CDT SAT OCT 5 2013
.DISCUSSION...
322 AM...PRIMARY FORECAST CONCERN/CHALLENGE IS POTENTIAL FOR
SEVERE WEATHER INTO THIS EVENING.
FRONTAL BOUNDARY HAS BEEN SLOWLY LIFTING NORTH ACROSS NORTHERN IL
WITH SOUTHERLY WINDS REACHING A RFD/ORD LINE. WHILE VISIBILITIES
HAVE REMAINED GENERALLY IN THE 1-3SM RANGE NEAR THE FRONT...ACROSS
FAR NORTHEAST IL SATELLITE IMAGERY SUGGESTS FOG IS RATHER THICK
OVER NORTHERN SECTIONS OF LAKE AND MCHENRY COUNTIES WITH UGN
REPORTING 1/4SM FOR THE PAST FEW HRS. WHILE THIS WILL LIKELY BE
SHORT-LIVED...OPTED TO ISSUE A DENSE FOG ADVISORY FOR THESE TWO
COUNTIES THROUGH 8AM. AS WINDS TURN SOUTHERLY...VISIBILITIES WILL
IMPROVE.
SOUTH OF THE FRONT...FAIRLY IMPRESSIVE AIRMASS THIS FAR NORTH FOR
EARLY OCTOBER WITH DEWPOINTS IN THE UPPER 60S AND MOISTURE IS
EXPECTED TO POOL THIS MORNING WITH PERHAPS LOWER 70 DEWPOINTS
ACROSS MUCH OF THE AREA. UPSTREAM CLOUD COVER IS MOSTLY MID/HIGH
CLOUDS THAT WILL LIKELY THIN THROUGH MID MORNING...SO APPEARS MUCH
OF THIS MORNING WILL BE MOSTLY SUNNY/PARTLY CLOUDY. THIS SHOULD
AID TEMPERATURES RISING INTO THE LOWER 80S ACROSS THE SOUTHEAST
HALF OF THE AREA AND WITH SUCH A MOIST AIRMASS IN PLACE...ONCE
HEATING BEGINS...POSSIBLE FOR ISOLATED THUNDERSTORMS THIS MORNING.
BULK OF THE ACTIVITY HOWEVER APPEARS TO HOLD OFF UNTIL THIS
AFTERNOON...BOTH FROM INCREASING DIURNALLY DRIVEN STORMS BUT ALSO
AS A SHORTWAVE LIFTS NORTHEAST ACROSS NORTH CENTRAL ILLINOIS THIS
AFTERNOON INTO THIS EVENING...AHEAD OF THE APPROACHING COLD FRONT.
WITH THUNDERSTORMS SPREADING EAST THIS EVENING BUT SLOWING.
OVERALL CONFIDENCE REGARDING THIS SCENARIO IS SOMEWHAT LOW IN
ADDITION TO THE POTENTIAL FOR SEVERE WEATHER. THE MAIN SEVERE
WEATHER THREAT WILL BE DAMAGING WINDS GUSTS BUT LACK OF STRONG
SHEAR ALOFT WOULD SUGGEST THESE WOULD BE MORE ISOLATED...RATHER
THEN A LINE OF STRONG/SEVERE STORMS. IN ADDITION...THE VERY MOIST
LOW LEVELS WILL YIELD LOW LCL HEIGHTS AND MODELS ARE IN FAIR
AGREEMENT WITH SURFACE WINDS BACKING SOME THIS AFTERNOON. THUS
INDIVIDUAL CELLS THAT FORM AWAY FROM CLUSTERS OR LINES OF
CONVECTION WILL HAVE SOME POTENTIAL TO PRODUCE A TORNADO.
FORECAST PRECIPITABLE WATER VALUES OF 1.5 INCHES OR HIGHER WILL
LEAD TO LOCALLY VERY HEAVY RAIN AND WITH LITTLE CHANGE TO STORM
MOTION...GENERALLY SOUTHWEST TO NORTHEAST...ANY TRAINING OF STORMS
COULD EASILY CAUSE FLOODING CONCERNS.
ACTIVITY WILL SLOWLY SHIFT EAST LATE TONIGHT INTO SUNDAY MORNING
AND HAVE INCLUDED CHANCE POPS EAST OF I-57 INTO THE MORNING.
UNCERTAINTY HAS INCREASED WITH THE ARRIVAL OF THE 00Z ECMWF WHICH
IS CONSIDERABLY FASTER THAN OTHER 00Z GUIDANCE WITH THE
PROGRESSION OF THE UPPER LOW EAST ACROSS THE LAKES REGION. SUNDAY
WAS SHAPING UP TO BE MAINLY DRY WITH PERHAPS SOME INSTABILITY
SHOWERS ARRIVING IN THE WEST BY EVENING. AND WITH THE POSSIBILITY
OF SOME SUNSHINE...TEMPS PERHAPS IN THE 60S AND WHILE THAT WILL BE
MUCH COLDER THAN TODAY...IT WOULD ONLY BE A FEW DEGREES BELOW
NORMAL. A FASTER SHIFT EAST OF THE UPPER LOW WILL ALSO END THE
SHOWER POTENTIAL MONDAY OR MONDAY EVENING...RATHER THAN TUESDAY
MORNING WITH THE SLOWER SOLUTIONS. CHANGES TO THE SUNDAY-TUESDAY
TIME PERIOD CAN BE EXPECTED DEPENDING ON THE SPEED OF THE UPPER
LOW. HOWEVER...THE WARMING TREND STILL LOOKS ON TRACK...PERHAPS
JUST DELAYED BY A DAY OR SO WITH HIGHS BACK INTO THE 70S BY
WEDNESDAY AND THURSDAY. CMS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* LOWERING VISIBILITY AND CIGS INTO IFR CATEGORY INTO OVERNIGHT.
* NORTHEAST WINDS BECOMING EAST THEN SOUTHEAST TONIGHT WITH SPEEDS
MOST OF TIME BELOW 10 KT.
* SMALL CHANCE OF TSRA SAT MORNING GRADUALLY INCREASING INTO MID-
AFTERNOON.
* THUNDERSTORMS LIKELY 22Z-00Z SOME OF WHICH COULD BE STRONG.
BEACHLER
//DISCUSSION...UPDATED 06Z...
VERY CHALLENGEING AVIATION CONDITIONS ARE IN STORE FOR THE NEXT 24
HOURS ACROSS THE REGION...ESPECIALLY OVER NORTHERN IL/NORTHWEST
IN. A STALLED FRONTAL BOUNDARY WAS ORIENTED ACROSS NORTHERN
IL...WHICH HAS RESULTED IN LIGHT WINDS TO AT TIMES CALM FOR
DPA/ORD/MDW/GYY. IN ADDITION VERY MOIST AIR WAS OVER THESE
AIRFIELDS AND HAS RESULTED IN VSBYS BEING REDUCED. IT APPEARS ORD
SHOULD ONLY REDUCE TO ARND 3-4SM OVERNIGHT...HOWEVER ELSEWHERE
MDW/GYY/DPA/RFD WILL LIKELY SEE VSBYS DOWN BTWN 1/2SM AT RFD/DPA
TO 2-3SM AT GYY/MDW. IR IMAGERY INDICATED SOME IFR CIGS WERE
DEVELOPING OVER FAR NORTHWEST IL WHICH HAS BROUGHT CIGS DOWN AT
RFD...AND IT IS POSSIBLE CIGS COULD DROP TO ARND 200-300FT AGL
BEFORE DAYBREKA THEN SLOWLY IMPROVE AFT DAYBREAK.
THEN THE FOCUS TURNS TOWARDS CONVECTIVE TIMING/PLACEMENT LATER
TODAY. AFTER SUNRISE VSBYS SHUD BE SLOW TO IMPROVE WITH JUST A
CIRRUS SHIELD EXPECTED OVERHEAD TO START THE DAY. THE COLD FRONT
WILL BE WELL WEST OF THE REGION...HOWEVER STEADILY PIVOTING EAST
TOWARDS NORTHERN IL AIRFIELDS. GUIDANCE CONTINUES TO INDICATE
WINDS BY MID MORNING WILL BECOME SOUTHERLY ARND 10KT AND
OCCASIONAL GUSTS TO THE MID-TEENS ARE LIKELY. CLOUDS WILL THICKEN
BY MIDDAY WITH A DECK ARND 3-4KFT AGL. WITH CONSIDERABLE ELEMENTS
SUGGESTING CONVECTION WILL BE FIRING ARND 18-19Z...IT IS LIKELY
THAT THE BEST CHC FOR CONVECTION WILL BE ARND 19Z-00Z...AND THE
BETTER COVERAGE WILL FALL WITHIN A 22-00Z TIMEFRAME. WINDS WILL
SLOWLY TURN TO THE 240-260 DEG RANGE FRONTAL PASSAGE...WITH
RAIN/THUNDER SLOWLY ENDING AFT 03-06Z SUN.
BEACHLER
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE IN STABLE/SLIGHTLY LOWERING TREND OF
CIG...MEDIUM CONFIDENCE ON VISIBILITY. MEDIUM CONFIDENCE ON HOW
LOW CIG AND VISIBILITY WILL FALL.
* MEDIUM-HIGH CONFIDENCE IN WIND FORECAST.
* MEDIUM CONFIDENCE ON TSRA TIMING OF 21Z-02Z.
BEACHLER
//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...
SUNDAY...VFR DURING THE DAY WITH MVFR CIGS AND CHC SHRA DURING THE
NIGHT.
MONDAY...CHC OF MVFR AND SLT CHC OF SHRA DURING THE MORNING.
TUESDAY-THURSDAY...MAINLY VFR.
MTF
&&
.MARINE...
341 PM CDT
A TROUGH OF LOW PRESSURE AND ASSOCIATED FRONTAL BOUNDARY ARE
SITUATED ACROSS THE UPPER MISSISSIPPI VALLEY EAST ACROSS TO THE
SOUTHERN GREAT LAKES REGION...WITH THESE FEATURES STEMMING FROM AN
AREA OF LOW PRESSURE SITUATED OVER THE CENTRAL PLAINS. ITS THESE
FEATURES THAT ARE PROVIDING...AND WILL CONTINUE TO PROVIDE
DRASTICALLY VARYING CONDITIONS ACROSS THE ENTIRE LAKE. A LIGHTER
WIND FIELD IS CURRENTLY PRESENT OVER THE SOUTHERN PORTIONS OF THE
LAKE WHERE THE PRESSURE GRADIENT IS RELAXED...BUT WITH SPEEDS
INCREASING TO 15 TO 25 KT FOR THE FAR NORTHERN PORTIONS OF THE
LAKE. THIS BOUNDARY WILL LIFT BACK NORTH ACROSS THE LAKE TONIGHT
INTO SATURDAY WHILE THIS LOW PRESSURE SYSTEM SLOWLY TRACKS
NORTHEAST TOWARDS THE MISSISSIPPI VALLEY. AS THIS OCCURS...EXPECT
A GRADUAL TRANSITION TO THE EAST SOUTHEAST WITH SPEEDS INCREASING
ACROSS THE ENTIRE LAKE. EXPECT THE HIGHEST SPEEDS OF 30KT TO BE
OBSERVED ACROSS THE NORTH...WITH THESE EASTERLY WINDS/SPEEDS
LIKELY PERSISTING INTO EARLY SATURDAY NIGHT. EXPECT THIS LOW TO
THEN CONTINUE NORTHEAST AND REACH THE CENTRAL GREAT LAKES LATE
SATURDAY NIGHT INTO SUNDAY...AND THEN CONTINUE EAST TOWARDS THE
EASTERN GREAT LAKES SUNDAY NIGHT INTO MONDAY. AS THIS
OCCURS...EXPECT SPEEDS TO DIMINISH WHILE BECOMING MORE SOUTHERLY
ON SUNDAY AND THEN WEST/NORTHWEST INTO MONDAY.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...DENSE FOG ADVISORY...ILZ005-ILZ006 UNTIL 8 AM SATURDAY.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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[top]
Area Forecast Discussion
National Weather Service Lincoln IL
301 AM CDT Sat Oct 5 2013
.DISCUSSION...
ISSUED 301 AM CDT Sat Oct 5 2013
After a stormy day across central Illinois today, much cooler
weather will arrive for early next week.
07z/2am surface map shows 1000mb low centered over South Dakota,
with cold front extending southeastward into Iowa/Missouri. Very
warm and humid airmass remains in place ahead of the front, with
temps in the 70s and dewpoints in the upper 60s. Meanwhile,
sharply colder conditions are noted further west behind the
boundary where readings are only in the 30s across the Dakotas and
Nebraska.
SHORT TERM...Today through Monday
Deep upper-level low currently spinning over South Dakota will be
the main weather-maker across the region for the next couple of
days. As this system slowly wobbles eastward, it will push a
strong cold front through central Illinois later today into tonight.
00z models have slowed eastward progression of the front just a bit,
bringing it into the Illinois River Valley by around 21z/4pm.
Given occluded nature of system, this slower trend seems
reasonable. As such, have lowered POPs across the western KILX CWA
into the chance category during the morning hours, opting to hit
POPs hardest during the afternoon and evening as best forcing
arrives. The front will have plenty of moisture to work with as
forecast soundings show precipitable water values greater than
1.50. The airmass will also be moderately unstable, with CAPE
values ranging from 1500 to 2000J/kg. Main mitigating factor for
widespread severe weather will be weak wind fields/shear. While
instability axis will be positioned across Illinois and the Ohio
River Valley this afternoon, strongest wind shear will be
displaced well to the west across Iowa and Missouri. With these
two key severe weather parameters not coinciding with one another,
am not expecting a major severe event today. Thunderstorms will
increase in areal coverage during the afternoon, with perhaps a
few of them producing severe wind gusts. Outside of thunderstorms,
it will be another very warm day with highs ranging from the
middle 70s west to the lower 80s east. Based on expected speed of
front, temps will likely drop into the 60s along/west of the
Illinois River late this afternoon after FROPA.
Due to slower frontal movement, have increased POPs tonight. Will
carry likely to categorical POPs along/east of the Illinois River
during the evening, with best rain chances shifting to the I-57
corridor and eastward after midnight. Once front passes, skies
will clear across the Illinois River Valley late tonight. Low
temperatures will range from the lower 40s far west around
Galesburg and Rushville, to the upper 50s near the Indiana border.
Will linger some shower chances along/east of I-57 through Sunday
morning, as front slowly progresses eastward across Indiana. Mid-level
dry slot behind front and immediately ahead of slowly approaching
upper low will allow skies to be partly to mostly sunny across the
central and western CWA Sunday morning before clouds begin to
increase from the west by late in the day. Given slow movement of
system, have pulled back POPs from previous forecast to feature
only a slight chance for showers across the far west Sunday afternoon.
Cold core upper low will track overhead Sunday night into Monday,
creating a chilly and showery weather pattern. NAM/GFS/GEM are all
in excellent agreement with the position of the 500mb closed low
over Illinois by 12z Mon. Meanwhile, the latest run of the ECMWF
has made a drastic shift from its previous solution, now placing
the low over Michigan Monday morning. Will reject the ECMWF in
favor of the model consensus here. As a result, have added low
POPs for showers both Sunday night and Monday. Have also lowered
highs considerably for Monday, with readings only reaching the
lower 60s.
LONG TERM...Tuesday through Friday
Once upper low lifts further northeast, upper heights will once
again be on the rise across the central and eastern CONUS next
week. 850mb temps respond accordingly, with readings back into the
14 to 16c range by Thursday and Friday. This will support highs
well into the 70s and perhaps the lower 80s by the end of the week.
Barnes
&&
.AVIATION...
ISSUED 1151 PM CDT Fri Oct 4 2013
Latest runs of the high resolution models and the 00z NAM/GFS
indicate that the aviation forecast for central IL TAF sites needs
few changes from the previous issuance.
Still looking for light fog/mist to form toward early morning,
although it is looking less likely that a stratus ceiling will
develop. Plenty of high and mid clouds from upstream convective
debris will move into central and eastern Illinois overnight.
Radar trends, as well as the latest HRRR and RAP forecasts,
indicating that convective remnants to approach central Illinois
shortly after daybreak ahead of the cold front. Plenty of moisture,
instability and increasing low/mid level wind shear will be
present for t-storms to redevelop in a linear fashion by early
afternoon. Maintained the predominant thunderstorm forecast to
account for this expected development and movement of a line of
storms.
The higher resolution models were also indicating that the front
will move a bit slower than previously forecast. Thus, the 06z TAFs
will extend the thunderstorms a couple of hours from the previous
forecast, and also hold off the frontal passage/wind shift until
late afternoon- evening.
Miller
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
105 AM CDT SAT OCT 5 2013
.DISCUSSION...
804 PM CDT
THIS EVENING...WARM FRONT STRETCHES FROM NEAR DBQ ESE TO JOT...THEN
EAST TO VPZ. TEMPERATURES CONTINUE TO RUN IN THE MID TO UPPER 70S
SOUTH OF THE FRONT...WITH DEWPOINTS INTO THE MID TO UPPER 60S. NORTH
OF THE BOUNDARY...TEMPERATURES QUICKLY TAPER INTO THE MID 60S...WITH
LOW DEW POINT DEPRESSIONS. FOG/LOW STRATUS ALREADY STARTING TO
DEVELOP ACROSS THESE AREAS...AND SHOULD CONTINUE TO EXPAND OVERNIGHT.
REMOVED PRECIP MENTION OVERNIGHT FOR ALL BUT THE NORTHERN TIER OF
COUNTIES. LAST VISIBLE SATELLITE IMAGES BEFORE SUNSET SHOWED CU
FIELD QUICKLY DISSIPATING...AND THE MAIN IMPETUS FOR ANY PRECIP
OVERNIGHT IS NEAR THE IL/WI STATE LINE WHERE THE BEST FOCUSED
ISENTROPIC ASCENT IS NOTED. FORECAST OTHERWISE ON TRACK WITH ONLY
MINOR TWEAKS TO THE HOURLY TRENDS.
DEUBELBEISS
//PREV DISCUSSION...
240 PM
FOR THE REMAINDER OF THE AFTERNOON THROUGH SATURDAY...THE MAIN
CONCERN WILL BE SEVERE WEATHER POTENTIAL...WITH A SECONDARY CONCERN
FOR TEMPERATURES.
EARLY THIS AFTERNOON...CONVECTIVE ACTIVITY IS FOCUSING ON THE NOSE
OF A STRONG LOW LEVEL JET POINTING INTO NRN IL...WHICH IS ENHANCING
THE ISENTROPIC LIFT ALREADY IN PLACE AS WARM MOIST AIR CONTINUES TO
STREAM INTO THE REGION. A SECONDARY FOCUS OF CONVECTIVE ACTIVITY IS
A SFC TROUGH/SECONDARY WARM FRONT EXTENDING FROM NRN MO...THROUGH
NRN IL AND NRN INDIANA. LATEST RADAR IMAGERY SHOWS THE WARM
ADVECTION CONVECTION ALREADY INTO NWRN IL AND WITH COPIOUS AMOUNTS
OF HEAT...TEMPS IN THE UPPERS 70S-LOW 80S...MOISTURE...DEWPOINTS IN
THE UPPER 60S TO LOWERS 70S...AND INSTABILITY...MIXED LAYER CAPE OF
1500-2000 J/KG...EXPLOSIVE CONVECTION IS QUITE POSSIBLE WHERE ALL
ELEMENTS LINE UP JUST RIGHT. WITH THE LOW LEVEL JET OF 30KT+ OVER
THE AREA...STRONGER WINDS CAN CERTAINLY MIX DOWN TO THE SURFACE.
THE ONE QUESTION MARK AT THIS TIME IS THE CLOUD COVER. LATEST
SATELLITE IMAGERY SHOWS DENSE OVC OVER NRN IL...WITH MORE
CONVECTIVELY DRIVEN CU/TOWERING CU SOUTH OF THE I-80 CORRIDOR. OF
PARTICULAR CONCERN IS THE SECONDARY WARM FRONT...WHICH LIES IN THE
AREA OF GREATER SFC INSOLATION SOUTH OF I-80. THE 12Z ILX SOUNDING
INDICATES AT LEAST SOME VEERING OF WINDS THROUGH THE LOWER LEVELS
WHICH WOULD HELP ADD SOME ROTATIONAL ASPECT TO STORMS...WHICH IN
TURN COULD ADD A LARGE HAIL OR TORNADIC POTENTIAL TO THE STRONG WIND
THREAT. ON TOP OF ALL OF THIS WILL BE A HEAVY RAINFALL POTENTIAL.
THE 12Z KDVN SOUNDING INDICATES PWAT OF 1.4 INCHES...SO DEEP LAYER
MOISTURE IS ALREADY IN PLACE. THE VARIOUS MODEL FORECAST PWATS
INDICATE THAT A CORRIDOR OF EXTREME DEEP LAYER MOISTURE POOLING IN A
CORRIDOR FROM SWRN WISCONSIN TO NERN KANSAS. WITH TIME AND
PROGRESSION OF THE PATTERN...EXPECT THAT PWATS WILL ONLY INCREASE
OVER THE LOCAL AREA THROUGH THE NEXT 36HRS. THE KDVN PWAT
CLIMATOLOGY INDICATES THAT FOR OCTOBER...2 STANDARD DEVIATIONS FROM
NORMAL IS 1.6 INCHES AND THE 99TH PERCENTILE PWAT IS 1.9 INCHES.
THE LATEST MODEL RUNS SHOW PWAT INCREASING TO IN EXCESS OF 1.5
INCHES IN THE ENVIRONMENT AHEAD OF THE APPROACHING COLD FRONT.
SO...FOR THE SEVERE WEATHER THREAT...TIMING AND COVERAGE ARE THE BIG
QUESTIONS. ANTICIPATE THAT THE GREATEST SEVERE WEATHER THREAT WILL
BE WITH THE COLD FRONT DUE TO THE GREATER SFC FORCING WHICH WILL
LINE UP WITH THE FAVORABLE UPPER DYNAMICS WITH THE UPPER TROUGH.
HOWEVER...THERE WILL STILL BE A MORE ISOLATED SEVERE WEATHER THREAT
ACROSS THE LOCAL AREA SIMPLY DUE TO THE UNSEASONABLY STRONG LOWER
LEVEL THERMODYNAMICS AND EXTREME DEEP LAYER MOISTURE. ALONG WITH
THE SEVERE WEATHER THREAT...HEAVY RAINFALL AND LOCALIZED FLOODING
WILL BE A CONCERN. THE PRIMARY LOCATION FOR POSSIBLE FLOODING WILL
BE ALONG THE SECONDARY WARM FRONT AS RADAR TRENDS INDICATE THAT THE
BOUNDARY ITSELF IS QUASISTATIONARY WHILE INDIVIDUAL CELLS TRACK TO
THE EAST. THE CURRENT CONVECTIVE ACTIVITY ALONG THIS BOUNDARY IS
CURRENTLY OVER NRN INDIANA...BUT RADAR SHOWS A FINE-LINE WEST INTO
NERN IL. IF CONVECTION FILLS IN ALONG THE BOUNDARY AND IT REMAINS
QUASISTATIONARY OR AT LEAST SLOWLY PROGRESSIVE...LOCALIZED FLOODING
WILL BECOME AN INCREASING CONCERN.
FOR TIMING OF THE PROGRESSION OF THE COLD FRONT...THE VARIOUS MODELS
HAVE CONVERGED INTO GOOD AGREEMENT ON THE PROGRESSION...CROSSING THE
RIVER INTO NWRN IL BY ARND 12Z SATURDAY AND STEADILY PROGRESSING EWD
TO NRN INDIANA BY LATE AFTERNOON OR EARLY EVENING. THE THUNDERSTORM
THREAT SHOULD BE CONFINED TO A ZONE ALONG AND AHEAD OF THE FRONT.
FOLLOWING THE FRONTAL PASSAGE...CONDITIONS SHOULD QUICKLY
IMPROVE...FOR A TIME...WITH TEMPERATURES DROPPING OFF QUICKLY.
TEMPERATURES WILL DROP OFF FROM HIGHS IN THE LOW TO MIDDLE 80S TODAY
AND SATURDAY TO LOWS IN THE UPPER 40S TO MIDDLE 50S SUNDAY MORNING
AND LOWS IN THE MIDDLE 40S BY MONDAY MORNING. HIGHS FOR SUNDAY AND
MONDAY SHOULD BE IN THE LOWER TO MIDDLE 60S. THERE WILL STILL BE
SOME CHANCE FOR SOME PCPN SUNDAY AND MONDAY AS THE CENTER OF THE
UPPER LOW TRACKS RIGHT OVER NRN IL/IN...BUT ANY PCPN SHOULD
GENERALLY BE SCT SHOWERS AND PCPN AMOUNTS GENERALLY LIGHT.
FOR THE EXTENDED FORECAST PERIOD...FROM TUESDAY THROUGH
FRIDAY...EXPECT A PERIOD OF SLOWLY MODERATING TEMPERATURES WITH
LITTLE TO NO CHANCE OF PCPN. FOLLOWING THE PASSAGE OF THE UPPER
LOW...A BUILDING UPPER LEVEL RIDGE WILL SLOWLY MOVE OUT OVER THE
PLAINS AND MISSISSIPPI VALLEY AS ANOTHER DEEP UPPER LOW DROPS DOWN
THE WEST COAST INTO THE DESERT SOUTHWEST. THE AMPLIFYING...BUT
SLOWLY PROGRESSIVE PATTERN ALOFT WILL KEEP CONDITIONS DRY WITH ABOVE
NORMAL TEMPS OVER THE LOCAL WITH HIGHS IN THE LOWER TO MIDDLE 70S
AND LOWS IN THE UPPER 40S TO MIDDLE 50S.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* LOWERING VISIBILITY AND CIGS INTO IFR CATEGORY INTO OVERNIGHT.
* NORTHEAST WINDS BECOMING EAST THEN SOUTHEAST TONIGHT WITH SPEEDS
MOST OF TIME BELOW 10 KT.
* SMALL CHANCE OF TSRA SAT MORNING GRADUALLY INCREASING INTO MID-
AFTERNOON.
* THUNDERSTORMS LIKELY 22Z-00Z SOME OF WHICH COULD BE STRONG.
BEACHLER
//DISCUSSION...UPDATED 06Z...
VERY CHALLENGEING AVIATION CONDITIONS ARE IN STORE FOR THE NEXT 24
HOURS ACROSS THE REGION...ESPECIALLY OVER NORTHERN IL/NORTHWEST
IN. A STALLED FRONTAL BOUNDARY WAS ORIENTED ACROSS NORTHERN
IL...WHICH HAS RESULTED IN LIGHT WINDS TO AT TIMES CALM FOR
DPA/ORD/MDW/GYY. IN ADDITION VERY MOIST AIR WAS OVER THESE
AIRFIELDS AND HAS RESULTED IN VSBYS BEING REDUCED. IT APPEARS ORD
SHOULD ONLY REDUCE TO ARND 3-4SM OVERNIGHT...HOWEVER ELSEWHERE
MDW/GYY/DPA/RFD WILL LIKELY SEE VSBYS DOWN BTWN 1/2SM AT RFD/DPA
TO 2-3SM AT GYY/MDW. IR IMAGERY INDICATED SOME IFR CIGS WERE
DEVELOPING OVER FAR NORTHWEST IL WHICH HAS BROUGHT CIGS DOWN AT
RFD...AND IT IS POSSIBLE CIGS COULD DROP TO ARND 200-300FT AGL
BEFORE DAYBREKA THEN SLOWLY IMPROVE AFT DAYBREAK.
THEN THE FOCUS TURNS TOWARDS CONVECTIVE TIMING/PLACEMENT LATER
TODAY. AFTER SUNRISE VSBYS SHUD BE SLOW TO IMPROVE WITH JUST A
CIRRUS SHIELD EXPECTED OVERHEAD TO START THE DAY. THE COLD FRONT
WILL BE WELL WEST OF THE REGION...HOWEVER STEADILY PIVOTING EAST
TOWARDS NORTHERN IL AIRFIELDS. GUIDANCE CONTINUES TO INDICATE
WINDS BY MID MORNING WILL BECOME SOUTHERLY ARND 10KT AND
OCCASIONAL GUSTS TO THE MID-TEENS ARE LIKELY. CLOUDS WILL THICKEN
BY MIDDAY WITH A DECK ARND 3-4KFT AGL. WITH CONSIDERABLE ELEMENTS
SUGGESTING CONVECTION WILL BE FIRING ARND 18-19Z...IT IS LIKELY
THAT THE BEST CHC FOR CONVECTION WILL BE ARND 19Z-00Z...AND THE
BETTER COVERAGE WILL FALL WITHIN A 22-00Z TIMEFRAME. WINDS WILL
SLOWLY TURN TO THE 240-260 DEG RANGE FRONTAL PASSAGE...WITH
RAIN/THUNDER SLOWLY ENDING AFT 03-06Z SUN.
BEACHLER
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE IN STABLE/SLIGHTLY LOWERING TREND OF
CIG...MEDIUM CONFIDENCE ON VISIBILITY. MEDIUM CONFIDENCE ON HOW
LOW CIG AND VISIBILITY WILL FALL.
* MEDIUM-HIGH CONFIDENCE IN WIND FORECAST.
* MEDIUM CONFIDENCE ON TSRA TIMING OF 21Z-02Z.
BEACHLER
//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...
SUNDAY...VFR DURING THE DAY WITH MVFR CIGS AND CHC SHRA DURING THE
NIGHT.
MONDAY...CHC OF MVFR AND SLT CHC OF SHRA DURING THE MORNING.
TUESDAY-THURSDAY...MAINLY VFR.
MTF
&&
.MARINE...
341 PM CDT
A TROUGH OF LOW PRESSURE AND ASSOCIATED FRONTAL BOUNDARY ARE
SITUATED ACROSS THE UPPER MISSISSIPPI VALLEY EAST ACROSS TO THE
SOUTHERN GREAT LAKES REGION...WITH THESE FEATURES STEMMING FROM AN
AREA OF LOW PRESSURE SITUATED OVER THE CENTRAL PLAINS. ITS THESE
FEATURES THAT ARE PROVIDING...AND WILL CONTINUE TO PROVIDE
DRASTICALLY VARYING CONDITIONS ACROSS THE ENTIRE LAKE. A LIGHTER
WIND FIELD IS CURRENTLY PRESENT OVER THE SOUTHERN PORTIONS OF THE
LAKE WHERE THE PRESSURE GRADIENT IS RELAXED...BUT WITH SPEEDS
INCREASING TO 15 TO 25 KT FOR THE FAR NORTHERN PORTIONS OF THE
LAKE. THIS BOUNDARY WILL LIFT BACK NORTH ACROSS THE LAKE TONIGHT
INTO SATURDAY WHILE THIS LOW PRESSURE SYSTEM SLOWLY TRACKS
NORTHEAST TOWARDS THE MISSISSIPPI VALLEY. AS THIS OCCURS...EXPECT
A GRADUAL TRANSITION TO THE EAST SOUTHEAST WITH SPEEDS INCREASING
ACROSS THE ENTIRE LAKE. EXPECT THE HIGHEST SPEEDS OF 30KT TO BE
OBSERVED ACROSS THE NORTH...WITH THESE EASTERLY WINDS/SPEEDS
LIKELY PERSISTING INTO EARLY SATURDAY NIGHT. EXPECT THIS LOW TO
THEN CONTINUE NORTHEAST AND REACH THE CENTRAL GREAT LAKES LATE
SATURDAY NIGHT INTO SUNDAY...AND THEN CONTINUE EAST TOWARDS THE
EASTERN GREAT LAKES SUNDAY NIGHT INTO MONDAY. AS THIS
OCCURS...EXPECT SPEEDS TO DIMINISH WHILE BECOMING MORE SOUTHERLY
ON SUNDAY AND THEN WEST/NORTHWEST INTO MONDAY.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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Area Forecast Discussion
National Weather Service Lincoln IL
1151 PM CDT Fri Oct 4 2013
.DISCUSSION...
ISSUED 850 PM CDT Fri Oct 4 2013
Updated the forecast for tonight to increase the PoPs early in
southeast IL for the isolated showers and few rumbles of thunder.
Also dropped the PoPs a bit in areas west of the IL River. Radar
trends with the convection in Iowa and western Missouri, along
with high res model solutions from the HRRR and RAP, indicate that
the showers and t-storms may not impact west central IL until
close to daybreak.
Otherwise, the forecast low temperatures, sky cover and wind are
all on track for the rest of tonight.
&&
.AVIATION...
ISSUED 1151 PM CDT Fri Oct 4 2013
Latest runs of the high resolution models and the 00z NAM/GFS
indicate that the aviation forecast for central IL TAF sites needs
few changes from the previous issuance.
Still looking for light fog/mist to form toward early morning,
although it is looking less likely that a stratus ceiling will
develop. Plenty of high and mid clouds from upstream convective
debris will move into central and eastern Illinois overnight.
Radar trends, as well as the latest HRRR and RAP forecasts,
indicating that convective remnants to approach central Illinois
shortly after daybreak ahead of the cold front. Plenty of moisture,
instability and increasing low/mid level wind shear will be
present for t-storms to redevelop in a linear fashion by early
afternoon. Maintained the predominant thunderstorm forecast to
account for this expected development and movement of a line of
storms.
The higher resolution models were also indicating that the front
will move a bit slower than previously forecast. Thus, the 06z TAFs
will extend the thunderstorms a couple of hours from the previous
forecast, and also hold off the frontal passage/wind shift until
late afternoon- evening.
Miller
&&
.PREV DISCUSSION...
ISSUED 300 PM CDT Fri Oct 4 2013
The current heat and humidity will be displaced by a chilly
Canadian airmass after a strong cold front moves through on
Saturday. Severe weather potential will increase as we head into
Saturday afternoon, especially if sunshine is able to help
destabilized the boundary layer for any portion of the day. A
slight risk for severe storms has been outlined by SPC for nearly
all of Illinois. The timing of the front remains in question, with
a compromise used between the faster NAM/Canadian and the slower
GFS/ECMWF. That basically allowed for some consistency with the
going forecast. Dry air will be wrapping into the back side of the
cold front, but as the occlusion process occurs, bands of moisture
will trail the front and allow for a few post frontal showers to
linger into Sunday and possibly even Monday.
SHORT TERM...Tonight through Sunday night.
A Pacific moisture connection will continue to feed into the warm
sector across the nations heartland over the next 24-36 hours...as
the warm front lingers in N Iowa and S Wisconsin. Localized
pockets of energy will tap into that moisture to fuel isolated
showers in our SE counties as well as our far NW counties into
this evening. Most areas should remain dry this evening, and even
overnight. We left a wide area of slight chance pops across the
area after midnight, with chance PoPs in the far NW closer to the
expected storm track.
Tonight and early Saturday, low pressure in the western plains will
lift north into eastern South Dakota before stalling during
occlusion. It`s eastward progression will pick up speed as a
kicker trough enters the northwest coast. The timing of the front
will be key in where severe potential is maximized, mainly from
the amount of sunshine for low level heating. There may be some
isolated severe storms overnight west of our area as the nocturnal
jet intensifies ahead of the cold front. The cold front is
projected to reach the I-55 corridor by Noon or 1 pm, then slow
down and reach the Indiana border mid- evening.
Instability params and hodographs are pointing toward damaging
winds as the main hazard in our area, with better directional
shear and rotating storms farther north near the warm front and
track of the low. Hail potential will increase closer to the cold
front and moisture pooling and updraft strength intensify. Severe
chances will linger into the evening east of I-57, but should
become more isolated as the front slows down.
We kept likely PoPs east of I-57 Sat eve, and near the Indiana
border after midnight. Coverage of storms will likely diminish Sat
night as will intensity. Some clearing behind the cold front will
low temps drop into the 40s by Sunday morning west of I-55.
The cold air will limit highs on Sunday to the upper 50s near GBG
and mid 60s near LWV. Scattered rain will be possible across
the east and north associated with cold pool-instability
showers...as the upper trough lingers just west of IL.
Sunday night will be coldest night of the next week, with lows in
the low to mid 40s everywhere.
LONG TERM...Monday through Friday.
The upper vortex may still be over IL on Monday if the GFS and
ECMWF verify, which would put showers across IL during the day. We
left Mon dry for now, but at least sprinkles may be needed if the
next couple of model runs show the slower progression.
A warming trend will begin on Tue and continue through Friday.
Highs should reach above normal into the mid 70s Thur/Fri. Dry
conditions are expected to prevail all week, with comfortable
humidity levels. The next chance of rain may hold off until the
Sunday Oct 13.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1157 PM CDT Fri Oct 4 2013
.UPDATE:
Issued at 950 PM CDT Fri Oct 4 2013
Inherited forecast still looks on track...so made no major
changes. Warm advection SHRAS have moved out of SW IL. SHRA/TSTMS
along and ahead of the front across ern KS/wrn MO timed to reach
the wrn CWA around 9-10Z...if it holds together. Several
solutions have moisture convergence along the front weakening
significantly overnight across nthrn MO. Going fcst reflects the
assumption that precip in one form or another will reach our CWA
prior to daybreak. Besides massaging other grids to reflect
ongoing trends...existing fcst looks good.
2%
&&
.SHORT TERM: (Through Late Tonight)
Issued at 330 PM CDT Fri Oct 4 2013
Diurnal heating of the unseasonably warm and moist air mass has
resulted in weak instability across the region this afternoon.
However with little impetus, attempts for convective development
thus far across far southeast Missouri and southern Illinois have
been short-lived. The HRRR continues to indicate potential for
spot storms through sunset within the southern CWA so will
continue with some slight chance pops until then. Otherwise
attention for tonight turns to the strong storm system currently
across the Plains region. Anticipating that a squall line will
evolve ahead of the attendant cold front from Nebraska into
Oklahoma this evening and this will move eastward as the whole
system progresses, with a swath of precipitation also developing
overnight in the wake of the front in response to frontogenetical
forcing and large scale ascent as a short-wave rotates through the
base of the progressive upper trof. The main question then is just
how far eastward all of this precipitation will get before
daybreak Saturday. The consensus of the model guidance is that it
may be after 12z before entering the CWA. At this time I didn`t
deviate dramatically from the previous forecast with the leading
edge just making it into the western CWA, but reduced pops further
east. Areas to the east of the main line will still be under the
threat of spotty warm advection activity overnight.
Glass
.LONG TERM: (Saturday through Next Friday)
Issued at 300 PM CDT Fri Oct 4 2013
By Saturday morning, surface cold front to be just west of St. Louis
metro area. As the occluded surface low, over southeastern SD,
associated with it slowly lifts out to the northeast, front to
slowly slide through rest of forecast area. Expect activity that
initially forms tonight to diminish by mid morning. Then trying to
determine when and where activity will refire as atmosphere becomes
more unstable by early afternoon is hard to pin down. With front
extending from Quincy to just west of St. Louis to near Monett by
18z Saturday, best chances of storms refiring and some severe
weather will be over southeast MO and southern IL. This matches well
with the day 2 outlook with this area in a slight risk. Another
forecast issue will be temperatures on Saturday. Will see a
non-diurnal trend as high temps will be reached early in the day
then either remain steady or fall during the afternoon hours.
Showers and isolated thunderstorms will taper off Saturday evening
before coming to an end. However, could see some scattered showers
on Sunday, especially during the afternoon hours as wrap around
clouds on back side of system moves through with an upper level
shortwave. So have added low chance pops over northeast MO/west
central IL with silent slight chance pops further south for now as
well as increase cloud cover through this period. Lows Saturday
night will be in the low 40s to low 50s with highs only rising
into the mid 50s to mid 60s on Sunday.
Sunday night could be our coldest night depending on how fast the
clouds clear out. For now will err on side of caution and keep more
clouds over the region with lows in the low to mid 40s. If clouds
completely clear out and winds remain light, could see even cooler
temps.
Beyond that, surface ridge moves off to the east with a slow warming
trend through the week. Temperatures to warm back up into the mid to
upper 70s by Thursday.
Byrd
&&
.AVIATION: (For the 06z TAFs through 06z Saturday Night)
Issued at 1125 PM CDT Fri Oct 4 2013
Latest surface analysis shows the cold frontal boundary entering
western Missouri. Band of showers and thunderstorms extending
north-central Missouri through north-central Oklahoma continues to
move northeast. Expect scattered showers and possible thunderstorm
to enter Columbia MO area and Quincy IL around 0900 UTC. Scattered
showers and a few thunderstorms will enter STL area after 1500
UTC. Cold front expected to move across STL area after 1700 UTC.
Post frontal light rain will continue through late afternoon.
Specifics for KSTL: Scattered showers and a few thunderstorms will
move through STL area after 1500 UTC. Southwest winds of 8 to 10
kts expected during the mid to late morning hours. Brief stronger
gusts are possible in the vicinty of thunderstorms. Cold front
expected through STL between 1700 and 1800 UTC. Post frontal light
rain expected much of the afternoon and ending late afternoon.
Westerly wind of 8 to 10 kts expected during the afternoon.
RP
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
357 AM CDT SAT OCT 5 2013
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 350 AM CDT SAT OCT 5 2013
THE MSAS SHOWS THE SFC LOW NEARLY STATIONARY THIS MORNING ACROSS
SCNTL SD. THE LOW IS IN THE PROCESS OF DOING A LOOP. THIS
AFTERNOON IT WILL DRIFT EAST AT 5 MPH INTO SERN SD AND THIS IS
CONSISTENT WITH THE MOTION OF THE 500 MB LOW AT JUST 6 KT.
VERY SLOW STORM MOTIONS OF THIS TYPE...5 MPH...OFTEN PRODUCE HIGH
WIND EVENTS IN THE CNTL PLAINS. THE GFS...ECM AND RAP SHOW
SUSTAINED WINDS INCREASING TO AROUND 40 MPH ACROSS NCNTL NEB THIS
AFTERNOON WITH GUSTS TO 58 MPH IN THE RAP AND HRRR MODELS. THE
NAM KEEPS THE GUSTS BELOW 58 MPH THIS AFTN. MEANWHILE THE MET
GUIDANCE SHOWS NO HIGH WIND EVENT AT ALL WHILE THE MAV GUIDANCE
FAVORS SWRN NEB. THE MULTI LAYER WINDS IN THE RAP MODEL FROM
H850MB TO H700MB KEEP WINDS AT 60 KTS OR LESS AND THIS IS
CONSISTENT WITH A HIGH END WIND ADVISORY WITH A FEW GUSTS TO 58
MPH.
THUS THERE IS A SPLIT IN THE MODEL DATA. A HIGH END WIND ADVISORY
EVENT WOULD APPEAR TO BE THE MOST LIKELY SOLN INDICATED BY THE
MODELS BUT LOCAL STUDIES SUGGEST A HIGH WIND EVENT WOULD UNFOLD
THIS AFTERNOON. A WIND ADVISORY WILL CONTINUE TODAY ACROSS ALL
AREAS EXCEPT WHERE THE WINTER STORM WARNING IS IN EFFECT.
WINTER STORM CONDITIONS ARE LIKELY ONGOING ACROSS NRN SHERIDAN
AND WRN CHERRY COUNTIES THIS MORNING. THE RADAR MAY BE
OVERSHOOTING THE DENDRITIC LAYER. THE ELLSWORTH NEDOR CAM IS
QUIET WHILE THE RUSHVILLE CAM CONTINUES TO SHOW SNOW AND BLOWING
SNOW WITH VISIBILITY AROUND 2 MILES OR SO. THE 08Z KIEN OB SHOWS
1/2 MILE VISIBILITY WITH A VERTICAL VISIBILITY OF JUST 500 FEET.
THE REST OF THE NEDOR CAMS ARE DARK SO WE WILL HAVE TO WAIT FOR
SUNRISE TO GET A BETTER ANALYSIS OF THE SITUATION ACROSS NW NEB.
THE WINTER STORM WARNING WILL CONTINUE UNTIL 18Z AS FORECAST.
GIVEN THE UPPER LOW HAS STALLED ACROSS THE CNTL PLAINS...THE
MODEL CONSENSUS SHOWS WRAPAROUND RAIN AND SNOW TODAY THROUGH
SUNDAY MORNING. THE UPPER LEVEL LOW IS EXPECTED TO CONTINUE
MOVING SLOWLY EAST SOUTHEAST INTO SRN IOWA BY LATE SUNDAY
AFTERNOON. A MULTI MODEL CONSENSUS WAS USED FOR POPS TONIGHT AND
SUNDAY. THE RAP MODEL WAS USED EXCLUSIVELY FOR THE TODAY PERIOD.
NONE OF THE MODELS ARE SHOWING VERY HEAVY QPF AND SNOW TOTALS OF
2 INCHES OR LESS ARE EXPECTED BASED ON THAT OUTPUT. THERE IS SOME
UNCERTAINTY WITH THIS FORECAST AS THE 850 MB MOISTURE TRANSPORT
IS STILL QUITE STRONG ACROSS THE NRN PLAINS AND OCCASIONAL
LIGHTNING STRIKES ARE STILL SHOWING UP AT 08Z. THE NAM WHICH
APPEARS TO HAVE THE BEST HANDLE THE MASSIVE QPF ASSOCIATED WITH
THIS STORM GENERALLY KEEPS QPF LESS THAN 0.10 INCHES IN ANY 3
HOUR PERIOD ACROSS NRN NEB.
OTHERWISE...HIGHS TODAY RISE INTO THE 30S AND 40S ACCORDING TO A
BLEND OF BIAS CORRECTED AND DETERMINISTIC DATA. THE MODELS ARE
FORECASTING LOWS IN THE MID 20S TONIGHT ACROSS THE SNOW FIELD
ACROSS NWRN NEB WITH LOWER 30S ELSEWHERE. IF THE WRN HALF OF THE
FORECAST AREA CLEARS OUT TONIGHT AS INDICATED IN THE MODELS THEN
THESE LOWS COULD BE 5 OR MORE DEGREES COLDER. HIGHS SUNDAY RISE
INTO THE 40S ACROSS THE SNOW COVERED NORTHWEST WITH 50S AND 60S
ELSEWHERE.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 350 AM CDT SAT OCT 5 2013
BY SUNDAY NIGHT THE LOW PRESSURE SYSTEM WILL HAVE PUSHED TOWARDS
THE MID MISS RVR VALLEY AND THE WRAP AROUND MOISTURE WILL HAVE
SHIFTED INTO EASTERN NEB. MEANWHILE AN UPPER LEVEL RIDGE WILL
BUILD ACROSS THE WEST...AS THE NEXT TROUGH PUSHES ACROSS
NORTHEASTERN PACIFIC OCEAN.
MONDAY THROUGH THURSDAY THE PACIFIC TROUGH WILL DIG TOWARDS THE
DESERT SOUTHWEST WHILE THE UPPER RIDGE SHIFTS EAST ACROSS THE
PLAINS. AT THE SFC HIGH PRESSURE WILL DOMINATE THE PLAINS THROUGH
MUCH OF THE WEEK. THUS EXPECT MILD CONDITIONS WITH 70S AND A FEW
MID/UPPER 60S ACROSS THE NW ZONES WHERE SOME INFLUENCE FROM THE
HEAVY SNOW PACK IS LIKELY TO LIMIT THE HEATING. ONCE THE SNOW
MELTS...COULD SEE MORE WIDESPREAD HIGHS INTO THE 70S ACROSS THE
NW. WITH THE WARM AIR MASS...EXPECT SEASONALLY WARM
LOWS...GENERALLY IN THE 40S SPOTTED WITH A FEW UPPER 30S.
LATE THURSDAY INTO FRIDAY THE LOW OVER THE SW WILL BEGIN TO EJECT
ONTO THE NORTHERN PLAINS. MODELS IN FAIR AGREEMENT...CONSIDERING
6/7 DAYS OUT...WITH A TRACK OF THE UPPER LOW ACROSS THE CENTRAL
ROCKIES AND INTO S DAKOTA. THE MODELS CONTINUE TO TRACK THE LOW TO
THE NE...INTO CANADA OVER THE WEEKEND. AS THE LOW PUSHES ONTO THE
ROCKIES...GOOD MOISTURE TRANSPORT WITH S WINDS EXPECTED ACROSS THE
AREA. POPS ARE NEEDED FOR THURSDAY INTO FRIDAY...HOWEVER PENDING
THE TRACK AND THE DRY SLOT...CONCERNED AMOUNTS MAY NOT AMOUNT TO
TOO MUCH OVER PART OF THE CWA. THUS WILL HOLD POPS IN THE SLIGHT
CHANCE AND LOWER CHANCE CATEGORY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1226 AM CDT SAT OCT 5 2013
WIDESPREAD SNOW IN NORTHWEST NEBRASKA WILL CONTINUE TONIGHT. IN
BBW...LIGHT SNOW IS POSSIBLE BUT LITTLE ACCUMULATION IS EXPECTED.
FOR LBF...OGA AND IML...THE PROBABILITY OF PRECIPITATION IN
EITHER FORM IS LOW.
CLEAR SKY IN SOUTHWEST NEBRASKA IS LIKELY TO BECOME OVERCAST
AGAIN BY 08Z...BUT THE CEILING IS LIKELY BE ABOVE 3000 FEET AGL.
OTHERWISE...WIND WILL CONTINUE TO BE A CONCERN THROUGH AT LEAST
SATURDAY AFTERNOON WITH 310-340 AT 24-28G35-38KT IN THE
MORNING...INCREASING TO 32-36G40-44KT BY 15Z OR 16Z AS THE STORM
SYSTEM MOVES OUT AND A BLAST OF CANADIAN AIR POURS IN BEHIND IT.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 7 PM CDT /6 PM MDT/ THIS EVENING FOR NEZ008-
022>027-035>038-056>059-069>071.
WINTER WEATHER ADVISORY UNTIL 1 PM CDT THIS AFTERNOON FOR NEZ005.
WINTER STORM WARNING UNTIL NOON MDT TODAY FOR NEZ004-094.
WIND ADVISORY FROM 10 AM THIS MORNING TO 7 PM CDT THIS EVENING
FOR NEZ006-007-009-010-028-029.
&&
$$
SYNOPSIS...CDC
LONG TERM...MASEK
AVIATION...CDC
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
1135 PM MDT FRI OCT 4 2013
.AVIATION...
06Z TAF CYCLE
VFR CIGS AND VIZ NEXT 24 HRS. WEATHER SYSTEM CORE EJECTING INTO
SOUTH DAKOTA WITH BROAD INTENSE CIRCULATION ALOFT PUSHING WESTERLY
WINDS ACROSS NEW MEXICO...AND THESE WILL SHIFT RAPIDLY NORTHERLY
BY 00Z SAT EVENING. CLOUD COVER AOA BKN/OVC100 ACROSS THE HEART OF
NEW MEXICO WILL EJECT RAPIDLY TO THE NORTHEAST THROUGH 15Z SAT
MORNING WITH NEXT ROUND OF GUSTS REDEVELOPING FROM 16Z ONWARD
ACROSS WESTERN AND CENTRAL PORTIONS OF THE STATE. WIND SPEEDS
DROPPING OFF AFTER 03Z SATURDAY EVENING.
SHY
&&
.PREV DISCUSSION...315 PM MDT FRI OCT 4 2013...
FRONT HAS BEEN HUNG UP JUST NORTH OF THE UNION COUNTY BORDER ALL
DAY...ALTHOUGH THE LOW CLOUDS ASSOCIATED WITH IT LAST NIGHT HAVE
DISSIPATED OVER SOUTHEAST AND EAST CENTRAL CO. RUC INDICATES THE
BOUNDARY TO PLUNGE SWD WITHIN THE NEXT 3 HOURS. IT ALSO INDICATES A
LITTLE MORE MOISTURE OVER PARTS OF THE NORTHEAST...AND RESULT HAS
BEEN TO UPGRADE SKY COVER TO PARTLY CLOUDY RATHER THAN CLEAR. STILL
MODELS NOT SUGGESTING A HUGE UPTICK IN DEW POINTS THERE OVERNIGHT.
NORTHERLY WINDS ASSOCIATED WITH THE FRONT AS IT TRACKS THROUGH THE
PLAINS TO BE GUSTY BUT NOT QUITE AS STRONG AS INDICATED 24 HOURS
AGO.
AS FOR FREEZE HIGHLIGHTS...STILL SOME MARGINAL TEMPERATURES FOR
PORTIONS OF THE EAST CENTRAL AND RGV AS WELL AS THE SOUTH CENTRAL
HIGHLANDS. AND SATURDAY NIGHT TEMPERATURE GUIDANCE IS STILL LEANING
TOWARDS SOME WARMING. FORECAST BOUNDARY LAYER WINDS TONIGHT
NORTHEAST OVER THE PLAINS BUT FOR SATURDAY NIGHT THE GFS FORECASTS A
MORE WLY WIND FLOW IN THE LOWER LEVELS...AS OPPOSED TO THE NAM/S
LIGHT AND VRBL TO WEAK NW WINDS. FORECAST SOUNDINGS INDICATE
SOME STEEP INVERSIONS OFF THE DECK AT SELECTED POINTS SATURDAY NIGHT
BUT OVERALL THE SOUNDINGS EXHIBIT A WARMING TREND. THINK THERE
MAY BE SOME POINTS IN SHELTERED AREAS UNAFFECTED BY WIND THAT COULD
REACH THE MAGIC 32 OR SLIGHTLY BELOW OUTSIDE OF OUR FORECAST POINTS
TONIGHT...SO WENT AHEAD AND UPGRADED REMAINING EAST CENTRAL ZONES IN
THE WATCH. ALSO ADDED THE SOUTH CENTRAL HIGHLANDS TO THE WARNING
TONIGHT WITH FORECAST LOWS AGAIN HOVERING NEAR THE FREEZING MARK.
BASED ON THE ABOVE MODEL DISCUSSION...HAVE HELD OFF ON ISSUING
FURTHER FREEZE HIGHLIGHTS FOR SATURDAY NIGHT. WILL WAIT TO SEE WHAT
THE GUIDANCE DOES AS WELL AS WHAT MINS TONIGHT DO.
WINDS STILL TO TAPER OFF SATURDAY WITH A WARMING TREND SUNDAY
THROUGH TUESDAY. MODELS CONTINUE TO FOCUS ON AN UPPER LOW DIGGING
INTO THE SW US AROUND THE MID TO LATE WEEK PERIOD NEXT WEEK. WINDS
LOOK TO INCREASE TUESDAY AND MORE SO WEDNESDAY WITH TEMPERATURES
FALLING THURSDAY/FRIDAY. WE NOW HAVE SOME MEAGER POPS FOR THE NORTH
AND WEST DURING THIS PERIOD...BUT MODELS NOT EXACTLY IN AGREEMENT
HOW THIS WILL PLAY OUT.
.FIRE WEATHER...
CURRENT FIRE WEATHER HIGHLIGHTS ARE MARGINAL BUT WILL KEEP THEM
RUNNING THROUGH EVENT EXPIRATION. TUCUMCARI IS SHOWING NEAR RED FLAG
CONDITIONS WITH GUSTY WINDS AND TEEN HUMIDITY.
THE UPPER LOW WHICH IS CURRENTLY OVER THE CENTRAL ROCKIES AND GREAT
PLAINS WILL GRADUALLY SHIFT EASTWARD THE REST OF TODAY...TONIGHT
INTO SATURDAY. THE SURFACE WIND FLOW WILL GENERALLY RELAX AS A
RESULT ALTHOUGH A BACK DOOR COLD FRONT WILL PUSH ACROSS THE EASTERN
PLAINS TONIGHT AND INCREASE WINDS FOR A TIME. A CHILLY NIGHT IS IN
STORE WITH FREEZING TO NEAR FREEZING TEMPERATURES EXPECTED ACROSS
THE MAJORITY OF THE FIRE WEATHER FORECAST AREA. A HARD FREEZE WILL
BE FELT ACROSS THE NORTHERN AND WESTERN MOUNTAINS AND INCLUDE SOME
LOWLAND SITES AS WELL.
HIGH PRESSURE WILL BE IN CONTROL DURING THE WEEKEND. THE SURFACE
WIND FLOW WILL BE MUCH MORE RELAXED ALTHOUGH LOOK FOR SOME NORTHERLY
BREEZES ACROSS SOME WESTERN AND CENTRAL AREAS SATURDAY AFTERNOON.
THE FLOW ALOFT WILL BE MUCH WEAKER SO MAINLY SURFACE DRIVEN. FAIRLY
LIGHT WINDS FOR SUNDAY WITH JUST A FEW BREEZES ALONG INTERSTATE 25
BETWEEN LAS VEGAS TO RATON. MIXING HEIGHTS WILL BE ON THE LOWER SIDE
THANKS TO POST COLD FRONTAL INVERSION EFFECTS. THUS VENTILATION
RATES WILL BE LOWER. VENTILATION WILL BE THE POOREST ON SUNDAY.
EXPECTING A STRONG LOW LEVEL RADIATION INVERSION TO DEVELOP SATURDAY
NIGHT. THIS WILL BE ACCOMPANIED BY ADDITIONAL FREEZING TEMPERATURES
WITHIN BASINS AND VALLEYS. HIGH TEMPERATURES WILL BE WELL BELOW
NORMAL SATURDAY AND BE AROUND 5 TO 10 DEGREES BELOW NORMAL SUNDAY
AFTERNOON. HUMIDITY VALUES WILL BE NEAR SEASONABLE LEVELS ON
SATURDAY BUT LOWER ON SUNDAY WITH LOTS OF MINIMUM VALUES IN THE
TEENS. A MID LEVEL DRY INTRUSION PLUS A WARM UP WILL BE THE CATALYST
FOR LOWER HUMIDITY VALUES SUNDAY.
WEATHER MODELS REMAIN PERSISTENT WITH DEPICTING RIDGING ON MONDAY
AND THEN BREAKING DOWN OR SHIFTING EASTWARD ON TUESDAY. TEMPERATURES
WOULD CONTINUE TO WARM WHILE THE UPPER FLOW TURNS MORE SOUTHWESTERLY
ON TUESDAY. DRY CONDITIONS WOULD CONTINUE. VENTILATION RATES WILL
REMAIN ON THE LOWER SIDE MONDAY ALTHOUGH IMPROVE IN A FEW AREAS
COMPARED TO SUNDAY/S READINGS. TRANSPORT WINDS WILL INCREASE TUESDAY
SO THE VENTILATION WILL IMPROVE SIGNIFICANTLY THEN. NEAR TO ABOVE
NORMAL TEMPERATURES EXPECTED EARLY NEXT WEEK AND SURFACE HUMIDITY
WILL REMAIN ON THE LOWER SIDE. CURRENTLY HAVE SOME LOCALIZED
CRITICAL FIRE WEATHER GROWTH CONDITIONS DEPICTED WITHIN OUR GRIDDED
FORECAST TUESDAY AFTERNOON ACROSS THE NORTHEAST SO WILL BE
MONITORING THAT TREND.
THE LATEST LONG RANGE MODELS CONTINUE TO SHOW A BREEZY TO WINDY
PATTERN WEDNESDAY THROUGH FRIDAY AS ANOTHER PACIFIC TROUGH CROSSES
OVER THE INTERMOUNTAIN WEST. IT STILL APPEARS TO BE A DRY TROUGH
PASSAGE FOR THE FORECAST AREA. THUS...CANT RULE OUT SOME CRITICAL
FIRE WEATHER AREAS...MOST LIKELY FAVORING THE EAST...WHERE
TEMPERATURES WOULD BE ABOVE NORMAL FOR THE LONGEST. COOLING EXPECTED
ACROSS THE WEST ON THURSDAY AND SPREAD ACROSS THE ENTIRE AREA ON
FRIDAY. THIS AIR MASS APPEARS TO BE LESS CHILLY COMPARED TO THE
CURRENT ONE. VENTILATION WOULD BE QUITE HIGH WEDNESDAY AND THURSDAY
AND PROBABLY LOWER SOME ON FRIDAY. CONFIDENCE IS AT LEAST MODERATE
FOR THIS SCENARIO.
50
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
FREEZE WARNING UNTIL 9 AM MDT SATURDAY FOR THE FOLLOWING ZONES...
NMZ518-519-524-530>534.
&&
$$
33
AREA FORECAST DISCUSSION
NWS RALEIGH NC
314 AM EDT SAT OCT 5 2013
.SYNOPSIS...
HIGH PRESSURE OVER THE REGION WILL MOVE SLOWLY EAST OFFSHORE THE
CAROLINA COAST TONIGHT AND SUNDAY. A COLD FRONT WILL APPROACH THE
MOUNTAINS FROM THE WEST SUNDAY NIGHT...THEN TRACK EASTWARD THROUGH
THE CAROLINAS ON MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 940 PM FRIDAY...
LITTLE CHANGE TO THE OVERNIGHT FORECAST NEEDED AS HIGH PRESSURE
REMAINS PERSISTENT OVER THE CAROLINAS. SKIES HAVE CLEARED AND
WINDS. DEWPOINTS HAVE RECOVERED ANOTHER 2 TO 4 DEGREES SINCE 24
HOURS AGO...MAINLY ACROSS THE SOUTH... AND DEWPOINT DEPRESSIONS ARE
ALREADY LESS THAN 5 DEGREES AT MANY OBSERVING SITES. RH CROSS
SECTIONS FAVOR SOUTHERN AREAS FOR FOG...AND THE RECENT HRRR RUNS
SUPPORT THIS. LOWS MOSTLY IN THE 60-63 RANGE.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
AS OF 255 PM FRIDAY...
SATURDAY AND SATURDAY NIGHT...HIGH PRESSURE PERSISTS...WITH
MID-LEVEL HEIGHTS ACTUALLY RISING FOR A TIME SATURDAY BEFORE
BEGINNING TO FALL AGAIN SATURDAY NIGHT. BUFR SOUNDINGS FROM BOTH THE
NAM AND THE GFS SUGGEST A COUPLE OF DEGREES OR SO OF WARMING ALOFT
AROUND 500MB SATURDAY...WITH SOME 850MB MOISTURE AVAILABLE ONCE
AGAIN SUGGESTIVE OF SOME DIURNAL CUMULUS WITH MIXING SATURDAY
MORNING INTO THE AFTERNOON. SUBSIDENCE CONTINUES TO DOMINATE...AND K
INDICES ACTUALLY FALL SOMEWHAT ON THE GFS DURING THE DAY SATURDAY.
ANOTHER DRY DAY ANTICIPATED WITH LIGHT WINDS EARLY INCREASING A
TOUCH...UNDER 10KT...AND SHOWING A SOUTHERLY COMPONENT BEFORE AGAIN
DIMINISHING TO FAIRLY LIGHT SOUTHERLY SATURDAY NIGHT. 1000-850MB
THICKNESSES SUPPORT HIGHS AROUND THE MOS GUIDANCE...MANY UPPER 80S
AND A FEW READINGS AT 90. AVAILABLE LOW-LEVEL MOISTURE SUPPORTS A
GREATER PROBABILITY OF AREAS OF FOG ACROSS CENTRAL NORTH CAROLINA
LATE SATURDAY NIGHT INTO SUNDAY MORNING...AND HAVE AGAIN CONTINUED
THIS IN THE GRIDDED AND WORDED FORECASTS. OVERNIGHT LOWS SATURDAY
NIGHT MAINLY LOWER 60S. -DJF
SUNDAY...WINDS ALOFT WILL BACK TO SOUTHWESTERLY AS THE MID-UPPER
RIDGE AXIS SHIFTS EAST AND OFFSHORE...WHICH WILL PROMOTE A GRADUAL
INCREASE IN MID TO ESPECIALLY HIGH LEVEL MOISTURE THROUGHOUT THE DAY
SUNDAY. THE COMBINATION OF THE INCREASING CLOUDS AND THE EASTWARD
DEPARTURE OF THE RIDGE ALOFT WILL LIKELY RESULT IN TEMPERATURES UP
TO A FEW DEGREES COOLER THAN THOSE OF SAT - OR WITHIN A COUPLE OF
DEGREES EITHER SIDE OF 85. THE TIGHTENING MSL PRESSURE GRADIENT IN
RETURN FLOW WILL ALSO PROMOTE THE DEVELOPMENT OF A SOUTHERLY BREEZE
THAT WILL PEAK IN THE 10-15 KT RANGE OVER THE WESTERN PIEDMONT
ACCORDING TO MIXED LAYER WINDS DEPICTED BY BUFR FORECAST SOUNDINGS.
DESPITE THE INCREASING MAINLY HIGH CLOUDS...PRECIPITATION CHANCES
WILL REMAIN RELATIVELY LOW. WILL ACCORDINGLY TRIM INHERITED
PRECIPITATION CHANCES AND CONFINE A SLIGHT CHANCE TO ROUGHLY THE
SOUTHERN HALF OF THE CWFA...TO ACCOUNT FOR THE PROPAGATION OF
SHOWERS THAT FORM OWING TO ONSHORE FLOW/FRICTIONAL CONVERGENCE AND
WEAK HEIGHT FALLS ALOFT...IN A WEAKLY INHIBITED AND UNSTABLE
ENVIRONMENT ALONG AND INVOF COASTAL AREAS. -MWS
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 300 AM SATURDAY...
THE LATEST INFORMATION FROM THE NHC CONCERNING "KAREN" CONTINUES TO
DOWNGRADE THE TROPICAL SYSTEM. IT HAS BEEN DESCRIBED AS ALREADY
BEING `DECAPITATED" BY ONE FORECASTER - DUE TO STRONGER WINDS ALOFT.
THEREFORE... THE CONFIDENCE OF WHETHER ANY REMNANTS OF `KAREN" WILL
BE LEFT TO BRING INDIRECT IMPACTS (RAIN, SEVERE THREAT) FOR CENTRAL
NC BY EARLY NEXT WEEK HAS LOWERED.
ON A MORE CONFIDENT NOTE... A MID/UPPER LEVEL TROUGH IS FORECAST TO
BE APPROACHING THE APPALACHIANS MONDAY... THEN SWING ACROSS OUR
REGION TUE AND TUE NIGHT. THE MAIN UPPER DYNAMICS ARE FORECAST TO
PUSH FROM THE MIDWEST TO THE GREAT LAKES. HOWEVER... MOISTURE IS
EXPECTED TO SURGE NORTHWARD ALONG THE EASTERN SEABOARD BRINGING
WIDESPREAD SHOWERS AND ISOLATED THUNDERSTORMS ALONG THE COLD FRONT.
IF THE REMNANT LOW PRESSURE OF `KAREN` TRACKS NE INTO NC AS SOME OF
THE MODELS STILL SUGGEST... THERE CAN STILL BE ENHANCED RAINFALL FOR
12-24 HOURS. OTHERWISE... THIS WOULD BE A TYPICAL RAINFALL EVENT
ASSOCIATED WITH A MID-LATITUDE TROUGH EARLY NEXT WEEK.
ONCE THE TROUGH PASSES... CLEARING AND COOLER CONDITIONS ARE
EXPECTED MID THROUGH LATE WEEK. LOWS 50-55. HIGHS 70-75.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 300 AM SATURDAY...
24-HR TAF PERIOD:
FOG IS EXPECTED TO DEVELOP EARLY THIS MORNING IN ASSOCIATION WITH
CLEAR SKIES...CALM WINDS...AND A SEASONABLY MOIST AIRMASS. FOG WILL
BE MOST LIKELY AT THE FAY/RWI TERMINALS WHERE IFR-VLIFR VISBYS ARE
EXPECTED IN THE 08-12Z TIME FRAME...FOLLOWED BY RDU WHERE MVFR/IFR
VISBYS WILL BE POSSIBLE BETWEEN 08-12Z...AND FINALLY THE INT/GSO
TERMINALS WHERE MVFR VISBYS WILL BE POSSIBLE BETWEEN 09-12Z. FOG
WILL LIFT AND SCATTER OUT TO VFR BETWEEN 12-14Z...WITH VFR
CONDITIONS AND LIGHT WINDS THE REMAINDER OF THE TAF PERIOD.
LOOKING AHEAD:
ASIDE FROM A POTENTIAL FOR FOG OR SUB-VFR CEILINGS BETWEEN 08-12Z
SUNDAY MORNING...VFR CONDS ARE EXPECTED TO PREVAIL DURING THE DAY
SUNDAY WITH CEILINGS SOMEWHAT LOWER THAN PREVIOUS DAYS (3500-4500 FT
AGL) IN ASSOC/W A STRENGTHENING SOUTHERLY RETURN FLOW AS HIGH
PRESSURE MOVES OFFSHORE. EXPECT AN INCREASING CHANCE FOR MVFR/IFR
CEILINGS AT ALL TERMINALS IN ADVANCE OF A COLD FRONT PROGRESSING
SLOWLY EAST INTO THE SOUTHERN APPALACHIANS SUNDAY NIGHT...ALONG WITH
AN INCREASING CHANCE FOR RAIN AT THE INT/GSO TERMINALS BETWEEN
06-12Z MONDAY MORNING. EXPECT WIDESPREAD SHOWERS/THUNDERSTORMS
DURING THE DAY MONDAY AS THE COLD FRONT TRACKS EAST INTO THE
CAROLINAS. UNCERTAINTY IN THE FCST INCREASES THEREAFTER...
HOWEVER...IT IS POSSIBLE THAT RAIN AND SUB-VFR CONDITIONS PERSIST
MONDAY NIGHT INTO TUESDAY. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...SMITH
SHORT TERM...DJF/MWS
LONG TERM...BADGETT
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
300 AM EDT SAT OCT 5 2013
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO RESIDE OVER THE REGION THROUGH
SUNDAY. INCREASING MOISTURE AHEAD OF BOTH A COLD FRONT...AND
TROPICAL STORM KAREN...WILL SPREAD INTO THE REGION FOR THE START OF
THE NEXT WORK WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 940 PM FRIDAY...
LITTLE CHANGE TO THE OVERNIGHT FORECAST NEEDED AS HIGH PRESSURE
REMAINS PERSISTENT OVER THE CAROLINAS. SKIES HAVE CLEARED AND
WINDS. DEWPOINTS HAVE RECOVERED ANOTHER 2 TO 4 DEGREES SINCE 24
HOURS AGO...MAINLY ACROSS THE SOUTH... AND DEWPOINT DEPRESSIONS ARE
ALREADY LESS THAN 5 DEGREES AT MANY OBSERVING SITES. RH CROSS
SECTIONS FAVOR SOUTHERN AREAS FOR FOG...AND THE RECENT HRRR RUNS
SUPPORT THIS. LOWS MOSTLY IN THE 60-63 RANGE.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
AS OF 255 PM FRIDAY...
SATURDAY AND SATURDAY NIGHT...HIGH PRESSURE PERSISTS...WITH
MID-LEVEL HEIGHTS ACTUALLY RISING FOR A TIME SATURDAY BEFORE
BEGINNING TO FALL AGAIN SATURDAY NIGHT. BUFR SOUNDINGS FROM BOTH THE
NAM AND THE GFS SUGGEST A COUPLE OF DEGREES OR SO OF WARMING ALOFT
AROUND 500MB SATURDAY...WITH SOME 850MB MOISTURE AVAILABLE ONCE
AGAIN SUGGESTIVE OF SOME DIURNAL CUMULUS WITH MIXING SATURDAY
MORNING INTO THE AFTERNOON. SUBSIDENCE CONTINUES TO DOMINATE...AND K
INDICES ACTUALLY FALL SOMEWHAT ON THE GFS DURING THE DAY SATURDAY.
ANOTHER DRY DAY ANTICIPATED WITH LIGHT WINDS EARLY INCREASING A
TOUCH...UNDER 10KT...AND SHOWING A SOUTHERLY COMPONENT BEFORE AGAIN
DIMINISHING TO FAIRLY LIGHT SOUTHERLY SATURDAY NIGHT. 1000-850MB
THICKNESSES SUPPORT HIGHS AROUND THE MOS GUIDANCE...MANY UPPER 80S
AND A FEW READINGS AT 90. AVAILABLE LOW-LEVEL MOISTURE SUPPORTS A
GREATER PROBABILITY OF AREAS OF FOG ACROSS CENTRAL NORTH CAROLINA
LATE SATURDAY NIGHT INTO SUNDAY MORNING...AND HAVE AGAIN CONTINUED
THIS IN THE GRIDDED AND WORDED FORECASTS. OVERNIGHT LOWS SATURDAY
NIGHT MAINLY LOWER 60S. -DJF
SUNDAY...WINDS ALOFT WILL BACK TO SOUTHWESTERLY AS THE MID-UPPER
RIDGE AXIS SHIFTS EAST AND OFFSHORE...WHICH WILL PROMOTE A GRADUAL
INCREASE IN MID TO ESPECIALLY HIGH LEVEL MOISTURE THROUGHOUT THE DAY
SUNDAY. THE COMBINATION OF THE INCREASING CLOUDS AND THE EASTWARD
DEPARTURE OF THE RIDGE ALOFT WILL LIKELY RESULT IN TEMPERATURES UP
TO A FEW DEGREES COOLER THAN THOSE OF SAT - OR WITHIN A COUPLE OF
DEGREES EITHER SIDE OF 85. THE TIGHTENING MSL PRESSURE GRADIENT IN
RETURN FLOW WILL ALSO PROMOTE THE DEVELOPMENT OF A SOUTHERLY BREEZE
THAT WILL PEAK IN THE 10-15 KT RANGE OVER THE WESTERN PIEDMONT
ACCORDING TO MIXED LAYER WINDS DEPICTED BY BUFR FORECAST SOUNDINGS.
DESPITE THE INCREASING MAINLY HIGH CLOUDS...PRECIPITATION CHANCES
WILL REMAIN RELATIVELY LOW. WILL ACCORDINGLY TRIM INHERITED
PRECIPITATION CHANCES AND CONFINE A SLIGHT CHANCE TO ROUGHLY THE
SOUTHERN HALF OF THE CWFA...TO ACCOUNT FOR THE PROPAGATION OF
SHOWERS THAT FORM OWING TO ONSHORE FLOW/FRICTIONAL CONVERGENCE AND
WEAK HEIGHT FALLS ALOFT...IN A WEAKLY INHIBITED AND UNSTABLE
ENVIRONMENT ALONG AND INVOF COASTAL AREAS. -MWS
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 300 AM SATURDAY...
THE LATEST INFORMATION FROM THE NHC CONCERNING "KAREN" CONTINUES TO
DOWNGRADE THE TROPICAL SYSTEM. IT HAS BEEN DESCRIBED AS ALREADY
BEING `DECAPITATED" BY ONE FORECASTER - DUE TO STRONGER WINDS ALOFT.
THEREFORE... THE CONFIDENCE OF WHETHER ANY REMNANTS OF `KAREN" WILL
BE LEFT TO BRING INDIRECT IMPACTS (RAIN, SEVERE THREAT) FOR CENTRAL
NC BY EARLY NEXT WEEK HAS LOWERED.
ON A MORE CONFIDENT NOTE... A MID/UPPER LEVEL TROUGH IS FORECAST TO
BE APPROACHING THE APPALACHIANS MONDAY... THEN SWING ACROSS OUR
REGION TUE AND TUE NIGHT. THE MAIN UPPER DYNAMICS ARE FORECAST TO
PUSH FROM THE MIDWEST TO THE GREAT LAKES. HOWEVER... MOISTURE IS
EXPECTED TO SURGE NORTHWARD ALONG THE EASTERN SEABOARD BRINGING
WIDESPREAD SHOWERS AND ISOLATED THUNDERSTORMS ALONG THE COLD FRONT.
IF THE REMNANT LOW PRESSURE OF `KAREN` TRACKS NE INTO NC AS SOME OF
THE MODELS STILL SUGGEST... THERE CAN STILL BE ENHANCED RAINFALL FOR
12-24 HOURS. OTHERWISE... THIS WOULD BE A TYPICAL RAINFALL EVENT
ASSOCIATED WITH A MID-LATITUDE TROUGH EARLY NEXT WEEK.
ONCE THE TROUGH PASSES... CLEARING AND COOLER CONDITIONS ARE
EXPECTED MID THROUGH LATE WEEK. HOWEVER... THE 00Z/05 OCTOBER
OPERATIONAL EC SUGGESTS THE FRONT MAY HANG UP OVER SC/GA WED... WITH
THE MID/UPPER TROUGH HANGING BACK OVER THE SE STATES INTO THURS. WE
WILL INCORPORATE A LOW PERCENTAGE OF THIS SOLUTION INTO THE FORECAST
AT THE CURRENT TIME. THIS WOULD YIELD PARTLY CLOUDY SKIES IN THE
EAST AND SOUTH LATE TUE AND WED. LOWS 50-55. HIGHS 70-75.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
AS OF 745 PM FRIDAY...
AREAS OF FOG ARE EXPECTED DEVELOP LATE TONIGHT BETWEEN 06 TO
12Z......WITH THE HIGHEST PROBABILITY AND CORRESPONDINGLY LOWER
VISIBILITIES EXPECTED IN THE EAST AT KRWI AND KFAY.
BEYOND THE 18Z VALID TAF PERIOD...AREAS OF FOG WILL BE POSSIBLE
AGAIN EARLY SUNDAY MORNING...OTHERWISE EXPECT PREDOMINATELY VFR
CONDITIONS THROUGH THE WEEKEND. MOISTURE ASSOCIATED WITH REMNANTS
OF TS KAREN WILL SPREAD INTO THE AREA LATE SUNDAY NIGHT AND INTO
MONDAY. SUB-VFR CONDITIONS WILL BE POSSIBLE AGAIN LATE SUNDAY NIGHT
AND MONDAY MORNING WITH WIDESPREAD SHOWERS AND STORMS MONDAY
AFTERNOON THROUGH MONDAY NIGHT WITH CORRESPONDING AREAS OF SUB-VFR
CONDITIONS. WIDESPREAD VFR CONDITIONS ARE LIKELY TO RETURN BY
TUESDAY AFTERNOON AS A COLD FRONT PUSHES EAST AND OFFSHORE.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DJF
NEAR TERM...SMITH
SHORT TERM...DJF/MWS
LONG TERM...BADGETT
AVIATION...CBL
AREA FORECAST DISCUSSION
NWS TULSA OK
1141 PM CDT FRI OCT 4 2013
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
LEAD EDGE OF SHOWES/THUNDERSTORMS IS CURRENTLY MOVING
INTO NE OKLAHOMA...AND WILL IMPACT THE KBVO/KTUL AND KRVS
TAF SITES THROUGH ABOUT 09-10Z. THIS ACTIVITY SHOULD
APPROACH SE OKLAHOMA AND NW ARKANSAS LATER TONIGHT TOWARD
10-12Z. OVERALL THUNDERSTORM INTENSITY WILL CONTINUE TO
DECREASE. EXPECT AREAS OF MVFR CONDITIONS IN THE STRONGER
STORMS.
&&
.PREV DISCUSSION... /ISSUED 910 PM CDT FRI OCT 4 2013/
..UPDATE...
DISCUSSION...
THUNDERSTORMS CONTINUED TO RIDE ALONG THE INITIAL WIND SHIFT OF
THE COLD FRONT THIS EVENING FROM SOUTHWEST OKLAHOMA TO JUST WEST OF
OSAGE COUNTY AS OF 9 PM THIS EVENING. THE DRIER AIR REMAINED
FURTHER WEST ACROSS NORTHWEST OKLAHOMA. THESE THUNDERSTORMS WILL
PUSH INTO THE CWA OVER THE NEXT HOUR AS THE FRONT CONTINUES TO
PUSH EAST SOUTHEASTWARD. WITH THE LOSS OF DAYTIME HEATING THE CAP
HAS BEGUN TO STRENGHTEN ACROSS THE CWA...HOWEVER DEEP LAYER SHEAR
NEAR AND JUST BEHIND THE FRONT WILL ALLOW FOR THE POTENTIAL FOR
SOME STORMS TO BECOME STRONG TO SEVERE. LARGE HAIL AND STRONG
WINDS CONTINUE TO BE THE MAIN THREATS WITH THIS ACTIVITY. GREATEST
POTENTIAL FOR ANY SEVERE STORMS LOOKS TO BE MAINLY NORTHWEST OF
INTERSTATE 44 OVER THE NEXT FEW HOURS. THE SEVERE THUNDERSTORM
WATCH FOR OSAGE AND PAWNEE COUNTIES REMAINS IN EFFECT UNTIL 3Z.
LATEST RUNS OF THE HRRR AND THE LOCAL IN-HOUSE MODEL INDICATE THAT
THUNDERSTORMS COULD BE NEAR EAST CENTRAL OKLAHOMA BY 06Z AND INTO
SOUTHEAST OKLAHOMA AND NORTHWEST ARKANSAS BY 9Z. INSTABILITY
ACROSS THE REST OF THE CWA SHOULD WEAKEN OVERNIGHT AS THE CAP
CONTINUES TO STRENGHTEN...THOUGH AN ISOLATED STRONG TO SEVERE
STORM COULD BE POSSIBLE.
GUSTY NORTHWESTERLY WINDS IN THE 20 TO 30 MPH RANGE HAVE BEEN
OBSERVED BEHIND THE FRONT WITHIN THE DRIER/COOLER AIR AND WILL
CONTINUE TO FILTER INTO THE REGION OVERNIGHT. TEMPERATURES BY
EARLY SATURDAY MORNING LOOK BE AROUND 50 TO LOWER 50S NEAR THE
KANSAS BORDER TO THE 60S FOR FAR SOUTHEAST OKLAHOMA AND WEST
CENTRAL ARKANSAS. EVENING UPDATE WILL BE TO ADJUST POPS/WX/SKY
GRIDS BASED ON LATEST TRENDS AND TIMING...WHILE THE REST OF THE
FORECAST SEEMS TO BE HANDLING WELL AT THIS TIME.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 54 64 47 68 / 90 20 10 0
FSM 70 73 46 68 / 80 70 10 0
MLC 59 60 44 70 / 90 60 10 0
BVO 52 65 43 66 / 80 20 10 0
FYV 63 65 42 63 / 80 80 10 10
BYV 66 68 44 62 / 80 80 10 10
MKO 57 59 45 68 / 90 60 10 0
MIO 53 61 43 64 / 90 50 10 10
F10 55 60 46 69 / 90 40 10 0
HHW 71 73 46 72 / 80 50 10 0
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
AVIATION...18
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
456 AM EDT SAT OCT 5 2013
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OVER THE REGION TODAY AND TONIGHT. A
LOW PRESSURE SYSTEM TRACKING FROM THE CENTRAL PLAINS TO THE GREAT
LAKES WILL PUSH A STRONG COLD FRONT THROUGH THE AREA ON MONDAY.
THE LOW AND COLD FRONT WILL MOVE OFFSHORE BY TUESDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 345 AM EDT SATURDAY...
SURFACE HIGH PRESSURE AND A 500 MB RIDGE WILL REMAIN OVER THE
CENTRAL AND SOUTHERN APPALACHIANS TODAY AND TONIGHT. LOCAL WRF AS
WELL AS HRRR AND LATEST RAP GUIDANCE SUGGEST THERE IS STILL A LOW
CHANCE OF SHOWERS THIS AFTERNOON...MAINLY NORTH OF I-64. ASIDE
FROM THE WEST TO SOUTHWEST UPSLOPE WINDS...LITTLE IN THE WAY OF
SHORT WAVES TO HELP TRIGGER ANY PRECIPITATION.
DEEP SOUTHWEST WINDS THIS AFTERNOON...EVEN THOUGH WIND SPEEDS WILL
NOT BE VERY STRONG...WILL PROVIDE SOME DOWNSLOPNIG AND
COMPRESSION. COMBINED WITH 850 MB TEMPERATURES OF +16 TO
+18...MAXIMUM TEMPERATURES WILL AGAIN BE WELL ABOVE NORMAL.
EXPECTING SIMILAR TEMPERATURES COMPARED TO FRIDAY...AND POSSIBLY A
DEGREE OR TWO HIGH AS LONG AS THERE IS NOT CLOUD COVER.
ANY SCATTERED TO BROKEN STRATOCUMULUS THAT DEVELOPS TODAY WILL
DISSIPATE THIS EVENING. USED A BLEND OF BIAS CORRECTED MAV/MET
GUIDANCE FOR OVERNIGHT LOWS.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 453 AM EDT SATURDAY...
MODELS REMAINING CONSISTENT WITH MOVING A COLD FRONT AND ASSOCIATED
SHOWERS INTO THE OHIO VALLEY ON SUNDAY. MODELS HAVE SLOWED DOWN THE
FRONTS MOVEMENT INTO THE AREA SUNDAY NIGHT AND ACROSS THE REGION
MONDAY/MONDAY NIGHT. THE SLOWER PROGRESSION OF THE FRONT IS DUE TO
UPPER LEVEL FORCING BECOMING DETACHED FROM THE LOW LEVEL BOUNDARY.
TROPICAL STORM KAREN OR REMNANTS OF...MAY ALSO PLAYING A PART IN
SLOWING THE FRONT DOWN TO A CRAWL AS IT CROSSES OVER THE AREA. BASED
ON THE 00Z MODEL TRENDS...LOWERED POPS INTO SUNDAY EVENING.
MEASURABLE RAIN BEGINS TO TRACK ACROSS THE SOUTHWEST EARLY MONDAY
MORNING...THEN SPREADS ACROSS THE REST OF THE MOUNTAINS AROUND
SUNRISE. RAIN CHANCES INCREASE EAST OF THE BLUE RIDGE TOWARD THE
AFTERNOON AND CONTINUES INTO THE EVENING. WITH A COLD FRONT
INTERACTING WITH TROPICAL MOISTURE...IT WAS A NO BRAINER TO INCREASE
POPS TO 100 PERCENT MONDAY. WITH THE FRONT BEING SLOWER...ALSO
INCREASED POPS MONDAY EVENING...TRENDING DOWN TUESDAY MORNING AS THE
FRONT TRACKS EAST.
WITH SHOWERS NOT DUE TO MOVE ACROSS THE PIEDMONT UNTIL THE
AFTERNOON...THERE MAY BE ENOUGH INSTABILITIES TO GENERATE A RUMBLE
OF THUNDER. IF ENOUGH INSTABILITIES IS PRESENT WHEN THE 850 JET
PASSES OVERHEAD...A STORM OR TWO MAY PRODUCE STRONG WINDS. FOR THE
MOST PART...THIS WILL BE A HYDRO EVENT. PWATS ON MONDAY APPROACH 2
INCHES WHICH IS CLOSE TO BEING 2 STANDARD DEVIATIONS ABOVE NORMAL.
RAINFALL AMOUNTS FROM SUNDAY NIGHT INTO MONDAY EVENING SHOULD RANGE
FROM 1 TO 2 INCHES. WITH THE RECENT DRY SPELL...THE FORECAST AREA
SHOULD NOT SEE ANY WIDESPREAD WATER PROBLEMS. LOCALIZE FLOODING IS
NOT OUT OF THE QUESTION IN POOR DRAINAGE AREAS...ESPECIALLY IF HIGH
RAINFALL RATES OR TRAINING OF STORMS PERSIST OVER AN AREA FOR
SEVERAL HOURS.
THE UPPER LEVEL RIDGE THAT BROUGHT WARMTH TO THE AREA ON SATURDAY
WILL BEGIN TO SLIDE OFF THE SOUTHEAST COAST ON SUNDAY. WITH THE
FRONT REMAINING WEST OF THE AREA FOR MOST OF SUNDAY...WARMER THAN
NORMAL TEMPERATURES WILL AGAIN COVER THE REGION. SUNDAY TEMPERATURES
WILL RANGE FROM THE LOW TO MID 80S ACROSS THE WEST TO MID TO UPPER
80S IN THE EAST. A DRAMATIC COOL DOWN COMES MONDAY WITH THE RAIN.
FORECASTED HIGH TEMPERATURES MONDAY WILL RANGE FROM THE MID 60S IN
THE WEST TO LOWER 70S ACROSS THE PIEDMONT.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 1215 PM EDT FRIDAY...
FORECAST EARLY IN THE PERIOD CENTERS AROUND THE FRONT/REMNANTS OF
KAREN AND THE UPPER TROUGH MOVING ACROSS THE GREAT
LAKES/NORTHEAST/MID ATLANTIC. THE LATEST GFS (12Z) CONTINUES TO BE
SLOWER...AND IS ACTUALLY SLOWER THAN THE 06Z RUN IN MOVING THE FRONT
OUT...WITH A STRONGER UPPER LOW...BUT IS FURTHER EAST WITH KAREN.
PER NHC/WPC...WILL BE LEANING TOWARD THE 00Z ECMWF AND THE PREVIOUS
FORECAST. THERE WILL STILL BE LINGERING SHOWERS ACROSS THE PIEDMONT
TUESDAY AND NOT OUT OF THE QUESTION THAT STRONG SUBSIDENCE BEHIND
THE DEPARTING TROPICAL SYSTEM MAY START TO DRY THINGS OUT FASTER.
FOR MID TO LATE WEEK...THE FORECAST MAINTAINS A CHALLENGE IN TERMS
OF SFC HIGH PRESSURE WEDGING SOUTH INTO OUR AREA...WHILE A RESIDUAL
UPPER TROUGH LINGERS OVER THE SOUTHEAST. QUESTION WILL BE WHERE
DEEPER MOISTURE RESIDES. WITH THE ECMWF THINK MOST OF THE CLOUD
COVER WILL BE HUGGING OUR SOUTHEAST CWA WITH MORE RESIDING ACROSS
THE SOUTHEAST...WHILE THE WESTERN CWA SEES MORE SUN DURING THE DAY.
TEMPERATURES GIVEN A LIGHT NE-E FLOW WILL BE CLOSER TO NORMAL...WITH
THE THREAT OF RAIN BEING LESS THAN 10 PERCENT.
&&
.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
AS OF 130 AM EDT SATURDAY...
TEMPERATURE/DEW POINT SPREAD WAS ALREADY CLOSE TO ZERO AT
KBCB/KLYH AND KDAN. HIGH CONFIDENCE OF IFR TO LIFR FOG ALONG AREA
RIVERS EARLY THIS MORNING WHICH WILL RESULT IN LIFR VISIBILITIES
AT KBCB AND KLWB.
ONCE FOG MIXES OUT IN THE MORNING THE REST OF THE DAY WILL BE VFR.
TIMING OF HOW FAST FOG LIFTS SHOULD BE BETWEEN 8AM AND 10AM. MID
AND HIGH LEVEL CLOUDS WILL ARRIVE SUNDAY THOUGH AS THE COLD FRONT
ENTERS THE OHIO VALLEY.
OUR NEXT CHANCE FOR WIDESPREAD AND PROLONGED SUB-VFR CONDITIONS
WILL COME SUNDAY NIGHT INTO MONDAY WHEN A COLD FRONT APPROACHES
FROM THE WEST...AND WHAT IS LEFT OF TROPICAL CYCLONE KAREN RIDES
NORTH THROUGH OR NEAR OUR REGION IN ADVANCE OF IT. THIS WOULD
ALLOW A TREND TOWARD DECREASING CEILING HEIGHTS AND INCREASED
COVERAGE OF RAIN. VISIBILITIES WOULD TREND LOWER AS
WELL...ESPECIALLY SUNDAY INTO MONDAY AS PRECIPITATION INTENSIFIES
AND FOG POTENTIAL INCREASES.
RAIN ENDS MONDAY NIGHT BUT THERE STILL MAY BE RESTRICTIONS IN
CEILING AND VISIBILITY AS PRECIP COULD STILL BE HEAVY ACROSS THE
VA/NC PIEDMONT WITH POTENTIALLY SOME FOG ACROSS SE WEST VA. A
DRIER PATTERN IS EXPECTED TUESDAY AND WEDNESDAY WITH MORNING FOG.
&&
.CLIMATE...
RECORD HIGH TEMPS FOR SATURDAY.
ROANOKE 98/1941
LYNCHBURG 96/1941
DANVILLE 98/1951
BLACKSBURG 86/1954
BLUEFIELD 85/2007
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...RCS
LONG TERM...JH/WP
AVIATION...AMS/KK/KM
CLIMATE...RCS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
414 AM CDT SAT OCT 5 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 413 AM CDT SAT OCT 5 2013
MOST EFFORT THIS FORECAST SHIFT WAS PUT TOWARD GETTING THE NEXT 24
HOURS AS ACCURATE AS POSSIBLE. SCREAMING MESSAGE IS THE SLOWER
EASTWARD PROGRESSION OF THE FRONT AND INSTABILITY...MAKING FOR A
BIT HIGHER SEVERE WEATHER CHANCE IN WI TODAY.
WATER VAPOR SHOWING THE MONSTER LOW THAT BROUGHT 25-45 INCHES OF
SNOW TO SD OVER CENTRAL SD AT 08Z AND NEARLY STATIONARY. OCCLUDED
FRONT CURRENTLY POSITIONED FROM KRWF TO KCCY...WHERE THE TRIPLE
POINT IS LOCATED. THE WARM FRONT EXTENDS EAST FROM NEAR KCCY TO
THE DELLS IN WI...WITH THE SURFACE COLD FRONT RUNNING SOUTH FROM
KCCY. THIS WARM FRONT IS THE LEADING EDGE OF THE HIGHER DEWPOINT
AIR...MIDDLE 60S...AND THE ENERGY FOR THIS AFTERNOONS STORMS. THE
OVERNIGHT CONVECTION HAS NOW PASSED OFF TO THE EAST...AND WITH IT
THE FLASH FLOOD THREAT.
EVALUATING THE 04.00Z MODEL GUIDANCE...THE TREND IS SLOWER WITH
THE NORTHEAST PROGRESSION OF THE OCCLUDED/COLD FRONT. THIS ALLOWS
MORE OF THE FORECAST AREA IN WI TO BE PRE-FRONTAL AND IN THE WARM
SECTOR FOR A HIGHER PROBABILITY OF SEVERE WEATHER. AS THE DAY
PROGRESSES...QVECTOR CONVERGENCE WILL INCREASE AS A SHORTWAVE
TROUGH IN COLORADO ROTATES AROUND THE LARGER SD TROUGH AND BEGINS
ITS EASTWARD PROGRESSION. AS THE FORCING BEGINS TO INCREASE...NEAR/POST
FRONTAL SHOWERS WILL LIKELY DEVELOP MUCH LIKE SEEN ON RADAR ALONG
I-35 EARLY THIS MORNING. ALSO...BETTER UPPER LEVEL FORCING WILL
BEGIN TO WORK TOWARD THE WARM SECTOR AND WORK WITH 0-2KM THETA-E
CONVERGENCE ALONG THE FRONT. INSTABILITY IN THE WARM SECTOR WILL HIGHLY
DEPEND ON THE EXTENT OF THE SHOWERS AND CLOUDS OVER WI...HOWEVER
BECAUSE THE DEWPOINTS ARE ALREADY MIDDLE 60S...AT LEAST MARGINAL
INSTABILITY WILL BE PRESENT BY 18Z. MUCAPES AROUND 1000-1500 J/KG
LOOK TO BE A GOOD ESTIMATE ON AFTERNOON CAPE...POSSIBLY HIGHER
WITH MORE CLOUD BREAKS.
WIND SHEAR LOOKS TO INCREASE TODAY BUT RIGHT ON THE COLD/OCCLUDED
FRONTAL BOUNDARY...TO MAKE IT A MARGINAL SUPERCELL DAY WITH
MULTICELLS ALSO PRESENT. THE 05.06Z NAM AND 05.07Z RAP BOTH
SUGGEST NEAR 40 KTS OF 0-6KM SHEAR...CERTAINLY ENOUGH FOR
SUPERCELLS. THE 05.07Z RAP MIXES ALL THE PRE-FRONTAL SURFACE
WINDS TO SOUTHERLY. THE 05.06Z NAM AND LATEST HRRR RUNS ARE VERY
AGREEABLE THAT THE WARM FRONT WILL SHIFT NORTH TO ABOUT BLACK
RIVER FALLS WI TODAY...VERY CLOSE TO THE SPC DAY 1 NORTHERN EXTENT
OF THE SLIGHT RISK. EASTERLY FLOW IS FOUND NORTH OF THE WARM
FRONT...WHICH EXTENDS TO THE EAST TOWARD KGRB...SO A GOOD
CONVERGENT BOUNDARY. WHILE TORNADO PROBABILITIES DONT LOOK
HIGH...THE TRIPLE POINT AREA AND ALONG THAT WARM FRONT THIS
AFTERNOON WILL BE A FOCAL POINT. OTHERWISE...DAMAGING WIND
SEGMENTS OR LARGE HAIL ARE THE MAIN THREATS FROM THE STORMS IN WI.
NORTH OF THE WARM FRONT...LOW-LEVEL INVERTED CONDITIONS AND
ELEVATED STORMS ARE FAVORED...HEAVY RAIN IS THE MAIN THREAT...WITH AN
ISOLATED HAIL STORM POSSIBLE. THE FRONT SHOULD SHIFT EAST OF THE
FORECAST AREA BY EARLY EVENING WITH STRONG DEWPOINT DECREASES.
THUS...THE MAIN SEVERE WEATHER THREAT LOOKS TO BE ABOUT 1 PM TO 5
PM.
BY TONIGHT...THE NE AND EASTERNMOST FORECAST AREA MAY STILL HAVE
SOME RAIN REMAINING. HAVE SLOWED THAT SLIGHTLY FROM THE PREVIOUS
FORECAST. A DECREASING TREND OCCURS THROUGH THE EVENING AS WEATHER
SHIFTS EAST.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 413 AM CDT SAT OCT 5 2013
THE LATEST MODEL CONSENSUS IS TO NOW KEEP THE DEFORMATION
ASSOCIATED WITH THE CYCLONIC MOIST FLOW WRAPPING AROUND THE LOW TO
THE WEST-NORTHWEST ON SATURDAY. THIS IS HIGHLY DEPENDENT ON THE
TRACK OF THE LOW WHICH IS A BIT FURTHER SOUTH IN THE LATEST
GUIDANCE. IN ANY CASE...CHANGES WERE MADE TO SUNDAY TO TRY AND DRY
IT OUT WITH THE RAIN SHOWERS JUST WEST OF THE AREA. ALTHOUGH THE
CONSENSUS OF THE MODELS IS TO BRING THAT BAND INTO THE FORECAST
AREA FOR MONDAY NOW...THE LATEST 05.00Z ECMWF IS MUCH MORE
PROGRESSIVE AND RAPIDLY SHIFTS THE SHOWERS EAST. HAVE A SMALL
CHANCE OF SHOWERS TO ADDRESS THAT SITUATION.
THE REMAINDER OF THE PERIOD IS DOMINATED BY DRY WEATHER UNDER
LARGER SCALE RIDGING AND ABOVE NORMAL TEMPERATURES.
&&
.HYDROLOGY...
ISSUED AT 413 AM CDT SAT OCT 5 2013
CONCERNING THE FLASH FLOOD WATCH...WITH CURRENT CONVECTION EAST
OF THE AREA...MAIN THREAT HAS DIMINISHED. AS AFTERNOON CONVECTION
INCREASES...IT SHOULD BE AFFECTING AREAS THAT HAVE HAD LESS RAIN
OVERALL THAN THOSE WEST OF THE MISS RIVER. AREAS EAST OF THE MISS
RIVER CAN TAKE ANOTHER 1-2 INCHES...ESPECIALLY SWRN WI. THERE IS A
SMALL PROBABILITY OF LOCALIZED FLASH FLOODING TODAY IN THE CENTRAL
WI CORRIDOR IN THE PRE-FRONTAL AIR MASS WHICH WILL STILL HAVE 1.25
TO 1.75 INCH PRECIPITABLE WATER VALUES. RAIN RATES ARE EXPECTED TO
BE HIGH...PROBABLY 2 TO 3 INCH PER HOUR SHOULD CAPE DEVELOP AS
FORECAST. THE SLOW MOVEMENT OF THE FRONT DOES GIVE SOME CONCERN
FOR FLOODING SO WILL ISSUE ANOTHER HYDROLOGICAL DISCUSSION FOR
THAT AREA AND CANCEL THE FLASH FLOOD WATCH.
THERE ARE SOME RIVER RESPONSES CURRENTLY OCCURRING. MONITORING THE
ROOT RIVER BASIN AND THE UPPER IOWA RIVERS BOTH HAVE RESPONSES.
ALSO THE WHITEWATER RIVER MIDDLE FORK THAT RUNS THROUGH WHITEWATER
STATE PARK IS RISING. AT THIS TIME THESE WILL APPROACH FLOOD STAGE
BUT IT IS BELIEVED THEY WILL NOT REACH IT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1140 PM CDT FRI OCT 4 2013
BACK EDGE OF THE CONVECTION IS MAKING STEADY EASTWARD PROGRESS AND
STILL EXPECT IT TO CLEAR BOTH TAF SITES BY 08Z. UNTIL IT
DOES...IFR CONDITIONS WILL REMAIN POSSIBLE AS LOCALLY HEAVY RAIN
COULD DROP THE VISIBILITY AND POSSIBLY THE CEILINGS DOWN. ONCE THE
RAIN MOVES THROUGH...A TEMPORARY DRY SLOT WILL MOVE INTO TO ALLOW
FOR A PERIOD OF PRIMARILY VFR CONDITIONS. AS THE MAIN SURFACE LOW
STARTS TO TRACK TOWARD THE AREA SATURDAY MORNING...EXPECT TO SEE
THE OCCLUDED FRONT LIFT INTO AND THROUGH THE AREA. THE 05.00Z NAM
SUGGESTS THAT AS THIS HAPPENS...THE LOW LEVEL MOISTURE TRANSPORT
WILL INCREASE WITH THE NOSE OF THIS INTO THE AREA LONG THE
OCCLUDED FRONT. THE MAIN UPPER LEVEL SYSTEM WILL ALSO BE
APPROACHING TO PROVIDE ADDITIONAL FORCING AND EXPECTING TO SEE
ANOTHER AREA OF SHOWERS AND SOME THUNDERSTORMS DEVELOP BY MID
MORNING AND CONTINUE INTO THE EARLY AFTERNOON. CONSIDERABLE
UNCERTAINTY ON WHAT THE CEILINGS WILL DO WITH THE OCCLUDED FRONT
BUT MOST GUIDANCE SUGGEST A RETURN TO MVFR BEFORE DRIER STARTS TO
SPREAD IN FROM THE WEST TO ALLOW THE RAIN TO END AND VFR
CONDITIONS TO RETURN.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BAUMGARDT
LONG TERM...BAUMGARDT
AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1140 PM CDT FRI OCT 4 2013
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 330 PM CDT FRI OCT 4 2013
FORECAST CONCERNS ARE ON SEVERE THUNDERSTORM POTENTIAL TONIGHT AND
THE POSSIBILITY OF A FEW SEVERE STORMS IN CENTRAL WISCONSIN LATE
SATURDAY MORNING INTO EARLY SATURDAY AFTERNOON.
LATEST SURFACE OBSERVATIONS SHOWED SURFACE LOW PRESSURE OVER
CENTRAL NEBRASKA...LIFTING NORTHEAST. A WARM FRONT EXTENDED
SOUTHEAST THROUGH SOUTHWEST AND CENTRAL IOWA. THE FRONT WILL LIFT
NORTH LATE THIS AFTERNOON INTO THIS EVENING AND BE THE FOCUS FOR
STRONG TO SEVERE THUNDERSTORM DEVELOPMENT AS A POTENT UPPER LOW
PUSHES EAST ACROSS THE NEBRASKA PANHANDLE.
THE WARM FRONT IS EXPECTED TO LIFT NORTH INTO NORTHERN IOWA AND
PERHAPS EXTREME SOUTHWEST WISCONSIN THIS EVENING. STRONG 850 MB
MOISTURE TRANSPORT FOCUSES INTO THE FRONT THIS EVENING...LEADING TO
SHOWERS AND THUNDERSTORMS DEVELOPING OVER NORTHEAST IOWA...SOUTHEAST
MINNESOTA AND PORTIONS OF SOUTHWEST WISCONSIN. MEANWHILE THE SURFACE
LOW WILL LIFT NORTH INTO SOUTHEAST SOUTH DAKOTA AS THE LOW OCCLUDES.
A TRIPLE POINT LIFTS NORTHEAST FROM NORTHEAST IOWA INTO SOUTH
CENTRAL MINNESOTA LATE IN THE EVENING. THE 04.17 HRRR SHOWS ISOLATED
STRONG STORMS DEVELOPING ALONG THE FRONT. STORMS ALSO DEVELOP OVER
WESTERN IOWA EARLY THIS EVENING CLOSER TO THE OCCLUSION. THESE STORMS
WILL LIKELY BE SUPERCELLS...CAPABLE OF PRODUCING LARGE
HAIL...DAMAGING WINDS AND ISOLATED TORNADOES. THE STORMS FURTHER TO
THE NORTH OVER THE FORECAST AREA...SHOULD BE NORTH OF THE WARM
FRONT AND ELEVATED IN NATURE. 1-7 KM BULK SHEAR VALUES HOVER RIGHT
AROUND 30 KTS DURING THE EVENING HOURS SO CANNOT RULE OUT ISOLATED
SEVERE STORMS CAPABLE OF PRODUCING LARGE HAIL...HEAVY
RAINFALL...AND POSSIBLY DAMAGING WINDS. THE HIGHEST CHANCES FOR
SEVERE WEATHER WILL BE OVER NORTHEAST IOWA AND SOUTHEAST
MINNESOTA...WEST OF HIGHWAY 52. A FEW OF THESE STRONGER STORMS
COULD MAINTAIN INTENSITY INTO PORTIONS OF WESTERN WISCONSIN BUT
SHOULD THEN WEAKEN AS THEY MOVE EAST...BUT STILL CAPABLE OF
PRODUCING HEAVY RAINFALL. THE 850 MB MOISTURE TRANSPORT GRADUALLY
SHIFTS EAST INTO WESTERN WISCONSIN OVERNIGHT WITH WIDESPREAD
SHOWERS AND STORMS PERSISTING. THE MAIN THREAT FROM THE STORMS
SHOULD GRADUALLY SHIFT TOWARDS HEAVY RAIN LATE IN THE NIGHT. A
COLD FRONT THEN PUSHES EAST ACROSS THE REGION EARLY SATURDAY
MORNING AND SHOULD BE POSITIONED RIGHT ALONG THE MISSISSIPPI RIVER
BY THE MID TO LATE MORNING HOURS. IF ENOUGH INSTABILITY CAN BUILD
AHEAD OF THE FRONT...THERE IS THE POSSIBILITY OF SEEING A FEW
STRONG TO SEVERE STORMS OVER CENTRAL WISCONSIN. THE MAIN HAZARDS
FROM THESE STORMS WOULD BE DAMAGING WINDS. SHOWERS AND STORMS WILL
END FROM WEST TO EAST SATURDAY AFTERNOON AS A DRY SLOT PUSHES INTO
THE REGION. TEMPERATURES SHOULD FALL ACROSS THE AREA SATURDAY
AFTERNOON IN THE WAKE OF THE COLD FRONT.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 330 PM CDT FRI OCT 4 2013
MOST OF THE FORECAST AREA WILL REMAIN IN THE DRY SLOT SATURDAY
NIGHT...WITH THE EXCEPTION OF NORTH CENTRAL WISCONSIN WHERE A FEW
SHOWERS MAY LINGER. PLAN ON A COOLER NIGHT WITH LOWS FALLING INTO
THE 40S. A FEW 30S CANNOT BE RULED OUT OVER CENTRAL WISCONSIN. THE
UPPER LOW MOVES INTO INTO WESTERN IOWA ON SUNDAY AND EVENTUALLY
INTO WESTERN ILLINOIS SUNDAY NIGHT. SHOWERS WRAPPING AROUND THE
LOW LOOK TO MOVE INTO THE REGION SUNDAY AND WILL LIKELY CONTINUE
INTO SUNDAY NIGHT AS THE LOW PROGRESSES EAST. THE LOW THEN LOOKS
TO MOVE INTO THE EASTERN GREAT LAKES LATE ON TUESDAY WITH HIGH
PRESSURE BUILDING INTO THE AREA IN ITS WAKE. HIGH PRESSURE THEN
BUILDS OVER THE AREA WEDNESDAY INTO THURSDAY WITH DRY AND QUIET
WEATHER EXPECTED...OUTSIDE OF THE POSSIBILITY OF OF SOME EARLY
MORNING VALLEY FOG. A TROUGH IS EXPECTED TO DIG INTO THE SOUTHWEST
CONUS LATE IN THE WEEK. SOUTHWEST FLOW LOOKS TO DEVELOP OVER THE
UPPER MISSISSIPPI RIVER VALLEY LATE FRIDAY INTO SATURDAY. FORECAST
MODELS SHOWS THE TROUGH EJECTING INTO THE CENTRAL AND NORTHERN
PLAINS...WILL HAVE TO KEEP A VERY CLOSE EYE ON THIS SYSTEM OVER
THE NEXT SEVERAL MODEL RUNS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1140 PM CDT FRI OCT 4 2013
BACK EDGE OF THE CONVECTION IS MAKING STEADY EASTWARD PROGRESS AND
STILL EXPECT IT TO CLEAR BOTH TAF SITES BY 08Z. UNTIL IT
DOES...IFR CONDITIONS WILL REMAIN POSSIBLE AS LOCALLY HEAVY RAIN
COULD DROP THE VISIBILITY AND POSSIBLY THE CEILINGS DOWN. ONCE THE
RAIN MOVES THROUGH...A TEMPORARY DRY SLOT WILL MOVE INTO TO ALLOW
FOR A PERIOD OF PRIMARILY VFR CONDITIONS. AS THE MAIN SURFACE LOW
STARTS TO TRACK TOWARD THE AREA SATURDAY MORNING...EXPECT TO SEE
THE OCCLUDED FRONT LIFT INTO AND THROUGH THE AREA. THE 05.00Z NAM
SUGGESTS THAT AS THIS HAPPENS...THE LOW LEVEL MOISTURE TRANSPORT
WILL INCREASE WITH THE NOSE OF THIS INTO THE AREA LONG THE
OCCLUDED FRONT. THE MAIN UPPER LEVEL SYSTEM WILL ALSO BE
APPROACHING TO PROVIDE ADDITIONAL FORCING AND EXPECTING TO SEE
ANOTHER AREA OF SHOWERS AND SOME THUNDERSTORMS DEVELOP BY MID
MORNING AND CONTINUE INTO THE EARLY AFTERNOON. CONSIDERABLE
UNCERTAINTY ON WHAT THE CEILINGS WILL DO WITH THE OCCLUDED FRONT
BUT MOST GUIDANCE SUGGEST A RETURN TO MVFR BEFORE DRIER STARTS TO
SPREAD IN FROM THE WEST TO ALLOW THE RAIN TO END AND VFR
CONDITIONS TO RETURN.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...FLASH FLOOD WATCH UNTIL 7 AM CDT SATURDAY FOR WIZ017-029-032>034-
041>044-053.
MN...FLASH FLOOD WATCH UNTIL 7 AM CDT SATURDAY FOR MNZ079-086>088-
094>096.
IA...FLASH FLOOD WATCH UNTIL 7 AM CDT SATURDAY FOR IAZ008>011-018-019.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM...WETENKAMP
AVIATION...04
AREA FORECAST DISCUSSION
NWS ALBANY NY
641 AM EDT SAT OCT 5 2013
.SYNOPSIS...
A STATIONARY FRONTAL BOUNDARY OVER THE NEW YORK PENNSYLVANIA
BORDER...WILL KEEP CLOUDS ALONG WITH AN ISOLATED TO SCATTERED
THREAT OF SHOWERS FOR THE FIRST HALF OF THIS WEEKEND. AS THE
BOUNDARY MOVES NORTH OF THE CAPITAL REGION TONIGHT INTO
SUNDAY...MORE WIDESPREAD SHOWERS AND ISOLATED THUNDERSTORMS WILL
INCREASE ACROSS THE REGION...ALONG WITH HIGHER HUMIDITY LEVELS.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 630 AM EDT...A FEW LIGHT SHOWERS PER THE LATEST 88D SCANS WERE
TRACKING ACROSS THE DACKS WITH A MORE CONCENTRATED AREA OF
CONVECTION IN THE BUFFALO VICINITY. LATEST HRRR REFLECTIVITY
FORECASTS SUGGESTS THIS UPSTREAM BAND OF CONVECTION SHOULD WEAKEN AS
IT APPROACHES A MORE STABLE DOWNSTREAM AIR MASS. OTHERWISE...THE
FRONTAL BOUNDARY HAS MOVED LITTLE WITH THE BETTER PROGRESS ACROSS
SOUTHWEST NY STATE. NO OTHER CHANGES AT THIS TIME.
PREV DISC...
QUASI-STATIONARY BOUNDARY WAS SITUATED ALONG THE NY/PA BORDER.
REGIONAL RADAR MOSAIC REVEALS WIDELY SCATTERED SHOWERS ACROSS
CENTRAL AND WESTERN NY WITH MORE ROBUST CONVECTION ACROSS LOWER
MICHIGAN AND APPROACHING LOWER ONTARIO PROVENCE. H2O VAPOR LOOP
DOES HINT AT A WEAK SHORT WAVE EMBEDDED WITHIN THE WESTERLY FLOW
NORTH OF THIS FRONTAL BOUNDARY THAT IS THE LIKELY CULPRIT FOR THE
AFOREMENTIONED DEEPER CONVECTION UPSTREAM. LATEST HOURLY RUN OF
THE RUC13/HRRR AND 4KM SPC WRF MODELS SUGGEST THIS UPSTREAM SHOULD
WEAKEN AS IT OUTRUNS THE LOW LEVEL JET /AOA 20KTS/ AND ELEVATED
INSTABILITY. MEANWHILE...SURFACE HIGH SITUATED NORTH OF THE GREAT
LAKES REGION CONTINUES TO EXTEND ITS INFLUENCE EAST AND SOUTHWARD
WHICH WILL LIKELY KEEP THIS FRONTAL BOUNDARY FROM MOVING FURTHER
NORTH THROUGH THE DAY. WITH THAT SAID...WE REMAIN ON THE COOLER
SIDE OF THE BOUNDARY WITH CONSIDERABLE CLOUD COVER AND THE CHANCE
/SLIGHT-CHC FOR SOME SHOWER ACTIVITY. WE WILL SHADE ON THE COOLER
SIDE OF THE GUIDANCE...CLOSER TO THE MET MOS VALUES AND HOURLY
LAMP/LAV.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
00Z NCEP MODEL SUITE AND INTERNATIONAL GUIDANCE HAVE RESULTED IN A
LARGER SHIFT TOWARD A SLOWER MORE AMPLIFIED PATTERN. THE RESULT IS
A SLOWER TIMING OF THE WARM FRONTAL PASSAGE TO BE FOLLOWED BY THE
COLD FRONT LATE MONDAY OR MONDAY NIGHT.
TONIGHT...THE LOW LEVEL JET UPSTREAM WILL INCREASE IN EARNEST AS
PRECIPITATION/CONVECTION UNFOLD. THE BEST WARM ADVECTION AND
ISENTROPIC LIFT IS EXPECTED TO OCCUR OVER WESTERN AND CENTRAL NY.
PER THE CORFIDI VECTORS AND THICKNESS...THIS ACTIVITY WILL LIKELY
SPREAD INTO THE WESTERN ZONES AND THE DACKS THROUGH THE OVERNIGHT
AND GRADUALLY SPREAD ACROSS THE REMAINDER OF THE CWA. WE WILL
GRADUALLY INCREASE POPS FROM WEST TO EAST AND KEEP TEMPERATURES A
BIT STEADY AS THE WARMER AIR BEGINS TO ADVECT NORTHWARD.
THROUGH SUNDAY...THE PROGRESS OF THIS WARM FRONT WILL BE
INTERESTING TO WATCH AS THE SURFACE HIGH /1024MB/ NORTH OF THE
GREAT LAKES MIGRATES ACROSS NORTHERN NEW ENGLAND AND KEEPING THE
LOWER LEVEL AGEOSTROPHIC FLOW ACROSS THE HUDSON RIVER VALLEY AND
POINTS EAST. ONCE AGAIN CONSIDERABLE CLOUD COVER ALONG WITH
SHOWERS AS WE WILL FAVOR A MOS BLEND OF THE NAM/GFS.
SUNDAY NIGHT...TRENDS ARE FAVORING FOR A MID LEVEL DRY SLOT TO
ADVECT INTO THE REGION WHICH SHOULD REDUCE COVERAGE OF PRECIP BUT
KEEP THE LOW LEVEL MOISTURE IN PLACE. IN FACT...CROSS SECTIONS
REVEAL AMPLE WIND SHEAR AT OR JUST ABOVE THE LOW LEVEL MOISTURE
THAT POCKETS OF DRIZZLE MAY DEVELOP. TEMPERATURES SHOULD BE A
LITTLE MILDER.
MONDAY...A FAIRLY DEEP UPR LOW ACROSS THE MID WEST AND ITS
ASSOCIATED SURFACE LOW/COLD FRONT ARE EXPECTED TO SLOW THE FORWARD
PROGRESSION OF THIS SYSTEM. THIS WILL LIKELY PLACE OUR REGION WELL
WITHIN THE WARM SECTOR...HOWEVER...MARINE INFLUENCE COMPONENT
REMAINS TO BE SEEN AS THE LOW LEVEL JET WILL BE INCREASING FROM
THE SSW. FOR NOW WE WILL FAVOR A BLENDED APPROACH TO THE MAV/MET
MOS. AS FOR PRECIP CHANCES...WE WILL REDUCE THE POPS FROM THE
PREVIOUS FORECAST DUE TO THE SLOWER ARRIVAL TIME BUT STILL KEEP
THE MENTION OF THUNDER.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
A DYNAMIC STORM SYSTEM WILL BE APPROACHING AT THE START OF THE
EXTENDED PERIOD. A LARGE CLOSED LOW WILL BE MOVING ACROSS THE OHIO
VALLEY/EASTERN GREAT LAKES WITH A STRONG COLD FRONT AT THE SURFACE.
AHEAD OF THIS BOUNDARY...A STRONG SOUTHERLY LOW LEVEL JET WILL
TRANSPORT PLENTY OF MOISTURE /SOME OF WHICH WAS ASSOCIATED WITH THE
REMAINS OF TC KAREN...WHICH WILL ALREADY HAVE BEEN ABSORBED INTO THE
FRONTAL ZONE ACROSS THE SOUTHEAST/ TOWARDS THE REGION. THE 00Z GEFS
SHOWS PWAT VALUES 2-3 STD ABOVE NORMAL ACROSS THE REGION FOR MON
NIGHT INTO TUESDAY.
THE MODELS CONTINUE TO SHOW PLENTY OF DISAGREEMENT WITH THE TIMING
OF THIS FRONT. THE ECMWF DOESN/T CLOSE THE UPPER LOW OFF...AND A
RESULT...IS MUCH QUICKER WITH THE BOUNDARY. WE WILL FAVOR THE SLOWER
00Z GFS SOLUTION...WHICH IS ALSO BETTER IN LINE WITH THE 00Z GGEM
AND 00Z GEFS. AS A RESULT...MONDAY NIGHT MAY START OFF VERY MILD
AND MUGGY WITH TEMPS IN THE 60S AND ONLY SCT RAIN SHOWERS...AND
STEADY PRECIP MAY NOT ARRIVE UNTIL VERY LATE AT NIGHT OR UNTIL
DURING THE DAY TUESDAY. TEMPS WILL STILL BE MILD ON TUESDAY...WITH
UPPER 60S TO LOW 70S ACROSS THE REGION.
A LINE OF SHOWERS ALONG/JUST AHEAD OF THE FRONT LOOK TO MOVE THROUGH
SOMETIME ON TUESDAY. THE RAIN MAY BRIEFLY FALL HEAVY AT TIMES. WE
WILL INCLUDE A SLIGHT CHC FOR THUNDER...BUT MEAGER INSTABILITY
LEVELS SHOULD KEEP THUNDER FROM BEING MORE WIDESPREAD. MOST AREAS
WILL SEE AROUND AN INCH OF RAINFALL...WHICH IS ACTUALLY NEEDED DUE
TO THE RECENT DRY STRETCH. FLOODING ISSUES OUTSIDE LOW
LYING/URBAN/POOR DRAINAGE AREAS AREN/T ANTICIPATED DUE TO THE DRY
ANTECEDENT CONDITIONS AND HIGH FFG.
BEHIND THE FRONT...STEADY RAIN WILL MOVE OFF TO THE EAST AND
END...AND TEMPS AND HUMIDITY LEVELS WILL START TO FALL OFF. THE
THREAT FOR PRECIP WON/T BE ENTIRELY GONE...AS THE UPPER LOW LOOKS TO
PASS OVER THE REGION...SO THE THREAT FOR RAIN SHOWERS WILL CONTINUE
FOR WED/THURS...MAINLY ACROSS THE HIGH TERRAIN AND NORTHERN AREAS.
TEMPS WILL BE COOLER FOR TUES NIGHT BEHIND THE FRONT WITH 40S AND
50S. DAYTIME TEMPS ON WED/THURS WILL BE A BIT COOLER THAN RECENT
DAYS...BUT STILL ABOVE NORMAL...WITH MID 60S FOR VALLEY AREAS.
OVERNIGHT LOWS WED AND THURS NIGHTS WILL MAINLY BE IN THE 40S.
ONCE THE UPPER LOW EXITS...A STRONG RIDGE WILL ESTABLISH ITSELF
ALONG THE EASTERN SEABOARD...ALLOWING FOR EVEN MILDER AIR TO RETURN
TO THE REGION. AN EXTENDED PERIOD OF DRY WEATHER LOOKS TO BE IN
PLACE FROM THURSDAY NIGHT INTO MUCH OF THE WEEKEND...WITH ABOVE
NORMAL WARMTH. DAYTIME TEMPS MAY RETURN TO NEAR 70 FOR
FRI/SAT...WHICH IS ABOUT 10 DEGREES ABOVE NORMAL FOR MID OCT.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
FLYING CONDITIONS LOOK TO STAY MVFR FOR KALB/KGFL FOR MUCH OF THE
MORNING WITH LOTS OF LINGERING LOW CLOUDS AS A STALLED OUT FRONTAL
BOUNDARY WILL CONTINUE TO BE DRAPED OVER THE REGION. KPOU/KPSF MAY
CONTINUE TO SEE A FEW MORE HOURS OF IFR CIGS BEFORE CIGS RISE TO
MVFR CONDITIONS BY MID TO LATE MORNING. THERE MAY BE A BRIEF PERIOD
OF IMPROVEMENT DURING AFTERNOON WITH VFR CONDITIONS POSSIBLE AT
KGFL/KALB/KPOU. SOME SCT RAIN SHOWERS MAY AFFECT THE REGION WITH
LIGHT AND VARIABLE SFC WINDS DURING THE AFTN HOURS AS WELL.
ALL SITES LOOK TO BE BACK IN MVFR CONDITIONS FOR LOW CIGS BY THIS
EVENING WITH CALM WINDS AND POSSIBLE RAIN SHOWERS AS THE SLOW MOVING
FRONTAL BOUNDARY REMAINS NEARLY STATIONARY OVER THE AREA. IFR
CONDITIONS FOR LOW CIGS MAY BE POSSIBLE LATE TONIGHT AS WELL...BUT
CONFIDENCE IN THIS IS NOT HIGH ENOUGH TO INCLUDE IN THE TAFS AT THIS
TIME.
OUTLOOK...
SUNDAY NIGHT-MONDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF
SHRA...TSRA.
MONDAY NIGHT-TUESDAY: HIGH OPERATIONAL IMPACT. LIKELY SHRA...TSRA.
TUESDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
WEDNESDAY: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.FIRE WEATHER...
LOW LEVEL MOISTURE WILL REMAIN RATHER HIGH ALONG WITH THE INCREASE
THREAT FOR MORE SHOWERS. WINDS WILL BE RATHER LIGHT WITH A
TENDENCY FROM THE NORTHERLY DIRECTION THROUGH TONIGHT AT SPEEDS
LESS THAN 10 MPH. FIRE WEATHER CONCERNS WILL BE AT A MINIMUM.
&&
.HYDROLOGY...
NO WIDESPREAD PROBLEMS ARE EXPECTED ON THE MAIN STEM RIVERS OVER
THE NEXT 5 DAYS. FLOWS CONTINUE AT NORMAL TO BELOW NORMAL LEVELS
FOR EARLY OCTOBER.
RAINFALL FORECASTS WILL RANGE FROM ONE QUARTER TO ONE HALF OF AN
INCH BASIN AVERAGE NORTH AND WEST OF THE CAPITAL DISTRICT WITH ONE
TENTH TO ONE QUARTER OF AN INCH FROM THE CAPITAL DISTRICT TO
POINTS EAST AND SOUTH. THESE VALUES WILL BE SLIGHTLY HIGHER ACROSS
THE HIGHER TERRAIN BUT LIKELY HAVE LITTLE IMPACT TO THE RIVERS
WITH SLIGHT RISES EXPECTED.
MAIN CHALLENGE WILL BE THE INCREASING MOISTURE PROFILES HEADING
INTO MONDAY. MOISTURE FROM WHAT IS LEFT OF TS KAREN MAY BECOME
ABSORBED WITHIN THE FRONTAL SYSTEM AS IT APPROACHES LATE MONDAY.
RAINFALL AMOUNTS UP TO AND OVER ONE INCH ARE POSSIBLE. WITHIN BANK
RIVER RISES ARE EXPECTED WITH POSSIBLE ISSUES FROM FALLEN LEAFS
BLOCKING STORM DRAINS TO RESULT IN PONDING WATER. PLEASE REFER TO
THE LATEST TROPICAL GUIDANCE FROM THE NATIONAL HURRICANE CENTER.
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...BGM
NEAR TERM...BGM
SHORT TERM...BGM
LONG TERM...FRUGIS
AVIATION...FRUGIS
FIRE WEATHER...BGM/WASULA
HYDROLOGY...BGM/WASULA
FOR THE LATEST UPDATES...PLEASE VISIT OUR WEBPAGE AT
WWW.WEATHER.GOV/ALBANY
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1147 AM EDT SAT OCT 5 2013
.SYNOPSIS...
ISSUED AT 342 AM EDT SAT OCT 5 2013
A LARGE LOW PRESSURE SYSTEM WILL BRING INCREASING CHANCES FOR
SHOWERS AND THUNDERSTORMS THROUGH EARLY NEXT WEEK. THIS LOW
PRESSURE SYSTEM WILL ALSO SEND A COLD FRONT THROUGH THE AREA WITH
TEMPERATURES RETURNING TO NEAR NORMAL VALUES AFTER HIGHS IN THE
LOW 80S AGAIN TODAY.
&&
.UPDATE...
ISSUED AT 1125 AM EDT SAT OCT 5 2013
A COUPLE OF SMALL SCALE EMBEDDED WAVES IN SOUTHWEST UPPER FLOW
HAVE RESULTED IN CLUSTERS OF SHOWERS AND ISOLATED THUNDERSTORMS
ACROSS CENTRAL/NORTHEAST INDIANA. ADDITIONAL SCATTERED SHOWERS AND
THUNDERSTORMS CONTINUE TO DEVELOP OTHER SOUTHERN LAKE MICHIGAN IN
CLOSER PROXIMITY TO MORE PRONOUNCED UPPER LEVEL DIFFLUENCE
DOWNSTREAM OF VIGOROUS NORTHERN PLAINS UPPER TROUGH. AREAS
ROUGHLY ALONG AND SOUTHEAST OF A HUNTINGTON INDIANA TO FORT WAYNE
INDIANA TO DEFIANCE LINE HAVE LIKELY RECEIVED BETWEEN A HALF INCH
TO AN INCH OF RAINFALL SO FAR THIS MORNING. SOME OF THESE SAME
LOCATIONS ACROSS NORTHWEST OHIO HAVE ALSO RECEIVED HEAVY RAINFALL
YESTERDAY. GIVEN INCREASING CONFIDENCE IN SIGNIFICANT RAINFALL
LATE TONIGHT INTO SUNDAY EVENING ALONG WITH RECENT HEAVY
RAIN...WILL BE ISSUING A FLASH FLOOD WATCH SHORTLY FOR FAR
NORTHEAST INDIANA...PORTIONS OF SOUTH CENTRAL LOWER
MICHIGAN....AND ALL OF NORTHWEST OHIO COUNTIES FROM 06Z TONIGHT TO
06Z MONDAY.
IN TERMS OF CONVECTIVE POTENTIAL...15Z RUC ANALYSIS DEPICTS
1000-1500 J/KG OF 100 HPA MLCAPES ACROSS MUCH OF WESTERN HALF OF
THE AREA WITH 0 TO 6 KM BULK SHEAR VALUES IN THE 25 TO 30 KNOT
RANGE. DESPITE SIGNIFICANT CLOUD COVER...DEEP MOISTURE PROFILES
SHOULD CONTINUE TO YIELD CAPES ON THE ORDER OF 1000-1500 J/KG
THIS AFTERNOON. DEEP LAYER SHEAR TO ALSO INCREASE LATE AFTERNOON
ACROSS WESTERN HALF OF THE AREA AS A 500 HPA SPEED MAX LIFTS INTO
NORTHWEST INDIANA AFTER 21Z. THUS...NO CHANGE IN THINKING FROM
PREVIOUS FORECAST WITH LOW/ISOLATED SEVERE THREAT ACROSS
ESPECIALLY WESTERN AREAS LATE AFTERNOON/EARLY EVENING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 342 AM EDT SAT OCT 5 2013
GRADUAL APPROACH OF IMPRESSIVE CLOSED OFF CYCLONIC GYRE EXTENDING
THROUGH THE BULK OF THE TROPOSPHERE WILL BRING INCREASING CHANCES
FOR RAIN THROUGH THE SHORT TERM PERIOD. SURFACE FRONTAL BOUNDARY
EXTENDING INTO THE SOUTHERN GREAT LAKES WILL MOVE LITTLE THROUGH
THE PERIOD WITH PERSISTENT THETA-E ADVECTION IN A LARGELY UNCAPPED
ENVIRONMENT LEADING TO CONTINUED PERIODS OF CONVECTION. SMALL
SCALE VORTICES IN SOUTHWEST FLOW ALOFT EMANATING FROM THE CENTRAL
CONUS WILL ALSO SUPPORT INCREASING CHANCES FOR RAINFALL AS THE
MAIN SYSTEM APPROACHES. OCCLUSION PROCESS IS ALREADY BEGINNING AND
EARLIER NOTED SLOWING TREND HAS CONTINUED. MAIN SURFACE COLD FRONT
IS NOT EXPECTED TO REACH OUR CWA UNTIL LATE TONIGHT. WILL STILL BE
PLENTY OF RAIN AHEAD OF THE MAIN FRONT THOUGH. TIGHTENING LOW
LEVEL MASS GRADIENT ASSOCIATED WITH APPROACHING PV ANOMALY WILL
LEAD TO A STRENGTHENING OF THE LLJ AND A CORRESPONDING UPTICK IN
305K ISENTROPIC ASCENT. MOISTURE WILL CERTAINLY NOT BE LACKING
EITHER. 305K MIXING RATIOS ARE ABOVE 8 G/KG AND PW VALUES ARE
HOVERING AROUND 1.75 INCHES...NEAR THE 99TH PERCENTILE FOR THIS
TIME OF YEAR BASED ON REGIONAL UPPER AIR CLIMATOLOGY. EXACT
TIMING/PLACEMENT OF CONVECTION REMAINS HIGHLY UNCERTAIN BUT EXPECT
COVERAGE TO INCREASE AS THE DAY WEARS ON GIVEN INCREASING DIURNAL
INSTABILITY AND APPROACHING TROUGH. LATEST HI-RES GUIDANCE SHOWS
CONVECTION NEAR INDIANAPOLIS WILL CONTINUE TO SPREAD NORTH THROUGH
THE MORNING WITH A BRIEF BREAK BEFORE ADDITIONAL CONVECTION
ARRIVES IN THE LATE AFTERNOON. TRIED TO INCORPORATE THIS INTO THE
LATEST POP FORECAST BUT MAINTAINED FAIRLY BROADBRUSH APPROACH
GIVEN UNCERTAINTY IN CONVECTIVE TRENDS. HIGHER CONFIDENCE THAT
SHOWERS AND THUNDERSTORMS WILL BECOME WIDESPREAD BY TONIGHT THOUGH
AS THE COLD FRONT APPROACHES...AND HAVE PUSHED POPS INTO
CATEGORICAL VALUES. HIGHS TODAY WILL BE SIMILAR TO YESTERDAY...AS
ANY BREAKS IN THE CLOUD COVER WILL ALLOW TEMPS TO MAKE A RUN AT
THE MID 80S GIVEN WARM PROFILES ALOFT. LOWS TONIGHT WILL BE HIGHLY
DEPENDENT ON EXACT TIMING OF FRONT BUT HAVE RAISED THEM A BIT IN
ANTICIPATION OF A SLOWER FRONTAL PASSAGE. LAPSE RATES NEARLY MOIST
ADIABATIC WILL LIKELY ONLY SUPPORT AROUND 1000 J/KG OR LESS OF
SBCAPE TODAY. DEEP LAYER SHEAR IS ALSO MARGINAL DURING THE DAY AND
EXPECT ONLY A SLIGHT CHANCE FOR SEVERE WEATHER...MAINLY IN AREAS
THAT SEE A SUSTAINED PERIOD OF INSOLATION THAT ALLOWS INSTABILITY
TO BUILD. SHEAR WILL INCREASE BY TONIGHT...BUT INSTABILITY WILL BE
AT A MINIMUM AND AGAIN ONLY EXPECTING A LOW RISK OF SEVERE WEATHER
AT THE MOMENT. HEAVY RAIN WILL LIKELY BE THE BIGGEST THREAT. A
VERY MOIST ENVIRONMENT AND CONTINUED POTENTIAL FOR TRAINING STORMS
COULD LEAD TO HIGH RAINFALL TOTALS BY THE TIME ALL IS SAID AND
DONE EARLY NEXT WEEK.
&&
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 342 AM EDT SAT OCT 5 2013
RATHER DRAMATIC CHGS REQUIRED TO BEGIN THE PD ON ACCOUNT OF CONTD
MODEL CONSENSUS SLWG IN EWD PROGRESSION OF PLAINS BOWLING BALL.
INTERESTINGLY STILL SOME SIG SPREAD ALOFT STILL AT THIS TIME RANGE
W/POSITION AND INTENSITY OF MID LVL CYCLONE WHICH RANGES FROM NRN IL
IN NAM TO SRN IL IN GEM AT FHR60. REGARDLESS ENOUGH OF A CONSENSUS
SIGNAL EXISTS TO EXTEND/BUMP POPS/WX THROUGH MON NIGHT. HWVR WILL
FORGO ALLBLEND POP GUIDANCE FOR TUE IN LIGHT OF RAPID UPSTREAM HGT
RISES FOLLOWING IN WAKE OF UPR TROUGH WHICH AT THAT POINT SHLD BE IN
SE CANADA.
OF GREATEST INTEREST W/SLWG SOLUTIONS ALOFT IS CONTD PUMP OF
ANOMALOUS GOMEX MSTR FLUX INTO THE GREAT LAKES INADV OF MIDLVL
CYCLONE WHICH SHOWS LTL SIGN OF WKNG UNTIL MON. SLWR EWD ADV OF FNTL
BNDRY ALG W/PWS OF NEAR 1.8IN (99TH PERCENTILE) WOULD PREPOSE AT
LEAST THE ERN HALF OF CWA FOR A CLASSIC MADDOX TYPE I HEAVY RAIN
EVENT AND NOTED IN SVRL DETERMINISTIC QPF SOLUTIONS SUN-SUN NIGHT.
SINCE THIS THREAT IS XPCD TO DVLP DY2 WILL FOLLOWUP PRIOR WELL
DESERVED ESF. AS AN ASIDE...FAIR NUMBER OF SOLUTIONS DEPICT THE
DVLPMNT OF A SFC FNTL WAVE SUN AFTN WHICH IF TRUE WOULD YIELD A
HEIGHTENED RISK FOR LOW TOPPED SUPERCELLS ACRS ERN IN/WRN OH AND
INHERENT TOR THREAT W/FVRBL OVERLAP OF MIXED LYR CAPE/SHEAR.
OTRWS SWD TRENDING PROGRESSION OF AT LEAST MOD INTENSE MID LVL
CYCLONE LEADS TO ADDNL ESCALATION/EXPANSION OF POPS MON AFTN/MON
NIGHT. IN FACT SWD CNTRD CLUSTER OF SVRL SOLUTIONS INCLUDING GFS/GEM
WOULD PORTEND A SECONDARY DEFORMATION ZONE DVLPG IN RESPONSE TO
TRAILING FNTL WAVE MON NIGHT W/ASSUMED SEPARATION W/REMNANTS OF TS
KAREN AS SOME SEMBLANCE OF THE TROWAL REMAINS INTACT.
GIVEN ALL OF THE ABOVE...SIG CHGS TO TEMPS WERE MADE SUN/MON. HWVR
SIG MODERATION STILL ON TAP IN WAKE OF THIS INTENSE SYS MID WEEK
TIMED W/SECONDARY DEEP WRN TROUGH DVLPMNT AND DOWNSTREAM RIDGE
AMPLIFICATION W/RTN TO ABV NORMAL TEMPS XPCD BY THU.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 555 AM EDT SAT OCT 5 2013
AREA OF CONVECTION CURRENTLY OVER CENTRAL INDIANA WILL CONTINUE TO
SLOWLY WORK NORTHWARD THIS MORNING...AIDED BY PERSISTENT THETA-E
ADVECTION AND A WEAK SHORTWAVE EMBEDDED IN SOUTHWEST FLOW ALOFT.
PRECIP MAY CLIP KFWA BUT PLAN TO LEAVE OUT THUNDER MENTION SINCE
LIGHTNING HAS BEEN FAIRLY ISOLATED AND MAY PASS TO THE SOUTHEAST
OF THE TERMINAL. SPORADIC SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE FOR MUCH OF THE TAF PERIOD AND TIMING THIS PRECIP WILL BE
NEARLY IMPOSSIBLE MORE THAN A FEW HOURS OUT. HAVE HIGHLIGHTED LATE
AFTERNOON AS THE BEST CHANCE GIVEN DIURNAL INSTABILITY PEAK BUT
SCATTERED CONVECTION WILL BE POSSIBLE THROUGH THE OVERNIGHT PERIOD
WITH MVFR...OR LOWER...CONDITIONS IN THE STRONGER STORMS.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...FLASH FLOOD WATCH FROM LATE TONIGHT THROUGH LATE SUNDAY NIGHT
FOR INZ007-009-018-026-027-033-034.
MI...FLASH FLOOD WATCH FROM LATE TONIGHT THROUGH LATE SUNDAY NIGHT
FOR MIZ081.
OH...FLASH FLOOD WATCH FROM LATE TONIGHT THROUGH LATE SUNDAY NIGHT
FOR OHZ001-002-004-005-015-016-024-025.
LM...NONE.
&&
$$
UPDATE...MARSILI
SYNOPSIS...AGD
SHORT TERM...AGD
LONG TERM...T
AVIATION...AGD
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1048 AM CDT SAT OCT 5 2013
.UPDATE...
ISSUED AT 1034 AM CDT SAT OCT 5 2013
A TRICKY FORECAST TO SAY THE LEAST FOR TODAY. DRY SLOT HAS MOVED
IN BEHIND THE OCCLUDED FRONT THIS MORNING...WITH PARTIAL CLEARING
OF SKIES SEEN WEST AND SOUTH OF THE TWIN CITIES. AFTER MAKING GOOD
PROGRESS OVERNIGHT...THIS CLEARING HAS PUT ON THE BREAKS AS THE
LOW OVER SE SODAK HAS STARTED TO DRIFT ESE. THIS WILL KEEP THE
CLEARING FROM MAKING IT MUCH FARTHER NORTH...BUT IT WILL CONTINUE
TO SLOWLY CRAWL TOWARD THE EAST TODAY.
OF COURSE AS THIS IS GOING ON THE BIGGEST CHANGE TO THE FORECAST
IS THE ADDITION OF SHOWERS THIS AFTERNOON FROM MANKATO TO ST.
CLOUD ON EAST. THE HRRR HAS BEEN SHOWING THIS AREA OF SHOWERS
DEVELOPING BACK TO THE WEST FOR SEVERAL RUNS NOW. LOOKING AT THE
RAP...THIS IS IN RESPONSE TO A STRONG BAND OF FGEN COMING UP FROM
IOWA IN THE H7-H5 LAYER. LOOKING DOWN TO THE SOUTHWEST ON
SATELLITE...YOU CAN SEE THIS AREA OF PRECIP STARTING TO TAKE
SHAPE FROM ERN KANSAS UP INTO WRN IOWA. BOOSTED POPS UP TO AROUND
50 PERCENT BACK TO THE CITIES THIS AFTERNOON...BUT IF THE HRRR IS
CORRECT...MAY NEED TO BOOST THEM UP SIGNIFICANTLY IN THE NEAR
FUTURE...ESPECIALLY CONSIDERING ALL 4 MEMBERS OF THE 05.09 HOPWRF
SHOW SOMETHING SIMILAR HAPPENING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 342 AM CDT SAT OCT 5 2013
THE POTENCY OF THIS EARLY FALL SYSTEM WAS AGAIN ON DISPLAY LAST
NIGHT WITH STRONG TO SEVERE STORMS IN THE WARM SECTOR AND A RAGING
BLIZZARD IN WESTERN SOUTH DAKOTA. FURTHERMORE...THE SYSTEM HAS
BEEN OCCLUDED FOR 12-18 HOURS NOW AND WE STILL SAW A 1-2 MB MSLP
PRESSURE DROP OVERNIGHT. THE TROWAL IS CREATING A HOME RUN HITTING
DEFORMATION BAND FROM NORTHERN MN TO ND TO SD. IN FACT...THE
PRECIP SHIELD ALONG THE COLD CONVEYOR BELT ACTUALLY EXTENDS ALL
THE WAY FROM WYOMING TO MICHIGAN...AND THUNDERSTORMS ALONG THE
COLD FRONT EXTEND FROM MICHIGAN TO TEXAS. NOT A SMALL SYSTEM BY
ANY MEANS.
THE FORECAST AREA WILL FIND ITSELF IN THE DRY SLOT MOST OF THE DAY
TODAY AND ALSO TONIGHT TO SOME DEGREE. HOWEVER SOME DRIZZLE IS
POSSIBLE AND THE CLOUDS SHOULD LARGELY STAY IN TACT. THE OCCLUDED
BOUNDARY ISN`T GOING ANYWHERE...ESPECIALLY FOR CENTRAL MN/WI.
SOUTHERN PORTIONS OF THE FORECAST AREA /THAT`S RIGHT...SOUTHERN/
ARE CLOSER TO THE COLDER AND DRIER AIR...SO THERE IS A BETTER
CHANCE OF AT LEAST PARTIAL CLEARING TODAY IN SOUTHERN MN. MUCH
COLDER AIR ALOFT ARRIVES TONIGHT...SO THE STRATUS WON`T BE FAR
BEHIND EVEN IF THERE IS CLEARING DURING THE DAY TODAY. THE 00-06Z
GUIDANCE IS TOO FAR SOUTH WITH THE DEFORMATION PRECIP BAND THIS
MORNING...AS THE FORECAST AREA IS VIRTUALLY PRECIP FREE. IT`S ALSO
NOT DEEP ENOUGH WITH THE SURFACE LOW. TRIED TO KEEP THE POPS TODAY
ON THE OUTER EDGES OF THE FORECAST AREA TO COUNTER THIS AND ALSO
TO STAY CLOSE TO SURROUND FORECAST OFFICES. OTHERWISE...WINDS WILL
FALL OFF AS THE LOW SLOWLY FILLS AND MOVES OVERHEAD. IF THE CLOUDS
CLEAR ANYWHERE TONIGHT...FOG COULD BE A PROBLEM...TOOK THE SIDE OF
LOW STRATUS FOR NOW. NEAR STEADY TEMPERATURE TODAY SO MADE LITTLE
ADJUSTMENT TO THE PREVIOUS FORECAST. WE ADJUSTED DEWPOINTS BY
KEEPING SLIGHTLY HIGHER VALUES NEAR THE FRONT AND COOLER VALUES
CLOSER TO THE DRY SLOT.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 342 AM CDT SAT OCT 5 2013
THE SFC LOW FROM THE POTENT/DEEP SYSTEM AFFECTING THE REGION WILL
SHIFT INTO WI BY DAYBREAK SUN MRNG WHILE THE LOW PRES CENTER ALOFT
WILL SHIFT SE INTO NRN IA. AS THESE TWO LOWS MOVE EAST IN TANDEM
SLOWLY DURG THE DAY ON SUN...THE DRY SLOT OVER MUCH OF THE AREA
WILL FILL BACK IN WITH DEEPER MOISTURE WRAPPING AROUND THE UPPER
LEVEL LOW. COLD ALOFT COMBINED WITH LOW LEVEL WINDS SHIFTING TO A
MORE NLY DIRECTION WILL AID IN KEEPING LOW CLOUDS IN PLACE FOR
MUCH OF THE DAY...ALONG WITH A DRIZZLE/RAIN SCENARIO FOR SENSIBLE
WX. THE UPPER LOW WILL SHIFT ESE INTO CENTRAL IL BY MON
MRNG...DRAGGING MUCH OF THE MOISTURE WITH IT BUT THERE WILL STILL
BE A CHC FOR LINGERING SHOWERS IN WRN WI ON MON WHILE SRN/CENTRAL
MN STARTS TO CLEAR OUT. CONDS WILL GRADUALLY IMPROVE DURG THE DAY
ON MON AS HIGH PRES FROM SW CANADA DROPS IN. DESPITE THE COOL
ORIGIN OF THIS AIRMASS...IT WILL BE QUICKLY MODIFIED BY AN UPPER
LEVEL RIDGE THAT WITH INCRG H5 HEIGHTS WILL SPELL A WARMING TREND
ALONG WITH A PROLONGED DRYING-OUT PERIOD FOR THE AREA. DRY WX IS
FORECAST MON THRU THU WITH HIGHS RISING BACK INTO THE MID 70S.
MODELS CONTINUE TO ADVERTISE ANOTHER POTENT SYNOPTIC-SCALE LOW
PRES SYSTEM TO DEVELOP IN THE LEE OF THE ROCKIES THU NIGHT INTO
FRI MORNING...WITH IT QUICKLY MOVG NEWD INTO THE DAKOTAS FRI. THIS
MAY ALLOW FOR SOME MID-TO-LATE DAY SHWRS/TSTMS OVER WRN MN ON FRI
AS THIS SYSTEM ADVANCES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 623 AM CDT SAT OCT 5 2013
CONDITIONS HAVE GENERALLY BEEN IFR WITH LIFR AT TIMES AND MVFR AT
OTHERS. WE EXPECTED LITTLE CHANGE FOR THE NEXT 2-4 AT THE TAF
SITES AS THE DRIER AIR TAKES ITS TIME TO ARRIVE. HOWEVER...WE DO
EXPECT IMPROVEMENT BY THE LATE MORING OR EARLY AFTERNOON. ITS HARD
TO IMAGINE SKIES GOING MOSTLY SUNNY FOR TOO LONG...AS CU WITH MVFR
CEILINGS SHOULD FILL IN...BUT WE THINK KMSP/KEAU/KRNH/KSTC ALL
HAVE A CHANCE FOR MVFR OR EVEN VFR THIS AFTERNOON. LITTLE RAIN IS
EXPECTED TODAY AND EVEN TONIGHT - LIGHT RAIN THIS MORNING OR
DRIZZLE AS LONG AS THERE ARE LOW CLOUDS AROUND.
KMSP...
LOW CEILINGS WILL CONTINUE FOR WHAT REMAINS OF THE EARLY
MORNING...BUT WE HAVE HIGH CONFIDENCE IN IMPROVEMENT BY THE EARLY
AFTERNOON. ANY CLEARING LATER TODAY SHOULD BE RELATIVELY SHORT
LIVED WITH WRAP AROUND CLOUD COVER MOVING BACK IN LATE THIS
EVENING. ONLY A LITTLE BIT OF LIGHT RAIN OR DRIZZLE TODAY AND THAT
SHOULD PRIMARILY BE CONFINED TO THE MORNING. THE STEADIER LIGHT
RAIN RETURNS TOMORROW.
/OUTLOOK FOR KMSP/
SUN...MVFR OR IFR LIKELY. PERIODS OF -RA/-DZ. WINDS NW 10-15 KTS.
MON...VFR...MVFR POSSIBLE EARLY. WINDS W 5-10 KT.
TUE...VFR. WINDS S 5-10 KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
UPDATE...MPG
SHORT TERM...CLF
LONG TERM...JPC
AVIATION...CLF
AREA FORECAST DISCUSSION
NWS DULUTH MN
1030 AM CDT SAT OCT 5 2013
.UPDATE...
ISSUED AT 1029 AM CDT SAT OCT 5 2013
THE SURFACE LOW WAS LOCATED IN SOUTHEAST SOUTH DAKOTA AS OF 15Z
WITH AN OCCLUDED FRONT EXTENDING FROM THIS LOW ACROSS PORTIONS OF
S-C MINNESOTA INTO FAR SOUTHWEST WISCONSIN. 925MB BOUNDARY IS IN
NEARLY THE SAME LOCATION WITH HIGHER THETA-E AIR NORTH AND EAST OF THE
BOUNDARY. THIS FRONT MARKED A CLEARING LINE WITH DRY CONDITIONS
BEHIND IT OVER MUCH OF SOUTHERN MINNESOTA. LIGHT RAIN/DRIZZLE
CONTINUED OVER PORTIONS OF THE NORTHLAND THIS MORNING...BUT WASN`T
REAL WIDESPREAD. WE TRIMMED BACK SOME ON POPS THROUGH MID
AFTERNOON BUT MAY HAVE TO FURTHER AS SEVERAL OBSERVATIONS WERE NOT
REPORTING ANY RAIN AS OF 15Z. WE DO EXPECT AN INCREASE IN COVERAGE
LATER THIS AFTERNOON AS THE STACKED LOW PRESSURE SYSTEM MOVES
FURTHER EAST. THE LATEST HRRR WAS DOING A DECENT JOB DEPICTING THE
LIGHT RAIN THIS MORNING AND SHOWS COVERAGE INCREASING QUITE A BIT
MID TO LATE AFTERNOON ACROSS THE SOUTHERN THIRD...THEN FURTHER
NORTH THIS EVENING. THE 12Z NAM SUPPORTS THE HRRR BUT STILL MAY BE
OVERDONE WITH IT`S QPF. AREAS OF DRIZZLE WILL ALSO OCCUR AROUND
LAKE SUPERIOR. WE CONTINUE TO MONITOR RADAR TRENDS AND LATEST
MODEL OUTPUT AND ADJUST AS NEEDED.
IT REMAINS WINDY AROUND LAKE SUPERIOR...ESPECIALLY FROM SILVER BAY
TO THE TWIN PORTS AND ALONG THE BAYFIELD PENINSULA. KDLH WAS
GUSTING TO 42 MPH AS OF THE 1008 AM OBSERVATION AND TO 46 MPH ON
PARK POINT. WE`LL KEEP THE WIND ADVISORY GOING AS IS FOR NOW. WE
MAY NEED TO EXTEND IT FOR THE TWIN PORTS AREA TO TWO HARBORS/SILVER
BAY. THE WIND WASN`T AS STRONG ACROSS BAYFIELD/ASHLAND COUNTIES
BUT SOME HIGHER GUSTS WILL REMAIN POSSIBLE THERE AS WELL.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 410 AM CDT SAT OCT 5 2013
AT 4 AM...RAIN CONTINUED TO MOVE NORTHWARD ACROSS THE CWA. THE
MASSIVE LOW PRESSURE SYSTEM WAS LOCATED IN CENTRAL SOUTH
DAKOTA...WITH AN OCCLUDED FRONT STRETCHING EASTWARD THROUGH SW MN.
TEMPERATURES AT 4 AM WERE GENERALLY IN THE MID TO UPPER 40S NORTH
AND LOWER TO MIDDLE 50S SOUTH. STRONG WINDS CONTINUED NEAR LAKE
SUPERIOR...WITH KDYT AND KDLH STILL GUSTING ABOVE 40 MPH. THE RAIN
HAD DIMINISHED CONSIDERABLY ACROSS THE SOUTHERN THIRD OF THE CWA
BUT CONTINUED FROM THE TWIN PORTS NORTHWARD.
THE MAIN FOCUS FOR TODAY THROUGH SUNDAY IS THE EXTENT AND TIMING
OF VARIOUS WAVES OF PRECIPITATION. THE NAM AND THE NSSL AND NCEP
WRF RUNS SEEM TO HAVE A DECENT HANDLE ON THE SITUATION. THEY ALL
BRING A REPRIEVE IN THE RAIN TO THE SOUTHERN CWA...BEFORE
INCREASING AGAIN THIS AFTERNOON. DESPITE SOME BREAKS IN THE
PRECIPITATION...THERE SHOULD BE AREAS OF DRIZZLE AS WELL. WILL
CONTINUE WITH HIGH POPS. A LITTLE CONCERNED WE MAY NEED TO
EVENTUALLY PULL BACK ON POPS IN THE SOUTH...BUT KEPT THEM HIGH DUE
TO THE POTENTIAL FOR DRIZZLE.
RAIN SHOULD BECOME WIDESPREAD AGAIN TONIGHT...AS SURFACE LOW
PRESSURE RE-FORMS OVER WISCONSIN. FOR THAT REASON...WILL CONTINUE
WITH HIGH POPS TONIGHT...AND THEN GRADUALLY DECREASE IN PLACE AS
THE LOW STARTS TO FALL APART ON SUNDAY. WILL CONTINUE POPS
THROUGHOUT THE DAY THOUGH...AS THERE SHOULD BE SOME LINGERING
PRECIPITATION.
WILL CONTINUE WITH THE WIND ADVISORY FOR TODAY DUE TO THE STRONG
EASTERLY WINDS COMING OFF LAKE SUPERIOR.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 410 AM CDT SAT OCT 5 2013
ANOMALOUS SFC/MID LVL LOW WILL DRIFT EAST OF REGION BE EARLY MONDAY
AS SPLIT FLOW IN WESTERLIES ALLOWS NRN BRANCH TO DEEPEN OVER REGION.
PRECIP WILL GRADUALLY DIMINISH OVER THE ERN CWA AS CYCLONIC
CIRCULATION LOOSENS ITS GRIP MONDAY. MDLS AGREE THAT A RELATIVELY
QUIET DRY WEATHER PATTERN WILL COMMENCE TUESDAY AND PERSIST THROUGH
THE WEEK. SYNOPTIC PATTERN WILL FEATURE A DEVELOPING LARGE AMPLITUDE
UPPER TROF OVER CALIFORNIA WITH A BROAD UPPER RIDGE ACROSS THE NRN
PLAINS AND THE WRN GT LAKES. A SFC TROUGH WILL BEGIN TO FORM OVER
THE PLAINS AND EXTEND NORTH INTO NWRN MN BY WED EVENING. ALTHOUGH A
WARM ADVECTION REGIME WILL BECOME MORE PRONOUNCED ACROSS THE CWA AT
THIS TIME IT APPEARS THE MORE FAVORABLE LIFT WILL OCCUR TO THE WEST
OF THE REGION THROUGH THURSDAY. CONFIDENCE LOWERS BY FRIDAY AS TO
HOW FAR EAST THE EJECTING MID LVL SYSTEM WILL TRACK DUE TO
DOWNSTREAM UPPER RIDGE OVER MS RIVER VALLEY. WILL KEEP MAINLY DRY
OVER ALL OF CWA THROUGH FRIDAY BEFORE ALLOWING POPS TO RENTER THE
CWA FRIDAY NIGHT. TEMPS WILL RISE ABOVE CLIMO MOST OF THE WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 643 AM CDT SAT OCT 5 2013
INITIAL AREA OF RAIN IS PUSHING NORTH OF MOST TERMINALS WITH
REDEVELOPMENT OVER SERN MN. LOW CLOUDS WILL BE EXTENSIVE TODAY AS
MID LVL DRY SLOT MOVES OVERHEAD. CONFIDENCE ON REDEVELOPMENT OF
RAIN AT MOST TERMINALS IS LOW. SHOULD SEE SOME INCREASE IN
CEILINGS TODAY WITH BDRY LYR WARMING BUT LOWERING OVERNIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 49 44 51 41 / 80 80 60 20
INL 47 39 54 38 / 70 50 40 10
BRD 52 44 53 40 / 80 80 60 20
HYR 57 46 59 41 / 80 80 50 30
ASX 53 46 57 44 / 80 80 60 40
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WIND ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR MNZ020-037.
WI...WIND ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR WIZ001-002.
LS...GALE WARNING UNTIL 10 PM CDT THIS EVENING FOR LSZ141>147.
SMALL CRAFT ADVISORY UNTIL 4 AM CDT SUNDAY FOR LSZ121-140-148.
&&
$$
UPDATE...MELDE
SHORT TERM...DAP
LONG TERM...CANNON
AVIATION...CANNON
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
637 AM CDT SAT OCT 5 2013
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 350 AM CDT SAT OCT 5 2013
THE MSAS SHOWS THE SFC LOW NEARLY STATIONARY THIS MORNING ACROSS
SCNTL SD. THE LOW IS IN THE PROCESS OF DOING A LOOP. THIS
AFTERNOON IT WILL DRIFT EAST AT 5 MPH INTO SERN SD AND THIS IS
CONSISTENT WITH THE MOTION OF THE 500 MB LOW AT JUST 6 KT.
VERY SLOW STORM MOTIONS OF THIS TYPE...5 MPH...OFTEN PRODUCE HIGH
WIND EVENTS IN THE CNTL PLAINS. THE GFS...ECM AND RAP SHOW
SUSTAINED WINDS INCREASING TO AROUND 40 MPH ACROSS NCNTL NEB THIS
AFTERNOON WITH GUSTS TO 58 MPH IN THE RAP AND HRRR MODELS. THE
NAM KEEPS THE GUSTS BELOW 58 MPH THIS AFTN. MEANWHILE THE MET
GUIDANCE SHOWS NO HIGH WIND EVENT AT ALL WHILE THE MAV GUIDANCE
FAVORS SWRN NEB. THE MULTI LAYER WINDS IN THE RAP MODEL FROM
H850MB TO H700MB KEEP WINDS AT 60 KTS OR LESS AND THIS IS
CONSISTENT WITH A HIGH END WIND ADVISORY WITH A FEW GUSTS TO 58
MPH.
THUS THERE IS A SPLIT IN THE MODEL DATA. A HIGH END WIND ADVISORY
EVENT WOULD APPEAR TO BE THE MOST LIKELY SOLN INDICATED BY THE
MODELS BUT LOCAL STUDIES SUGGEST A HIGH WIND EVENT WOULD UNFOLD
THIS AFTERNOON. A WIND ADVISORY WILL CONTINUE TODAY ACROSS ALL
AREAS EXCEPT WHERE THE WINTER STORM WARNING IS IN EFFECT.
WINTER STORM CONDITIONS ARE LIKELY ONGOING ACROSS NRN SHERIDAN
AND WRN CHERRY COUNTIES THIS MORNING. THE RADAR MAY BE
OVERSHOOTING THE DENDRITIC LAYER. THE ELLSWORTH NEDOR CAM IS
QUIET WHILE THE RUSHVILLE CAM CONTINUES TO SHOW SNOW AND BLOWING
SNOW WITH VISIBILITY AROUND 2 MILES OR SO. THE 08Z KIEN OB SHOWS
1/2 MILE VISIBILITY WITH A VERTICAL VISIBILITY OF JUST 500 FEET.
THE REST OF THE NEDOR CAMS ARE DARK SO WE WILL HAVE TO WAIT FOR
SUNRISE TO GET A BETTER ANALYSIS OF THE SITUATION ACROSS NW NEB.
THE WINTER STORM WARNING WILL CONTINUE UNTIL 18Z AS FORECAST.
GIVEN THE UPPER LOW HAS STALLED ACROSS THE CNTL PLAINS...THE
MODEL CONSENSUS SHOWS WRAPAROUND RAIN AND SNOW TODAY THROUGH
SUNDAY MORNING. THE UPPER LEVEL LOW IS EXPECTED TO CONTINUE
MOVING SLOWLY EAST SOUTHEAST INTO SRN IOWA BY LATE SUNDAY
AFTERNOON. A MULTI MODEL CONSENSUS WAS USED FOR POPS TONIGHT AND
SUNDAY. THE RAP MODEL WAS USED EXCLUSIVELY FOR THE TODAY PERIOD.
NONE OF THE MODELS ARE SHOWING VERY HEAVY QPF AND SNOW TOTALS OF
2 INCHES OR LESS ARE EXPECTED BASED ON THAT OUTPUT. THERE IS SOME
UNCERTAINTY WITH THIS FORECAST AS THE 850 MB MOISTURE TRANSPORT
IS STILL QUITE STRONG ACROSS THE NRN PLAINS AND OCCASIONAL
LIGHTNING STRIKES ARE STILL SHOWING UP AT 08Z. THE NAM WHICH
APPEARS TO HAVE THE BEST HANDLE THE MASSIVE QPF ASSOCIATED WITH
THIS STORM GENERALLY KEEPS QPF LESS THAN 0.10 INCHES IN ANY 3
HOUR PERIOD ACROSS NRN NEB.
OTHERWISE...HIGHS TODAY RISE INTO THE 30S AND 40S ACCORDING TO A
BLEND OF BIAS CORRECTED AND DETERMINISTIC DATA. THE MODELS ARE
FORECASTING LOWS IN THE MID 20S TONIGHT ACROSS THE SNOW FIELD
ACROSS NWRN NEB WITH LOWER 30S ELSEWHERE. IF THE WRN HALF OF THE
FORECAST AREA CLEARS OUT TONIGHT AS INDICATED IN THE MODELS THEN
THESE LOWS COULD BE 5 OR MORE DEGREES COLDER. HIGHS SUNDAY RISE
INTO THE 40S ACROSS THE SNOW COVERED NORTHWEST WITH 50S AND 60S
ELSEWHERE.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 350 AM CDT SAT OCT 5 2013
BY SUNDAY NIGHT THE LOW PRESSURE SYSTEM WILL HAVE PUSHED TOWARDS
THE MID MISS RVR VALLEY AND THE WRAP AROUND MOISTURE WILL HAVE
SHIFTED INTO EASTERN NEB. MEANWHILE AN UPPER LEVEL RIDGE WILL
BUILD ACROSS THE WEST...AS THE NEXT TROUGH PUSHES ACROSS
NORTHEASTERN PACIFIC OCEAN.
MONDAY THROUGH THURSDAY THE PACIFIC TROUGH WILL DIG TOWARDS THE
DESERT SOUTHWEST WHILE THE UPPER RIDGE SHIFTS EAST ACROSS THE
PLAINS. AT THE SFC HIGH PRESSURE WILL DOMINATE THE PLAINS THROUGH
MUCH OF THE WEEK. THUS EXPECT MILD CONDITIONS WITH 70S AND A FEW
MID/UPPER 60S ACROSS THE NW ZONES WHERE SOME INFLUENCE FROM THE
HEAVY SNOW PACK IS LIKELY TO LIMIT THE HEATING. ONCE THE SNOW
MELTS...COULD SEE MORE WIDESPREAD HIGHS INTO THE 70S ACROSS THE
NW. WITH THE WARM AIR MASS...EXPECT SEASONALLY WARM
LOWS...GENERALLY IN THE 40S SPOTTED WITH A FEW UPPER 30S.
LATE THURSDAY INTO FRIDAY THE LOW OVER THE SW WILL BEGIN TO EJECT
ONTO THE NORTHERN PLAINS. MODELS IN FAIR AGREEMENT...CONSIDERING
6/7 DAYS OUT...WITH A TRACK OF THE UPPER LOW ACROSS THE CENTRAL
ROCKIES AND INTO S DAKOTA. THE MODELS CONTINUE TO TRACK THE LOW TO
THE NE...INTO CANADA OVER THE WEEKEND. AS THE LOW PUSHES ONTO THE
ROCKIES...GOOD MOISTURE TRANSPORT WITH S WINDS EXPECTED ACROSS THE
AREA. POPS ARE NEEDED FOR THURSDAY INTO FRIDAY...HOWEVER PENDING
THE TRACK AND THE DRY SLOT...CONCERNED AMOUNTS MAY NOT AMOUNT TO
TOO MUCH OVER PART OF THE CWA. THUS WILL HOLD POPS IN THE SLIGHT
CHANCE AND LOWER CHANCE CATEGORY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 637 AM CDT SAT OCT 5 2013
STRONG TO PERHAPS HIGH WIND CONDITION TODAY WITH WINDS OPERATING
AT 31032G45KT. GIVEN THE STORM MOTION OF JUST 6 KTS INDICATED BY
THE RAP MODEL...STRONGER WINDS COULD DEVELOP.
IFR/MVFR IN SNOW AND LOW CIGS SHOULD GRADUALLY DRIFT EAST OF
HIGHWAY 83 LATE TONIGHT. THIS AREA OF CLOUDS WILL ALSO DRIFT EAST
AT 6 KTS. THE AREA AFFECTED WILL BE MOSTLY ALONG AND NORTH OF
NEBRASKA HIGHWAY 2.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 7 PM CDT /6 PM MDT/ THIS EVENING FOR NEZ008-
022>027-035>038-056>059-069>071.
WINTER WEATHER ADVISORY UNTIL 1 PM CDT THIS AFTERNOON FOR NEZ005.
WINTER STORM WARNING UNTIL NOON MDT TODAY FOR NEZ004-094.
WIND ADVISORY FROM 10 AM THIS MORNING TO 7 PM CDT THIS EVENING
FOR NEZ006-007-009-010-028-029.
&&
$$
LONG TERM...MASEK
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1155 AM EDT SAT OCT 5 2013
.SYNOPSIS...
A STATIONARY FRONT WILL REMAIN OVER THE REGION THROUGH TONIGHT
THEN LIFT NORTH AS A WARM FRONT ON SUNDAY. THIS WILL KEEP OUR
WEATHER UNSETTLED THROUGH THE WEEKEND WITH SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS, PRIMARILY DURING THE DAYLIGHT HOURS.
&&
.NEAR TERM /THROUGH TONIGHT/...
1155 AM UPDATE...CURRENT SFC ANALYSIS SHOWS STATIONARY FRONT
SLIGHTLY FURTHER SOUTH THEN YESTERDAY. ATTM IT STRETCHES ACROSS
THE SOUTHERN TIER OF NYS THEN DROPS SOUTHEAST INTO THE POCONOS.
CONVECTION OVER THE NRN FINGER LAKES REGION HAS ALMOST DISSIPATED
AS IT ENCOUNTERED A FAIRLY STABLE AIRMASS WELL NORTH OF THE
BOUNDARY. SATELLITE SHOWS STRATUS BEGINNING TO MIX OUT OVER NE PA
AND THE SOUTHERN TIER. THESE LOCATIONS WILL SEE SOME SUNNY BREAKS
THIS AFTERNOON WITH THE WYOMING VALLEY LIKELY TO SEE THE MOST
SUNSHINE. MODELS CONTINUE TO SUGGEST A WEAK SHORT WAVE WILL MOVE
ALONG THE BOUNDARY LATER THIS AFTERNOON AND INTO THE EARLY EVENING.
CURRENT POPS LOOK REASONABLE WITH ONLY MINOR ADJUSTMENTS. ISOLATED
THUNDER IS STILL POSSIBLE LATER TODAY ALONG AND SOUTH OF THE SFC
FEATURE.
915 AM UPDATE...LOCAL RADAR SHOWS A CLUSTER OF SHOWERS WITH
EMBEDDED ISOLATED THUNDER MOVING INTO THE FINGER LAKES REGION.
BASED ON CURRENT MOVEMENT AND HRRR OUTPUT THIS CLUSTER WILL MOVE
ACROSS THE FINGER LAKES REGION AND INTO THE NRN CWA THROUGH LATE
MORNING. INCREASED POPS IN THE ABOVE MENTIONED AREAS AND INCLUDED
ISOLATED T EXCEPT FAR NRN CWA WHERE MODEL SOUNDINGS INDICATE NO
INSTABILITY. REST OF FORECAST IN GOOD SHAPE.
620 AM UPDATE...
TEMPS HV STAYED UP IN THE 60S UNDER EXTENSIVE STRATUS AND FOG
DECK. EXPECT PATCHY DENSE FOG WL CONTINUE THRU 14Z ALONG WITH
ISOLD SHOWERS WITH STATIONARY FRONT LURKING ACRS THE AREA. AREA OF
SHOWERS MVG INTO NIAGARA FRONTIER AHD OF S/WV MAY MV INTO WRN
CNTYS TWD 12Z. KEPT SLGT CHC POPS IN ALL NIGHT FOR CNTRL CNTYS AND
EXPECT POPS TO INCRS IN CVRG ACRS TWIN TIERS TWD LATE MRNG. THUS
NO CHGS NEEDED AT THIS TIME OTHER THAN T/TD GRIDS TO COME MORE
INTO LINE WITH REALITY.
PREV DISCUSSION BLO...
330 AM UPDATE...
WMFNT IS CURRENTLY STRETCHED FM SFC LOW NR PIERRE SD ALONG THE I-90
CORRIDOR TO BTWN KBUF AND KERI AND ALONG NY/PA BORDER. DO NOT EXPECT
MUCH IN THE WAY OF MVMNT TDA AS 1028MB HIPRES RMNS LOCKED ACRS ERN
CANADA AND CLOSED LOW JUST CREEPS ALONG, ROUGHLY 100 MILES IN 12
HRS, AS IT WAITS FOR AN UPSTREAM KICKER.
AS FOR TDA`S FCST EXPECT ISOLD/SCTD CONVECTION AS WMFNT RMNS OVR
AREA. ISOLD SHOWERS EXPECTED UNTIL ABOUT NOON TDA AS ANY EMBEDDED
S/WVS MAY KICK SOMETHING OFF WITH FRONTAL BNDRY IN AREA. HWVR AFT
ABOUT 16Z INSTABILITY LOOKS TO NOSE INTO REGION MAINLY ALONG BNDRY
WITH CAPES BTWN 200-400 J/KG AND K-INDICES APPCHG 35. EXPECT
CONVECTION AFT THIS TIME ACRS THE SRN TIER/SUSQ REGION, THEN SOUTH
INTO NEPA AFT 18Z. NRN CNTYS EXPECTED TO BE SOCKED IN WITH LOCLDS
ALL DAY NORTH OF THE BNDRY SIMILAR TO YDA. THUS HV NOT ADDED ANY
THUNDER INTO ZONES ALONG AND NORTH OF THE NY THRUWAY AT THIS TIME.
SKIES EXPECTED TO RMN CLDY ACRS NRN AREAS WITH SOME SUN POSSIBLY
BREAKING OUT BRIEFLY ACRS THE SOUTH. EXPECT AFTN MAXES SIMILAR TO
YDA WITH HIGHS ARND 80 ACRS WRN AND SRN ZONES AND ONLY INTO THE 60S
OVR NE CNTYS.
FNT WL BEGIN LIFTING NORTH SAT NGT AS HIPRES BUILDS INTO THE
CANADIAN MARITIMES AND SRLY WINDS INCRS. EXPECT SLGT/CHC SHOWERS
THRU THE OVRNGT ACRS CWA, INCRSG TO LKLY TWD SUN MRNG ACRS NRN ZONES
AS EJECTING WV FM UPSTREAM CLOSED LOW RIDES ALONG FRONTAL BNDRY AND
INITIATES CONVECTION.
OVRNGT LOWS FOR SUN MRNG WL LKLY RMN ARND NRML VALUES (L/M 60S) FOR
HIGHS THIS TIME OF YR, NOT EVEN CLOSE TO NORMAL LOWS.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
330 AM UPDATE...
CWA WL BE IN WM SECTOR ON SUNDAY WITH SCTD CONVECTION EXPECTED OFF
AND ON THROUGHOUT THE DAY AS ANY SUBTLE WVS THAT CAN MV THRU WL
GENERATE CHCS FOR SHRA/TSRA. FOR NOW, HV NOT MADE MANY CHGS DUE TO
UNSETTLED PATTERN AND DIFFICULTY RESOLVING ANY TRIGGERS.
AREA RMNS IN WARM SECTOR ON SUN NGT AND CAN EXPECT JUST CHC SHOWERS
THRU 12Z MON SO HV DROPPED POPS TO JUST 30% AT THIS TIME FOR THE PD.
WARM AND HUMID CONDS WL CONT THRU MON MRNG WITH TEMPS AND TDS IN THE
U50S/L60S.
MOISTURE FM TROPICAL STORM KAREN PROGGED BY GFS TO WORK UP INTO AREA
MON NGT. HWVR, THIS WL ALL DEPEND ON HOW MUCH H5 SYSTEM SLOWS DOWN
AND IF FRONTAL BNDRY CAN HOLD OFF ENUF TO BRING MOISTURE INTO AREA.
AS OF NOW WITH PW VALUES INCRSG TO BTWN 1.5 AND 1.75 INCHES ON MON
NGT EXPECTED 12-HR QPF VALUES FM HPC WL AVG ARND 1 INCH THRU THE END
OF THE SHORT TERM. FROPA LOOKS TO HV SLOWED DOWN ENUF TO OCCUR AT
THE VRY TAIL END OF THE SHORT TERM.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
345 AM UPDATE...
MED RNG GRIDS UPDATED WITH 00Z WPC GDNC (BLENDED WITH SOME GFS/MOS
DATA) TO REFLECT A SLOWER MVMNT OF THE UPR LOW...WITH AN EXTENSION OF
CHC POPS INTO MID WEEK AND MORE IN THE WAY OF CLDS DUE TO THIS
SYSTEM. PREV BLO...
2 PM UPDATE...
MAIN INTEREST IN THE LONG TERM FORECAST WILL BE THE POTENTIAL FOR
HEAVY RAIN MONDAY NIGHT. THE MAIN WEATHER PLAYERS WILL BE AN UPPER
LEVEL LOW NOW OVER SE WYOMING...AND ASSOCIATED COLD FRONT OVER THE
CENTRAL PLAINS. AS THESE FEATURES MOVE EAST THE SOUTHERLY FLOW OF
AIR AHEAD OF THEM WILL TRANSPORT MOISTURE...SOME OF IT WILL BE
WHATS LEFT OF TS KAREN...NORTHWARD INTO OUR AREA. WITH HIGH
VARIANCE IN THE MODELS JUST 24 HOURS AGO...THE 12Z NAM AND GFS ARE
FAIRLY SIMILAR IN SHOWING AN AREA OF STEADY RAIN ALONG AND AHEAD
OF THE COLD FRONT MOVING INTO OUR AREA MONDAY EVENING. BOTH THE
GFS AND WPC GUIDANCE SHOW A GENERAL 1" TO 2" RAIN ACROSS THE AREA
MONDAY NIGHT...WITH ISOLATED HIGHER AMOUNTS POSSIBLE. WITH OUR
RECENT STRETCH OF DRY WEATHER AND THE PROGRESSIVE NATURE OF THE
FRONT (RAIN FALLING IN 12 HOURS OR LESS)...WIDESPREAD PROBLEMS ARE
NOT EXPECTED AT THIS EARLY JUNCTURE. IN FACT FOR MOST THIS WILL BE
A WELCOME BENEFICIAL FALL RAIN.
LATER TUESDAY AND BEYOND...THE GFS IS NOW THE SLOWEST WITH THE
UPPER LEVEL LOW MOVING OVER OUR AREA AND KEEPING US
CLOUDY/UNSETTLED FOR ONE MORE DAY. WILL LEAN WITH WPC GUIDANCE
DRYING US OUT BY TUESDAY NIGHT. HIGH PRESSURE CONTROLS THE REST OF
THE PERIOD WITH QUIET WEATHER EXPECTED.
&&
.AVIATION /16Z SATURDAY THROUGH WEDNESDAY/...
FNTL BNDRY DRAPED OVER THE TWIN TIERS/NRN PA WITH LIFR/IFR TO THE N
OF THE FNT. PROFILES SUGGEST THESE CONDITIONS TO CONTINUE THRU THE
MID MRNG HRS...WITH ITH/ELM/BGM/SYR/AVP BLO ALT MINS AND BRIEFLY
LIKELY BLO AIRPORT MINS THRU 14Z. COULD SEE SCT -SHRA THIS MRNG
14-16Z AT SYR/RME IF ACTIVITY OVER WRN NY HOLDS TOGETHER. XPCT CIGS TO SLOWLY
LIFT LATE THIS MRNG/AFTN TO MVFR MOST SITES. CHCS FOR SHRA APPEAR
TO BE GREATEST THIS AFTN NEAR THE FNT AND INCLUDED TEMPOS FOR
SHRA AT ITH/ELM/BGM/AVP THIS AFTN. POTNL FOR TSRA ACRS SRN SITES
WHICH MAY BE ADDED WITH LATER FCST UPDATES. TNGT...MVFR XPCTD TO
PREVAIL THRU 06Z...WITH POTNL FOR MVFR/IFR MAINLY AFTER 06Z AS -SHRA
MOV BACK IN. WINDS ON THE LGT SIDE AND RATHER VRBL...MAINLY FROM A
NORTHERLY DIRECTION ACRS CNTRL NY...BECMG ERLY OR SELY TNGT.
OUTLOOK...
SATURDAY NIGHT THROUGH WEDNESDAY...AN UNSETTLED PERIOD...WITH SCATTERED
TO WIDESPREAD SHOWERS ANTICIPATED...ALG WITH THE LIKELIHOOD OF
RESTRICTIVE CONDS FROM TIME TO TIME.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...PVN
NEAR TERM...PVN/RRM
SHORT TERM...PVN
LONG TERM...
AVIATION...
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
922 AM EDT SAT OCT 5 2013
.SYNOPSIS...
A STATIONARY FRONT WILL REMAIN OVER THE REGION THROUGH TONIGHT
THEN LIFT NORTH AS A WARM FRONT ON SUNDAY. THIS WILL KEEP OUR
WEATHER UNSETTLED THROUGH THE WEEKEND WITH SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS, PRIMARILY DURING THE DAYLIGHT HOURS.
&&
.NEAR TERM /THROUGH TONIGHT/...
915 AM UPDATE...LOCAL RADAR SHOWS A CLUSTER OF SHOWERS WITH
EMBEDDED ISOLATED THUNDER MOVING INTO THE FINGER LAKES REGION.
BASED ON CURRENT MOVEMENT AND HRRR OUTPUT THIS CLUSTER WILL MOVE
ACROSS THE FINGER LAKES REGION AND INTO THE NRN CWA THROUGH LATE
MORNING. INCREASED POPS IN THE ABOVE MENTIONED AREAS AND INCLUDED
ISOLATED T EXCEPT FAR NRN CWA WHERE MODEL SOUNDINGS INDICATE NO
INSTABILITY. REST OF FORECAST IN GOOD SHAPE.
620 AM UPDATE...
TEMPS HV STAYED UP IN THE 60S UNDER EXTENSIVE STRATUS AND FOG
DECK. EXPECT PATCHY DENSE FOG WL CONTINUE THRU 14Z ALONG WITH
ISOLD SHOWERS WITH STATIONARY FRONT LURKING ACRS THE AREA. AREA OF
SHOWERS MVG INTO NIAGARA FRONTIER AHD OF S/WV MAY MV INTO WRN
CNTYS TWD 12Z. KEPT SLGT CHC POPS IN ALL NIGHT FOR CNTRL CNTYS AND
EXPECT POPS TO INCRS IN CVRG ACRS TWIN TIERS TWD LATE MRNG. THUS
NO CHGS NEEDED AT THIS TIME OTHER THAN T/TD GRIDS TO COME MORE
INTO LINE WITH REALITY.
PREV DISCUSSION BLO...
330 AM UPDATE...
WMFNT IS CURRENTLY STRETCHED FM SFC LOW NR PIERRE SD ALONG THE I-90
CORRIDOR TO BTWN KBUF AND KERI AND ALONG NY/PA BORDER. DO NOT EXPECT
MUCH IN THE WAY OF MVMNT TDA AS 1028MB HIPRES RMNS LOCKED ACRS ERN
CANADA AND CLOSED LOW JUST CREEPS ALONG, ROUGHLY 100 MILES IN 12
HRS, AS IT WAITS FOR AN UPSTREAM KICKER.
AS FOR TDA`S FCST EXPECT ISOLD/SCTD CONVECTION AS WMFNT RMNS OVR
AREA. ISOLD SHOWERS EXPECTED UNTIL ABOUT NOON TDA AS ANY EMBEDDED
S/WVS MAY KICK SOMETHING OFF WITH FRONTAL BNDRY IN AREA. HWVR AFT
ABOUT 16Z INSTABILITY LOOKS TO NOSE INTO REGION MAINLY ALONG BNDRY
WITH CAPES BTWN 200-400 J/KG AND K-INDICES APPCHG 35. EXPECT
CONVECTION AFT THIS TIME ACRS THE SRN TIER/SUSQ REGION, THEN SOUTH
INTO NEPA AFT 18Z. NRN CNTYS EXPECTED TO BE SOCKED IN WITH LOCLDS
ALL DAY NORTH OF THE BNDRY SIMILAR TO YDA. THUS HV NOT ADDED ANY
THUNDER INTO ZONES ALONG AND NORTH OF THE NY THRUWAY AT THIS TIME.
SKIES EXPECTED TO RMN CLDY ACRS NRN AREAS WITH SOME SUN POSSIBLY
BREAKING OUT BRIEFLY ACRS THE SOUTH. EXPECT AFTN MAXES SIMILAR TO
YDA WITH HIGHS ARND 80 ACRS WRN AND SRN ZONES AND ONLY INTO THE 60S
OVR NE CNTYS.
FNT WL BEGIN LIFTING NORTH SAT NGT AS HIPRES BUILDS INTO THE
CANADIAN MARITIMES AND SRLY WINDS INCRS. EXPECT SLGT/CHC SHOWERS
THRU THE OVRNGT ACRS CWA, INCRSG TO LKLY TWD SUN MRNG ACRS NRN ZONES
AS EJECTING WV FM UPSTREAM CLOSED LOW RIDES ALONG FRONTAL BNDRY AND
INITIATES CONVECTION.
OVRNGT LOWS FOR SUN MRNG WL LKLY RMN ARND NRML VALUES (L/M 60S) FOR
HIGHS THIS TIME OF YR, NOT EVEN CLOSE TO NORMAL LOWS.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
330 AM UPDATE...
CWA WL BE IN WM SECTOR ON SUNDAY WITH SCTD CONVECTION EXPECTED OFF
AND ON THROUGHOUT THE DAY AS ANY SUBTLE WVS THAT CAN MV THRU WL
GENERATE CHCS FOR SHRA/TSRA. FOR NOW, HV NOT MADE MANY CHGS DUE TO
UNSETTLED PATTERN AND DIFFICULTY RESOLVING ANY TRIGGERS.
AREA RMNS IN WARM SECTOR ON SUN NGT AND CAN EXPECT JUST CHC SHOWERS
THRU 12Z MON SO HV DROPPED POPS TO JUST 30% AT THIS TIME FOR THE PD.
WARM AND HUMID CONDS WL CONT THRU MON MRNG WITH TEMPS AND TDS IN THE
U50S/L60S.
MOISTURE FM TROPICAL STORM KAREN PROGGED BY GFS TO WORK UP INTO AREA
MON NGT. HWVR, THIS WL ALL DEPEND ON HOW MUCH H5 SYSTEM SLOWS DOWN
AND IF FRONTAL BNDRY CAN HOLD OFF ENUF TO BRING MOISTURE INTO AREA.
AS OF NOW WITH PW VALUES INCRSG TO BTWN 1.5 AND 1.75 INCHES ON MON
NGT EXPECTED 12-HR QPF VALUES FM HPC WL AVG ARND 1 INCH THRU THE END
OF THE SHORT TERM. FROPA LOOKS TO HV SLOWED DOWN ENUF TO OCCUR AT
THE VRY TAIL END OF THE SHORT TERM.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
345 AM UPDATE...
MED RNG GRIDS UPDATED WITH 00Z WPC GDNC (BLENDED WITH SOME GFS/MOS
DATA) TO REFLECT A SLOWER MVMNT OF THE UPR LOW...WITH AN EXTENSION OF
CHC POPS INTO MID WEEK AND MORE IN THE WAY OF CLDS DUE TO THIS
SYSTEM. PREV BLO...
2 PM UPDATE...
MAIN INTEREST IN THE LONG TERM FORECAST WILL BE THE POTENTIAL FOR
HEAVY RAIN MONDAY NIGHT. THE MAIN WEATHER PLAYERS WILL BE AN UPPER
LEVEL LOW NOW OVER SE WYOMING...AND ASSOCIATED COLD FRONT OVER THE
CENTRAL PLAINS. AS THESE FEATURES MOVE EAST THE SOUTHERLY FLOW OF
AIR AHEAD OF THEM WILL TRANSPORT MOISTURE...SOME OF IT WILL BE
WHATS LEFT OF TS KAREN...NORTHWARD INTO OUR AREA. WITH HIGH
VARIANCE IN THE MODELS JUST 24 HOURS AGO...THE 12Z NAM AND GFS ARE
FAIRLY SIMILAR IN SHOWING AN AREA OF STEADY RAIN ALONG AND AHEAD
OF THE COLD FRONT MOVING INTO OUR AREA MONDAY EVENING. BOTH THE
GFS AND WPC GUIDANCE SHOW A GENERAL 1" TO 2" RAIN ACROSS THE AREA
MONDAY NIGHT...WITH ISOLATED HIGHER AMOUNTS POSSIBLE. WITH OUR
RECENT STRETCH OF DRY WEATHER AND THE PROGRESSIVE NATURE OF THE
FRONT (RAIN FALLING IN 12 HOURS OR LESS)...WIDESPREAD PROBLEMS ARE
NOT EXPECTED AT THIS EARLY JUNCTURE. IN FACT FOR MOST THIS WILL BE
A WELCOME BENEFICIAL FALL RAIN.
LATER TUESDAY AND BEYOND...THE GFS IS NOW THE SLOWEST WITH THE
UPPER LEVEL LOW MOVING OVER OUR AREA AND KEEPING US
CLOUDY/UNSETTLED FOR ONE MORE DAY. WILL LEAN WITH WPC GUIDANCE
DRYING US OUT BY TUESDAY NIGHT. HIGH PRESSURE CONTROLS THE REST OF
THE PERIOD WITH QUIET WEATHER EXPECTED.
&&
.AVIATION /13Z SATURDAY THROUGH WEDNESDAY/...
FNTL BNDRY DRAPED OVER THE TWIN TIERS/NRN PA WITH LIFR/IFR TO THE N
OF THE FNT. PROFILES SUGGEST THESE CONDITIONS TO CONTINUE THRU THE
MID MRNG HRS...WITH ITH/ELM/BGM/SYR/AVP BLO ALT MINS AND BRIEFLY
LIKELY BLO AIRPORT MINS THRU 14Z. COULD SEE SCT -SHRA THIS MRNG
14-16Z AT SYR/RME IF ACTIVITY OVER WRN NY HOLDS TOGETHER. XPCT CIGS TO SLOWLY
LIFT LATE THIS MRNG/AFTN TO MVFR MOST SITES. CHCS FOR SHRA APPEAR
TO BE GREATEST THIS AFTN NEAR THE FNT AND INCLUDED TEMPOS FOR
SHRA AT ITH/ELM/BGM/AVP THIS AFTN. POTNL FOR TSRA ACRS SRN SITES
WHICH MAY BE ADDED WITH LATER FCST UPDATES. TNGT...MVFR XPCTD TO
PREVAIL THRU 06Z...WITH POTNL FOR MVFR/IFR MAINLY AFTER 06Z AS -SHRA
MOV BACK IN. WINDS ON THE LGT SIDE AND RATHER VRBL...MAINLY FROM A
NORTHERLY DIRECTION ACRS CNTRL NY...BECMG ERLY OR SELY TNGT.
OUTLOOK...
SATURDAY NIGHT THROUGH WEDNESDAY...AN UNSETTLED PERIOD...WITH SCATTERED
TO WIDESPREAD SHOWERS ANTICIPATED...ALG WITH THE LIKELIHOOD OF
RESTRICTIVE CONDS FROM TIME TO TIME.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...PVN
NEAR TERM...PVN/RRM
SHORT TERM...PVN
LONG TERM...
AVIATION...
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1000 AM EDT SAT OCT 5 2013
.SYNOPSIS...
HIGH PRESSURE OVER THE REGION WILL MOVE SLOWLY EAST OFFSHORE THE
CAROLINA COAST TONIGHT AND SUNDAY. A COLD FRONT WILL APPROACH THE
MOUNTAINS FROM THE WEST SUNDAY NIGHT...THEN TRACK EASTWARD THROUGH
THE CAROLINAS ON MONDAY.
&&
.NEAR TERM /TODAY AND TONIGHT/...
AS OF 1000 AM SATURDAY...
SURFACE RIDGE REMAINS IN PLACE OVER CENTRAL NORTH CAROLINA...AND
THE MORNING UPPER-AIR ANALYSIS SHOWED THE RIDGE AXIS ALOFT JUST TO
OUR WEST. MORNING AMDAR SOUNDINGS AS WELL AS THE SOUNDING FROM KGSO
NOTED WARMING ALOFT AROUND 600MB OVER THE LAST 24 HOURS...
REPRESENTING STRONG CAPPING. THE LATEST RAP SHOWS THE RIDGE ALOFT
BUILDING EAST OVERHEAD DURING THE AFTERNOON...WITH GOOD SUBSIDENCE
AND LITTLE OR NO MIXED-LAYER CAPE IN THE LOWEST KM. MORNING
SOUNDINGS AND THE KRAX VAD WIND PROFILE NOTED A FAIRLY DEEP...BUT
LIGHT...NORTHERLY COMPONENT TO THE WIND WHICH SHOULD VEER DURING THE
DAY BASED ON THE LATEST RAP AND MOS GUIDANCE. MAIN CHANGES...ALL
MINOR...TO THE FORECAST FOR THE AFTERNOON WERE TO MODIFY THE
DIRECTION OF THE LIGHT WIND INTO THE MID-AFTERNOON HOURS...AND NOTE
JUST A FEW MORE CLOUDS WITH SOME MOSTLY THIN CIRRUS WORKING ITS WAY
EAST OF THE RIDGE AXIS ALOFT. 1000-850MB THICKNESSES FROM THE KGSO
12Z SOUNDING COMBINED WITH THE FORECAST MAXIMUM VALUE OF THAT
PARAMETER THIS AFTERNOON GIVES MAXES IN LINE WITH THE FORECAST.
LOWS TONIGHT WILL BE SIMILAR TO THIS MORNING...IN THE LOWER/MID
60S...COOLEST IN RURAL AND LOW-LYING AREAS. EXPECT AREAS OF FOG
AGAIN TONIGHT UNDER A MAINLY CLEAR SKY...LIGHT WIND...AND SURFACE
DEW POINTS LATE AT NIGHT 60 TO 65.
&&
.SHORT TERM /SUNDAY AND SUNDAY NIGHT/...
AS OF 345 AM SATURDAY...
AN IMPRESSIVE UPPER LEVEL LOW CENTERED OVER THE UPPER MIDWEST THIS
MORNING WILL TRACK INTO THE CENTRAL MS RIVER VALLEY SUN INTO SUN
NIGHT...WHILE ADDITIONAL SHORTWAVE ENERGY (OVER THE 4-CORNERS REGION
THIS MORNING) DIGS SOUTHEAST THROUGH THE LOWER MIDWEST INTO THE
LOWER MS RIVER VALLEY ALONG THE SOUTHERN PERIPHERY OF THE UPPER LOW.
ADDITIONALLY...TROPICAL CYCLONE KAREN IS EXPECTED TO TRACK SLOWLY
NORTH TOWARD THE GULF COAST ON SUN...MOVING ASHORE SOMEWHERE IN THE
DEEP SOUTH SUN NIGHT. IN THE LOWER LEVELS...A COLD FRONT ASSOC/W AN
OCCLUDED SFC LOW ATTENDANT THE UPPER LEVEL LOW WILL TRACK EAST INTO
THE TN/OH VALLEY ON SUN...APPROACHING THE SOUTHERN APPALACHIANS SUN
NIGHT.
PER THE 00Z GUIDANCE...SOUTHERLY RETURN FLOW AND LOW-LEVEL WARM
ADVECTION WILL NOT SIGNIFICANTLY STRENGTHEN UNTIL SUN NIGHT...AND
THE AIRMASS ON SUNDAY IS EXPECTED TO BE VERY SIMILAR TO TODAY WITH A
PRONOUNCED MID-LEVEL CAP AND MEAGER DIURNAL DESTABILIZATION (AT
BEST). FORCING FOR ASCENT WILL LARGELY BE ABSENT OVER CENTRAL
NC...CONFINED TO THE SEABREEZE OVER THE COASTAL CAROLINAS AND SMALL
AMPLITUDE DISTURBANCES IN STRENGTHENING SW FLOW ALOFT OVER FAR
WESTERN PORTIONS OF THE STATE DURING THE AFT/EVE. AS A RESULT...WILL
CONTINUE TO INDICATE A DRY FCST ON SUN. A RAPID INCREASE IN
LOW-LEVEL MOISTURE ASSOC/W STRENGTHENING SOUTHERLY FLOW WILL OCCUR
SUN NIGHT AND MON MORNING...WITH ASCENT INCREASING IN THE FORM OF
LOW-LEVEL WARM ADVECTION AND DPVA ASSOC/W SMALL AMPLITUDE
DISTURBANCES IN SW FLOW ALOFT. ALL OF THE 00Z GUIDANCE INDICATES
MEASURABLE PRECIP IN THE WESTERN PIEDMONT BY 12Z MON...AND THIS
SEEMS CONSISTENT WITH THE AFOREMENTIONED DISCUSSION. WILL INDICATE
PRECIP CHANCES INCREASING FROM THE WEST AFTER MIDNIGHT...RANGING
FROM 60-80% IN THE FAR WESTERN PIEDMONT TO ~20% ALONG THE I-95
CORRIDOR. EAST OF I-95...FORCING FOR ASCENT WILL BE MUCH WEAKER AND
PRECIP CHANCES WILL LARGELY BE TIED TO SHOWER ACTIVITY MOVING INLAND
FROM THE ATLANTIC IN ASSOC/W ONSHORE FLOW. AS A RESULT...WILL
INDICATE A DRY FCST IN THE FAR NE COASTAL PLAIN WITH A SLIGHT CHANCE
SOUTH OF HWY 64 IN THE SE COASTAL PLAIN.
THICKNESSES WILL BE SLIGHTLY LOWER (PERHAPS 5-10M) THAN TODAY.
THIS...ALONG WITH INCREASING CLOUD COVER DURING THE AFTERNOON SHOULD
RESULT IN HIGHS A FEW DEGREES COOLER THAN TODAY IN THE MID 80S
(84-88F)...COOLEST IN THE WESTERN PIEDMONT. LOWS SUN NIGHT WILL BE
TEMPERED BY CLOUD COVER AND A LIGHT SOUTHERLY BREEZE...IN THE UPPER
60S TO NEAR 70F IN THE SOUTH. -VINCENT
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 300 AM SATURDAY...
THE LATEST INFORMATION FROM THE NHC CONCERNING "KAREN" CONTINUES TO
DOWNGRADE THE TROPICAL SYSTEM. IT HAS BEEN DESCRIBED AS ALREADY
BEING `DECAPITATED" BY ONE FORECASTER - DUE TO STRONGER WINDS ALOFT.
THEREFORE... THE CONFIDENCE OF WHETHER ANY REMNANTS OF `KAREN" WILL
BE LEFT TO BRING INDIRECT IMPACTS (RAIN, SEVERE THREAT) FOR CENTRAL
NC BY EARLY NEXT WEEK HAS LOWERED.
ON A MORE CONFIDENT NOTE... A MID/UPPER LEVEL TROUGH IS FORECAST TO
BE APPROACHING THE APPALACHIANS MONDAY... THEN SWING ACROSS OUR
REGION TUE AND TUE NIGHT. THE MAIN UPPER DYNAMICS ARE FORECAST TO
PUSH FROM THE MIDWEST TO THE GREAT LAKES. HOWEVER... MOISTURE IS
EXPECTED TO SURGE NORTHWARD ALONG THE EASTERN SEABOARD BRINGING
WIDESPREAD SHOWERS AND ISOLATED THUNDERSTORMS ALONG THE COLD FRONT.
IF THE REMNANT LOW PRESSURE OF `KAREN` TRACKS NE INTO NC AS SOME OF
THE MODELS STILL SUGGEST... THERE CAN STILL BE ENHANCED RAINFALL FOR
12-24 HOURS. OTHERWISE... THIS WOULD BE A TYPICAL RAINFALL EVENT
ASSOCIATED WITH A MID-LATITUDE TROUGH EARLY NEXT WEEK.
ONCE THE TROUGH PASSES... CLEARING AND COOLER CONDITIONS ARE
EXPECTED MID THROUGH LATE WEEK. LOWS 50-55. HIGHS 70-75.
&&
.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
AS OF 1000 AM SATURDAY...
24-HR TAF PERIOD:
VFR CONDITIONS AND WINDS UNDER 10KT WILL PREVAIL THE REMAINDER OF
THE TAF PERIOD. SURFACE WINDS MAY SHOW A NORTHERLY COMPONENT VEERING
GRADUALLY SOUTH DURING THE LATE MORNING AND EARLY AFTERNOON. LATE
TONIGHT...UNDER A MOSTLY CLEAR SKY...LIGHT SOUTHERLY WIND...AND
PERSISTENT LATE-NIGHT SURFACE DEW POINTS FROM 60 TO 65...EXPECT
AREAS OF FOG...WITH LOWEST VISIBILITIES TOWARD KFAY AND KRWI.
LOOKING AHEAD:
ASIDE FROM A POTENTIAL FOR FOG OR SUB-VFR CEILINGS BETWEEN 08-12Z
SUNDAY MORNING...VFR CONDS ARE EXPECTED TO PREVAIL DURING THE DAY
SUNDAY WITH CEILINGS SOMEWHAT LOWER THAN PREVIOUS DAYS (3500-4500 FT
AGL) IN ASSOC/W THE ONSET OF A LIGHT SOUTHERLY RETURN FLOW OVER
WESTERN PORTIONS OF THE STATE AS HIGH PRESSURE MOVES OFFSHORE.
EXPECT AN INCREASING CHANCE FOR MVFR/IFR CEILINGS AT ALL TERMINALS
IN ADVANCE OF A COLD FRONT PROGRESSING SLOWLY EAST TOWARD THE
SOUTHERN APPALACHIANS SUNDAY NIGHT...ALONG WITH AN INCREASING CHANCE
FOR RAIN AT THE INT/GSO TERMINALS BETWEEN 06-12Z MONDAY MORNING.
EXPECT WIDESPREAD SHOWERS/STORMS DURING THE DAY MONDAY AS THE COLD
FRONT TRACKS EAST INTO THE CAROLINAS. UNCERTAINTY IN THE FCST
INCREASES THEREAFTER...HOWEVER...IT IS POSSIBLE THAT RAIN AND
SUB-VFR CONDITIONS MAY PERSIST MONDAY NIGHT INTO TUESDAY. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...DJF/VINCENT
SHORT TERM...VINCENT
LONG TERM...BADGETT
AVIATION...DJF/VINCENT
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1038 AM EDT SAT OCT 5 2013
.SYNOPSIS...
SOUTHWEST FLOW OF WARM...MUGGY AIR CONTINUES INTO SUNDAY. COLD FRONT
BRINGS SHOWERS ALONG WITH SOME STORMS LATE SUNDAY INTO MONDAY.
UPPER LOW PULLS OUT MIDWEEK...YIELDING TO HIGH PRESSURE LATE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...
A FEW SMALL WAVES EMBEDDED WITHIN THE UPPER RIDGE HAVE SPARKED
SOME CONVECTION OVER THE OHIO VALLEY THIS MORNING...BUT THIS IS
NOT ABLE TO GET MUCH IN TERMS OF VERTICAL EXTENT. HAD TO DRAG THE
POPS A LITTLE FURTHER TO THE SOUTHEAST...BUT LEFT THEM OUT OF CRW.
WILL REASSESS WHEN THE NEW MODELS ARE IN. HRRR HAS BEEN VALUABLE
THIS MORNING.
PREVIOUS DISCUSSION...
SUMMER REPRISE CONTINUES. ALTOCU THIS MORNING AIDS IN ERADICATING
THE DENSE VALLEY FOG OF EARLY MORNING...OR HOLDS IT IN IF IT
SURVIVES DAWN....AND CU THIS AFTERNOON IN VERY WARM AND HUMID SW
FLOW AS UPPER RIDGE MOVES E ACROSS AREA. WEAK RIPPLES IN THE UPPER
LEVEL SW FLOW ONCE THE RIDGE GOES BY COULD GRAZE NW PORTION OF AREA
WITH CONVECTION MIDDAY TODAY INTO THIS EVENING.
FLOW GOES MORE SOUTHERLY TONIGHT...SO CONVECTION ASSOCIATED WITH
RIPPLES IN FLOW WILL SHIFT N OF THE AREA WHILE THAT ASSOCIATED WITH
COLD FRONT TO THE W REMAINS W OF THE AREA THROUGH 12Z SUN. ALTOCU
LIMITED TO THE W. BOUNDARY LATER FLOW SHOULD PRECLUDE DENSE VALLEY
FOG SAVE FOR THE DEEPER VALLEYS OF EASTERN WV LATE TONIGHT.
ROLLED WITH BIAS CORRECTED ADJMET AND BIAS CORRECTED ALL BLEND
TOGETHER WITH PREVIOUS FOR HIGHS TODAY WITH ADJMAV BEING TOO HIGH.
LOWER TO MID 80S LOWLANDS IS 5-10F BELOW RECORD HIGHS. DID BLEND IN
BIAS CORRECTED ADJMAV FOR LOWS TONIGHT...A TICK OR SO HIGHER THAN
PREVIOUS ON RIDGE/HILL TOPS.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
UNSETTLED WEATHER IN THE SHORT TERM PERIOD. RATHER WARM AND HUMID
DAY ON TAP SUNDAY...AS UPPER LOW ACROSS CENTRAL U.S. DIGS SOUTH AND
EAST...CAUSING FLOW TO BACK...AND SLOWING THE PROGRESSION OF THE
COLD FRONT AND ASSOCIATED PRECIPITATION INTO THE CWA. STILL
EXPECTING SOME DECENT RAINFALL TOTALS...AS LLJ AIDS IN MOISTURE
TRANSPORT TO THE REGION...WITH PW VALUES EXPECTED TO RISE TO 1.6 TO
1.7 INCHES. AS WITH PREVIOUS FORECASTER...WILL LEAVE A MENTION OF
WATER PROBLEMS OUT OF THE HWO DUE TO RECENT DRY SPELL...AND OVERALL
PROGRESSIVE NATURE OF THE SYSTEM. IN ADDITION...AT THIS POINT...SPC
HAS ISSUED ONLY A SEE TEXT AREA FOR THE CWA...AS CLOUD COVER...AND
OVERALL LACK OF INSTABILITY SHOULD HOPEFULLY LIMIT THE SEVERE
POTENTIAL ACROSS THE REGION. STILL...EXPECTING SOME RATHER GUSTY
CONDITIONS ASSOCIATED WITH FRONTAL PASSAGE...SET TO TAKE PLACE ON
MONDAY...PARTICULARLY ACROSS HIGHER ELEVATIONS. HOWEVER...THIS WILL
NEED TO BE MONITORED AS MODELS ARE INDICATING STRONG FORCING WITH
THE FRONT. MODELS CONTINUE TO INDICATE THAT REMNANTS OF KAREN WILL
REMAIN FAR ENOUGH TO THE EAST OF THE AREA...THAT THE CWA WILL SEE
LITTLE TO NO EFFECT.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
LOOKING AT UPR RIDGE TO BUILD ACROSS EASTERN CONUS IN THE EXTENDED
WITH STALLED SFC FRONT LINGERING ALONG E COAST. SEASONABLE TEMPS
DURING THE DAY AND COOL NIGHTS ON TAP.
&&
.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
FOG WAS MORE LIMITED EARLY THIS MORNING COMPARED WITH FRI MORNING
AND WILL BE EVEN MORE LIMITED SUN MORNING GIVEN ANOTHER DAY OF LOW
SHOWER/THUNDERSTORM COVERAGE...AND SOMEWHAT INCREASED BOUNDARY LAYER
FLOW. AS FOR THIS MORNING...THE FOG WILL FINISH THINNING OUT 13-14Z.
CIRRUS AND ALTOCU MOVING ACROSS THIS MORNING FOLLOWED BY A BUILDING
CU FIELD THIS AFTERNOON. SHOWERS AND THUNDERSTORMS COULD AFFECT THE
MIDDLE OHIO VALLEY MIDDAY TODAY INTO THIS EVENING. AN ISOLATED
SHOWER OR THUNDERSTORM COULD ALSO POP UP OVER THE NORTHERN WV
MOUNTAINS THIS AFTERNOON.
LIGHT AND VARIABLE SFC FLOW TODAY BECOMES LIGHT S TO SE TONIGHT
WHILE LIGHT NW FLOW ALOFT SWITCHES TO LIGHT SW THIS MORNING AND THEN
BECOMES LIGHT S TO SW TONIGHT.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z SUNDAY...
FORECAST CONFIDENCE: HIGH.
ALTERNATE SCENARIOS: LITTLE MORE THEN MINOR VARIATIONS ARE EXPECTED
IN THE FCST.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
EDT 1HRLY 10 11 12 13 14 15 16 17 18 19 20 21
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY L H H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 12Z SUNDAY...
IFR POSSIBLE ALONG COLD FRONT...MOVING W TO E...SUN NT INTO
MON...AND IN POST-RAIN FOG/STRATUS TUE MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...TRM/SL
NEAR TERM...TRM/26
SHORT TERM...SL
LONG TERM...30
AVIATION...TRM
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1021 AM CDT SAT OCT 5 2013
.DISCUSSION...
THE COLD FRONT WAS PROGRESSING STEADILY ACROSS THE NORTHERN AND
CENTRAL PORTIONS OF THE STATE. UPDATED THE WIND SHIFT WITH THE
LATEST RAP FORECAST. A 12Z ANALYSIS SHOWED A SURFACE RIDGE OVER
THE TEXAS COASTAL AREAS WITH LOW-LEVEL MOISTURE STREAMING
NORTHWARD FROM THE GULF INTO AREAS MAINLY EAST OF FREEPORT. OVER
MOST OF THE FORECAST AREA THE AIR MASS WAS FAIRLY DRY AND CAPPED
AND EXPECT THAT MOST CONVECTION THIS AFTERNOON WILL BE CONFINED TO
THE EASTERN AND NORTHERN SET OF COUNTIES WHERE THE DEEPER MOISTURE
AND COOLER AIRMASS ALOFT RESIDES.
WILL UPDATE MAINLY FOR THE WINDS. OTHERWISE...THE REMAINDER OF THE
FORECAST LOOKS ON TARGET.
40
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 89 58 81 52 83 / 20 20 10 0 0
HOUSTON (IAH) 92 62 80 53 83 / 50 30 10 0 0
GALVESTON (GLS) 89 69 81 65 80 / 40 30 20 0 0
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 7 PM CDT THIS EVENING
FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE
MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM HIGH
ISLAND TO FREEPORT 20 TO 60 NM.
&&
$$
DISCUSSION...40
AVIATION/MARINE...47
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1017 AM EDT SAT OCT 5 2013
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OVER THE REGION THROUGH TONIGHT. A LOW
PRESSURE SYSTEM TRACKING FROM THE CENTRAL PLAINS TO THE GREAT
LAKES WILL PUSH A STRONG COLD FRONT THROUGH THE AREA ON MONDAY.
THE LOW AND COLD FRONT WILL MOVE OFFSHORE BY TUESDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 945 AM EDT SATURDAY...
SHOULD BE A WARM...POTENTIALLY RECORD BREAKING DAY...ESPECIALLY AT
BLACKSBURG/BLUEFIELD (SEE CLIMATE SECTION BELOW)...AS HIGH
PRESSURE RESIDES OVERHEAD. FOG WILL BE LIFTING ACROSS THE
VALLEYS...BUT HAS HELD STRONG IN THE GREENBRIER VALLEY.
TEMPS STARTING TO RUN A COUPLE DEGREES WARMER OUT EAST THAN
CURRENT FORECAST...SO BUMPED UP HIGHS A COUPLE DEGREES...LOOKING
AT UPPER 70S TO LOWER 80S ACROSS THE HIGHER TERRAIN...TO MID TO
UPPER 80S VALLEYS AND POINTS EAST OF THE BLUE RIDGE.
PREVIOUS VALID DISCUSSION...
SURFACE HIGH PRESSURE AND A 500 MB RIDGE WILL REMAIN OVER THE
CENTRAL AND SOUTHERN APPALACHIANS THROUGH TONIGHT. LOCAL WRF AS
WELL AS HRRR AND LATEST RAP GUIDANCE SUGGEST THERE IS STILL A LOW
CHANCE OF SHOWERS THIS AFTERNOON...MAINLY NORTH OF I-64. ASIDE
FROM THE WEST TO SOUTHWEST UPSLOPE WINDS...LITTLE IN THE WAY OF
SHORT WAVES TO HELP TRIGGER ANY PRECIPITATION.
ANY SCATTERED TO BROKEN CU THAT DEVELOPS TODAY WILL DISSIPATE
THIS EVENING. USED A BLEND OF BIAS CORRECTED MAV/MET GUIDANCE FOR
OVERNIGHT LOWS.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 453 AM EDT SATURDAY...
MODELS REMAINING CONSISTENT WITH MOVING A COLD FRONT AND ASSOCIATED
SHOWERS INTO THE OHIO VALLEY ON SUNDAY. MODELS HAVE SLOWED DOWN THE
FRONTS MOVEMENT INTO THE AREA SUNDAY NIGHT AND ACROSS THE REGION
MONDAY/MONDAY NIGHT. THE SLOWER PROGRESSION OF THE FRONT IS DUE TO
UPPER LEVEL FORCING BECOMING DETACHED FROM THE LOW LEVEL BOUNDARY.
TROPICAL STORM KAREN OR REMNANTS OF...MAY ALSO PLAYING A PART IN
SLOWING THE FRONT DOWN TO A CRAWL AS IT CROSSES OVER THE AREA. BASED
ON THE 00Z MODEL TRENDS...LOWERED POPS INTO SUNDAY EVENING.
MEASURABLE RAIN BEGINS TO TRACK ACROSS THE SOUTHWEST EARLY MONDAY
MORNING...THEN SPREADS ACROSS THE REST OF THE MOUNTAINS AROUND
SUNRISE. RAIN CHANCES INCREASE EAST OF THE BLUE RIDGE TOWARD THE
AFTERNOON AND CONTINUES INTO THE EVENING. WITH A COLD FRONT
INTERACTING WITH TROPICAL MOISTURE...IT WAS A NO BRAINER TO INCREASE
POPS TO 100 PERCENT MONDAY. WITH THE FRONT BEING SLOWER...ALSO
INCREASED POPS MONDAY EVENING...TRENDING DOWN TUESDAY MORNING AS THE
FRONT TRACKS EAST.
WITH SHOWERS NOT DUE TO MOVE ACROSS THE PIEDMONT UNTIL THE
AFTERNOON...THERE MAY BE ENOUGH INSTABILITIES TO GENERATE A RUMBLE
OF THUNDER. IF ENOUGH INSTABILITIES IS PRESENT WHEN THE 850 JET
PASSES OVERHEAD...A STORM OR TWO MAY PRODUCE STRONG WINDS. FOR THE
MOST PART...THIS WILL BE A HYDRO EVENT. PWATS ON MONDAY APPROACH 2
INCHES WHICH IS CLOSE TO BEING 2 STANDARD DEVIATIONS ABOVE NORMAL.
RAINFALL AMOUNTS FROM SUNDAY NIGHT INTO MONDAY EVENING SHOULD RANGE
FROM 1 TO 2 INCHES. WITH THE RECENT DRY SPELL...THE FORECAST AREA
SHOULD NOT SEE ANY WIDESPREAD WATER PROBLEMS. LOCALIZE FLOODING IS
NOT OUT OF THE QUESTION IN POOR DRAINAGE AREAS...ESPECIALLY IF HIGH
RAINFALL RATES OR TRAINING OF STORMS PERSIST OVER AN AREA FOR
SEVERAL HOURS.
THE UPPER LEVEL RIDGE THAT BROUGHT WARMTH TO THE AREA ON SATURDAY
WILL BEGIN TO SLIDE OFF THE SOUTHEAST COAST ON SUNDAY. WITH THE
FRONT REMAINING WEST OF THE AREA FOR MOST OF SUNDAY...WARMER THAN
NORMAL TEMPERATURES WILL AGAIN COVER THE REGION. SUNDAY TEMPERATURES
WILL RANGE FROM THE LOW TO MID 80S ACROSS THE WEST TO MID TO UPPER
80S IN THE EAST. A DRAMATIC COOL DOWN COMES MONDAY WITH THE RAIN.
FORECASTED HIGH TEMPERATURES MONDAY WILL RANGE FROM THE MID 60S IN
THE WEST TO LOWER 70S ACROSS THE PIEDMONT.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 1215 PM EDT FRIDAY...
FORECAST EARLY IN THE PERIOD CENTERS AROUND THE FRONT/REMNANTS OF
KAREN AND THE UPPER TROUGH MOVING ACROSS THE GREAT
LAKES/NORTHEAST/MID ATLANTIC. THE LATEST GFS (12Z) CONTINUES TO BE
SLOWER...AND IS ACTUALLY SLOWER THAN THE 06Z RUN IN MOVING THE FRONT
OUT...WITH A STRONGER UPPER LOW...BUT IS FURTHER EAST WITH KAREN.
PER NHC/WPC...WILL BE LEANING TOWARD THE 00Z ECMWF AND THE PREVIOUS
FORECAST. THERE WILL STILL BE LINGERING SHOWERS ACROSS THE PIEDMONT
TUESDAY AND NOT OUT OF THE QUESTION THAT STRONG SUBSIDENCE BEHIND
THE DEPARTING TROPICAL SYSTEM MAY START TO DRY THINGS OUT FASTER.
FOR MID TO LATE WEEK...THE FORECAST MAINTAINS A CHALLENGE IN TERMS
OF SFC HIGH PRESSURE WEDGING SOUTH INTO OUR AREA...WHILE A RESIDUAL
UPPER TROUGH LINGERS OVER THE SOUTHEAST. QUESTION WILL BE WHERE
DEEPER MOISTURE RESIDES. WITH THE ECMWF THINK MOST OF THE CLOUD
COVER WILL BE HUGGING OUR SOUTHEAST CWA WITH MORE RESIDING ACROSS
THE SOUTHEAST...WHILE THE WESTERN CWA SEES MORE SUN DURING THE DAY.
TEMPERATURES GIVEN A LIGHT NE-E FLOW WILL BE CLOSER TO NORMAL...WITH
THE THREAT OF RAIN BEING LESS THAN 10 PERCENT.
&&
.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
AS OF 740 AM EDT SATURDAY...
NEW RIVER AND GREENBRIER VALLEYS HAD DENSE FOG THIS MORNING...
INCLUDING LIFR VISIBILITIES AT KBCB AND KLWB. EXPECT IMPROVEMENT IN
CONDITIONS BY 10AM. ONCE FOG MIXES OUT THIS MORNING...HIGH
CONFIDENCE THAT THE REST OF THE DAY WILL BE VFR. HAVE ADDED FOG IN
AGAIN FOR TONIGHT IN KLWB AND KBCB, WITH DEW POINTS GRADUALLY
RISING...THERE IS A POSSIBILITY FOR MVFR FOG AT KDAN AND KLYH
AFTER 06Z2AM TONIGHT.
MID AND HIGH LEVEL CLOUDS WILL ARRIVE SUNDAY THOUGH AS THE COLD
FRONT ENTERS THE OHIO VALLEY. OUR NEXT CHANCE FOR WIDESPREAD AND
PROLONGED SUB-VFR CONDITIONS WILL COME SUNDAY NIGHT INTO MONDAY
WHEN A COLD FRONT APPROACHES FROM THE WEST...AND WHAT IS LEFT OF
TROPICAL CYCLONE KAREN RIDES NORTH THROUGH OR NEAR OUR REGION IN
ADVANCE OF IT. THIS WOULD ALLOW A TREND TOWARD DECREASING CEILING
HEIGHTS AND INCREASED COVERAGE OF RAIN. VISIBILITIES WOULD TREND
LOWER AS WELL...ESPECIALLY SUNDAY INTO MONDAY AS PRECIPITATION
INTENSIFIES AND FOG POTENTIAL INCREASES.
RAIN ENDS MONDAY NIGHT BUT THERE STILL MAY BE RESTRICTIONS IN
CEILING AND VISIBILITY AS PRECIP COULD STILL BE HEAVY ACROSS THE
VA/NC PIEDMONT WITH POTENTIALLY SOME FOG ACROSS SE WEST VA. A
DRIER PATTERN IS EXPECTED TUESDAY AND WEDNESDAY WITH MORNING FOG.
&&
.CLIMATE...
RECORD HIGH TEMPS FOR SATURDAY.
ROANOKE 98/1941
LYNCHBURG 96/1941
DANVILLE 98/1951
BLACKSBURG 86/1954
BLUEFIELD 85/2007
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS/WP
NEAR TERM...AMS/WP
SHORT TERM...RCS
LONG TERM...JH/WP
AVIATION...AMS/KK/KM
CLIMATE...RCS
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
746 AM EDT SAT OCT 5 2013
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OVER THE REGION TODAY AND TONIGHT. A
LOW PRESSURE SYSTEM TRACKING FROM THE CENTRAL PLAINS TO THE GREAT
LAKES WILL PUSH A STRONG COLD FRONT THROUGH THE AREA ON MONDAY.
THE LOW AND COLD FRONT WILL MOVE OFFSHORE BY TUESDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 345 AM EDT SATURDAY...
SURFACE HIGH PRESSURE AND A 500 MB RIDGE WILL REMAIN OVER THE
CENTRAL AND SOUTHERN APPALACHIANS TODAY AND TONIGHT. LOCAL WRF AS
WELL AS HRRR AND LATEST RAP GUIDANCE SUGGEST THERE IS STILL A LOW
CHANCE OF SHOWERS THIS AFTERNOON...MAINLY NORTH OF I-64. ASIDE
FROM THE WEST TO SOUTHWEST UPSLOPE WINDS...LITTLE IN THE WAY OF
SHORT WAVES TO HELP TRIGGER ANY PRECIPITATION.
DEEP SOUTHWEST WINDS THIS AFTERNOON...EVEN THOUGH WIND SPEEDS WILL
NOT BE VERY STRONG...WILL PROVIDE SOME DOWNSLOPNIG AND
COMPRESSION. COMBINED WITH 850 MB TEMPERATURES OF +16 TO
+18...MAXIMUM TEMPERATURES WILL AGAIN BE WELL ABOVE NORMAL.
EXPECTING SIMILAR TEMPERATURES COMPARED TO FRIDAY...AND POSSIBLY A
DEGREE OR TWO HIGH AS LONG AS THERE IS NOT CLOUD COVER.
ANY SCATTERED TO BROKEN STRATOCUMULUS THAT DEVELOPS TODAY WILL
DISSIPATE THIS EVENING. USED A BLEND OF BIAS CORRECTED MAV/MET
GUIDANCE FOR OVERNIGHT LOWS.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 453 AM EDT SATURDAY...
MODELS REMAINING CONSISTENT WITH MOVING A COLD FRONT AND ASSOCIATED
SHOWERS INTO THE OHIO VALLEY ON SUNDAY. MODELS HAVE SLOWED DOWN THE
FRONTS MOVEMENT INTO THE AREA SUNDAY NIGHT AND ACROSS THE REGION
MONDAY/MONDAY NIGHT. THE SLOWER PROGRESSION OF THE FRONT IS DUE TO
UPPER LEVEL FORCING BECOMING DETACHED FROM THE LOW LEVEL BOUNDARY.
TROPICAL STORM KAREN OR REMNANTS OF...MAY ALSO PLAYING A PART IN
SLOWING THE FRONT DOWN TO A CRAWL AS IT CROSSES OVER THE AREA. BASED
ON THE 00Z MODEL TRENDS...LOWERED POPS INTO SUNDAY EVENING.
MEASURABLE RAIN BEGINS TO TRACK ACROSS THE SOUTHWEST EARLY MONDAY
MORNING...THEN SPREADS ACROSS THE REST OF THE MOUNTAINS AROUND
SUNRISE. RAIN CHANCES INCREASE EAST OF THE BLUE RIDGE TOWARD THE
AFTERNOON AND CONTINUES INTO THE EVENING. WITH A COLD FRONT
INTERACTING WITH TROPICAL MOISTURE...IT WAS A NO BRAINER TO INCREASE
POPS TO 100 PERCENT MONDAY. WITH THE FRONT BEING SLOWER...ALSO
INCREASED POPS MONDAY EVENING...TRENDING DOWN TUESDAY MORNING AS THE
FRONT TRACKS EAST.
WITH SHOWERS NOT DUE TO MOVE ACROSS THE PIEDMONT UNTIL THE
AFTERNOON...THERE MAY BE ENOUGH INSTABILITIES TO GENERATE A RUMBLE
OF THUNDER. IF ENOUGH INSTABILITIES IS PRESENT WHEN THE 850 JET
PASSES OVERHEAD...A STORM OR TWO MAY PRODUCE STRONG WINDS. FOR THE
MOST PART...THIS WILL BE A HYDRO EVENT. PWATS ON MONDAY APPROACH 2
INCHES WHICH IS CLOSE TO BEING 2 STANDARD DEVIATIONS ABOVE NORMAL.
RAINFALL AMOUNTS FROM SUNDAY NIGHT INTO MONDAY EVENING SHOULD RANGE
FROM 1 TO 2 INCHES. WITH THE RECENT DRY SPELL...THE FORECAST AREA
SHOULD NOT SEE ANY WIDESPREAD WATER PROBLEMS. LOCALIZE FLOODING IS
NOT OUT OF THE QUESTION IN POOR DRAINAGE AREAS...ESPECIALLY IF HIGH
RAINFALL RATES OR TRAINING OF STORMS PERSIST OVER AN AREA FOR
SEVERAL HOURS.
THE UPPER LEVEL RIDGE THAT BROUGHT WARMTH TO THE AREA ON SATURDAY
WILL BEGIN TO SLIDE OFF THE SOUTHEAST COAST ON SUNDAY. WITH THE
FRONT REMAINING WEST OF THE AREA FOR MOST OF SUNDAY...WARMER THAN
NORMAL TEMPERATURES WILL AGAIN COVER THE REGION. SUNDAY TEMPERATURES
WILL RANGE FROM THE LOW TO MID 80S ACROSS THE WEST TO MID TO UPPER
80S IN THE EAST. A DRAMATIC COOL DOWN COMES MONDAY WITH THE RAIN.
FORECASTED HIGH TEMPERATURES MONDAY WILL RANGE FROM THE MID 60S IN
THE WEST TO LOWER 70S ACROSS THE PIEDMONT.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 1215 PM EDT FRIDAY...
FORECAST EARLY IN THE PERIOD CENTERS AROUND THE FRONT/REMNANTS OF
KAREN AND THE UPPER TROUGH MOVING ACROSS THE GREAT
LAKES/NORTHEAST/MID ATLANTIC. THE LATEST GFS (12Z) CONTINUES TO BE
SLOWER...AND IS ACTUALLY SLOWER THAN THE 06Z RUN IN MOVING THE FRONT
OUT...WITH A STRONGER UPPER LOW...BUT IS FURTHER EAST WITH KAREN.
PER NHC/WPC...WILL BE LEANING TOWARD THE 00Z ECMWF AND THE PREVIOUS
FORECAST. THERE WILL STILL BE LINGERING SHOWERS ACROSS THE PIEDMONT
TUESDAY AND NOT OUT OF THE QUESTION THAT STRONG SUBSIDENCE BEHIND
THE DEPARTING TROPICAL SYSTEM MAY START TO DRY THINGS OUT FASTER.
FOR MID TO LATE WEEK...THE FORECAST MAINTAINS A CHALLENGE IN TERMS
OF SFC HIGH PRESSURE WEDGING SOUTH INTO OUR AREA...WHILE A RESIDUAL
UPPER TROUGH LINGERS OVER THE SOUTHEAST. QUESTION WILL BE WHERE
DEEPER MOISTURE RESIDES. WITH THE ECMWF THINK MOST OF THE CLOUD
COVER WILL BE HUGGING OUR SOUTHEAST CWA WITH MORE RESIDING ACROSS
THE SOUTHEAST...WHILE THE WESTERN CWA SEES MORE SUN DURING THE DAY.
TEMPERATURES GIVEN A LIGHT NE-E FLOW WILL BE CLOSER TO NORMAL...WITH
THE THREAT OF RAIN BEING LESS THAN 10 PERCENT.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 740 AM EDT SATURDAY...
NEW RIVER AND GREENBRIER VALLEYS HAD DENSE FOG THIS MORNING...
INCLUDING LIFR VISIBILITIES AT KBCB AND KLWB. EXPECT IMPROVEMENT IN
CONDITIONS BY 10AM. ONCE FOG MIXES OUT THIS MORNING...HIGH
CONFIDENCE THAT THE REST OF THE DAY WILL BE VFR. HAVE ADDED FOG IN
AGAIN FOR TONIGHT IN KLWB AND KBCB, WITH DEW POINTS GRADUALLY
RISING...THERE IS A POSSIBILITY FOR MVFR FOG AT KDAN AND KLYH
AFTER 06Z2AM TONIGHT.
MID AND HIGH LEVEL CLOUDS WILL ARRIVE SUNDAY THOUGH AS THE COLD
FRONT ENTERS THE OHIO VALLEY. OUR NEXT CHANCE FOR WIDESPREAD AND
PROLONGED SUB-VFR CONDITIONS WILL COME SUNDAY NIGHT INTO MONDAY
WHEN A COLD FRONT APPROACHES FROM THE WEST...AND WHAT IS LEFT OF
TROPICAL CYCLONE KAREN RIDES NORTH THROUGH OR NEAR OUR REGION IN
ADVANCE OF IT. THIS WOULD ALLOW A TREND TOWARD DECREASING CEILING
HEIGHTS AND INCREASED COVERAGE OF RAIN. VISIBILITIES WOULD TREND
LOWER AS WELL...ESPECIALLY SUNDAY INTO MONDAY AS PRECIPITATION
INTENSIFIES AND FOG POTENTIAL INCREASES.
RAIN ENDS MONDAY NIGHT BUT THERE STILL MAY BE RESTRICTIONS IN
CEILING AND VISIBILITY AS PRECIP COULD STILL BE HEAVY ACROSS THE
VA/NC PIEDMONT WITH POTENTIALLY SOME FOG ACROSS SE WEST VA. A
DRIER PATTERN IS EXPECTED TUESDAY AND WEDNESDAY WITH MORNING FOG.
&&
.CLIMATE...
RECORD HIGH TEMPS FOR SATURDAY.
ROANOKE 98/1941
LYNCHBURG 96/1941
DANVILLE 98/1951
BLACKSBURG 86/1954
BLUEFIELD 85/2007
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...RCS
LONG TERM...JH/WP
AVIATION...AMS/KK/KM
CLIMATE...RCS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
634 AM CDT SAT OCT 5 2013
.UPDATE...
ISSUED AT 523 AM CDT SAT OCT 5 2013
WITH CONVECTION SHIFTING EAST AND LACK OF OVERALL ACTIVITY
EXPECTED THROUGH THE NEXT SEVERAL HOURS...HAVE TRENDED THE MORNING
MUCH DRIER. ONLY ISOLATED SHOWERS AND THUNDERSTORMS THROUGH THE
MORNING...RAMPING UP TOWARD AFTERNOON.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 413 AM CDT SAT OCT 5 2013
MOST EFFORT THIS FORECAST SHIFT WAS PUT TOWARD GETTING THE NEXT 24
HOURS AS ACCURATE AS POSSIBLE. SCREAMING MESSAGE IS THE SLOWER
EASTWARD PROGRESSION OF THE FRONT AND INSTABILITY...MAKING FOR A
BIT HIGHER SEVERE WEATHER CHANCE IN WI TODAY.
WATER VAPOR SHOWING THE MONSTER LOW THAT BROUGHT 25-45 INCHES OF
SNOW TO SD OVER CENTRAL SD AT 08Z AND NEARLY STATIONARY. OCCLUDED
FRONT CURRENTLY POSITIONED FROM KRWF TO KCCY...WHERE THE TRIPLE
POINT IS LOCATED. THE WARM FRONT EXTENDS EAST FROM NEAR KCCY TO
THE DELLS IN WI...WITH THE SURFACE COLD FRONT RUNNING SOUTH FROM
KCCY. THIS WARM FRONT IS THE LEADING EDGE OF THE HIGHER DEWPOINT
AIR...MIDDLE 60S...AND THE ENERGY FOR THIS AFTERNOONS STORMS. THE
OVERNIGHT CONVECTION HAS NOW PASSED OFF TO THE EAST...AND WITH IT
THE FLASH FLOOD THREAT.
EVALUATING THE 04.00Z MODEL GUIDANCE...THE TREND IS SLOWER WITH
THE NORTHEAST PROGRESSION OF THE OCCLUDED/COLD FRONT. THIS ALLOWS
MORE OF THE FORECAST AREA IN WI TO BE PRE-FRONTAL AND IN THE WARM
SECTOR FOR A HIGHER PROBABILITY OF SEVERE WEATHER. AS THE DAY
PROGRESSES...QVECTOR CONVERGENCE WILL INCREASE AS A SHORTWAVE
TROUGH IN COLORADO ROTATES AROUND THE LARGER SD TROUGH AND BEGINS
ITS EASTWARD PROGRESSION. AS THE FORCING BEGINS TO INCREASE...NEAR/POST
FRONTAL SHOWERS WILL LIKELY DEVELOP MUCH LIKE SEEN ON RADAR ALONG
I-35 EARLY THIS MORNING. ALSO...BETTER UPPER LEVEL FORCING WILL
BEGIN TO WORK TOWARD THE WARM SECTOR AND WORK WITH 0-2KM THETA-E
CONVERGENCE ALONG THE FRONT. INSTABILITY IN THE WARM SECTOR WILL HIGHLY
DEPEND ON THE EXTENT OF THE SHOWERS AND CLOUDS OVER WI...HOWEVER
BECAUSE THE DEWPOINTS ARE ALREADY MIDDLE 60S...AT LEAST MARGINAL
INSTABILITY WILL BE PRESENT BY 18Z. MUCAPES AROUND 1000-1500 J/KG
LOOK TO BE A GOOD ESTIMATE ON AFTERNOON CAPE...POSSIBLY HIGHER
WITH MORE CLOUD BREAKS.
WIND SHEAR LOOKS TO INCREASE TODAY BUT RIGHT ON THE COLD/OCCLUDED
FRONTAL BOUNDARY...TO MAKE IT A MARGINAL SUPERCELL DAY WITH
MULTI-CELLS ALSO PRESENT. THE 05.06Z NAM AND 05.07Z RAP BOTH SUGGEST
NEAR 40 KTS OF 0-6KM SHEAR...CERTAINLY ENOUGH FOR SUPERCELLS. THE
05.07Z RAP MIXES ALL THE PRE-FRONTAL SURFACE WINDS TO SOUTHERLY. THE
05.06Z NAM AND LATEST HRRR RUNS ARE VERY AGREEABLE THAT THE WARM
FRONT WILL SHIFT NORTH TO ABOUT BLACK RIVER FALLS WI TODAY...VERY
CLOSE TO THE SPC DAY 1 NORTHERN EXTENT OF THE SLIGHT RISK. EASTERLY
FLOW IS FOUND NORTH OF THE WARM FRONT...WHICH EXTENDS TO THE EAST
TOWARD KGRB...SO A GOOD CONVERGENT BOUNDARY. WHILE TORNADO
PROBABILITIES DONT LOOK HIGH...THE TRIPLE POINT AREA AND ALONG THAT
WARM FRONT THIS AFTERNOON WILL BE A FOCAL POINT.
OTHERWISE...DAMAGING WIND SEGMENTS OR LARGE HAIL ARE THE MAIN
THREATS FROM THE STORMS IN WI. NORTH OF THE WARM FRONT...LOW-LEVEL
INVERTED CONDITIONS AND ELEVATED STORMS ARE FAVORED...HEAVY RAIN IS
THE MAIN THREAT...WITH AN ISOLATED HAIL STORM POSSIBLE. THE FRONT
SHOULD SHIFT EAST OF THE FORECAST AREA BY EARLY EVENING WITH STRONG
DEWPOINT DECREASES. THUS...THE MAIN SEVERE WEATHER THREAT LOOKS TO
BE ABOUT 1 PM TO 5 PM.
BY TONIGHT...THE NE AND EASTERNMOST FORECAST AREA MAY STILL HAVE
SOME RAIN REMAINING. HAVE SLOWED THAT SLIGHTLY FROM THE PREVIOUS
FORECAST. A DECREASING TREND OCCURS THROUGH THE EVENING AS WEATHER
SHIFTS EAST.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 413 AM CDT SAT OCT 5 2013
THE LATEST MODEL CONSENSUS IS TO NOW KEEP THE DEFORMATION
ASSOCIATED WITH THE CYCLONIC MOIST FLOW WRAPPING AROUND THE LOW TO
THE WEST-NORTHWEST ON SATURDAY. THIS IS HIGHLY DEPENDENT ON THE
TRACK OF THE LOW WHICH IS A BIT FURTHER SOUTH IN THE LATEST
GUIDANCE. IN ANY CASE...CHANGES WERE MADE TO SUNDAY TO TRY AND DRY
IT OUT WITH THE RAIN SHOWERS JUST WEST OF THE AREA. ALTHOUGH THE
CONSENSUS OF THE MODELS IS TO BRING THAT BAND INTO THE FORECAST
AREA FOR MONDAY NOW...THE LATEST 05.00Z ECMWF IS MUCH MORE
PROGRESSIVE AND RAPIDLY SHIFTS THE SHOWERS EAST. HAVE A SMALL
CHANCE OF SHOWERS TO ADDRESS THAT SITUATION.
THE REMAINDER OF THE PERIOD IS DOMINATED BY DRY WEATHER UNDER
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 634 AM CDT SAT OCT 5 2013
COLD/OCCLUDED FRONT CONTINUED TO WORK ITS WAY INTO AND ACROSS THE
FCST AREA EARLY THIS MORNING. AS OF 11Z IT WAS NEAR A KOWA-KAUM-KOLZ
LINE. SOUTHWEST OF THIS BOUNDARY CONDITIONS WERE GENERALLY GOOD VFR
WITH ONLY ISOLATED -SHRA. NORTHEAST OF THE BOUNDARY...CIGS WERE
HIGHLY VARIABLE RANGING FROM LIFR TO VFR. CIGS GENERALLY IMPROVED
BEHIND CLUSTERS OF CONVECTION OVERNIGHT...THEN DROPPING BACK DOWN A
COUPLE HOURS LATER. FRONT MAKING SLOW PROGRESS AND VARYING TIMING
SOLUTIONS AMONG THE MODELS...BUT APPEARS FRONT/BOUNDARY WILL LIFT
NORTHEAST OF KRST AROUND 14Z AND KLSE AROUND 19Z. WITH FRONT PAST KRST
AROUND 14Z...CONVECTION CHANCES DIMINISH FOR THE DAY AND ONLY
CARRIED VCSH IN THE 17-20Z TIME-FRAME. WITH FRONT NEAR KLSE AT
MID-DAY AND PEAK HEATING...CONTINUED A -SHRA/VCSH MENTION IN THE
MAINLY 19-22Z PERIOD. BOUNDARY CONTINUES LIFTING NORTHEAST LATE THIS
AFTERNOON/TONIGHT WITH FALLING DEW POINTS AND A DRIER AIRMASS
SPREADING ACROSS THE AREA. TREND FOR ONLY SCT CLOUDS TONIGHT
CONTINUES TO LOOK GOOD.
GIVEN THE RECENT RAINS...WILL HAVE TO WATCH VALLEY LOCATIONS FOR
BR/FG LATE TONIGHT IF SKIES DO END UP MOSTLY CLEAR AND THE VALLEY
WINDS DECOUPLE. APPEARS TO BE ENOUGH GRADIENT WINDS LATER TONIGHT
AND LEFT ANY BR/FG MENTION AFTER 09Z OUT OF KLSE FOR NOW.
&&
.HYDROLOGY...
ISSUED AT 413 AM CDT SAT OCT 5 2013
CONCERNING THE FLASH FLOOD WATCH...WITH CURRENT CONVECTION EAST
OF THE AREA...MAIN THREAT HAS DIMINISHED. AS AFTERNOON CONVECTION
INCREASES...IT SHOULD BE AFFECTING AREAS THAT HAVE HAD LESS RAIN
OVERALL THAN THOSE WEST OF THE MISS RIVER. AREAS EAST OF THE MISS
RIVER CAN TAKE ANOTHER 1-2 INCHES...ESPECIALLY SWRN WI. THERE IS A
SMALL PROBABILITY OF LOCALIZED FLASH FLOODING TODAY IN THE CENTRAL
WI CORRIDOR IN THE PRE-FRONTAL AIR MASS WHICH WILL STILL HAVE 1.25
TO 1.75 INCH PRECIPITABLE WATER VALUES. RAIN RATES ARE EXPECTED TO
BE HIGH...PROBABLY 2 TO 3 INCH PER HOUR SHOULD CAPE DEVELOP AS
FORECAST. THE SLOW MOVEMENT OF THE FRONT DOES GIVE SOME CONCERN
FOR FLOODING SO WILL ISSUE ANOTHER HYDROLOGICAL DISCUSSION FOR
THAT AREA AND CANCEL THE FLASH FLOOD WATCH.
THERE ARE SOME RIVER RESPONSES CURRENTLY OCCURRING. MONITORING THE
ROOT RIVER BASIN AND THE UPPER IOWA RIVERS BOTH HAVE RESPONSES.
ALSO THE WHITEWATER RIVER MIDDLE FORK THAT RUNS THROUGH WHITEWATER
STATE PARK IS RISING. AT THIS TIME THESE WILL APPROACH FLOOD STAGE
BUT IT IS BELIEVED THEY WILL NOT REACH IT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE.......BAUMGARDT
SHORT TERM...BAUMGARDT
LONG TERM....BAUMGARDT
HYDROLOGY....BAUMGARDT
AVIATION.....RRS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
525 AM CDT SAT OCT 5 2013
.UPDATE...
ISSUED AT 523 AM CDT SAT OCT 5 2013
WITH CONVECTION SHIFTING EAST AND LACK OF OVERALL ACTIVITY
EXPECTED THROUGH THE NEXT SEVERAL HOURS...HAVE TRENDED THE MORNING
MUCH DRIER. ONLY ISOLATED SHOWERS AND THUNDERSTORMS THROUGH THE
MORNING...RAMPING UP TOWARD AFTERNOON.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 413 AM CDT SAT OCT 5 2013
MOST EFFORT THIS FORECAST SHIFT WAS PUT TOWARD GETTING THE NEXT 24
HOURS AS ACCURATE AS POSSIBLE. SCREAMING MESSAGE IS THE SLOWER
EASTWARD PROGRESSION OF THE FRONT AND INSTABILITY...MAKING FOR A
BIT HIGHER SEVERE WEATHER CHANCE IN WI TODAY.
WATER VAPOR SHOWING THE MONSTER LOW THAT BROUGHT 25-45 INCHES OF
SNOW TO SD OVER CENTRAL SD AT 08Z AND NEARLY STATIONARY. OCCLUDED
FRONT CURRENTLY POSITIONED FROM KRWF TO KCCY...WHERE THE TRIPLE
POINT IS LOCATED. THE WARM FRONT EXTENDS EAST FROM NEAR KCCY TO
THE DELLS IN WI...WITH THE SURFACE COLD FRONT RUNNING SOUTH FROM
KCCY. THIS WARM FRONT IS THE LEADING EDGE OF THE HIGHER DEWPOINT
AIR...MIDDLE 60S...AND THE ENERGY FOR THIS AFTERNOONS STORMS. THE
OVERNIGHT CONVECTION HAS NOW PASSED OFF TO THE EAST...AND WITH IT
THE FLASH FLOOD THREAT.
EVALUATING THE 04.00Z MODEL GUIDANCE...THE TREND IS SLOWER WITH
THE NORTHEAST PROGRESSION OF THE OCCLUDED/COLD FRONT. THIS ALLOWS
MORE OF THE FORECAST AREA IN WI TO BE PRE-FRONTAL AND IN THE WARM
SECTOR FOR A HIGHER PROBABILITY OF SEVERE WEATHER. AS THE DAY
PROGRESSES...QVECTOR CONVERGENCE WILL INCREASE AS A SHORTWAVE
TROUGH IN COLORADO ROTATES AROUND THE LARGER SD TROUGH AND BEGINS
ITS EASTWARD PROGRESSION. AS THE FORCING BEGINS TO INCREASE...NEAR/POST
FRONTAL SHOWERS WILL LIKELY DEVELOP MUCH LIKE SEEN ON RADAR ALONG
I-35 EARLY THIS MORNING. ALSO...BETTER UPPER LEVEL FORCING WILL
BEGIN TO WORK TOWARD THE WARM SECTOR AND WORK WITH 0-2KM THETA-E
CONVERGENCE ALONG THE FRONT. INSTABILITY IN THE WARM SECTOR WILL HIGHLY
DEPEND ON THE EXTENT OF THE SHOWERS AND CLOUDS OVER WI...HOWEVER
BECAUSE THE DEWPOINTS ARE ALREADY MIDDLE 60S...AT LEAST MARGINAL
INSTABILITY WILL BE PRESENT BY 18Z. MUCAPES AROUND 1000-1500 J/KG
LOOK TO BE A GOOD ESTIMATE ON AFTERNOON CAPE...POSSIBLY HIGHER
WITH MORE CLOUD BREAKS.
WIND SHEAR LOOKS TO INCREASE TODAY BUT RIGHT ON THE COLD/OCCLUDED
FRONTAL BOUNDARY...TO MAKE IT A MARGINAL SUPERCELL DAY WITH
MULTICELLS ALSO PRESENT. THE 05.06Z NAM AND 05.07Z RAP BOTH
SUGGEST NEAR 40 KTS OF 0-6KM SHEAR...CERTAINLY ENOUGH FOR
SUPERCELLS. THE 05.07Z RAP MIXES ALL THE PRE-FRONTAL SURFACE
WINDS TO SOUTHERLY. THE 05.06Z NAM AND LATEST HRRR RUNS ARE VERY
AGREEABLE THAT THE WARM FRONT WILL SHIFT NORTH TO ABOUT BLACK
RIVER FALLS WI TODAY...VERY CLOSE TO THE SPC DAY 1 NORTHERN EXTENT
OF THE SLIGHT RISK. EASTERLY FLOW IS FOUND NORTH OF THE WARM
FRONT...WHICH EXTENDS TO THE EAST TOWARD KGRB...SO A GOOD
CONVERGENT BOUNDARY. WHILE TORNADO PROBABILITIES DONT LOOK
HIGH...THE TRIPLE POINT AREA AND ALONG THAT WARM FRONT THIS
AFTERNOON WILL BE A FOCAL POINT. OTHERWISE...DAMAGING WIND
SEGMENTS OR LARGE HAIL ARE THE MAIN THREATS FROM THE STORMS IN WI.
NORTH OF THE WARM FRONT...LOW-LEVEL INVERTED CONDITIONS AND
ELEVATED STORMS ARE FAVORED...HEAVY RAIN IS THE MAIN THREAT...WITH AN
ISOLATED HAIL STORM POSSIBLE. THE FRONT SHOULD SHIFT EAST OF THE
FORECAST AREA BY EARLY EVENING WITH STRONG DEWPOINT DECREASES.
THUS...THE MAIN SEVERE WEATHER THREAT LOOKS TO BE ABOUT 1 PM TO 5
PM.
BY TONIGHT...THE NE AND EASTERNMOST FORECAST AREA MAY STILL HAVE
SOME RAIN REMAINING. HAVE SLOWED THAT SLIGHTLY FROM THE PREVIOUS
FORECAST. A DECREASING TREND OCCURS THROUGH THE EVENING AS WEATHER
SHIFTS EAST.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 413 AM CDT SAT OCT 5 2013
THE LATEST MODEL CONSENSUS IS TO NOW KEEP THE DEFORMATION
ASSOCIATED WITH THE CYCLONIC MOIST FLOW WRAPPING AROUND THE LOW TO
THE WEST-NORTHWEST ON SATURDAY. THIS IS HIGHLY DEPENDENT ON THE
TRACK OF THE LOW WHICH IS A BIT FURTHER SOUTH IN THE LATEST
GUIDANCE. IN ANY CASE...CHANGES WERE MADE TO SUNDAY TO TRY AND DRY
IT OUT WITH THE RAIN SHOWERS JUST WEST OF THE AREA. ALTHOUGH THE
CONSENSUS OF THE MODELS IS TO BRING THAT BAND INTO THE FORECAST
AREA FOR MONDAY NOW...THE LATEST 05.00Z ECMWF IS MUCH MORE
PROGRESSIVE AND RAPIDLY SHIFTS THE SHOWERS EAST. HAVE A SMALL
CHANCE OF SHOWERS TO ADDRESS THAT SITUATION.
THE REMAINDER OF THE PERIOD IS DOMINATED BY DRY WEATHER UNDER
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1140 PM CDT FRI OCT 4 2013
BACK EDGE OF THE CONVECTION IS MAKING STEADY EASTWARD PROGRESS AND
STILL EXPECT IT TO CLEAR BOTH TAF SITES BY 08Z. UNTIL IT
DOES...IFR CONDITIONS WILL REMAIN POSSIBLE AS LOCALLY HEAVY RAIN
COULD DROP THE VISIBILITY AND POSSIBLY THE CEILINGS DOWN. ONCE THE
RAIN MOVES THROUGH...A TEMPORARY DRY SLOT WILL MOVE INTO TO ALLOW
FOR A PERIOD OF PRIMARILY VFR CONDITIONS. AS THE MAIN SURFACE LOW
STARTS TO TRACK TOWARD THE AREA SATURDAY MORNING...EXPECT TO SEE
THE OCCLUDED FRONT LIFT INTO AND THROUGH THE AREA. THE 05.00Z NAM
SUGGESTS THAT AS THIS HAPPENS...THE LOW LEVEL MOISTURE TRANSPORT
WILL INCREASE WITH THE NOSE OF THIS INTO THE AREA LONG THE
OCCLUDED FRONT. THE MAIN UPPER LEVEL SYSTEM WILL ALSO BE
APPROACHING TO PROVIDE ADDITIONAL FORCING AND EXPECTING TO SEE
ANOTHER AREA OF SHOWERS AND SOME THUNDERSTORMS DEVELOP BY MID
MORNING AND CONTINUE INTO THE EARLY AFTERNOON. CONSIDERABLE
UNCERTAINTY ON WHAT THE CEILINGS WILL DO WITH THE OCCLUDED FRONT
BUT MOST GUIDANCE SUGGEST A RETURN TO MVFR BEFORE DRIER STARTS TO
SPREAD IN FROM THE WEST TO ALLOW THE RAIN TO END AND VFR
CONDITIONS TO RETURN.
&&
.HYDROLOGY...
ISSUED AT 413 AM CDT SAT OCT 5 2013
CONCERNING THE FLASH FLOOD WATCH...WITH CURRENT CONVECTION EAST
OF THE AREA...MAIN THREAT HAS DIMINISHED. AS AFTERNOON CONVECTION
INCREASES...IT SHOULD BE AFFECTING AREAS THAT HAVE HAD LESS RAIN
OVERALL THAN THOSE WEST OF THE MISS RIVER. AREAS EAST OF THE MISS
RIVER CAN TAKE ANOTHER 1-2 INCHES...ESPECIALLY SWRN WI. THERE IS A
SMALL PROBABILITY OF LOCALIZED FLASH FLOODING TODAY IN THE CENTRAL
WI CORRIDOR IN THE PRE-FRONTAL AIR MASS WHICH WILL STILL HAVE 1.25
TO 1.75 INCH PRECIPITABLE WATER VALUES. RAIN RATES ARE EXPECTED TO
BE HIGH...PROBABLY 2 TO 3 INCH PER HOUR SHOULD CAPE DEVELOP AS
FORECAST. THE SLOW MOVEMENT OF THE FRONT DOES GIVE SOME CONCERN
FOR FLOODING SO WILL ISSUE ANOTHER HYDROLOGICAL DISCUSSION FOR
THAT AREA AND CANCEL THE FLASH FLOOD WATCH.
THERE ARE SOME RIVER RESPONSES CURRENTLY OCCURRING. MONITORING THE
ROOT RIVER BASIN AND THE UPPER IOWA RIVERS BOTH HAVE RESPONSES.
ALSO THE WHITEWATER RIVER MIDDLE FORK THAT RUNS THROUGH WHITEWATER
STATE PARK IS RISING. AT THIS TIME THESE WILL APPROACH FLOOD STAGE
BUT IT IS BELIEVED THEY WILL NOT REACH IT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...BAUMGARDT
SHORT TERM...BAUMGARDT
LONG TERM...BAUMGARDT
AVIATION...04
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
519 PM CDT SAT OCT 5 2013
.UPDATE...
453 PM CDT
ONE CLUSTER OF SEVERE STORMS CONTINUES TO MOVE ACROSS NORTHERN
COOK COUNTY AND OUT OVER LAKE MICHIGAN AT 450 PM CDT WITH WEAKER
THOUGH STILL INTENSE STORMS SOUTHWARD INTO KANKAKEE COUNTY.
SURFACE OBS SHOW AN AREA OF LOW LEVEL CONVERGENCE WHICH HAS
DEVELOPED FROM EASTERN WILL OR CENTRAL KANKAKEE COUNTY
SOUTHWESTWARD TOWARD BLOOMINGTON AND LINCOLN. ANOTHER SHORTWAVE IS
MOVING NORTHEAST ACROSS WESTERN IL WITH AN AREA OF RAIN SHOWERS
CLOSELY TIED TO IT APPROACHING LACON...PEORIA AND SPRINGFIELD. RADAR
MOSAIC ALSO SHOWS SOME SPOTTY ECHOES DEVELOPING ALONG THE
AFOREMENTIONED CONVERGENCE/TROUGH...LIKELY BEING AIDED BY THE
APPROACHING WAVE. EXPECT THAT DEVELOPMENT WILL CONTINUE ALONG THE
TROUGH FROM GARY TO KANKAKEE TO PONTIAC AND MOVE EAST-NORTHEAST
OVER THE NEXT FEW HOURS. RAIN COOLED AIR IS TO THE SOUTH AND EAST
OF THIS AREA WITH TEMPS IN THE 60S BUT MUCH OF THE SOUTHEAST CWA
ITSELF HAS REMAINED NORTH OF THE RAIN ACTIVITY SO INSTABILITY IS
STILL SUFFICIENT. LATEST RAP ANALYSIS SHOWS THE EFFECTIVE SHEAR
HAS INCREASED INTO THE 40 KT RANGE. THEREFORE THE SEVERE THREAT
WILL CONTINUE AND LIKELY BE FOCUSED ALONG AND EAST OF THE GARY TO
KANKAKEE TO PONTIAC LINE WITH A SHORTER TERM THREAT ALSO
CONTINUING ACROSS EASTERN LAKE COUNTY IL AND ADJACENT LAKE
MICHIGAN WATERS AS EXISTING STORM CLUSTER MOVES OFFSHORE. HEAVY
RAINFALL WILL CONTINUE WITH ANY STORMS WITH REPORTS OF 1 TO 1.5
INCHES OF RAIN IN LESS THAN AN HOURS TIME. COVERAGE MAY STILL BE
FAIRLY LOCALIZED...ESPECIALLY WITH THE FAIRLY NARROW LINEAR
STRUCTURE OF NEWLY DEVELOPING STORMS.
AREAS TO THE NORTH AND WEST OF THE AREAS OUTLINED ABOVE WILL
LIKELY SEE ANOTHER BAND OF LIGHTER RAINFALL AND POSSIBLY SOME
EMBEDDED THUNDER ARRIVE FOR THE EARLY EVENING BASED ON THE
MOVEMENT OF CURRENT ACTIVITY TOWARDS PEORIA AND SPRINGFIELD. THE
ADDITIONAL SHORTWAVES NOTED IN THE EARLY AFTERNOON DISCUSSION
BELOW WILL ALSO BRING ADDITIONAL CHANCES FOR ADDITIONAL SHOWERS
AND POSSIBLY A FEW STORMS INTO THE OVERNIGHT...WITH THE WESTERN
EDGE OF THE COVERAGE GRADUALLY SHIFTING EAST WITH EACH WAVE. THE
THUNDER THREAT WILL DIMINISH OVERALL THROUGH THE EVENING AND END
ACROSS THE WESTERN CWA INTO THE OVERNIGHT.
MDB
//PREV DISCUSSION...
215 PM CDT
LATE AFTERNOON AND EARLY EVENING...STORMS AND ASSOCIATED SEVERE
POTENTIAL ARE THE INITIAL FOCUS WITH SHRA/TSRA COVERAGE OVERNIGHT
THE SECOND FOCUS. SURFACE LOW PRESSURE REMAINS CENTERED OVER FAR
EASTERN SOUTH DAKOTA WITH AN OCCLUDED FRONT ARCHING EAST THEN
SOUTHEAST TO A VERY WEAK LOW CIRCULATION NORTHEAST OF DECORAH
IOWA. A COLD FRONT THEN EXTENDS SOUTHWARD ACROSS THE QUAD CITIES
BACK INTO CENTRAL MISSOURI AS NOTED BY THE SHARP DROP OFF IN
DEWPOINTS. THERE IS ANOTHER TROUGH AHEAD OF THE FRONT WHICH MAY BE
THE REMNANTS OF EARLIER OUTFLOW THAT MOVED ACROSS EASTERN
MISSOURI. WATER VAPOR SHOWS SEVERAL UPPER SHORTWAVES MOVING
NORTHEASTWARD AROUND THE EASTERN FLANK OF A BIG CLOSED UPPER LOW
CENTERED OVER SOUTHEAST SOUTH DAKOTA. THE TRACK OF THESE WAVES
WILL BE RIGHT ACROSS THE LOCAL AREA THROUGH TONIGHT. THE FIRST
WAVE IS MOVING INTO EASTERN IOWA WITH ANOTHER WAVE OVER WEST
CENTRAL MISSOURI. A THIRD WAVE IS MOVING ACROSS EASTERN OKLAHOMA
AND WESTERN ARKANSAS. ADDITIONAL WAVES HAVE ALSO BEEN ROLLING
NORTHEAST ACROSS THE LOWER OHIO VALLEY AND CENTRAL IL/IN. ALL OF
THIS MAKES FOR A RATHER MESSY PRECIP SITUATION. CURRENT RADAR
MOSAIC SHOWS SEVERAL CLUSTERS OF BETTER ORGANIZED CONVECTION
MAINLY AFFECTING THE NORTHERN AND SOUTHEASTERN EXTENTS OF THE CWA
TIED TO VARIOUS SHORTWAVES TRAVERSING THE UPPER FLOW. ADDITIONAL
SPOTTY SHOWERS CONTINUE TO POP ACROSS THE CHICAGO METRO AREA WHERE
STRATUS HAS BEEN ERODING AND INSTABILITY GROWING. THE NEXT WAVE
COMING FROM EASTERN IOWA SEEMS TO BE DRIVING ANOTHER CLUSTER OF
WEAKER BUT SLOWLY INTENSIFYING CONVECTION NEAR STERLING AND PERU.
THE IMMEDIATE CONCERN IS THE MORE INTENSE STORMS MOVING INTO THE
SOUTHEASTERN CWA AND THE WEAKER CLUSTER NEAR PERU/STERLING WHICH
MAY INTENSIFY AS IT MOVES INTO THE CWA. WITH LOWEST CLOUDS ERODING
SIGNALING EROSION OF EARLIER CAP ALONG WITH WARMING ATMOSPHERE IS
BETTER PRIMED WITH MIXED LAYER CAPES AROUND 1500 J/KG. EFFECTIVE
SHEAR HAS BEEN ABLE TO INTENSIFY BASED ON LATEST RAP ANALYSIS WITH
AROUND 40 KT EXPECTED. STORMS THAT HAVE AFFECTED THE AREA THUS FAR
HAVE EXHIBITED LOW AND MID LEVEL ROTATION THOUGH IT HAS BEEN WEAK.
IT DOES APPEAR THAT COVERAGE WILL BEGIN TO EXPAND OUTSIDE AREAS
THAT ARE CURRENTLY SEEING STORMS SO WILL CONTINUE TO MONITOR FOR
SEVERE GIVEN THE SUPPORTIVE ATMOSPHERE. COVERAGE IS THE MAIN
QUESTION HOWEVER...WITH OVERALL SEVERE THREAT STILL SEEMING
ISOLATED-SCATTERED. THREATS REMAIN LARGE HAIL AND DAMAGING WIND
GUSTS...WITH ISOLATED TORNADOES STILL POSSIBLE BUT AT THIS POINT
WITH NORTHERN AREAS STILL FAVORED WITH LOCALLY BACKED FLOW A
BETTER POSSIBILITY GIVEN THE WEAK LOW CIRCULATION JUST TO THE
NORTHWEST...BUT HAVE SEEN SEVERAL SITES ACROSS THE CENTRAL AND
EASTERN CWA BACK SLIGHTLY. VERY HIGH LOW LEVEL CAPE IS IN PLACE
ACROSS MUCH OF THE AREA SO CANNOT DISCOUNT THE TORNADO THREAT
ELSEWHERE. WITH PRECIPITABLE WATER VALUES OF 1.5-1.7+ INCHES HEAVY
RAINFALL IS A CONCERN WITH ANY STRONGER STORMS. WITH RECENT DRY
WEATHER AND UNCERTAINTY IN THE COVERAGE OF THE MOST INTENSE STORMS
VS. LESS INTENSE BROADER RAIN/EMBEDDED THUNDER WILL HOLD OFF ON A
FLASH FLOOD WATCH FOR NOW BUT CONTINUE TO MONITOR.
TONIGHT...DURATION OF SEVERE POTENTIAL IS THE NEXT QUESTION. WITH
THE FRONT VERY SLOWLY MOVING EASTWARD THE MOIST AIRMASS WILL
REMAIN IN PLACE BUT SUNSET WILL LIKELY ALLOW INSTABILITY TO WANE
SO SEVERE THREAT SHOULD BE DIMINISHING THROUGH THE EVENING. POPS
HOWEVER LOOK TO REMAIN RATHER HIGH AS THE NEXT SEVERAL SHORTWAVES
MOVE ACROSS. THUS EXPECT THAT THERE WILL BE A FEW MORE ROUNDS OF
SHOWERS AND STORMS TO AFFECT THE AREA...WITH THE THUNDER THREAT
DIMINISHING ACROSS THE WESTERN CWA AS THE FRONT APPROACHES. WILL
NEED TO HANG ONTO POPS THROUGH MUCH OF THE NIGHT ACROSS THE
EASTERN HALF OR SO OF THE CWA...NAMELY BECAUSE THE OK/AR WAVE IS
EXPECTED TO ARRIVE AFTER MIDNIGHT BRINGING MORE SHRA/TSRA WITH IT.
ULTIMATELY...POPS WILL DECREASE FROM WEST TO EAST OVERNIGHT...WITH
A QUICKER EASTWARD PROGRESSION TOWARD DAYBREAK. DRIER AIR WILL
BEGIN TO WORK INTO THE WEST WITH DEWPOINTS FALLING INTO THE 40S
WEST AND 50S EAST OVERNIGHT.
MDB
SUNDAY THROUGH NEXT SATURDAY...
LINGERING UPPER LEVEL CUT OFF LOW AND ASSOCIATED INSTABILITY SHOWERS
INITIALLY WILL BE REPLACED BY HIGH PRESSURE AND A GRADUAL WARMING
TREND LATER IN THE WEEK LASTING INTO SATURDAY. UPPER LOW TO
TRUDGE ACROSS NORTHERN IL LATER SUNDAY AND SUNDAY NIGHT.. AND INTO
NW INDIANA MONDAY MORNING. MODELS APPEAR TO CONTINUE TO STRUGGLE
WITH THIS PROGRESSION WITH BOTH MODEL TO MODEL AND RUN TO RUN
INCONSISTENCIES. 12Z GFS SEEMS SOMEWHAT A MIDDLE GROUND BETWEEN
THE SLOWER NAM/CANADIAN AND FASTER ECMWF AND WILL TREND IN THIS
DIRECTION WITH DETERMINISTIC FORECAST/GRIDS. THE MOST SIGNIFICANT
WEATHER ELEMENT HAVING BEARING ON THE DEPARTURE SPEED OF THE
UPPER LOW IS LIKELY THE DURATION OF THE CHANCE OF INSTABILITY
SHOWERS ASSOCIATED WITH THE THERMAL TROUGH AND STEEPER LAPSE RATES
WITH AND IN THE WAKE OF THE LOW. MIDDLE GROUND APPROACH WOULD HAVE
INSTABILITY SHOWERS ENDING BY ABOUT DUSK MONDAY...BUT SHOULD A
SLOWER SOLUTION LIKE THE NAM/CANADIAN VERIFY...WE COULD SEE
ISOLATED SHOWERS LINGERING INTO TUESDAY. EVENING AND OVERNIGHT
FORECAST SHIFTS WILL MONITOR AND ADJUST ACCORDINGLY.
INITIAL RESIDUAL MOISTURE/LOW CLOUDS AND WIDELY SCT SHOWERS IN THE
WAKE OF THE FRONT WILL EXIT EASTERN ILLINOIS AND NW INDIANA SUNDAY
MORNING AS DRY SLOT PUNCHES INTO THE AREA FROM THE SW. GIVEN DRYING
SW SFC FLOW EXPECT VARIABLE CONDITIONS SUNDAY WITH A FAIR AMOUNT OF
SUNSHINE FOR A PERIOD AT MOST LOCATIONS AND DESPITE PASSAGE OF A
COLD FRONT MAX TEMPS WILL STILL BE NEAR TO ONLY A FEW DEGREES BELOW
SEASONAL NORMS. DEPENDING ON AFOREMENTIONED TIMING OF UPPER LOW...
MAY SEE WIDELY SCATTERED INSTABILITY SHOWERS DEVELOP WEST OF I-39
LATE IN THE DAY.
UPPER LEVEL THERMAL TROUGH TRAVERSES THE AREA EARLY MONDAY. GIVEN
THE PRESENCE OF LIMITED MOISTURE... AND THIS OUT OF PHASE TIMING OF
THE UPPER THERMAL TROUGH WITH THE MIN/MAX DIURNAL HEATING OF THE
DAY... FEEL COVERAGE OF INSTABILITY SHOWERS ON MONDAY WILL BE
SOMEWHAT LIMITED AND WILL CONTINUE TO PLAY LOW POPS FOR THAT EVENT.
INCREASED CLOUDINESS ON MONDAY WILL LIMIT MAX TEMPS TO LOWER 60S..
WITH PERHAPS A FEW AREAS STAYING IN THE UPPER 50S.
UPPER LEVEL HEIGHTS RISE RATHER ABRUPTLY IN THE WAKE OF THE UPPER
CUT OFF LOW TUESDAY AS A PROGRESSIVE UPPER LEVEL RIDGE BUILDS EAST
ACROSS THE PLAINS AND INTO THE WESTERN GREAT LAKES TUESDAY NIGHT
INTO WEDNESDAY. THIS ALLOWS FOR ABUNDANT SUNSHINE AND MILDER TEMPS
TO RETURN TO THE AREA ON TUESDAY... AND BE THE START OF A GRADUAL
WARMING TREND THAT WILL LAST THROUGH THE REST OF THE WEEK.
SPRAWLING HIGH PRESSURE WILL HELP ENABLE MOSTLY SUNNY MILD DAYS AND
MOSTLY CLEAR...COOL...AND CRISP NIGHTS MID TO LATE WEEK. WITH THE
HIGH SLIDING TO JUST EAST OF THE AREA THURS-SAT...AN EXTENDED
PERIOD OF WEAK SOUTHERLY FLOW WILL ALLOW FOR TEMPS TO RETURN TO
ABOVE SEASONAL AVERAGES AND ANOTHER STRETCH OF DELIGHTFUL AUTUMN
WEATHER. THE NEXT CHANCE OF RAIN WILL THEN COME LATE SATURDAY OR
SUNDAY.
ED F
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* SSE WINDS SLOWLY BECOMING SOUTHWEST BY LATE THIS EVENING.
* SCT -SHRA/-TSRA REMAINS POSSIBLE AROUND THE TERMINALS THROUGH
00Z...WITH MVFR CEILINGS IN THIS -TSRA.
RODRIGUEZ
//DISCUSSION...UPDATED 18Z...
VERY MESSY FORECAST FOR THIS AFTERNOON. THE SURFACE LOW IS OVER SE
SOUTH DAKOTA...ITS WARM FRONT IS OVER SOUTHERN WISCONSIN...AND ITS
COLD FRONT IS OVER EASTERN IOWA. STRATUS IS STILL HOLDING STRONG
ACROSS THE REGION...BUT LOOKING OUT THE WINDOW HERE...A FEW HOLES
ARE BEGINNING TO FORM. EXPECTING CIGS TO LIFT TO HIGH END MVFR BY
19Z.
WHILE THE LOW CIGS HAVE CAUSED HAVOC WITH BREAK AWAY POINTS...IT IS
LIMITING OUR MIXING AND HAVE LOWERED WIND GUSTS TO 15KT. THERE IS A
CHANCE WE MAY NOT SEE ANY WIND GUSTS AT ALL THIS AFTN. IN
ADDITION...INSTABILITY IS MUCH LOWER THAN INITIALLY THOUGHT DUE TO
THE STRATUS. THEREFORE MADE SOME CHANGES TO TS CHANCES THIS AFTN.
FIRST AT RFD...THINKING THE TSRA PASSING OVER THE TERMINAL NOW WILL
BE THE MAIN SHOW. EXPECTING JUST SHOWERS AFT 20Z...AND THEN DRY
CONDITIONS AFT 22Z. FOR THE EASTERN TERMINALS...TIMING OF THE
CURRENT AREA OF SCT TS HAS THEM ARRIVING AT 19Z. WIDER COVERAGE IS
EXPECTED BTWN 20Z AND 23Z. SOME OF THE STORMS MAY PULSE UP AND
BECOME STRONG TO SEVERE...BUT WIDESPREAD SEVERE WEATHER IS NO LONGER
EXPECTED.
THE SOUPY ENVIRONMENT OUTSIDE WILL RESULT IN REDUCED VSBYS IF ANY
STRONG SHOWERS OR TSRA PASS OVERHEAD. OBSERVED VSBYS RANGE FROM
2.5SM TO 5SM SO KEPT 3SM GOING. ADDITIONAL SHOWERS ARE EXPECTED
BEHIND THE TSRA FOR A FEW HOURS...THROUGH 03Z. WINDS WILL BECOME SW
TONIGHT ARND 8KT. DESPITE THE DRIER AIR MOVING INTO THE REGION
BEHIND THE COLD FRONT...KEPT MVFR CIGS IN THE TAFS AFT 00Z. ON
SATELLITE THERE IS A REGION OF MVFR CIGS JUST ALONG AND BEHIND THE
FRONT. GUIDANCE INDICATES THAT THE MOISTURE WILL LINGER BEHIND THE
FRONT WITH MVFR CIGS HOLDING ON. WITH NO GOOD REASON TO PULL THE
CIGS...DECIDED TO LEAVE THEM IN.
EXPECTING THE LOWER CIGS TO BURN OFF SUNDAY MORNING WITH SW WINDS
10-15KT. THERE WILL BE A WINDOW OF SCT TO CLEAR SKIES ASSOCIATED
WITH THE LOWS DRY SLOT MOVING OVER THE TERMINALS TOMORROW WITH
ANOTHER ROUND OF MVFR-VFR CIGS BEHIND IT.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* MEDIUM HIGH CONFIDENCE WITH WIND SPEED/DIRECTION.
* MEDIUM HIGH CONFIDENCE WITH -SHRA/-TSRA TRENDS.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...PSBL MVFR CIGS AND CHC SHRA.
MONDAY...MVFR CIGS/VSBYS WITH SHRA. PSBL POCKETS OF IFR CIGS.
TUESDAY THROUGH FRIDAY...VFR.
BEACHLER
&&
.MARINE...
1228 PM CDT
LOW PRESSURE WAS OVER EASTERN SOUTH DAKOTA THIS AFTERNOON WITH A
WITH AN OCCLUDED FRONT INTO WISCONSIN AND A COLD FRONT EXTENDING
SOUTH THROUGH ILLINOIS. THE COLD FRONT WILL MOVE THROUGH SOUTH AND
CENTRAL LAKE MICHIGAN TONIGHT WITH PERIODS OF SHOWERS AND
THUNDERSTORMS. THIS WILL TURN WINDS FROM SOUTH TO SOUTHWEST. STRONG
EASTERLY FLOW WILL CONTINUE NORTH OF THE FRONT OVER NORTHERN LAKE
MICHIGAN. THE FRONT WILL FINALLY REACH NORTHERN LAKE MICHIGAN
SUNDAY AS THE LOW MOVES TO EASTERN LAKE SUPERIOR. THIS WILL ALLOW
WINDS TO DIMINISH AND SHIFT SOUTH TO SOUTHWEST OVER THE NORTH END
OF THE LAKE. THE LOW WILL CONTINUE TO LIFT NORTHEAST INTO EASTERN
ONTARIO SUNDAY NIGHT AND MONDAY BUT A WEAK TROF OF LOW PRESSURE
WILL REMAIN OVER LAKE MICHIGAN. AS THE TROF PASSES...WINDS WILL
SHIFT TO NORTHWEST AND INCREASE MONDAY AFTERNOON. HIGH PRESSURE
WILL GRADUALLY BUILD INTO THE WESTERN GREAT LAKES MONDAY NIGHT AND
TUESDAY MORNING CAUSING WINDS TO BECOME LIGHT AND VARIABLE.
SOUTHERLY FLOW WILL RETURN TO LAKE MICHIGAN FOR AN EXTENDED PERIOD
FROM WEDNESDAY THROUGH THE END OF THE WEEK.
ALLSOPP
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
458 PM CDT SAT OCT 5 2013
.UPDATE...
453 PM CDT
ONE CLUSTER OF SEVERE STORMS CONTINUES TO MOVE ACROSS NORTHERN
COOK COUNTY AND OUT OVER LAKE MICHIGAN AT 450 PM CDT WITH WEAKER
THOUGH STILL INTENSE STORMS SOUTHWARD INTO KANKAKEE COUNTY.
SURFACE OBS SHOW AN AREA OF LOW LEVEL CONVERGENCE WHICH HAS
DEVELOPED FROM EASTERN WILL OR CENTRAL KANKAKEE COUNTY
SOUTHWESTWARD TOWARD BLOOMINGTON AND LINCOLN. ANOTHER SHORTWAVE IS
MOVING NORTHEAST ACROSS WESTERN IL WITH AN AREA OF RAIN SHOWERS
CLOSELY TIED TO IT APPROACHING LACON...PEORIA AND SPRINGFIELD. RADAR
MOSAIC ALSO SHOWS SOME SPOTTY ECHOES DEVELOPING ALONG THE
AFOREMENTIONED CONVERGENCE/TROUGH...LIKELY BEING AIDED BY THE
APPROACHING WAVE. EXPECT THAT DEVELOPMENT WILL CONTINUE ALONG THE
TROUGH FROM GARY TO KANKAKEE TO PONTIAC AND MOVE EAST-NORTHEAST
OVER THE NEXT FEW HOURS. RAIN COOLED AIR IS TO THE SOUTH AND EAST
OF THIS AREA WITH TEMPS IN THE 60S BUT MUCH OF THE SOUTHEAST CWA
ITSELF HAS REMAINED NORTH OF THE RAIN ACTIVITY SO INSTABILITY IS
STILL SUFFICIENT. LATEST RAP ANALYSIS SHOWS THE EFFECTIVE SHEAR
HAS INCREASED INTO THE 40 KT RANGE. THEREFORE THE SEVERE THREAT
WILL CONTINUE AND LIKELY BE FOCUSED ALONG AND EAST OF THE GARY TO
KANKAKEE TO PONTIAC LINE WITH A SHORTER TERM THREAT ALSO
CONTINUING ACROSS EASTERN LAKE COUNTY IL AND ADJACENT LAKE
MICHIGAN WATERS AS EXISTING STORM CLUSTER MOVES OFFSHORE. HEAVY
RAINFALL WILL CONTINUE WITH ANY STORMS WITH REPORTS OF 1 TO 1.5
INCHES OF RAIN IN LESS THAN AN HOURS TIME. COVERAGE MAY STILL BE
FAIRLY LOCALIZED...ESPECIALLY WITH THE FAIRLY NARROW LINEAR
STRUCTURE OF NEWLY DEVELOPING STORMS.
AREAS TO THE NORTH AND WEST OF THE AREAS OUTLINED ABOVE WILL
LIKELY SEE ANOTHER BAND OF LIGHTER RAINFALL AND POSSIBLY SOME
EMBEDDED THUNDER ARRIVE FOR THE EARLY EVENING BASED ON THE
MOVEMENT OF CURRENT ACTIVITY TOWARDS PEORIA AND SPRINGFIELD. THE
ADDITIONAL SHORTWAVES NOTED IN THE EARLY AFTERNOON DISCUSSION
BELOW WILL ALSO BRING ADDITIONAL CHANCES FOR ADDITIONAL SHOWERS
AND POSSIBLY A FEW STORMS INTO THE OVERNIGHT...WITH THE WESTERN
EDGE OF THE COVERAGE GRADUALLY SHIFTING EAST WITH EACH WAVE. THE
THUNDER THREAT WILL DIMINISH OVERALL THROUGH THE EVENING AND END
ACROSS THE WESTERN CWA INTO THE OVERNIGHT.
MDB
//PREV DISCUSSION...
215 PM CDT
LATE AFTERNOON AND EARLY EVENING...STORMS AND ASSOCIATED SEVERE
POTENTIAL ARE THE INITIAL FOCUS WITH SHRA/TSRA COVERAGE OVERNIGHT
THE SECOND FOCUS. SURFACE LOW PRESSURE REMAINS CENTERED OVER FAR
EASTERN SOUTH DAKOTA WITH AN OCCLUDED FRONT ARCHING EAST THEN
SOUTHEAST TO A VERY WEAK LOW CIRCULATION NORTHEAST OF DECORAH
IOWA. A COLD FRONT THEN EXTENDS SOUTHWARD ACROSS THE QUAD CITIES
BACK INTO CENTRAL MISSOURI AS NOTED BY THE SHARP DROP OFF IN
DEWPOINTS. THERE IS ANOTHER TROUGH AHEAD OF THE FRONT WHICH MAY BE
THE REMNANTS OF EARLIER OUTFLOW THAT MOVED ACROSS EASTERN
MISSOURI. WATER VAPOR SHOWS SEVERAL UPPER SHORTWAVES MOVING
NORTHEASTWARD AROUND THE EASTERN FLANK OF A BIG CLOSED UPPER LOW
CENTERED OVER SOUTHEAST SOUTH DAKOTA. THE TRACK OF THESE WAVES
WILL BE RIGHT ACROSS THE LOCAL AREA THROUGH TONIGHT. THE FIRST
WAVE IS MOVING INTO EASTERN IOWA WITH ANOTHER WAVE OVER WEST
CENTRAL MISSOURI. A THIRD WAVE IS MOVING ACROSS EASTERN OKLAHOMA
AND WESTERN ARKANSAS. ADDITIONAL WAVES HAVE ALSO BEEN ROLLING
NORTHEAST ACROSS THE LOWER OHIO VALLEY AND CENTRAL IL/IN. ALL OF
THIS MAKES FOR A RATHER MESSY PRECIP SITUATION. CURRENT RADAR
MOSAIC SHOWS SEVERAL CLUSTERS OF BETTER ORGANIZED CONVECTION
MAINLY AFFECTING THE NORTHERN AND SOUTHEASTERN EXTENTS OF THE CWA
TIED TO VARIOUS SHORTWAVES TRAVERSING THE UPPER FLOW. ADDITIONAL
SPOTTY SHOWERS CONTINUE TO POP ACROSS THE CHICAGO METRO AREA WHERE
STRATUS HAS BEEN ERODING AND INSTABILITY GROWING. THE NEXT WAVE
COMING FROM EASTERN IOWA SEEMS TO BE DRIVING ANOTHER CLUSTER OF
WEAKER BUT SLOWLY INTENSIFYING CONVECTION NEAR STERLING AND PERU.
THE IMMEDIATE CONCERN IS THE MORE INTENSE STORMS MOVING INTO THE
SOUTHEASTERN CWA AND THE WEAKER CLUSTER NEAR PERU/STERLING WHICH
MAY INTENSIFY AS IT MOVES INTO THE CWA. WITH LOWEST CLOUDS ERODING
SIGNALING EROSION OF EARLIER CAP ALONG WITH WARMING ATMOSPHERE IS
BETTER PRIMED WITH MIXED LAYER CAPES AROUND 1500 J/KG. EFFECTIVE
SHEAR HAS BEEN ABLE TO INTENSIFY BASED ON LATEST RAP ANALYSIS WITH
AROUND 40 KT EXPECTED. STORMS THAT HAVE AFFECTED THE AREA THUS FAR
HAVE EXHIBITED LOW AND MID LEVEL ROTATION THOUGH IT HAS BEEN WEAK.
IT DOES APPEAR THAT COVERAGE WILL BEGIN TO EXPAND OUTSIDE AREAS
THAT ARE CURRENTLY SEEING STORMS SO WILL CONTINUE TO MONITOR FOR
SEVERE GIVEN THE SUPPORTIVE ATMOSPHERE. COVERAGE IS THE MAIN
QUESTION HOWEVER...WITH OVERALL SEVERE THREAT STILL SEEMING
ISOLATED-SCATTERED. THREATS REMAIN LARGE HAIL AND DAMAGING WIND
GUSTS...WITH ISOLATED TORNADOES STILL POSSIBLE BUT AT THIS POINT
WITH NORTHERN AREAS STILL FAVORED WITH LOCALLY BACKED FLOW A
BETTER POSSIBILITY GIVEN THE WEAK LOW CIRCULATION JUST TO THE
NORTHWEST...BUT HAVE SEEN SEVERAL SITES ACROSS THE CENTRAL AND
EASTERN CWA BACK SLIGHTLY. VERY HIGH LOW LEVEL CAPE IS IN PLACE
ACROSS MUCH OF THE AREA SO CANNOT DISCOUNT THE TORNADO THREAT
ELSEWHERE. WITH PRECIPITABLE WATER VALUES OF 1.5-1.7+ INCHES HEAVY
RAINFALL IS A CONCERN WITH ANY STRONGER STORMS. WITH RECENT DRY
WEATHER AND UNCERTAINTY IN THE COVERAGE OF THE MOST INTENSE STORMS
VS. LESS INTENSE BROADER RAIN/EMBEDDED THUNDER WILL HOLD OFF ON A
FLASH FLOOD WATCH FOR NOW BUT CONTINUE TO MONITOR.
TONIGHT...DURATION OF SEVERE POTENTIAL IS THE NEXT QUESTION. WITH
THE FRONT VERY SLOWLY MOVING EASTWARD THE MOIST AIRMASS WILL
REMAIN IN PLACE BUT SUNSET WILL LIKELY ALLOW INSTABILITY TO WANE
SO SEVERE THREAT SHOULD BE DIMINISHING THROUGH THE EVENING. POPS
HOWEVER LOOK TO REMAIN RATHER HIGH AS THE NEXT SEVERAL SHORTWAVES
MOVE ACROSS. THUS EXPECT THAT THERE WILL BE A FEW MORE ROUNDS OF
SHOWERS AND STORMS TO AFFECT THE AREA...WITH THE THUNDER THREAT
DIMINISHING ACROSS THE WESTERN CWA AS THE FRONT APPROACHES. WILL
NEED TO HANG ONTO POPS THROUGH MUCH OF THE NIGHT ACROSS THE
EASTERN HALF OR SO OF THE CWA...NAMELY BECAUSE THE OK/AR WAVE IS
EXPECTED TO ARRIVE AFTER MIDNIGHT BRINGING MORE SHRA/TSRA WITH IT.
ULTIMATELY...POPS WILL DECREASE FROM WEST TO EAST OVERNIGHT...WITH
A QUICKER EASTWARD PROGRESSION TOWARD DAYBREAK. DRIER AIR WILL
BEGIN TO WORK INTO THE WEST WITH DEWPOINTS FALLING INTO THE 40S
WEST AND 50S EAST OVERNIGHT.
MDB
SUNDAY THROUGH NEXT SATURDAY...
LINGERING UPPER LEVEL CUT OFF LOW AND ASSOCIATED INSTABILITY SHOWERS
INITIALLY WILL BE REPLACED BY HIGH PRESSURE AND A GRADUAL WARMING
TREND LATER IN THE WEEK LASTING INTO SATURDAY. UPPER LOW TO
TRUDGE ACROSS NORTHERN IL LATER SUNDAY AND SUNDAY NIGHT.. AND INTO
NW INDIANA MONDAY MORNING. MODELS APPEAR TO CONTINUE TO STRUGGLE
WITH THIS PROGRESSION WITH BOTH MODEL TO MODEL AND RUN TO RUN
INCONSISTENCIES. 12Z GFS SEEMS SOMEWHAT A MIDDLE GROUND BETWEEN
THE SLOWER NAM/CANADIAN AND FASTER ECMWF AND WILL TREND IN THIS
DIRECTION WITH DETERMINISTIC FORECAST/GRIDS. THE MOST SIGNIFICANT
WEATHER ELEMENT HAVING BEARING ON THE DEPARTURE SPEED OF THE
UPPER LOW IS LIKELY THE DURATION OF THE CHANCE OF INSTABILITY
SHOWERS ASSOCIATED WITH THE THERMAL TROUGH AND STEEPER LAPSE RATES
WITH AND IN THE WAKE OF THE LOW. MIDDLE GROUND APPROACH WOULD HAVE
INSTABILITY SHOWERS ENDING BY ABOUT DUSK MONDAY...BUT SHOULD A
SLOWER SOLUTION LIKE THE NAM/CANADIAN VERIFY...WE COULD SEE
ISOLATED SHOWERS LINGERING INTO TUESDAY. EVENING AND OVERNIGHT
FORECAST SHIFTS WILL MONITOR AND ADJUST ACCORDINGLY.
INITIAL RESIDUAL MOISTURE/LOW CLOUDS AND WIDELY SCT SHOWERS IN THE
WAKE OF THE FRONT WILL EXIT EASTERN ILLINOIS AND NW INDIANA SUNDAY
MORNING AS DRY SLOT PUNCHES INTO THE AREA FROM THE SW. GIVEN DRYING
SW SFC FLOW EXPECT VARIABLE CONDITIONS SUNDAY WITH A FAIR AMOUNT OF
SUNSHINE FOR A PERIOD AT MOST LOCATIONS AND DESPITE PASSAGE OF A
COLD FRONT MAX TEMPS WILL STILL BE NEAR TO ONLY A FEW DEGREES BELOW
SEASONAL NORMS. DEPENDING ON AFOREMENTIONED TIMING OF UPPER LOW...
MAY SEE WIDELY SCATTERED INSTABILITY SHOWERS DEVELOP WEST OF I-39
LATE IN THE DAY.
UPPER LEVEL THERMAL TROUGH TRAVERSES THE AREA EARLY MONDAY. GIVEN
THE PRESENCE OF LIMITED MOISTURE... AND THIS OUT OF PHASE TIMING OF
THE UPPER THERMAL TROUGH WITH THE MIN/MAX DIURNAL HEATING OF THE
DAY... FEEL COVERAGE OF INSTABILITY SHOWERS ON MONDAY WILL BE
SOMEWHAT LIMITED AND WILL CONTINUE TO PLAY LOW POPS FOR THAT EVENT.
INCREASED CLOUDINESS ON MONDAY WILL LIMIT MAX TEMPS TO LOWER 60S..
WITH PERHAPS A FEW AREAS STAYING IN THE UPPER 50S.
UPPER LEVEL HEIGHTS RISE RATHER ABRUPTLY IN THE WAKE OF THE UPPER
CUT OFF LOW TUESDAY AS A PROGRESSIVE UPPER LEVEL RIDGE BUILDS EAST
ACROSS THE PLAINS AND INTO THE WESTERN GREAT LAKES TUESDAY NIGHT
INTO WEDNESDAY. THIS ALLOWS FOR ABUNDANT SUNSHINE AND MILDER TEMPS
TO RETURN TO THE AREA ON TUESDAY... AND BE THE START OF A GRADUAL
WARMING TREND THAT WILL LAST THROUGH THE REST OF THE WEEK.
SPRAWLING HIGH PRESSURE WILL HELP ENABLE MOSTLY SUNNY MILD DAYS AND
MOSTLY CLEAR...COOL...AND CRISP NIGHTS MID TO LATE WEEK. WITH THE
HIGH SLIDING TO JUST EAST OF THE AREA THURS-SAT...AN EXTENDED
PERIOD OF WEAK SOUTHERLY FLOW WILL ALLOW FOR TEMPS TO RETURN TO
ABOVE SEASONAL AVERAGES AND ANOTHER STRETCH OF DELIGHTFUL AUTUMN
WEATHER. THE NEXT CHANCE OF RAIN WILL THEN COME LATE SATURDAY OR
SUNDAY.
ED F
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* SOUTH WINDS ARND 10 KT. GUSTS ARND 15KT THIS AFTN AT MDW.
* SCATTERED THUNDERSTORMS EXPECTED THRU 23Z. SOME MAY BE STRONG TO
SEVERE.
* MODERATE RAIN THAT MAY CAUSE 6SM VSBY 00Z-03Z.
* WINDS BECOME SW AFTER THE FRONT ALONG WITH MVFR CIGS IMPROVING
TO VFR MID SUNDAY MORNING.
JEE
//DISCUSSION...UPDATED 18Z...
VERY MESSY FORECAST FOR THIS AFTERNOON. THE SURFACE LOW IS OVER SE
SOUTH DAKOTA...ITS WARM FRONT IS OVER SOUTHERN WISCONSIN...AND ITS
COLD FRONT IS OVER EASTERN IOWA. STRATUS IS STILL HOLDING STRONG
ACROSS THE REGION...BUT LOOKING OUT THE WINDOW HERE...A FEW HOLES
ARE BEGINNING TO FORM. EXPECTING CIGS TO LIFT TO HIGH END MVFR BY
19Z.
WHILE THE LOW CIGS HAVE CAUSED HAVOC WITH BREAK AWAY POINTS...IT IS
LIMITING OUR MIXING AND HAVE LOWERED WIND GUSTS TO 15KT. THERE IS A
CHANCE WE MAY NOT SEE ANY WIND GUSTS AT ALL THIS AFTN. IN
ADDITION...INSTABILITY IS MUCH LOWER THAN INITIALLY THOUGHT DUE TO
THE STRATUS. THEREFORE MADE SOME CHANGES TO TS CHANCES THIS AFTN.
FIRST AT RFD...THINKING THE TSRA PASSING OVER THE TERMINAL NOW WILL
BE THE MAIN SHOW. EXPECTING JUST SHOWERS AFT 20Z...AND THEN DRY
CONDITIONS AFT 22Z. FOR THE EASTERN TERMINALS...TIMING OF THE
CURRENT AREA OF SCT TS HAS THEM ARRIVING AT 19Z. WIDER COVERAGE IS
EXPECTED BTWN 20Z AND 23Z. SOME OF THE STORMS MAY PULSE UP AND
BECOME STRONG TO SEVERE...BUT WIDESPREAD SEVERE WEATHER IS NO LONGER
EXPECTED.
THE SOUPY ENVIRONMENT OUTSIDE WILL RESULT IN REDUCED VSBYS IF ANY
STRONG SHOWERS OR TSRA PASS OVERHEAD. OBSERVED VSBYS RANGE FROM
2.5SM TO 5SM SO KEPT 3SM GOING. ADDITIONAL SHOWERS ARE EXPECTED
BEHIND THE TSRA FOR A FEW HOURS...THROUGH 03Z. WINDS WILL BECOME SW
TONIGHT ARND 8KT. DESPITE THE DRIER AIR MOVING INTO THE REGION
BEHIND THE COLD FRONT...KEPT MVFR CIGS IN THE TAFS AFT 00Z. ON
SATELLITE THERE IS A REGION OF MVFR CIGS JUST ALONG AND BEHIND THE
FRONT. GUIDANCE INDICATES THAT THE MOISTURE WILL LINGER BEHIND THE
FRONT WITH MVFR CIGS HOLDING ON. WITH NO GOOD REASON TO PULL THE
CIGS...DECIDED TO LEAVE THEM IN.
EXPECTING THE LOWER CIGS TO BURN OFF SUNDAY MORNING WITH SW WINDS
10-15KT. THERE WILL BE A WINDOW OF SCT TO CLEAR SKIES ASSOCIATED
WITH THE LOWS DRY SLOT MOVING OVER THE TERMINALS TOMORROW WITH
ANOTHER ROUND OF MVFR-VFR CIGS BEHIND IT.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN THUNDERSTORM FORECAST.
* MEDIUM-LOW CONFIDENCE IN CIG HEIGHTS THIS EVENING AND OVERNIGHT.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...PSBL MVFR CIGS AND CHC SHRA.
MONDAY...MVFR CIGS/VSBYS WITH SHRA. PSBL POCKETS OF IFR CIGS.
TUESDAY THROUGH FRIDAY...VFR.
BEACHLER
&&
.MARINE...
1228 PM CDT
LOW PRESSURE WAS OVER EASTERN SOUTH DAKOTA THIS AFTERNOON WITH A
WITH AN OCCLUDED FRONT INTO WISCONSIN AND A COLD FRONT EXTENDING
SOUTH THROUGH ILLINOIS. THE COLD FRONT WILL MOVE THROUGH SOUTH AND
CENTRAL LAKE MICHIGAN TONIGHT WITH PERIODS OF SHOWERS AND
THUNDERSTORMS. THIS WILL TURN WINDS FROM SOUTH TO SOUTHWEST. STRONG
EASTERLY FLOW WILL CONTINUE NORTH OF THE FRONT OVER NORTHERN LAKE
MICHIGAN. THE FRONT WILL FINALLY REACH NORTHERN LAKE MICHIGAN
SUNDAY AS THE LOW MOVES TO EASTERN LAKE SUPERIOR. THIS WILL ALLOW
WINDS TO DIMINISH AND SHIFT SOUTH TO SOUTHWEST OVER THE NORTH END
OF THE LAKE. THE LOW WILL CONTINUE TO LIFT NORTHEAST INTO EASTERN
ONTARIO SUNDAY NIGHT AND MONDAY BUT A WEAK TROF OF LOW PRESSURE
WILL REMAIN OVER LAKE MICHIGAN. AS THE TROF PASSES...WINDS WILL
SHIFT TO NORTHWEST AND INCREASE MONDAY AFTERNOON. HIGH PRESSURE
WILL GRADUALLY BUILD INTO THE WESTERN GREAT LAKES MONDAY NIGHT AND
TUESDAY MORNING CAUSING WINDS TO BECOME LIGHT AND VARIABLE.
SOUTHERLY FLOW WILL RETURN TO LAKE MICHIGAN FOR AN EXTENDED PERIOD
FROM WEDNESDAY THROUGH THE END OF THE WEEK.
ALLSOPP
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
247 PM CDT SAT OCT 5 2013
.DISCUSSION...
215 PM CDT
LATE AFTERNOON AND EARLY EVENING...STORMS AND ASSOCIATED SEVERE
POTENTIAL ARE THE INITIAL FOCUS WITH SHRA/TSRA COVERAGE OVERNIGHT
THE SECOND FOCUS. SURFACE LOW PRESSURE REMAINS CENTERED OVER FAR
EASTERN SOUTH DAKOTA WITH AN OCCLUDED FRONT ARCHING EAST THEN
SOUTHEAST TO A VERY WEAK LOW CIRCULATION NORTHEAST OF DECORAH
IOWA. A COLD FRONT THEN EXTENDS SOUTHWARD ACROSS THE QUAD CITIES
BACK INTO CENTRAL MISSOURI AS NOTED BY THE SHARP DROP OFF IN
DEWPOINTS. THERE IS ANOTHER TROUGH AHEAD OF THE FRONT WHICH MAY BE
THE REMNANTS OF EARLIER OUTFLOW THAT MOVED ACROSS EASTERN
MISSOURI. WATER VAPOR SHOWS SEVERAL UPPER SHORTWAVES MOVING
NORTHEASTWARD AROUND THE EASTERN FLANK OF A BIG CLOSED UPPER LOW
CENTERED OVER SOUTHEAST SOUTH DAKOTA. THE TRACK OF THESE WAVES
WILL BE RIGHT ACROSS THE LOCAL AREA THROUGH TONIGHT. THE FIRST
WAVE IS MOVING INTO EASTERN IOWA WITH ANOTHER WAVE OVER WEST
CENTRAL MISSOURI. A THIRD WAVE IS MOVING ACROSS EASTERN OKLAHOMA
AND WESTERN ARKANSAS. ADDITIONAL WAVES HAVE ALSO BEEN ROLLING
NORTHEAST ACROSS THE LOWER OHIO VALLEY AND CENTRAL IL/IN. ALL OF
THIS MAKES FOR A RATHER MESSY PRECIP SITUATION. CURRENT RADAR
MOSAIC SHOWS SEVERAL CLUSTERS OF BETTER ORGANIZED CONVECTION
MAINLY AFFECTING THE NORTHERN AND SOUTHEASTERN EXTENTS OF THE CWA
TIED TO VARIOUS SHORTWAVES TRAVERSING THE UPPER FLOW. ADDITIONAL
SPOTTY SHOWERS CONTINUE TO POP ACROSS THE CHICAGO METRO AREA WHERE
STRATUS HAS BEEN ERODING AND INSTABILITY GROWING. THE NEXT WAVE
COMING FROM EASTERN IOWA SEEMS TO BE DRIVING ANOTHER CLUSTER OF
WEAKER BUT SLOWLY INTENSIFYING CONVECTION NEAR STERLING AND PERU.
THE IMMEDIATE CONCERN IS THE MORE INTENSE STORMS MOVING INTO THE
SOUTHEASTERN CWA AND THE WEAKER CLUSTER NEAR PERU/STERLING WHICH
MAY INTENSIFY AS IT MOVES INTO THE CWA. WITH LOWEST CLOUDS ERODING
SIGNALING EROSION OF EARLIER CAP ALONG WITH WARMING ATMOSPHERE IS
BETTER PRIMED WITH MIXED LAYER CAPES AROUND 1500 J/KG. EFFECTIVE
SHEAR HAS BEEN ABLE TO INTENSIFY BASED ON LATEST RAP ANALYSIS WITH
AROUND 40 KT EXPECTED. STORMS THAT HAVE AFFECTED THE AREA THUS FAR
HAVE EXHIBITED LOW AND MID LEVEL ROTATION THOUGH IT HAS BEEN WEAK.
IT DOES APPEAR THAT COVERAGE WILL BEGIN TO EXPAND OUTSIDE AREAS
THAT ARE CURRENTLY SEEING STORMS SO WILL CONTINUE TO MONITOR FOR
SEVERE GIVEN THE SUPPORTIVE ATMOSPHERE. COVERAGE IS THE MAIN
QUESTION HOWEVER...WITH OVERALL SEVERE THREAT STILL SEEMING
ISOLATED-SCATTERED. THREATS REMAIN LARGE HAIL AND DAMAGING WIND
GUSTS...WITH ISOLATED TORNADOES STILL POSSIBLE BUT AT THIS POINT
WITH NORTHERN AREAS STILL FAVORED WITH LOCALLY BACKED FLOW A
BETTER POSSIBILITY GIVEN THE WEAK LOW CIRCULATION JUST TO THE
NORTHWEST...BUT HAVE SEEN SEVERAL SITES ACROSS THE CENTRAL AND
EASTERN CWA BACK SLIGHTLY. VERY HIGH LOW LEVEL CAPE IS IN PLACE
ACROSS MUCH OF THE AREA SO CANNOT DISCOUNT THE TORNADO THREAT
ELSEWHERE. WITH PRECIPITABLE WATER VALUES OF 1.5-1.7+ INCHES HEAVY
RAINFALL IS A CONCERN WITH ANY STRONGER STORMS. WITH RECENT DRY
WEATHER AND UNCERTAINTY IN THE COVERAGE OF THE MOST INTENSE STORMS
VS. LESS INTENSE BROADER RAIN/EMBEDDED THUNDER WILL HOLD OFF ON A
FLASH FLOOD WATCH FOR NOW BUT CONTINUE TO MONITOR.
TONIGHT...DURATION OF SEVERE POTENTIAL IS THE NEXT QUESTION. WITH
THE FRONT VERY SLOWLY MOVING EASTWARD THE MOIST AIRMASS WILL
REMAIN IN PLACE BUT SUNSET WILL LIKELY ALLOW INSTABILITY TO WANE
SO SEVERE THREAT SHOULD BE DIMINISHING THROUGH THE EVENING. POPS
HOWEVER LOOK TO REMAIN RATHER HIGH AS THE NEXT SEVERAL SHORTWAVES
MOVE ACROSS. THUS EXPECT THAT THERE WILL BE A FEW MORE ROUNDS OF
SHOWERS AND STORMS TO AFFECT THE AREA...WITH THE THUNDER THREAT
DIMINISHING ACROSS THE WESTERN CWA AS THE FRONT APPROACHES. WILL
NEED TO HANG ONTO POPS THROUGH MUCH OF THE NIGHT ACROSS THE
EASTERN HALF OR SO OF THE CWA...NAMELY BECAUSE THE OK/AR WAVE IS
EXPECTED TO ARRIVE AFTER MIDNIGHT BRINGING MORE SHRA/TSRA WITH IT.
ULTIMATELY...POPS WILL DECREASE FROM WEST TO EAST OVERNIGHT...WITH
A QUICKER EASTWARD PROGRESSION TOWARD DAYBREAK. DRIER AIR WILL
BEGIN TO WORK INTO THE WEST WITH DEWPOINTS FALLING INTO THE 40S
WEST AND 50S EAST OVERNIGHT.
MDB
SUNDAY THROUGH NEXT SATURDAY...
LINGERING UPPER LEVEL CUT OFF LOW AND ASSOCIATED INSTABILITY SHOWERS
INITIALLY WILL BE REPLACED BY HIGH PRESSURE AND A GRADUAL WARMING
TREND LATER IN THE WEEK LASTING INTO SATURDAY. UPPER LOW TO
TRUDGE ACROSS NORTHERN IL LATER SUNDAY AND SUNDAY NIGHT.. AND INTO
NW INDIANA MONDAY MORNING. MODELS APPEAR TO CONTINUE TO STRUGGLE
WITH THIS PROGRESSION WITH BOTH MODEL TO MODEL AND RUN TO RUN
INCONSISTENCIES. 12Z GFS SEEMS SOMEWHAT A MIDDLE GROUND BETWEEN
THE SLOWER NAM/CANADIAN AND FASTER ECMWF AND WILL TREND IN THIS
DIRECTION WITH DETERMINISTIC FORECAST/GRIDS. THE MOST SIGNIFICANT
WEATHER ELEMENT HAVING BEARING ON THE DEPARTURE SPEED OF THE
UPPER LOW IS LIKELY THE DURATION OF THE CHANCE OF INSTABILITY
SHOWERS ASSOCIATED WITH THE THERMAL TROUGH AND STEEPER LAPSE RATES
WITH AND IN THE WAKE OF THE LOW. MIDDLE GROUND APPROACH WOULD HAVE
INSTABILITY SHOWERS ENDING BY ABOUT DUSK MONDAY...BUT SHOULD A
SLOWER SOLUTION LIKE THE NAM/CANADIAN VERIFY...WE COULD SEE
ISOLATED SHOWERS LINGERING INTO TUESDAY. EVENING AND OVERNIGHT
FORECAST SHIFTS WILL MONITOR AND ADJUST ACCORDINGLY.
INITIAL RESIDUAL MOISTURE/LOW CLOUDS AND WIDELY SCT SHOWERS IN THE
WAKE OF THE FRONT WILL EXIT EASTERN ILLINOIS AND NW INDIANA SUNDAY
MORNING AS DRY SLOT PUNCHES INTO THE AREA FROM THE SW. GIVEN DRYING
SW SFC FLOW EXPECT VARIABLE CONDITIONS SUNDAY WITH A FAIR AMOUNT OF
SUNSHINE FOR A PERIOD AT MOST LOCATIONS AND DESPITE PASSAGE OF A
COLD FRONT MAX TEMPS WILL STILL BE NEAR TO ONLY A FEW DEGREES BELOW
SEASONAL NORMS. DEPENDING ON AFOREMENTIONED TIMING OF UPPER LOW...
MAY SEE WIDELY SCATTERED INSTABILITY SHOWERS DEVELOP WEST OF I-39
LATE IN THE DAY.
UPPER LEVEL THERMAL TROUGH TRAVERSES THE AREA EARLY MONDAY. GIVEN
THE PRESENCE OF LIMITED MOISTURE... AND THIS OUT OF PHASE TIMING OF
THE UPPER THERMAL TROUGH WITH THE MIN/MAX DIURNAL HEATING OF THE
DAY... FEEL COVERAGE OF INSTABILITY SHOWERS ON MONDAY WILL BE
SOMEWHAT LIMITED AND WILL CONTINUE TO PLAY LOW POPS FOR THAT EVENT.
INCREASED CLOUDINESS ON MONDAY WILL LIMIT MAX TEMPS TO LOWER 60S..
WITH PERHAPS A FEW AREAS STAYING IN THE UPPER 50S.
UPPER LEVEL HEIGHTS RISE RATHER ABRUPTLY IN THE WAKE OF THE UPPER
CUT OFF LOW TUESDAY AS A PROGRESSIVE UPPER LEVEL RIDGE BUILDS EAST
ACROSS THE PLAINS AND INTO THE WESTERN GREAT LAKES TUESDAY NIGHT
INTO WEDNESDAY. THIS ALLOWS FOR ABUNDANT SUNSHINE AND MILDER TEMPS
TO RETURN TO THE AREA ON TUESDAY... AND BE THE START OF A GRADUAL
WARMING TREND THAT WILL LAST THROUGH THE REST OF THE WEEK.
SPRAWLING HIGH PRESSURE WILL HELP ENABLE MOSTLY SUNNY MILD DAYS AND
MOSTLY CLEAR...COOL...AND CRISP NIGHTS MID TO LATE WEEK. WITH THE
HIGH SLIDING TO JUST EAST OF THE AREA THURS-SAT...AN EXTENDED
PERIOD OF WEAK SOUTHERLY FLOW WILL ALLOW FOR TEMPS TO RETURN TO
ABOVE SEASONAL AVERAGES AND ANOTHER STRETCH OF DELIGHTFUL AUTUMN
WEATHER. THE NEXT CHANCE OF RAIN WILL THEN COME LATE SATURDAY OR
SUNDAY.
ED F
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* SOUTH WINDS ARND 10 KT. GUSTS ARND 15KT THIS AFTN AT MDW.
* SCATTERED THUNDERSTORMS EXPECTED THRU 23Z. SOME MAY BE STRONG TO
SEVERE.
* MODERATE RAIN THAT MAY CAUSE 6SM VSBY 00Z-03Z.
* WINDS BECOME SW AFTER THE FRONT ALONG WITH MVFR CIGS IMPROVING
TO VFR MID SUNDAY MORNING.
JEE
//DISCUSSION...UPDATED 18Z...
VERY MESSY FORECAST FOR THIS AFTERNOON. THE SURFACE LOW IS OVER SE
SOUTH DAKOTA...ITS WARM FRONT IS OVER SOUTHERN WISCONSIN...AND ITS
COLD FRONT IS OVER EASTERN IOWA. STRATUS IS STILL HOLDING STRONG
ACROSS THE REGION...BUT LOOKING OUT THE WINDOW HERE...A FEW HOLES
ARE BEGINNING TO FORM. EXPECTING CIGS TO LIFT TO HIGH END MVFR BY
19Z.
WHILE THE LOW CIGS HAVE CAUSED HAVOC WITH BREAK AWAY POINTS...IT IS
LIMITING OUR MIXING AND HAVE LOWERED WIND GUSTS TO 15KT. THERE IS A
CHANCE WE MAY NOT SEE ANY WIND GUSTS AT ALL THIS AFTN. IN
ADDITION...INSTABILITY IS MUCH LOWER THAN INITIALLY THOUGHT DUE TO
THE STRATUS. THEREFORE MADE SOME CHANGES TO TS CHANCES THIS AFTN.
FIRST AT RFD...THINKING THE TSRA PASSING OVER THE TERMINAL NOW WILL
BE THE MAIN SHOW. EXPECTING JUST SHOWERS AFT 20Z...AND THEN DRY
CONDITIONS AFT 22Z. FOR THE EASTERN TERMINALS...TIMING OF THE
CURRENT AREA OF SCT TS HAS THEM ARRIVING AT 19Z. WIDER COVERAGE IS
EXPECTED BTWN 20Z AND 23Z. SOME OF THE STORMS MAY PULSE UP AND
BECOME STRONG TO SEVERE...BUT WIDESPREAD SEVERE WEATHER IS NO LONGER
EXPECTED.
THE SOUPY ENVIRONMENT OUTSIDE WILL RESULT IN REDUCED VSBYS IF ANY
STRONG SHOWERS OR TSRA PASS OVERHEAD. OBSERVED VSBYS RANGE FROM
2.5SM TO 5SM SO KEPT 3SM GOING. ADDITIONAL SHOWERS ARE EXPECTED
BEHIND THE TSRA FOR A FEW HOURS...THROUGH 03Z. WINDS WILL BECOME SW
TONIGHT ARND 8KT. DESPITE THE DRIER AIR MOVING INTO THE REGION
BEHIND THE COLD FRONT...KEPT MVFR CIGS IN THE TAFS AFT 00Z. ON
SATELLITE THERE IS A REGION OF MVFR CIGS JUST ALONG AND BEHIND THE
FRONT. GUIDANCE INDICATES THAT THE MOISTURE WILL LINGER BEHIND THE
FRONT WITH MVFR CIGS HOLDING ON. WITH NO GOOD REASON TO PULL THE
CIGS...DECIDED TO LEAVE THEM IN.
EXPECTING THE LOWER CIGS TO BURN OFF SUNDAY MORNING WITH SW WINDS
10-15KT. THERE WILL BE A WINDOW OF SCT TO CLEAR SKIES ASSOCIATED
WITH THE LOWS DRY SLOT MOVING OVER THE TERMINALS TOMORROW WITH
ANOTHER ROUND OF MVFR-VFR CIGS BEHIND IT.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN THUNDERSTORM FORECAST.
* MEDIUM-LOW CONFIDENCE IN CIG HEIGHTS THIS EVENING AND OVERNIGHT.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...PSBL MVFR CIGS AND CHC SHRA.
MONDAY...MVFR CIGS/VSBYS WITH SHRA. PSBL POCKETS OF IFR CIGS.
TUESDAY THROUGH FRIDAY...VFR.
BEACHLER
&&
.MARINE...
1228 PM CDT
LOW PRESSURE WAS OVER EASTERN SOUTH DAKOTA THIS AFTERNOON WITH A
WITH AN OCCLUDED FRONT INTO WISCONSIN AND A COLD FRONT EXTENDING
SOUTH THROUGH ILLINOIS. THE COLD FRONT WILL MOVE THROUGH SOUTH AND
CENTRAL LAKE MICHIGAN TONIGHT WITH PERIODS OF SHOWERS AND
THUNDERSTORMS. THIS WILL TURN WINDS FROM SOUTH TO SOUTHWEST. STRONG
EASTERLY FLOW WILL CONTINUE NORTH OF THE FRONT OVER NORTHERN LAKE
MICHIGAN. THE FRONT WILL FINALLY REACH NORTHERN LAKE MICHIGAN
SUNDAY AS THE LOW MOVES TO EASTERN LAKE SUPERIOR. THIS WILL ALLOW
WINDS TO DIMINISH AND SHIFT SOUTH TO SOUTHWEST OVER THE NORTH END
OF THE LAKE. THE LOW WILL CONTINUE TO LIFT NORTHEAST INTO EASTERN
ONTARIO SUNDAY NIGHT AND MONDAY BUT A WEAK TROF OF LOW PRESSURE
WILL REMAIN OVER LAKE MICHIGAN. AS THE TROF PASSES...WINDS WILL
SHIFT TO NORTHWEST AND INCREASE MONDAY AFTERNOON. HIGH PRESSURE
WILL GRADUALLY BUILD INTO THE WESTERN GREAT LAKES MONDAY NIGHT AND
TUESDAY MORNING CAUSING WINDS TO BECOME LIGHT AND VARIABLE.
SOUTHERLY FLOW WILL RETURN TO LAKE MICHIGAN FOR AN EXTENDED PERIOD
FROM WEDNESDAY THROUGH THE END OF THE WEEK.
ALLSOPP
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
216 PM CDT SAT OCT 5 2013
.DISCUSSION...
215 PM CDT
LATE AFTERNOON AND EARLY EVENING...STORMS AND ASSOCIATED SEVERE
POTENTIAL ARE THE INITIAL FOCUS WITH SHRA/TSRA COVERAGE OVERNIGHT
THE SECOND FOCUS. SURFACE LOW PRESSURE REMAINS CENTERED OVER FAR
EASTERN SOUTH DAKOTA WITH AN OCCLUDED FRONT ARCHING EAST THEN
SOUTHEAST TO A VERY WEAK LOW CIRCULATION NORTHEAST OF DECORAH
IOWA. A COLD FRONT THEN EXTENDS SOUTHWARD ACROSS THE QUAD CITIES
BACK INTO CENTRAL MISSOURI AS NOTED BY THE SHARP DROP OFF IN
DEWPOINTS. THERE IS ANOTHER TROUGH AHEAD OF THE FRONT WHICH MAY BE
THE REMNANTS OF EARLIER OUTFLOW THAT MOVED ACROSS EASTERN
MISSOURI. WATER VAPOR SHOWS SEVERAL UPPER SHORTWAVES MOVING
NORTHEASTWARD AROUND THE EASTERN FLANK OF A BIG CLOSED UPPER LOW
CENTERED OVER SOUTHEAST SOUTH DAKOTA. THE TRACK OF THESE WAVES
WILL BE RIGHT ACROSS THE LOCAL AREA THROUGH TONIGHT. THE FIRST
WAVE IS MOVING INTO EASTERN IOWA WITH ANOTHER WAVE OVER WEST
CENTRAL MISSOURI. A THIRD WAVE IS MOVING ACROSS EASTERN OKLAHOMA
AND WESTERN ARKANSAS. ADDITIONAL WAVES HAVE ALSO BEEN ROLLING
NORTHEAST ACROSS THE LOWER OHIO VALLEY AND CENTRAL IL/IN. ALL OF
THIS MAKES FOR A RATHER MESSY PRECIP SITUATION. CURRENT RADAR
MOSAIC SHOWS SEVERAL CLUSTERS OF BETTER ORGANIZED CONVECTION
MAINLY AFFECTING THE NORTHERN AND SOUTHEASTERN EXTENTS OF THE CWA
TIED TO VARIOUS SHORTWAVES TRAVERSING THE UPPER FLOW. ADDITIONAL
SPOTTY SHOWERS CONTINUE TO POP ACROSS THE CHICAGO METRO AREA WHERE
STRATUS HAS BEEN ERODING AND INSTABILITY GROWING. THE NEXT WAVE
COMING FROM EASTERN IOWA SEEMS TO BE DRIVING ANOTHER CLUSTER OF
WEAKER BUT SLOWLY INTENSIFYING CONVECTION NEAR STERLING AND PERU.
THE IMMEDIATE CONCERN IS THE MORE INTENSE STORMS MOVING INTO THE
SOUTHEASTERN CWA AND THE WEAKER CLUSTER NEAR PERU/STERLING WHICH
MAY INTENSIFY AS IT MOVES INTO THE CWA. WITH LOWEST CLOUDS ERODING
SIGNALING EROSION OF EARLIER CAP ALONG WITH WARMING ATMOSPHERE IS
BETTER PRIMED WITH MIXED LAYER CAPES AROUND 1500 J/KG. EFFECTIVE
SHEAR HAS BEEN ABLE TO INTENSIFY BASED ON LATEST RAP ANALYSIS WITH
AROUND 40 KT EXPECTED. STORMS THAT HAVE AFFECTED THE AREA THUS FAR
HAVE EXHIBITED LOW AND MID LEVEL ROTATION THOUGH IT HAS BEEN WEAK.
IT DOES APPEAR THAT COVERAGE WILL BEGIN TO EXPAND OUTSIDE AREAS
THAT ARE CURRENTLY SEEING STORMS SO WILL CONTINUE TO MONITOR FOR
SEVERE GIVEN THE SUPPORTIVE ATMOSPHERE. COVERAGE IS THE MAIN
QUESTION HOWEVER...WITH OVERALL SEVERE THREAT STILL SEEMING
ISOLATED-SCATTERED. THREATS REMAIN LARGE HAIL AND DAMAGING WIND
GUSTS...WITH ISOLATED TORNADOES STILL POSSIBLE BUT AT THIS POINT
WITH NORTHERN AREAS STILL FAVORED WITH LOCALLY BACKED FLOW A
BETTER POSSIBILITY GIVEN THE WEAK LOW CIRCULATION JUST TO THE
NORTHWEST...BUT HAVE SEEN SEVERAL SITES ACROSS THE CENTRAL AND
EASTERN CWA BACK SLIGHTLY. VERY HIGH LOW LEVEL CAPE IS IN PLACE
ACROSS MUCH OF THE AREA SO CANNOT DISCOUNT THE TORNADO THREAT
ELSEWHERE. WITH PRECIPITABLE WATER VALUES OF 1.5-1.7+ INCHES HEAVY
RAINFALL IS A CONCERN WITH ANY STRONGER STORMS. WITH RECENT DRY
WEATHER AND UNCERTAINTY IN THE COVERAGE OF THE MOST INTENSE STORMS
VS. LESS INTENSE BROADER RAIN/EMBEDDED THUNDER WILL HOLD OFF ON A
FLASH FLOOD WATCH FOR NOW BUT CONTINUE TO MONITOR.
TONIGHT...DURATION OF SEVERE POTENTIAL IS THE NEXT QUESTION. WITH
THE FRONT VERY SLOWLY MOVING EASTWARD THE MOIST AIRMASS WILL
REMAIN IN PLACE BUT SUNSET WILL LIKELY ALLOW INSTABILITY TO WANE
SO SEVERE THREAT SHOULD BE DIMINISHING THROUGH THE EVENING. POPS
HOWEVER LOOK TO REMAIN RATHER HIGH AS THE NEXT SEVERAL SHORTWAVES
MOVE ACROSS. THUS EXPECT THAT THERE WILL BE A FEW MORE ROUNDS OF
SHOWERS AND STORMS TO AFFECT THE AREA...WITH THE THUNDER THREAT
DIMINISHING ACROSS THE WESTERN CWA AS THE FRONT APPROACHES. WILL
NEED TO HANG ONTO POPS THROUGH MUCH OF THE NIGHT ACROSS THE
EASTERN HALF OR SO OF THE CWA...NAMELY BECAUSE THE OK/AR WAVE IS
EXPECTED TO ARRIVE AFTER MIDNIGHT BRINGING MORE SHRA/TSRA WITH IT.
ULTIMATELY...POPS WILL DECREASE FROM WEST TO EAST OVERNIGHT...WITH
A QUICKER EASTWARD PROGRESSION TOWARD DAYBREAK. DRIER AIR WILL
BEGIN TO WORK INTO THE WEST WITH DEWPOINTS FALLING INTO THE 40S
WEST AND 50S EAST OVERNIGHT.
MDB
SUNDAY THROUGH NEXT SATURDAY...
LINGERING UPPER LEVEL CUT OFF LOW AND ASSOCIATED INSTABILITY SHOWERS
INITIALLY WILL BE REPLACED BY HIGH PRESSURE AND A GRADUAL WARMING
TREND LATER IN THE WEEK LASTING INTO SATURDAY. UPPER LOW TO
TRUDGE ACROSS NORTHERN IL LATER SUNDAY AND SUNDAY NIGHT.. AND INTO
NW INDIANA MONDAY MORNING. MODELS APPEAR TO CONTINUE TO STRUGGLE
WITH THIS PROGRESSION WITH BOTH MODEL TO MODEL AND RUN TO RUN
INCONSISTENCIES. 12Z GFS SEEMS SOMEWHAT A MIDDLE GROUND BETWEEN
THE SLOWER NAM/CANADIAN AND FASTER ECMWF AND WILL TREND IN THIS
DIRECTION WITH DETERMINISTIC FORECAST/GRIDS. THE MOST SIGNIFICANT
WEATHER ELEMENT HAVING BEARING ON THE DEPARTURE SPEED OF THE
UPPER LOW IS LIKELY THE DURATION OF THE CHANCE OF INSTABILITY
SHOWERS ASSOCIATED WITH THE THERMAL TROUGH AND STEEPER LAPSE RATES
WITH AND IN THE WAKE OF THE LOW. MIDDLE GROUND APPROACH WOULD HAVE
INSTABILITY SHOWERS ENDING BY ABOUT DUSK MONDAY...BUT SHOULD A
SLOWER SOLUTION LIKE THE NAM/CANADIAN VERIFY...WE COULD SEE
ISOLATED SHOWERS LINGERING INTO TUESDAY. EVENING AND OVERNIGHT
FORECAST SHIFTS WILL MONITOR AND ADJUST ACCORDINGLY.
INITIAL RESIDUAL MOISTURE/LOW CLOUDS AND WIDELY SCT SHOWERS IN THE
WAKE OF THE FRONT WILL EXIT EASTERN ILLINOIS AND NW INDIANA SUNDAY
MORNING AS DRY SLOT PUNCHES INTO THE AREA FROM THE SW. GIVEN DRYING
SW SFC FLOW EXPECT VARIABLE CONDITIONS SUNDAY WITH A FAIR AMOUNT OF
SUNSHINE FOR A PERIOD AT MOST LOCATIONS AND DESPITE PASSAGE OF A
COLD FRONT MAX TEMPS WILL STILL BE NEAR TO ONLY A FEW DEGREES BELOW
SEASONAL NORMS. DEPENDING ON AFOREMENTIONED TIMING OF UPPER LOW...
MAY SEE WIDELY SCATTERED INSTABILITY SHOWERS DEVELOP WEST OF I-39
LATE IN THE DAY.
UPPER LEVEL THERMAL TROUGH TRAVERSES THE AREA EARLY MONDAY. GIVEN
THE PRESENCE OF LIMITED MOISTURE... AND THIS OUT OF PHASE TIMING OF
THE UPPER THERMAL TROUGH WITH THE MIN/MAX DIURNAL HEATING OF THE
DAY... FEEL COVERAGE OF INSTABILITY SHOWERS ON MONDAY WILL BE
SOMEWHAT LIMITED AND WILL CONTINUE TO PLAY LOW POPS FOR THAT EVENT.
INCREASED CLOUDINESS ON MONDAY WILL LIMIT MAX TEMPS TO LOWER 60S..
WITH PERHAPS A FEW AREAS STAYING IN THE UPPER 50S.
UPPER LEVEL HEIGHTS RISE RATHER ABRUPTLY IN THE WAKE OF THE UPPER
CUT OFF LOW TUESDAY AS A PROGRESSIVE UPPER LEVEL RIDGE BUILDS EAST
ACROSS THE PLAINS AND INTO THE WESTERN GREAT LAKES TUESDAY NIGHT
INTO WEDNESDAY. THIS ALLOWS FOR ABUNDANT SUNSHINE AND MILDER TEMPS
TO RETURN TO THE AREA ON TUESDAY... AND BE THE START OF A GRADUAL
WARMING TREND THAT WILL LAST THROUGH THE REST OF THE WEEK.
SPRAWLING HIGH PRESSURE WILL HELP ENABLE MOSTLY SUNNY MILD DAYS AND
MOSTLY CLEAR...COOL...AND CRISP NIGHTS MID TO LATE WEEK. WITH THE
HIGH SLIDING TO JUST EAST OF THE AREA THURS-SAT...AN EXTENDED
PERIOD OF WEAK SOUTHERLY FLOW WILL ALLOW FOR TEMPS TO RETURN TO
ABOVE SEASONAL AVERAGES AND ANOTHER STRETCH OF DELIGHTFUL AUTUMN
WEATHER. THE NEXT CHANCE OF RAIN WILL THEN COME LATE SATURDAY OR
SUNDAY.
ED F
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* SOUTH WINDS ARND 10 KT WITH GUSTS ARND 15KT THIS AFTN.
* SCATTERED THUNDERSTORMS EXPECTED AFT 19Z WITH MORE WIDESPREAD
STORMS EXPECTED 20Z-23Z. SOME MAY BE STRONG TO SEVERE.
* MODERATE RAIN THAT MAY CAUSE 6SM VSBY 00Z-03Z.
* WINDS BECOME SW AFTER THE FRONT ALONG WITH MVFR CIGS IMPROVING
TO VFR MID SUNDAY MORNING.
JEE
//DISCUSSION...UPDATED 18Z...
VERY MESSY FORECAST FOR THIS AFTERNOON. THE SURFACE LOW IS OVER SE
SOUTH DAKOTA...ITS WARM FRONT IS OVER SOUTHERN WISCONSIN...AND ITS
COLD FRONT IS OVER EASTERN IOWA. STRATUS IS STILL HOLDING STRONG
ACROSS THE REGION...BUT LOOKING OUT THE WINDOW HERE...A FEW HOLES
ARE BEGINNING TO FORM. EXPECTING CIGS TO LIFT TO HIGH END MVFR BY
19Z.
WHILE THE LOW CIGS HAVE CAUSED HAVOC WITH BREAK AWAY POINTS...IT IS
LIMITING OUR MIXING AND HAVE LOWERED WIND GUSTS TO 15KT. THERE IS A
CHANCE WE MAY NOT SEE ANY WIND GUSTS AT ALL THIS AFTN. IN
ADDITION...INSTABILITY IS MUCH LOWER THAN INITIALLY THOUGHT DUE TO
THE STRATUS. THEREFORE MADE SOME CHANGES TO TS CHANCES THIS AFTN.
FIRST AT RFD...THINKING THE TSRA PASSING OVER THE TERMINAL NOW WILL
BE THE MAIN SHOW. EXPECTING JUST SHOWERS AFT 20Z...AND THEN DRY
CONDITIONS AFT 22Z. FOR THE EASTERN TERMINALS...TIMING OF THE
CURRENT AREA OF SCT TS HAS THEM ARRIVING AT 19Z. WIDER COVERAGE IS
EXPECTED BTWN 20Z AND 23Z. SOME OF THE STORMS MAY PULSE UP AND
BECOME STRONG TO SEVERE...BUT WIDESPREAD SEVERE WEATHER IS NO LONGER
EXPECTED.
THE SOUPY ENVIRONMENT OUTSIDE WILL RESULT IN REDUCED VSBYS IF ANY
STRONG SHOWERS OR TSRA PASS OVERHEAD. OBSERVED VSBYS RANGE FROM
2.5SM TO 5SM SO KEPT 3SM GOING. ADDITIONAL SHOWERS ARE EXPECTED
BEHIND THE TSRA FOR A FEW HOURS...THROUGH 03Z. WINDS WILL BECOME SW
TONIGHT ARND 8KT. DESPITE THE DRIER AIR MOVING INTO THE REGION
BEHIND THE COLD FRONT...KEPT MVFR CIGS IN THE TAFS AFT 00Z. ON
SATELLITE THERE IS A REGION OF MVFR CIGS JUST ALONG AND BEHIND THE
FRONT. GUIDANCE INDICATES THAT THE MOISTURE WILL LINGER BEHIND THE
FRONT WITH MVFR CIGS HOLDING ON. WITH NO GOOD REASON TO PULL THE
CIGS...DECIDED TO LEAVE THEM IN.
EXPECTING THE LOWER CIGS TO BURN OFF SUNDAY MORNING WITH SW WINDS
10-15KT. THERE WILL BE A WINDOW OF SCT TO CLEAR SKIES ASSOCIATED
WITH THE LOWS DRY SLOT MOVING OVER THE TERMINALS TOMORROW WITH
ANOTHER ROUND OF MVFR-VFR CIGS BEHIND IT.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN THUNDERSTORM TRENDS...MEDIUM-HIGH CONFIDENCE
IN TIMING.
* MEDIUM-LOW CONFIDENCE IN CIG HEIGHTS THIS EVENING AND OVERNIGHT.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...PSBL MVFR CIGS AND CHC SHRA.
MONDAY...MVFR CIGS/VSBYS WITH SHRA. PSBL POCKETS OF IFR CIGS.
TUESDAY THROUGH FRIDAY...VFR.
BEACHLER
&&
.MARINE...
1228 PM CDT
LOW PRESSURE WAS OVER EASTERN SOUTH DAKOTA THIS AFTERNOON WITH A
WITH AN OCCLUDED FRONT INTO WISCONSIN AND A COLD FRONT EXTENDING
SOUTH THROUGH ILLINOIS. THE COLD FRONT WILL MOVE THROUGH SOUTH AND
CENTRAL LAKE MICHIGAN TONIGHT WITH PERIODS OF SHOWERS AND
THUNDERSTORMS. THIS WILL TURN WINDS FROM SOUTH TO SOUTHWEST. STRONG
EASTERLY FLOW WILL CONTINUE NORTH OF THE FRONT OVER NORTHERN LAKE
MICHIGAN. THE FRONT WILL FINALLY REACH NORTHERN LAKE MICHIGAN
SUNDAY AS THE LOW MOVES TO EASTERN LAKE SUPERIOR. THIS WILL ALLOW
WINDS TO DIMINISH AND SHIFT SOUTH TO SOUTHWEST OVER THE NORTH END
OF THE LAKE. THE LOW WILL CONTINUE TO LIFT NORTHEAST INTO EASTERN
ONTARIO SUNDAY NIGHT AND MONDAY BUT A WEAK TROF OF LOW PRESSURE
WILL REMAIN OVER LAKE MICHIGAN. AS THE TROF PASSES...WINDS WILL
SHIFT TO NORTHWEST AND INCREASE MONDAY AFTERNOON. HIGH PRESSURE
WILL GRADUALLY BUILD INTO THE WESTERN GREAT LAKES MONDAY NIGHT AND
TUESDAY MORNING CAUSING WINDS TO BECOME LIGHT AND VARIABLE.
SOUTHERLY FLOW WILL RETURN TO LAKE MICHIGAN FOR AN EXTENDED PERIOD
FROM WEDNESDAY THROUGH THE END OF THE WEEK.
ALLSOPP
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
154 PM EDT SAT OCT 5 2013
.SYNOPSIS...
ISSUED AT 342 AM EDT SAT OCT 5 2013
A LARGE LOW PRESSURE SYSTEM WILL BRING INCREASING CHANCES FOR
SHOWERS AND THUNDERSTORMS THROUGH EARLY NEXT WEEK. THIS LOW
PRESSURE SYSTEM WILL ALSO SEND A COLD FRONT THROUGH THE AREA WITH
TEMPERATURES RETURNING TO NEAR NORMAL VALUES AFTER HIGHS IN THE
LOW 80S AGAIN TODAY.
&&
.UPDATE...
ISSUED AT 1125 AM EDT SAT OCT 5 2013
A COUPLE OF SMALL SCALE EMBEDDED WAVES IN SOUTHWEST UPPER FLOW
HAVE RESULTED IN CLUSTERS OF SHOWERS AND ISOLATED THUNDERSTORMS
ACROSS CENTRAL/NORTHEAST INDIANA. ADDITIONAL SCATTERED SHOWERS AND
THUNDERSTORMS CONTINUE TO DEVELOP OTHER SOUTHERN LAKE MICHIGAN IN
CLOSER PROXIMITY TO MORE PRONOUNCED UPPER LEVEL DIFFLUENCE
DOWNSTREAM OF VIGOROUS NORTHERN PLAINS UPPER TROUGH. AREAS
ROUGHLY ALONG AND SOUTHEAST OF A HUNTINGTON INDIANA TO FORT WAYNE
INDIANA TO DEFIANCE LINE HAVE LIKELY RECEIVED BETWEEN A HALF INCH
TO AN INCH OF RAINFALL SO FAR THIS MORNING. SOME OF THESE SAME
LOCATIONS ACROSS NORTHWEST OHIO HAVE ALSO RECEIVED HEAVY RAINFALL
YESTERDAY. GIVEN INCREASING CONFIDENCE IN SIGNIFICANT RAINFALL
LATE TONIGHT INTO SUNDAY EVENING ALONG WITH RECENT HEAVY
RAIN...WILL BE ISSUING A FLASH FLOOD WATCH SHORTLY FOR FAR
NORTHEAST INDIANA...PORTIONS OF SOUTH CENTRAL LOWER
MICHIGAN....AND ALL OF NORTHWEST OHIO COUNTIES FROM 06Z TONIGHT TO
06Z MONDAY.
IN TERMS OF CONVECTIVE POTENTIAL...15Z RUC ANALYSIS DEPICTS
1000-1500 J/KG OF 100 HPA MLCAPES ACROSS MUCH OF WESTERN HALF OF
THE AREA WITH 0 TO 6 KM BULK SHEAR VALUES IN THE 25 TO 30 KNOT
RANGE. DESPITE SIGNIFICANT CLOUD COVER...DEEP MOISTURE PROFILES
SHOULD CONTINUE TO YIELD CAPES ON THE ORDER OF 1000-1500 J/KG
THIS AFTERNOON. DEEP LAYER SHEAR TO ALSO INCREASE LATE AFTERNOON
ACROSS WESTERN HALF OF THE AREA AS A 500 HPA SPEED MAX LIFTS INTO
NORTHWEST INDIANA AFTER 21Z. THUS...NO CHANGE IN THINKING FROM
PREVIOUS FORECAST WITH LOW/ISOLATED SEVERE THREAT ACROSS
ESPECIALLY WESTERN AREAS LATE AFTERNOON/EARLY EVENING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 342 AM EDT SAT OCT 5 2013
GRADUAL APPROACH OF IMPRESSIVE CLOSED OFF CYCLONIC GYRE EXTENDING
THROUGH THE BULK OF THE TROPOSPHERE WILL BRING INCREASING CHANCES
FOR RAIN THROUGH THE SHORT TERM PERIOD. SURFACE FRONTAL BOUNDARY
EXTENDING INTO THE SOUTHERN GREAT LAKES WILL MOVE LITTLE THROUGH
THE PERIOD WITH PERSISTENT THETA-E ADVECTION IN A LARGELY UNCAPPED
ENVIRONMENT LEADING TO CONTINUED PERIODS OF CONVECTION. SMALL
SCALE VORTICES IN SOUTHWEST FLOW ALOFT EMANATING FROM THE CENTRAL
CONUS WILL ALSO SUPPORT INCREASING CHANCES FOR RAINFALL AS THE
MAIN SYSTEM APPROACHES. OCCLUSION PROCESS IS ALREADY BEGINNING AND
EARLIER NOTED SLOWING TREND HAS CONTINUED. MAIN SURFACE COLD FRONT
IS NOT EXPECTED TO REACH OUR CWA UNTIL LATE TONIGHT. WILL STILL BE
PLENTY OF RAIN AHEAD OF THE MAIN FRONT THOUGH. TIGHTENING LOW
LEVEL MASS GRADIENT ASSOCIATED WITH APPROACHING PV ANOMALY WILL
LEAD TO A STRENGTHENING OF THE LLJ AND A CORRESPONDING UPTICK IN
305K ISENTROPIC ASCENT. MOISTURE WILL CERTAINLY NOT BE LACKING
EITHER. 305K MIXING RATIOS ARE ABOVE 8 G/KG AND PW VALUES ARE
HOVERING AROUND 1.75 INCHES...NEAR THE 99TH PERCENTILE FOR THIS
TIME OF YEAR BASED ON REGIONAL UPPER AIR CLIMATOLOGY. EXACT
TIMING/PLACEMENT OF CONVECTION REMAINS HIGHLY UNCERTAIN BUT EXPECT
COVERAGE TO INCREASE AS THE DAY WEARS ON GIVEN INCREASING DIURNAL
INSTABILITY AND APPROACHING TROUGH. LATEST HI-RES GUIDANCE SHOWS
CONVECTION NEAR INDIANAPOLIS WILL CONTINUE TO SPREAD NORTH THROUGH
THE MORNING WITH A BRIEF BREAK BEFORE ADDITIONAL CONVECTION
ARRIVES IN THE LATE AFTERNOON. TRIED TO INCORPORATE THIS INTO THE
LATEST POP FORECAST BUT MAINTAINED FAIRLY BROADBRUSH APPROACH
GIVEN UNCERTAINTY IN CONVECTIVE TRENDS. HIGHER CONFIDENCE THAT
SHOWERS AND THUNDERSTORMS WILL BECOME WIDESPREAD BY TONIGHT THOUGH
AS THE COLD FRONT APPROACHES...AND HAVE PUSHED POPS INTO
CATEGORICAL VALUES. HIGHS TODAY WILL BE SIMILAR TO YESTERDAY...AS
ANY BREAKS IN THE CLOUD COVER WILL ALLOW TEMPS TO MAKE A RUN AT
THE MID 80S GIVEN WARM PROFILES ALOFT. LOWS TONIGHT WILL BE HIGHLY
DEPENDENT ON EXACT TIMING OF FRONT BUT HAVE RAISED THEM A BIT IN
ANTICIPATION OF A SLOWER FRONTAL PASSAGE. LAPSE RATES NEARLY MOIST
ADIABATIC WILL LIKELY ONLY SUPPORT AROUND 1000 J/KG OR LESS OF
SBCAPE TODAY. DEEP LAYER SHEAR IS ALSO MARGINAL DURING THE DAY AND
EXPECT ONLY A SLIGHT CHANCE FOR SEVERE WEATHER...MAINLY IN AREAS
THAT SEE A SUSTAINED PERIOD OF INSOLATION THAT ALLOWS INSTABILITY
TO BUILD. SHEAR WILL INCREASE BY TONIGHT...BUT INSTABILITY WILL BE
AT A MINIMUM AND AGAIN ONLY EXPECTING A LOW RISK OF SEVERE WEATHER
AT THE MOMENT. HEAVY RAIN WILL LIKELY BE THE BIGGEST THREAT. A
VERY MOIST ENVIRONMENT AND CONTINUED POTENTIAL FOR TRAINING STORMS
COULD LEAD TO HIGH RAINFALL TOTALS BY THE TIME ALL IS SAID AND
DONE EARLY NEXT WEEK.
&&
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 342 AM EDT SAT OCT 5 2013
RATHER DRAMATIC CHGS REQUIRED TO BEGIN THE PD ON ACCOUNT OF CONTD
MODEL CONSENSUS SLWG IN EWD PROGRESSION OF PLAINS BOWLING BALL.
INTERESTINGLY STILL SOME SIG SPREAD ALOFT STILL AT THIS TIME RANGE
W/POSITION AND INTENSITY OF MID LVL CYCLONE WHICH RANGES FROM NRN IL
IN NAM TO SRN IL IN GEM AT FHR60. REGARDLESS ENOUGH OF A CONSENSUS
SIGNAL EXISTS TO EXTEND/BUMP POPS/WX THROUGH MON NIGHT. HWVR WILL
FORGO ALLBLEND POP GUIDANCE FOR TUE IN LIGHT OF RAPID UPSTREAM HGT
RISES FOLLOWING IN WAKE OF UPR TROUGH WHICH AT THAT POINT SHLD BE IN
SE CANADA.
OF GREATEST INTEREST W/SLWG SOLUTIONS ALOFT IS CONTD PUMP OF
ANOMALOUS GOMEX MSTR FLUX INTO THE GREAT LAKES INADV OF MIDLVL
CYCLONE WHICH SHOWS LTL SIGN OF WKNG UNTIL MON. SLWR EWD ADV OF FNTL
BNDRY ALG W/PWS OF NEAR 1.8IN (99TH PERCENTILE) WOULD PREPOSE AT
LEAST THE ERN HALF OF CWA FOR A CLASSIC MADDOX TYPE I HEAVY RAIN
EVENT AND NOTED IN SVRL DETERMINISTIC QPF SOLUTIONS SUN-SUN NIGHT.
SINCE THIS THREAT IS XPCD TO DVLP DY2 WILL FOLLOWUP PRIOR WELL
DESERVED ESF. AS AN ASIDE...FAIR NUMBER OF SOLUTIONS DEPICT THE
DVLPMNT OF A SFC FNTL WAVE SUN AFTN WHICH IF TRUE WOULD YIELD A
HEIGHTENED RISK FOR LOW TOPPED SUPERCELLS ACRS ERN IN/WRN OH AND
INHERENT TOR THREAT W/FVRBL OVERLAP OF MIXED LYR CAPE/SHEAR.
OTRWS SWD TRENDING PROGRESSION OF AT LEAST MOD INTENSE MID LVL
CYCLONE LEADS TO ADDNL ESCALATION/EXPANSION OF POPS MON AFTN/MON
NIGHT. IN FACT SWD CNTRD CLUSTER OF SVRL SOLUTIONS INCLUDING GFS/GEM
WOULD PORTEND A SECONDARY DEFORMATION ZONE DVLPG IN RESPONSE TO
TRAILING FNTL WAVE MON NIGHT W/ASSUMED SEPARATION W/REMNANTS OF TS
KAREN AS SOME SEMBLANCE OF THE TROWAL REMAINS INTACT.
GIVEN ALL OF THE ABOVE...SIG CHGS TO TEMPS WERE MADE SUN/MON. HWVR
SIG MODERATION STILL ON TAP IN WAKE OF THIS INTENSE SYS MID WEEK
TIMED W/SECONDARY DEEP WRN TROUGH DVLPMNT AND DOWNSTREAM RIDGE
AMPLIFICATION W/RTN TO ABV NORMAL TEMPS XPCD BY THU.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 145 PM EDT SAT OCT 5 2013
CONVECTION BEGINNING TO INCREASE IN COVERAGE FROM SOUTHERN
ILLINOIS INTO SOUTHWEST LOWER MICHIGAN WITH A POCKET OF 1000-2000
J/KG OF 100 HPA MLCAPES ACROSS THE REGION. A COUPLE OF SHORT WAVES
EMBEDDED IN SOUTHWEST UPPER FLOW WILL AID IN EXPANSION OF
SHRA/TSRA COVERAGE THROUGH EARLY EVENING ACROSS NORTH CENTRAL
INDIANA...WITH LIKELIHOOD OF SHOWERS AND EMBEDDED THUNDERSTORMS
OVERSPREADING NORTHEAST INDIANA THROUGH THE EARLY TO LATE EVENING
HOURS. DIURNAL MIXING HAS IMPROVED THE IFR CIGS TO MVFR AT KSBN
EARLY THIS AFTERNOON. HAVE MAINTAINED TEMPO MVFR CONDS IN HEAVIER
SHOWERS AND THUNDERSTORMS THIS AFTERNOON/EARLY EVENING...WITH
TREND BACK TO IFR CONDITIONS LATE EVENING/HOUR NIGHT AS DEEPER
MOISTURE LIFTS NORTHWARD INTO THE AREA. A BRIEF LULL IN COVERAGE
OF SHOWERS AND THUNDERSTORMS IS POSSIBLE IN THE 04Z-08Z
TIMEFRAME...BUT SHOULD INCREASE ONCE AGAIN TOWARD DAYBREAK AS
LARGE SCALE FORCING/LOW LEVEL FRONTOGENESIS INCREASES WITH
APPROACHING UPPER TROUGH
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...FLASH FLOOD WATCH FROM LATE TONIGHT THROUGH LATE SUNDAY NIGHT
FOR INZ007-009-018-026-027-033-034.
MI...FLASH FLOOD WATCH FROM LATE TONIGHT THROUGH LATE SUNDAY NIGHT
FOR MIZ081.
OH...FLASH FLOOD WATCH FROM LATE TONIGHT THROUGH LATE SUNDAY NIGHT
FOR OHZ001-002-004-005-015-016-024-025.
LM...NONE.
&&
$$
UPDATE...MARSILI
SYNOPSIS...AGD
SHORT TERM...AGD
LONG TERM...T
AVIATION...MARSILI
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS TOPEKA KS
323 PM CDT Sat Oct 5 2013
.SHORT TERM...(This Evening through Sunday)
Issued at 320 PM CDT SAT OCT 5 2013
20Z water vapor imagery shows the closed upper low over southeast SD
slowly propagating east. A shortwave trough axis has rotated through
eastern KS helping to clear out the mid level clouds. At the surface
the cold front had pushed well east and south with dry cool air
advecting in from the west.
For tonight and Sunday, the forecast calls for generally dry weather
as there is little moisture to work with and large scale forcing
should remain to the north and east of the forecast area. Did leave
some slight chance pops in the far northeastern corner of the
forecast area during the day Sunday. As the upper low drifts across
southwest IA, lapse rates could steepen enough for some isolated
showers to move across Nemaha and Brown counties. The main thing to
watch will be the STRATOCU deck to the north. The RAP and NAM show
these clouds eventually moving into much of the forecast area
overnight. This should have an impact on MIN and MAX temps. Models
are in good agreement that the boundary layer will remain well mixed
overnight with increasing clouds from the north. Therefore am fairly
confident that MIN temps will not fall below 40 and even tweaks
temps up a degree or two. The forecast may still be on the cool side
if the clouds move in quicker. Highs Sunday are expected to warm
back into the 60s for most areas. Forecast soundings mix the
boundary layer almost to 800MB and models indicate the cold air
advection will have ended. The main question is whether clouds will
hold temps down. Added about 3 to 5 degrees to MAX temps across the
western and southern counties where there should be more insolation
with good mixing. Across northeastern KS where clouds are likely to
hang in tough, kept highs in the middle 50s.
Wolters
.LONG TERM...(Sunday Night through Saturday)
Issued at 320 PM CDT SAT OCT 5 2013
Upper low still on track to progress eastward through the mid MO and
OH river valleys through Monday. Most of the moisture wrapping
around the backside of the exiting upper may linger across the far
northeast corner of the cwa early Sunday evening...so have left a
slight chance in for that time period. Otherwise will go with a dry
fcst Monday through Thursday night as upper level ridging will
develop across the plains in the wake of the first trough exiting
trough and ahead of the second upper trough that deepens over the
west CONUS. Will continue to slowly but steadily increase high temps
through the 70s Monday through Thursday...with a few low 80s on
Thursday. As the western trough then lift out into the plains on Friday
and Friday night...with more clouds and the potential for showers
and thunderstorms cooled temps slightly for Friday before the
frontal passage and and even cooler readings in the low to middle
70s on Saturday. Warmed low temps from near 40 Monday morning into
the 50s by Wednesday on through the end of the week.
&&
.AVIATION...(For the 18Z TAFs through 18Z Sunday Afternoon)
Issued at 1209 PM CDT SAT OCT 5 2013
VFR forecast at KTOP/KFOE/KMHK with west winds gusting between 15
and 23 kts this afternoon. Winds stay up near 10 kts overnight as
upper low passes to the northeast. Latest RAP and high res
guidance are hinting at cigs redeveloping aft 08z at KMHK and 09z
at KTOP/KFOE. Not confident enough to lower to MVFR however
increased VFR cloud coverage at this time and will reevaluate MVFR
potential at next issuance.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Wolters
LONG TERM...63
AVIATION...Bowen
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1233 PM CDT Sat Oct 5 2013
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 316 AM CDT SAT OCT 5 2013
Closed upper level low is currently centered over central SD with a
well defined mid level dry punch stretched across the central
plains. Surface cold front responsible for yesterday`s thunderstorms
has moved east into western MO. Trailing stratiform behind the main
line of thunderstorms will continue for a few more hours in the far
southeast cwa. An area of scattered showers with isolated thunder is
working through parts of the cwa this morning due to some elevated
instability rooted at around 750 mb. These showers will move
northeast through the cwa during the next few hours exiting the area
by sunrise.
Cold dry air has begun to push into the region behind the front with
temperatures in the mid 40s already in north central KS. Low
temperatures tonight will range from the low 40s in north central KS
to the upper 50s in east central KS. The winds have shifted to the
west northwest and are forecast to increase to around 15 to 20 mph
with gusts up to 30 mph during the day today. Clouds will continue
to move east today with partly to mostly sunny skies expected by
this afternoon and high temperatures in the upper 50s to low 60s.
Cold air advection will persist through out the day today and
tonight. The 850 mb temperatures will approach 0C later tonight
therefore overnight low temperatures drop to around 40 across most
of the area.
.LONG TERM...(Sunday through Friday)
Issued at 316 AM CDT SAT OCT 5 2013
Through Sunday afternoon the upper low is forecast to drop east
southeast out from near Sioux Falls into Missouri. This takes an
area of stratus and the colder air aloft across the northeastern
counties. By afternoon hours, there is enough lift associated with
the low to generate showers through the saturated layer in the
column. In fact 850mb temperatures are running just near or below
freezing, and soundings suggest the top of the lift in the column
just clips where the -10/-20 layer is saturated aloft. However
expect to see enough warmer air in the low levels to keep precip
in the form of rain or a light drizzle. Could go on for a few
hours in the afternoon, and would not be surprised to see some
cold air funnels ad cold pool moves through. This will also keep
high temperatures across the NE down int he 50s with 60s possible
elsewhere.
Mon-Fro continue to advertise a nice warm up through the end of the
week as Monday starts out around 70 and Friday brings highs in the
upper 70s. Lows Sunday night into Morning may be pretty chilly as
skies clear and winds lighten before warm air advection returns.
May see lows around 40 common over the area. These lows slowly
moderate back into the 50s as southwesterly flow aloft returns to
the plains and the next trof approaches the Rockies on Friday.
Will carry just a slight chance for some pops mainly in the
western counties. 67
&&
.AVIATION...(For the 18Z TAFs through 18Z Sunday Afternoon)
Issued at 1209 PM CDT SAT OCT 5 2013
VFR forecast at KTOP/KFOE/KMHK with west winds gusting between 15
and 23 kts this afternoon. Winds stay up near 10 kts overnight as
upper low passes to the northeast. Latest RAP and high res
guidance are hinting at cigs redeveloping aft 08z at KMHK and 09z
at KTOP/KFOE. Not confident enough to lower to MVFR however
increased VFR cloud coverage at this time and will reevaluate MVFR
potential at next issuance.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Sanders
LONG TERM...67
AVIATION...Bowen
AREA FORECAST DISCUSSION
NWS JACKSON KY
553 PM EDT SAT OCT 5 2013
.UPDATE...
ISSUED AT 553 PM EDT SAT OCT 5 2013
SHOWERS/THUNDERSTORMS WHICH DEVELOPED IN CENTRAL KY HAVE HELD
TOGETHER AS THEY MOVED INTO THE JKL FORECAST AREA...BUT WERE
WEAKENING. UPDATED TO INCREASE POPS FOR EARLY THIS EVENING IN OUR
NORTHERN COUNTIES.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 303 PM EDT SAT OCT 5 2013
COLD FRONT THROUGH THE AREA TONIGHT...SUNDAY...AND INTO THE DAY
MONDAY. WILL CONCENTRATE ON TONIGHT THROUGH 0Z TUESDAY SINCE THIS IS
WHEN THE MAIN ACTION WILL OCCUR. LATEST HI-RES MODEL GUIDANCE
CONTINUES TO SHOW A SLOW PROGRESSION OF THE FRONT AND IT/S ASSOCIATED
PRECIP. CREDIT PREVIOUS FORECAST FOR TAKING A SLOWER APPROACH OF THE
SYSTEM...SINCE THIS SEEMS TO MATCH UP WELL WITH LATEST MODELS. AS IT
IS...LATEST HRRR SHOWS SOME ISO PRECIP DEVELOPING ACROSS THE WESTERN
EDGE OF THE CWA BY LATE THIS AFTERNOON...AHEAD OF THE MAIN LINE
CURRENTLY LOCATED ACROSS FAR WESTERN KY...NORTH CENTRAL KY...AND
PARTS OF INDIANA AND OHIO. WHAT CONVECTIVE INDUCED PRECIP THAT DOES
DEVELOP WILL THEN DIE OFF WITH LOSS OF DAYTIME HEATING OVERNIGHT...AS
THE MAIN LINE BEGINS ITS TREK SLIGHTLY EASTWARD. BY 15Z SUNDAY...THE
LINE OF PRECIP WILL HAVE PROGRESSED TO CENTRAL KY AND EXPANDED ACROSS
MUCH OF INDIANA AND WESTERN TN. IF THE LATEST NAM12 HOLDS
TRUE...PRECIP CHANCES WILL NOT RE-ENTER THE CWA UNTIL AFTER THIS
TIME.
BY THIS POINT THE LINE WILL BE MOVING SLIGHTLY QUICKER...BUT WILL
STILL HOLD ENOUGH MOISTURE TO DROP ABOUT AN INCH OF QPF IN IT/S
DURATION. BY 0Z MONDAY...MUCH OF THE PRECIP SHOULD HAVE MOVED OUT OF
THE REGION. HOWEVER...TROPICAL STORM KAREN...MOVING NE FROM THE GULF
OF MEXICO...WILL BEGIN MERGING WITH THE LOW PRESSURE SYSTEM. THIS
WILL CAUSE THE FRONT TO STALL OUT ONCE MORE ACROSS THE MORE
MOUNTAINOUS AREAS TO OUR EAST...WITH HEAVY RAINS EXPECTED. ALTHOUGH
THE UPPER LEVEL PATTERN IS IN FAIRLY GOOD AGREEMENT UP UNTIL THIS
POINT...BY 0Z MONDAY THE PLACEMENT OF THE UPPER LEVEL TROUGH STARTS
TO SHIFT DEPENDING ON THE MODEL. IF IT PASSES JUST A BIT FARTHER
NORTH THAN THE OHIO RIVER...ALL RAIN CHANCES WILL CEASE BY 0Z
TUESDAY. HOWEVER...IF THE LATEST NAM IS CORRECT...IT WILL TRACK THE
LOW JUST A BIT FURTHER SOUTHWARD. ENOUGH TO CAUSE SOME WRAP AROUND
MOISTURE ACROSS THE FAR NORTHERN SECTIONS OF THE STATE AS IT STALLS
OUT. AT THIS POINT IT SEEMS AS THOUGH THIS WRAP AROUND MOISTURE WILL
STAY JUST TO OUR WEST.
AS FOR INSTABILITY...FOR THIS AFTERNOON AND TOMORROW
AFTERNOON...WILL PROBABLY SEE THE BEST CHANCE FOR ANY ISOLATED TO
SCT THUNDERSTORM DEVELOPMENT. HOWEVER SOUNDINGS STILL LOOK WEAK AT
BEST FOR THIS TO HAPPEN. AS A RESULT...WILL NOT RULE OUT A FEW
RUMBLES OF THUNDER HERE AND THERE WITH ANY SCT SHOWERS...BUT THE
MAIN CONCERN WILL STILL BE THE RAINS. AS WAS NOTED BY THE PREVIOUS
FORECASTER...THERE IS SOME MID/LEVEL DRYING IN THE LATEST NAM
SOUNDINGS...SO SOME WINDY DOWNBURSTS COULD NOT BE OUT OF THE
QUESTION. THAT BEING SAID...BY 3Z MONDAY...FORECAST SOUNDINGS SHOW A
COMPLETELY SATURATED AIR MASS...LEADING TO THE LOSS OF CONVECTIVE
ABILITY AND TURNING TO A MORE STRATIFORM EVENT AS THE MAIN LINE
PASSES OVER. DRY AIR WILL FINALLY START TO WORK IN FOR MONDAY
MORNING...BRINGING AN END TO ANY LINGERING PRECIP.
AS FOR TEMPERATURES...AFTER A WARM START TO TODAY THANKS TO WARM AND
MOIST SOUTHERLY FLOW...EXPECT SIMILAR CONDITIONS TOMORROW. THIS WILL
HELP TO FURTHER INITIATE ANY SCT CONVECTION OUT AHEAD OF THE MAIN
LINE OF SHOWERS. ONCE THE MAIN LINE OF SHOWERS STARTS MOVING INTO
THE REGION DURING THE AFTERNOON HOURS...CONTINUOUS RAIN WILL BEGIN
DROPPING THE TEMPERATURES FROM WEST TO EAST. AS A RESULT...HIGHS
WILL BE MET EARLY ON...REACHING THE HIGHEST VALUES IN THE FAR EAST.
ONCE THE FRONT PASSES THROUGH ON MONDAY...COLD AIR WILL FILTER IN
BEHIND AND TEMPERATURES WILL START FALLING BEFORE THEY ARE ABLE TO
REACH THEIR MAXIMUM POTENTIAL. HIGHS WILL ONLY REACH THE LOW TO MID
60S BY EARLY AFTERNOON BEFORE THEY START DROPPING BACK DOWN.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 245 PM EDT SAT OCT 5 2013
ANY LINGERING SHOWERS IN THE FAR EAST WILL BE ENDING EARLY MONDAY
EVENING. THEN WITH THE COLD FRONT WELL TO OUR EAST AND SURFACE HIGH
PRESSURE BUILDING INTO THE AREA MONDAY NIGHT WE WILL SEE COOL
TEMPERATURES AND DRY WEATHER FOR THE START OF THE FORECAST PERIOD.
IN THE WAKE OF THE EXITING UPPER LOW TO OUR NORTHEAST EARLY IN THE
WEEK...RESIDUAL TROUGHING WILL GIVE WAY TO RISING HEIGHTS AS UPPER
RIDGING GRADUALLY BUILDS INTO THE OH VALLEY. WITH UPPER RIDGING
REMAINING OVER THE AREA INTO NEXT WEEKEND AND SURFACE HIGH PRESSURE
SHIFTING TO OUR EAST WE WILL SEE SLOWLY WARMING TEMPERATURES AS THE
WEEK CONTINUES...ESPECIALLY FOR MAXIMUMS. ALSO THE PATTERN WILL BE
CONDUCIVE FOR RIDGE VALLEY TEMPERATURE DIFFERENCES FOR OVERNIGHT
MINIMUMS...WITH INCREASING DIURNAL TEMPERATURE RANGES ESPECIALLY IN
THE VALLEYS LATER IN THE WEEK. THE COMING WEEK WILL BE DRY WITH THE
NEXT CHANCE FOR RAIN HOLDING OFF UNTIL THE APPROACH OF THE NEXT COLD
FRONT WHICH IS STILL MORE THAN SEVEN DAYS AWAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 119 PM EDT SAT OCT 5 2013
A LARGE AREA OF LOW PRESSURE OFF TO OUR NE HAS SPAWNED A STRONG COLD
FRONT AND A LARGE AREA OF PRECIPITATION TO ACCOMPANY IT. THIS PRECIP
IS CURRENTLY IMPACTING WESTERN KY...AND PORTIONS OF TN AND OHIO. THE
LINE WILL CONTINUE TO SLOWLY PUSH EASTERLY AHEAD OF THE COLD
FRONT...REACHING THE TAF SITES SOMETIME TOMORROW AFTERNOON. IF MODELS
CONTINUE WITH ONGOING SOLUTIONS...PRECIP SHOULD NOT ARRIVE AT TAF
LOCATIONS UNTIL AFTER THE FORECAST PERIOD. HOWEVER...PUT IN SOME VCSH
AT KSME AND KLON JUST IN CASE THINGS DO IN FACT SPEED UP AND TO
ACCOUNT FOR ANY PRECIP WHICH MAY DEVELOP OUT AHEAD OF THE MAIN LINE.
WITH THAT IN MIND...SOME OF THE HI-RES MODELS ARE ALSO POINTING AT SOME
DEVELOPING ISL TO SCT CONVECTION THIS AFTERNOON AS WELL. BUT WITH NO
EVIDENCE OF ANY SH/TSRA DEVELOPMENT AT THIS TIME IN OUR CWA...CONFIDENCE
ON WHETHER OR NOT THESE CONVECTIVE CELLS WILL AFFECT THE TAF SITES IS
QUITE LOW...SO CHOSE TO LEAVE OUT AT TAFS. IMPOSING CLOUD COVER
TONIGHT SHOULD BE ENOUGH TO KEEP ANY FOG POTENTIAL AT BAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HAL
SHORT TERM...JMW
LONG TERM...SBH
AVIATION...JMW
AREA FORECAST DISCUSSION
NWS JACKSON KY
303 PM EDT SAT OCT 5 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 303 PM EDT SAT OCT 5 2013
COLD FRONT THROUGH THE AREA TONIGHT...SUNDAY...AND INTO THE DAY
MONDAY. WILL CONCENTRATE ON TONIGHT THROUGH 0Z TUESDAY SINCE THIS IS
WHEN THE MAIN ACTION WILL OCCUR. LATEST HI-RES MODEL GUIDANCE
CONTINUES TO SHOW A SLOW PROGRESSION OF THE FRONT AND IT/S ASSOCIATED
PRECIP. CREDIT PREVIOUS FORECAST FOR TAKING A SLOWER APPROACH OF THE
SYSTEM...SINCE THIS SEEMS TO MATCH UP WELL WITH LATEST MODELS. AS IT
IS...LATEST HRRR SHOWS SOME ISO PRECIP DEVELOPING ACROSS THE WESTERN
EDGE OF THE CWA BY LATE THIS AFTERNOON...AHEAD OF THE MAIN LINE
CURRENTLY LOCATED ACROSS FAR WESTERN KY...NORTH CENTRAL KY...AND
PARTS OF INDIANA AND OHIO. WHAT CONVECTIVE INDUCED PRECIP THAT DOES
DEVELOP WILL THEN DIE OFF WITH LOSS OF DAYTIME HEATING OVERNIGHT...AS
THE MAIN LINE BEGINS ITS TREK SLIGHTLY EASTWARD. BY 15Z SUNDAY...THE
LINE OF PRECIP WILL HAVE PROGRESSED TO CENTRAL KY AND EXPANDED ACROSS
MUCH OF INDIANA AND WESTERN TN. IF THE LATEST NAM12 HOLDS
TRUE...PRECIP CHANCES WILL NOT RE-ENTER THE CWA UNTIL AFTER THIS
TIME.
BY THIS POINT THE LINE WILL BE MOVING SLIGHTLY QUICKER...BUT WILL
STILL HOLD ENOUGH MOISTURE TO DROP ABOUT AN INCH OF QPF IN IT/S
DURATION. BY 0Z MONDAY...MUCH OF THE PRECIP SHOULD HAVE MOVED OUT OF
THE REGION. HOWEVER...TROPICAL STORM KAREN...MOVING NE FROM THE GULF
OF MEXICO...WILL BEGIN MERGING WITH THE LOW PRESSURE SYSTEM. THIS
WILL CAUSE THE FRONT TO STALL OUT ONCE MORE ACROSS THE MORE
MOUNTAINOUS AREAS TO OUR EAST...WITH HEAVY RAINS EXPECTED. ALTHOUGH
THE UPPER LEVEL PATTERN IS IN FAIRLY GOOD AGREEMENT UP UNTIL THIS
POINT...BY 0Z MONDAY THE PLACEMENT OF THE UPPER LEVEL TROUGH STARTS
TO SHIFT DEPENDING ON THE MODEL. IF IT PASSES JUST A BIT FARTHER
NORTH THAN THE OHIO RIVER...ALL RAIN CHANCES WILL CEASE BY 0Z
TUESDAY. HOWEVER...IF THE LATEST NAM IS CORRECT...IT WILL TRACK THE
LOW JUST A BIT FURTHER SOUTHWARD. ENOUGH TO CAUSE SOME WRAP AROUND
MOISTURE ACROSS THE FAR NORTHERN SECTIONS OF THE STATE AS IT STALLS
OUT. AT THIS POINT IT SEEMS AS THOUGH THIS WRAP AROUND MOISTURE WILL
STAY JUST TO OUR WEST.
AS FOR INSTABILITY...FOR THIS AFTERNOON AND TOMORROW
AFTERNOON...WILL PROBABLY SEE THE BEST CHANCE FOR ANY ISOLATED TO
SCT THUNDERSTORM DEVELOPMENT. HOWEVER SOUNDINGS STILL LOOK WEAK AT
BEST FOR THIS TO HAPPEN. AS A RESULT...WILL NOT RULE OUT A FEW
RUMBLES OF THUNDER HERE AND THERE WITH ANY SCT SHOWERS...BUT THE
MAIN CONCERN WILL STILL BE THE RAINS. AS WAS NOTED BY THE PREVIOUS
FORECASTER...THERE IS SOME MID/LEVEL DRYING IN THE LATEST NAM
SOUNDINGS...SO SOME WINDY DOWNBURSTS COULD NOT BE OUT OF THE
QUESTION. THAT BEING SAID...BY 3Z MONDAY...FORECAST SOUNDINGS SHOW A
COMPLETELY SATURATED AIRMASS...LEADING TO THE LOSS OF CONVECTIVE
ABILITY AND TURNING TO A MORE STRATIFORM EVENT AS THE MAIN LINE
PASSES OVER. DRY AIR WILL FINALLY START TO WORK IN FOR MONDAY
MORNING...BRINGING AN END TO ANY LINGERING PRECIP.
AS FOR TEMPERATURES...AFTER A WARM START TO TODAY THANKS TO WARM AND
MOIST SOUTHERLY FLOW...EXPECT SIMILAR CONDITIONS TOMORROW. THIS WILL
HELP TO FURTHER INITIATE ANY SCT CONVECTION OUT AHEAD OF THE MAIN
LINE OF SHOWERS. ONCE THE MAIN LINE OF SHOWERS STARTS MOVING INTO
THE REGION DURING THE AFTERNOON HOURS...CONTINUOUS RAIN WILL BEGIN
DROPPING THE TEMPERATURES FROM WEST TO EAST. AS A RESULT...HIGHS
WILL BE MET EARLY ON...REACHING THE HIGHEST VALUES IN THE FAR EAST.
ONCE THE FRONT PASSES THROUGH ON MONDAY...COLD AIR WILL FILTER IN
BEHIND AND TEMPERATURES WILL START FALLING BEFORE THEY ARE ABLE TO
REACH THEIR MAXIMUM POTENTIAL. HIGHS WILL ONLY REACH THE LOW TO MID
60S BY EARLY AFTERNOON BEFORE THEY START DROPPING BACK DOWN.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 245 PM EDT SAT OCT 5 2013
ANY LINGERING SHOWERS IN THE FAR EAST WILL BE ENDING EARLY MONDAY
EVENING. THEN WITH THE COLD FRONT WELL TO OUR EAST AND SURFACE HIGH
PRESSURE BUILDING INTO THE AREA MONDAY NIGHT WE WILL SEE COOL
TEMPERATURES AND DRY WEATHER FOR THE START OF THE FORECAST PERIOD.
IN THE WAKE OF THE EXITING UPPER LOW TO OUR NORTHEAST EARLY IN THE
WEEK...RESIDUAL TROUGHING WILL GIVE WAY TO RISING HEIGHTS AS UPPER
RIDGING GRADUALLY BUILDS INTO THE OH VALLEY. WITH UPPER RIDGING
REMAINING OVER THE AREA INTO NEXT WEEKEND AND SURFACE HIGH PRESSURE
SHIFTING TO OUR EAST WE WILL SEE SLOWLY WARMING TEMPERATURES AS THE
WEEK CONTINUES...ESPECIALLY FOR MAXIMUMS. ALSO THE PATTERN WILL BE
CONDUCIVE FOR RIDGE VALLEY TEMPERATURE DIFFERENCES FOR OVERNIGHT
MINIMUMS...WITH INCREASING DIURNAL TEMPERATURE RANGES ESPECIALLY IN
THE VALLEYS LATER IN THE WEEK. THE COMING WEEK WILL BE DRY WITH THE
NEXT CHANCE FOR RAIN HOLDING OFF UNTIL THE APPROACH OF THE NEXT COLD
FRONT WHICH IS STILL MORE THAN SEVEN DAYS AWAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 119 PM EDT SAT OCT 5 2013
A LARGE AREA OF LOW PRESSURE OFF TO OUR NE HAS SPAWNED A STRONG COLD
FRONT AND A LARGE AREA OF PRECIPITATION TO ACCOMPANY IT. THIS PRECIP
IS CURRENTLY IMPACTING WESTERN KY...AND PORTIONS OF TN AND OHIO. THE
LINE WILL CONTINUE TO SLOWLY PUSH EASTERLY AHEAD OF THE COLD
FRONT...REACHING THE TAF SITES SOMETIME TOMORROW AFTERNOON. IF MODELS
CONTINUE WITH ONGOING SOLUTIONS...PRECIP SHOULD NOT ARRIVE AT TAF
LOCATIONS UNTIL AFTER THE FORECAST PERIOD. HOWEVER...PUT IN SOME VCSH
AT KSME AND KLON JUST IN CASE THINGS DO IN FACT SPEED UP AND TO
ACCOUNT FOR ANY PRECIP WHICH MAY DEVELOP OUT AHEAD OF THE MAIN LINE.
WITH THAT IN MIND...SOME OF THE HI-RES MODELS ARE ALSO POINTING AT SOME
DEVELOPING ISL TO SCT CONVECTION THIS AFTERNOON AS WELL. BUT WITH NO
EVIDENCE OF ANY SH/TSRA DEVELOPMENT AT THIS TIME IN OUR CWA...CONFIDENCE
ON WHETHER OR NOT THESE CONVECTIVE CELLS WILL AFFECT THE TAF SITES IS
QUITE LOW...SO CHOSE TO LEAVE OUT AT TAFS. IMPOSING CLOUD COVER
TONIGHT SHOULD BE ENOUGH TO KEEP ANY FOG POTENTIAL AT BAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...JMW
LONG TERM...SBH
AVIATION...JMW
AREA FORECAST DISCUSSION
NWS JACKSON KY
301 PM EDT SAT OCT 5 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 301 PM EDT SAT OCT 5 2013
ALL MODELS ARE STILL ON TRACK TO BRING US A POTENT AND SLOW MOVING
COLD FRONT THROUGH THE AREA TONIGHT...SUNDAY...AND INTO THE DAY
MONDAY. WILL CONCENTRATE ON TONIGHT THROUGH 0Z MONDAY SINCE THIS IS
WHEN THE MAIN ACTION WILL OCCUR. LATEST HI-RES MODEL GUIDANCE
CONTINUES TO SHOW A SLOW PROGRESSION OF THE FRONT AND IT/S
ASSOCIATED PRECIP. CREDIT PREVIOUS FORECAST FOR TAKING A SLOWER
APPROACH OF THE SYSTEM...SINCE THIS SEEMS TO MATCH UP WELL WITH
LATEST MODELS. AS IT IS...LATEST HRRR SHOWS SOME ISO PRECIP
DEVELOPING ACROSS THE WESTERN EDGE OF THE CWA BY LATE THIS
AFTERNOON...AHEAD OF THE MAIN LINE CURRENTLY LOCATED ACROSS FAR
WESTERN KY...NORTH CENTRAL KY...AND PARTS OF INDIANA AND OHIO. WHAT
CONVECTIVE INDUCED PRECIP THAT DOES DEVELOP WILL THEN DIE OFF WITH
LOSS OF DAYTIME HEATING OVERNIGHT...AS THE MAIN LINE BEGINS ITS TREK
SLIGHTLY EASTWARD. BY 15Z SUNDAY...THE LINE OF PRECIP WILL HAVE
PROGRESSED TO CENTRAL KY AND EXPANDED ACROSS MUCH OF INDIANA AND
WESTERN TN. IF THE LATEST NAM12 HOLDS TRUE...PRECIP CHANCES WILL NOT
RE-ENTER THE CWA UNTIL AFTER THIS TIME.
BY THIS POINT THE LINE WILL BE MOVING SLIGHTLY QUICKER...BUT WILL
STILL HOLD ENOUGH MOISTURE TO DROP ABOUT AN INCH OF QPF IN IT/S
DURATION. BY 0Z MONDAY...MUCH OF THE PRECIP SHOULD HAVE MOVED OUT OF
THE REGION. HOWEVER...TROPICAL STORM KAREN...MOVING NE FROM THE GULF
OF MEXICO...WILL BEGIN MERGING WITH THE LOW PRESSURE SYSTEM. THIS
WILL CAUSE THE FRONT TO STALL OUT ONCE MORE ACROSS THE MORE
MOUNTAINOUS AREAS TO OUR EAST...WITH HEAVY RAINS EXPECTED. ALTHOUGH
THE UPPER LEVEL PATTERN IS IN FAIRLY GOOD AGREEMENT UP UNTIL THIS
POINT...BY 0Z MONDAY THE PLACEMENT OF THE UPPER LEVEL TROUGH STARTS
TO SHIFT DEPENDING ON THE MODEL. IF IT PASSES JUST A BIT FARTHER
NORTH THAN THE OHIO RIVER...ALL RAIN CHANCES WILL CEASE BY 0Z
TUESDAY. HOWEVER...IF THE LATEST NAM IS CORRECT...IT WILL TRACK THE
LOW JUST A BIT FURTHER SOUTHWARD. ENOUGH TO CAUSE SOME WRAP AROUND
MOISTURE ACROSS THE FAR NORTHERN SECTIONS OF THE STATE AS IT STALLS
OUT. AT THIS POINT IT SEEMS AS THOUGH THIS WRAP AROUND MOISTURE WILL
STAY JUST TO OUR WEST.
AS FOR INSTABILITY...FOR THIS AFTERNOON AND TOMORROW
AFTERNOON...WILL PROBABLY SEE THE BEST CHANCE FOR ANY ISOLATED TO
SCT THUNDERSTORM DEVELOPMENT. HOWEVER SOUNDINGS STILL LOOK WEAK AT
BEST FOR THIS TO HAPPEN. AS A RESULT...WILL NOT RULE OUT A FEW
RUMBLES OF THUNDER HERE AND THERE WITH ANY SCT SHOWERS...BUT THE
MAIN CONCERN WILL STILL BE THE RAINS. AS WAS NOTED BY THE PREVIOUS
FORECASTER...THERE IS SOME MID/LEVEL DRYING IN THE LATEST NAM
SOUNDINGS...SO SOME WINDY DOWNBURSTS COULD NOT BE OUT OF THE
QUESTION. THAT BEING SAID...BY 3Z MONDAY...FORECAST SOUNDINGS SHOW A
COMPLETELY SATURATED AIRMASS...LEADING TO THE LOSS OF CONVECTIVE
ABILITY AND TURNING TO A MORE STRATIFORM EVENT AS THE MAIN LINE
PASSES OVER. DRY AIR WILL FINALLY START TO WORK IN FOR MONDAY
MORNING...BRINGING AN END TO ANY LINGERING PRECIP.
AS FOR TEMPERATURES...AFTER A WARM START TO TODAY THANKS TO WARM AND
MOIST SOUTHERLY FLOW...EXPECT SIMILAR CONDITIONS TOMORROW. THIS WILL
HELP TO FURTHER INITIATE ANY SCT CONVECTION OUT AHEAD OF THE MAIN
LINE OF SHOWERS. ONCE THE MAIN LINE OF SHOWERS STARTS MOVING INTO
THE REGION DURING THE AFTERNOON HOURS...CONTINUOUS RAIN WILL BEGIN
DROPPING THE TEMPERATURES FROM WEST TO EAST. AS A RESULT...HIGHS
WILL BE MET EARLY ON...REACHING THE HIGHEST VALUES IN THE FAR EAST.
ONCE THE FRONT PASSES THROUGH ON MONDAY...COLD AIR WILL FILTER IN
BEHIND AND TEMPERATURES WILL START FALLING BEFORE THEY ARE ABLE TO
REACH THEIR MAXIMUM POTENTIAL. HIGHS WILL ONLY REACH THE LOW TO MID
60S BY EARLY AFTERNOON BEFORE THEY START DROPPING BACK DOWN.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 245 PM EDT SAT OCT 5 2013
ANY LINGERING SHOWERS IN THE FAR EAST WILL BE ENDING EARLY MONDAY
EVENING. THEN WITH THE COLD FRONT WELL TO OUR EAST AND SURFACE HIGH
PRESSURE BUILDING INTO THE AREA MONDAY NIGHT WE WILL SEE COOL
TEMPERATURES AND DRY WEATHER FOR THE START OF THE FORECAST PERIOD.
IN THE WAKE OF THE EXITING UPPER LOW TO OUR NORTHEAST EARLY IN THE
WEEK...RESIDUAL TROUGHING WILL GIVE WAY TO RISING HEIGHTS AS UPPER
RIDGING GRADUALLY BUILDS INTO THE OH VALLEY. WITH UPPER RIDGING
REMAINING OVER THE AREA INTO NEXT WEEKEND AND SURFACE HIGH PRESSURE
SHIFTING TO OUR EAST WE WILL SEE SLOWLY WARMING TEMPERATURES AS THE
WEEK CONTINUES...ESPECIALLY FOR MAXIMUMS. ALSO THE PATTERN WILL BE
CONDUCIVE FOR RIDGE VALLEY TEMPERATURE DIFFERENCES FOR OVERNIGHT
MINIMUMS...WITH INCREASING DIURNAL TEMPERATURE RANGES ESPECIALLY IN
THE VALLEYS LATER IN THE WEEK. THE COMING WEEK WILL BE DRY WITH THE
NEXT CHANCE FOR RAIN HOLDING OFF UNTIL THE APPROACH OF THE NEXT COLD
FRONT WHICH IS STILL MORE THAN SEVEN DAYS AWAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 119 PM EDT SAT OCT 5 2013
A LARGE AREA OF LOW PRESSURE OFF TO OUR NE HAS SPAWNED A STRONG COLD
FRONT AND A LARGE AREA OF PRECIPITATION TO ACCOMPANY IT. THIS PRECIP
IS CURRENTLY IMPACTING WESTERN KY...AND PORTIONS OF TN AND OHIO. THE
LINE WILL CONTINUE TO SLOWLY PUSH EASTERLY AHEAD OF THE COLD
FRONT...REACHING THE TAF SITES SOMETIME TOMORROW AFTERNOON. IF MODELS
CONTINUE WITH ONGOING SOLUTIONS...PRECIP SHOULD NOT ARRIVE AT TAF
LOCATIONS UNTIL AFTER THE FORECAST PERIOD. HOWEVER...PUT IN SOME VCSH
AT KSME AND KLON JUST IN CASE THINGS DO IN FACT SPEED UP AND TO
ACCOUNT FOR ANY PRECIP WHICH MAY DEVELOP OUT AHEAD OF THE MAIN LINE.
WITH THAT IN MIND...SOME OF THE HI-RES MODELS ARE ALSO POINTING AT SOME
DEVELOPING ISL TO SCT CONVECTION THIS AFTERNOON AS WELL. BUT WITH NO
EVIDENCE OF ANY SH/TSRA DEVELOPMENT AT THIS TIME IN OUR CWA...CONFIDENCE
ON WHETHER OR NOT THESE CONVECTIVE CELLS WILL AFFECT THE TAF SITES IS
QUITE LOW...SO CHOSE TO LEAVE OUT AT TAFS. IMPOSING CLOUD COVER
TONIGHT SHOULD BE ENOUGH TO KEEP ANY FOG POTENTIAL AT BAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...JMW
LONG TERM...SBH
AVIATION...JMW
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
353 PM CDT SAT OCT 5 2013
.SYNOPSIS...
ISSUED AT 315 PM CDT SAT OCT 5 2013
OCCLUDED AND VERTICALLY STACKED LOW WAS SPINNING OVER SOUTHEAST
SODAK THIS AFTERNOON. AN OCCLUDED FRONT AT THE SFC STRETCHES FROM
NEAR AXN...DOWN TO THE NRN TWIN CITIES METRO AND SOUTHEAST FROM
THERE TO A TRIPLE POINT IN SW WISCONSIN. THIS LOW HAS STARTED TO
SLIP ESE TOWARD SW MN THIS AFTERNOON. THIS IS ALLOWING THE BLIZZARD
THAT HAS BEEN RAGING FOR THE BETTER PART OF 3 DAYS ACROSS THE NRN
HIGH PLAINS TO SLOWLY WIND DOWN TODAY...WITH AN IMPRESSIVE BANK OF
SNOW SHOWING UP ON VIS SATELLITE THIS AFTERNOON ACROSS WYOMING INTO
WRN NEB/SODAK.
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 315 PM CDT SAT OCT 5 2013
STRONG MID LEVEL JET HAS ROUNDED THE BASE OF THE STACKED LOW OVER
SODAK TODAY. THIS HAS HELPED ENHANCE MID-LEVEL TEMP GRADIENTS ACROSS
THE AREA. THIS HAS RESULTED IN AN ENHANCED AREA OF FGEN DEVELOPING
IN THE H7 TO H5 LAYER...MIX IN SOME ADIABATIC OMEGA ON THE 305K SFC
AND YOU GET THE DEVELOPING BAND OF SHOWERS ACROSS THE TWIN CITIES
METRO AT 300 PM. THE HRRR ALONG WITH THE HOPWRF HAVE BEEN CONSISTENT
IN DEVELOPING THIS FEATURE ALL DAY...SO FOLLOWED THESE MODELS
CLOSELY TO MOVE THIS BAND OF PRECIP THROUGH ERN AND CENTRAL MN AND
WRN WI THIS EVENING INTO TONIGHT. STILL HAVE BEST LI/S BETWEEN 0 AND
-2 OVER WRN WI..SO HAVE SOME ISO THUNDER WORDING IN THE EAST THIS
AFTERNOON. THIS ALSO MATCHES UP WELL WITH WHERE THE HRRR IS
DEVELOPING MORE ROBUST CONVECTION. THOUGH WE ARE NOT EXPECTING ANY
SEVERE WEATHER...COOLER TEMPERATURES ALOFT MOVING IN FROM THE
SOUTHWEST HAS RESULTED IN SOME GRAUPEL/SMALL HAIL BEING REPORTED
THIS AFTERNOON...WHICH WILL CONTINUE TO BE THE CASE THROUGH THIS
EVENING BEFORE WE LOOSE THE CONVECTIVE ASPECT OF THE PRECIP AND IT
BECOMES MAINLY STRATIFORM.
FOR TONIGHT...THE BIG QUESTION IS WHETHER OR NOT SKIES TRY TO CLEAR
OUT AGAIN ACROSS THE SOUTH AS THE DEVELOPING PRECIP BAND MOVES INTO
CENTRAL MN AND NW WI. TO SOME EXTENT...THE NAM/ECMWF/GFS ALL SHOW
SKIES CLEARING OUT TONIGHT FOR AT LEAST A PERIOD FROM SRN MN INTO
WRN WI. THE NAM IS THE MOST AGGRESSIVE WITH THIS...WITH LOWS DOWN
INTO THE 30S FROM SOUTH CENTRAL MN UP INTO WRN WI. BESIDE THE COOLER
TEMPS...IF SKIES DO CLEAR OUT LIKE THAT...THEN THOSE CLEAR SKIES
WOULD LIKELY FILL IN WITH DENSE FOG...SO THAT WILL NEED TO BE
WATCHED AS WE GO THROUGH THE NIGHT.
FOR SUNDAY...THINGS ARE LOOKING UP WEATHER WISE FOR THE TWIN CITIES
MARATHON IN THE MORNING...AS PRECIP LOOKS TO HOLD OFF IN THE TWIN
CITIES UNTIL THE AFTERNOON. BY 12Z THE LOW WILL HAVE FILLED IN TO
THE POINT WHERE IT WILL BE A RATHER BROAD AREA OF LOW PRESSURE
EXTENDING FROM SW MN UP INTO THE WRN UP OF MICH. COLD CONVEYOR
BELT PRECIP BY SUNDAY MORNING WILL STRETCH ACROSS NRN WI ACROSS
CENTRAL/NRN MN...THEN DOWN ACROSS THE ERN DAKOTAS...ALMOST WRAPPING
AROUND THE MPX AREA. AS SFC AND UPPER AIR FEATURES DRIFT TOWARD THE
GREAT LAKES DURING THE DAY...THE WRN EDGE OF THE PRECIP WILL BEGIN
MOVING ACROSS THE AREA. USED A BLEND OF THE GEM/NAM/SREF TO BRING
THIS PRECIP BACK EAST ACROSS THE AREA SUNDAY...THIS RESULTED IN A
SLOWING OF THE EWD PROGRESSION OF POPS TOMORROW. IN FACT...MOST OF
THE 12Z GUIDANCE KEEPS PRECIP THROUGH 7 PM SUNDAY EVENING WEST OF
WISCONSIN...SO A FURTHER SLOWING IN POP GRIDS MAY BE NEEDED TONIGHT.
OTHER CHANGE FOR SUNDAY WAS TO LOWER TEMPS A BIT...ESPECIALLY ACROSS
MN. WITH MOSTLY CLOUDY CONDITIONS EXPECTED TO PREVAIL...WILL BE A
STRUGGLE FOR MUCH OF THE MN AREA TO CRACK 50 FOR HIGHS.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 315 PM CDT SAT OCT 5 2013
AS THE SHORT TERM MENTIONED...THE UPPER LOW CONTINUES TO SLOW AND
LOW POPS REMAIN IN PLACE OVER ERN/SRN MN AND WRN WI INTO SUNDAY
NIGHT. CLEARING WILL GRADUALLY TAKE PLACE AND IT IS POSSIBLE
TO GET AREAS OF FOG BY MONDAY MORNING DEPENDING ON TIMING OF
CLEARING AND STRENGTH OF WIND.
ANOTHER LONG STRETCH OF LATE SUMMER WEATHER WILL TAKE HOLD NEXT
WEEK...PARTICULARLY TUESDAY ONWARD AS A DIGGING WEST COAST TROUGH
LEADS TO A LARGE RIDGE BUILDING EASTWARD ACROSS THE PLAINS. STRONG
RETURN FLOW AND GUSTY SOUTH WINDS TUESDAY WILL EASE MID/LATE WEEK
AS A BAGGIER PRESSURE PATTERN DEVELOPS UNDER THE RIDGE. 925 MB
TEMPS REACH THE MID/UPPER TEENS CELSIUS FOR MUCH OF NEXT
WEEK...BRINGING HIGHS FIRMLY INTO THE 70S. GUIDANCE IS IN STRONG
AGREEMENT FOR MID 70S...INCLUDING THE CLIMATOLOGICALLY FAVORING
MOS PRODUCT AT EXTENDED RANGES. HIGHS AND LOWS WILL BE ABOUT 15
DEGREES ABOVE AVERAGE WITH NEARLY UNRESTRICTED SUNSHINE EACH DAY
THROUGH THURSDAY.
ANOTHER POTENT STORM SYSTEM WILL DEVELOP TO THE LEE OF THE
ROCKIES THURSDAY NIGHT AND TRACK NORTHWARD INTO THE DAKOTAS
FRIDAY NIGHT. THIS SHOULD KEEP THE MAJORITY OF THE AREA DRY
THROUGH FRIDAY BEFORE THE COLD FRONT SWINGS THROUGH FRIDAY NIGHT.
OVERALL...THE GFS AND ECMWF REMAIN IN RATHER GOOD AGREEMENT SO
FORECAST CONFIDENCE IS HIGH THROUGHOUT THE LONG TERM PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1239 PM CDT SAT OCT 5 2013
LOW CONFIDENCE WITH CIG FORECAST IN TAFS. DRYING ASSOCIATED WITH
OCCLUDED LOW OVER SE SODAK HAS BEEN SLOWLY SPREADING NORTH/EAST.
THE RAP ALONG WITH THE GFS/NAM TAKES VFR CONDITIONS ACROSS ALL
TERMINALS FOR A TIME. THERE IS LOTS OF DISAGREEMENT WITH WHEN MVFR
CIGS WILL DROP BACK SOUTH AND EAST THIS EVENING...WITH RAP BEING
THE MOST AGGRESSIVE WITH BRINGING MVFR OR LOWER CIGS BACK AND
THE GFS/NAM SIGNIFICANTLY SLOWER. THESE TAFS WERE WRITTEN MORE
TOWARD THE GFS/NAM IDEA FOR CIGS. CONFIDENCE INCREASING IN AN AREA
OF SHRA DEVELOPING SHORTLY FROM STC DOWN TO MKT ON EAST FOR THE
AFTERNOON. THE HRRR ALONG WITH THE HOPWRF HAVE BOTH BEEN DEPICTING
THIS ALL MORNING AND WITH MID LEVEL CLOUDS EXPANDING ON SATELLITE
ALONG WITH RETURNS SHOWING UP ON RADAR IN SOUTH CENTRAL MN...SIDED
CLOSELY WITH THE HRRR IN BRINGING PRECIP BACK TO ALL BUT RWF. THE
LOW OFF TO THE WEST WILL DRIFT ACROSS MN TONIGHT...WITH WINDS
BECOMING LIGHT AND VRB AS A RESULT. WITH THE LIGHT WINDS...
ANYWHERE THAT REMAINS RELATIVELY CLEAR TONIGHT WILL HAVE TO THREAT
FOR DENSE FOG. AT THE MOMENT...THE MOST LIKELY PLACE FOR THAT TO
HAPPEN WOULD BE OVER WRN WI.
KMSP...TOUGH TO PIN DOWN THE CIGS FOR THIS FORECAST...AS THE 12Z
NAM/GFS WOULD BOTH INDICATE THAT CIGS WILL REMAIN VFR UNTIL LATE
SUNDAY AFTERNOON. CONFIDENCE HIGH IN ANOTHER ROUND OF SHOWERS
MOVING ACROSS THE FIELD BETWEEN 20Z AND 01Z PER THE HRRR AND
HOPWRF...THOUGH CONFIDENCE LOWER IN CIGS COMING BACK DOWN AS LOW
AS THEY ARE CURRENTLY FORECAST TO BE...MAY ONLY COME AS LOW AS 6K
FT WITH THE PRECIP. OPTIMISTIC CIG FORECAST TOMORROW BASED ON THE
GFS/NAM...BUT THE RAP SHOWS MVFR CIGS RETURNING TO MSP AROUND
09Z. IF THE CIGS DO COME IN BEFORE 12Z SUNDAY...THERE IS A GOOD
CHANCE THEY WILL COME IN BELOW 017.
/OUTLOOK FOR KMSP/
MON...VFR...MVFR POSSIBLE EARLY. WINDS NW 5-10 KT.
TUE...VFR. WINDS S 15G25 KT.
WED...VFR. WINDS SSE 10-15 KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SYNOPSIS...MPG
SHORT TERM...MPG
LONG TERM...BORGHOFF
AVIATION...MPG
AREA FORECAST DISCUSSION
NWS DULUTH MN
320 PM CDT SAT OCT 5 2013
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 319 PM CDT SAT OCT 5 2013
STACKED LOW PRESSURE OVER SOUTHEAST SOUTH DAKOTA WILL MOVE
EAST/SOUTHEAST TONIGHT...ALTHOUGH THE SURFACE LOW IS FORECAST TO
MOVE TOWARD UPPER MICHIGAN TONIGHT. AS THE SURFACE LOW NEARS THE
NORTHLAND LATER TONIGHT...WINDS SHOULD GRADUALLY SUBSIDE. WE
CONTINUE TO GET GUSTS OF 35 TO 45 MPH AT THE HEAD OF LAKE
SUPERIOR...AND WE`LL EXTEND THE WIND ADVISORY FOR
DOUGLAS...SOUTHERN SAINT LOUIS...CARLTON...AND SOUTHERN LAKE
COUNTIES UNTIL 10 PM. THE STRONGEST WINDS WILL REMAIN WILL BE
CLOSE TO LAKE SUPERIOR.
RAIN WAS DEVELOPING ACROSS PORTIONS OF CENTRAL/SOUTHEAST MINNESOTA
SIMILAR TO WHAT THE MODELS INCLUDING THE HRRR WERE DEPICTING. WE
SHOULD CONTINUE TO SEE RAIN DEVELOP AND MOVE NORTH THROUGH THE
NORTHLAND THIS EVENING/OVERNIGHT...BECOMING WIDESPREAD. WE`VE SEEN
A FEW LIGHTNING STRIKES CLOSE TO THE AREA...SO ADDED A SLIGHT
CHANCE FOR A STORM TO ALL AREAS LATE THIS AFTERNOON/EARLY
EVENING...THEN TO EASTERN AREAS THROUGH LATE EVENING. SOME FOG
WILL ALSO BE POSSIBLE...ESPECIALLY AROUND THE LAKE AND AS THE
GRADIENT RELAXES.
THERE WILL BE A CONTINUED CHANCE FOR SHOWERS ON SUNDAY...ALTHOUGH
COVERAGE WILL BE LESS THAN WHAT HAS OCCURRED TODAY AND WHAT IS
EXPECTED TONIGHT. THERE SHOULD STILL BE PLENTY OF CLOUDS AROUND
THOUGH...AND THE MODELS CONTINUE TO SHOW PLENTY OF LOW LEVEL
MOISTURE REMAINING. THE EXCEPTION WILL BE PORTIONS OF OUR
SOUTHEAST ZONES EARLY...AND OUR FAR NORTHWEST ZONES LATE. HIGHS
SUNDAY WILL RANGE FROM 55 TO 60 OVER OUR WESTERN/SOUTHEAST
ZONES...WITH AREAS BETWEEN AROUND 50.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 319 PM CDT SAT OCT 5 2013
TAIL END OF A DEPARTING LOW PRESSURE SYSTEM OVER THE GREAT LAKES
WILL ALLOW A FEW LIGHT RAIN SHOWERS TO LINGER ACROSS THE ERN HALF OF
THE FORECAST AREA SUNDAY NIGHT INTO EARLY MONDAY MORNING. RAINFALL
AMTS WILL BE LOW. HIGH PRESSURE WILL BUILD IN ACROSS THE UPPER
MIDWEST MONDAY AND TUESDAY WITH QUIET WEATHER CONDITIONS AND WARMER
TEMPERATURES. SKIES WILL REMAIN MOSTLY SUNNY EARLY IN THE WEEK
BEFORE A WEAK SFC FRONT SLIDES ACROSS THE NRN PLAINS AND USHERS IN
ADDITIONAL CLOUD COVER WED AND THURSDAY...MAINLY OVER THE NRN
COUNTIES. THE UPPER RIDGE OVER THE ERN US WILL AMPLIFY LATE IN THE
WEEK AS A TROUGH IN THE WEST DEEPENS THROUGH THE ROCKIES. THIS UPPER
LOW WILL EVENTUALLY MOVE INTO THE MIDWEST BY THE WEEKEND AND BRING
ADDITIONAL CHANCES FOR PRECIPITATION.
TEMPERATURES WILL REMAIN ABOVE AVERAGE THIS WEEK WITH VERY MILD
AFTERNOON HIGHS IN THE 60S AND LOWER 70S. OVERNIGHT LOWS EARLY IN
THE WEEK WILL BE SLIGHTLY CHILLY INTO THE 30S AND LOWER 40S...BUT
RISE INTO THE UPPER 40S AND LOWER 50S BY THE LATTER HALF OF THE WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1232 PM CDT SAT OCT 5 2013
IFR AND MVFR CIGS/VSBYS WILL PERSIST THROUGH TODAY AND MOST OF
TONIGHT BEFORE GRADUAL IMPROVEMENT IS SEEN BY LATE SUNDAY MORNING
ACROSS THE WRN TERMINALS. LIGHT SCATTERED RAIN SHOWERS ARE
EXPECTED THIS AFTERNOON WITH MORE WIDESPREAD HEAVIER SHOWERS
POSSIBLE THIS EVENING...AFTER 23/00Z...LASTING THROUGH 05/06Z.
VSBYS WILL LOWER IN THE STRONGER SHOWERS...WITH POSSIBLY PATCHY
FOG AROUND DLH AND HYR TONIGHT. GUSTY NE WINDS WILL SLOWLY
DIMINISH IN INTENSITY AND BACK TO THE NORTH TONIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 47 51 40 62 / 90 60 20 10
INL 39 55 37 62 / 60 40 0 0
BRD 46 51 39 65 / 80 60 10 0
HYR 46 56 40 61 / 80 50 30 10
ASX 49 54 43 62 / 80 60 40 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WIND ADVISORY UNTIL 10 PM CDT THIS EVENING FOR MNZ020-037.
WI...WIND ADVISORY UNTIL 10 PM CDT THIS EVENING FOR WIZ001.
LS...GALE WARNING UNTIL 10 PM CDT THIS EVENING FOR LSZ141>147.
SMALL CRAFT ADVISORY UNTIL 10 AM CDT SUNDAY FOR LSZ121-140-148.
&&
$$
SHORT TERM...MELDE
LONG TERM...BJT
AVIATION...BJT
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
111 PM CDT SAT OCT 5 2013
.UPDATE...
ISSUED AT 1034 AM CDT SAT OCT 5 2013
A TRICKY FORECAST TO SAY THE LEAST FOR TODAY. DRY SLOT HAS MOVED
IN BEHIND THE OCCLUDED FRONT THIS MORNING...WITH PARTIAL CLEARING
OF SKIES SEEN WEST AND SOUTH OF THE TWIN CITIES. AFTER MAKING GOOD
PROGRESS OVERNIGHT...THIS CLEARING HAS PUT ON THE BREAKS AS THE
LOW OVER SE SODAK HAS STARTED TO DRIFT ESE. THIS WILL KEEP THE
CLEARING FROM MAKING IT MUCH FARTHER NORTH...BUT IT WILL CONTINUE
TO SLOWLY CRAWL TOWARD THE EAST TODAY.
OF COURSE AS THIS IS GOING ON THE BIGGEST CHANGE TO THE FORECAST
IS THE ADDITION OF SHOWERS THIS AFTERNOON FROM MANKATO TO ST.
CLOUD ON EAST. THE HRRR HAS BEEN SHOWING THIS AREA OF SHOWERS
DEVELOPING BACK TO THE WEST FOR SEVERAL RUNS NOW. LOOKING AT THE
RAP...THIS IS IN RESPONSE TO A STRONG BAND OF FGEN COMING UP FROM
IOWA IN THE H7-H5 LAYER. LOOKING DOWN TO THE SOUTHWEST ON
SATELLITE...YOU CAN SEE THIS AREA OF PRECIP STARTING TO TAKE
SHAPE FROM ERN KANSAS UP INTO WRN IOWA. BOOSTED POPS UP TO AROUND
50 PERCENT BACK TO THE CITIES THIS AFTERNOON...BUT IF THE HRRR IS
CORRECT...MAY NEED TO BOOST THEM UP SIGNIFICANTLY IN THE NEAR
FUTURE...ESPECIALLY CONSIDERING ALL 4 MEMBERS OF THE 05.09 HOPWRF
SHOW SOMETHING SIMILAR HAPPENING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 342 AM CDT SAT OCT 5 2013
THE POTENCY OF THIS EARLY FALL SYSTEM WAS AGAIN ON DISPLAY LAST
NIGHT WITH STRONG TO SEVERE STORMS IN THE WARM SECTOR AND A RAGING
BLIZZARD IN WESTERN SOUTH DAKOTA. FURTHERMORE...THE SYSTEM HAS
BEEN OCCLUDED FOR 12-18 HOURS NOW AND WE STILL SAW A 1-2 MB MSLP
PRESSURE DROP OVERNIGHT. THE TROWAL IS CREATING A HOME RUN HITTING
DEFORMATION BAND FROM NORTHERN MN TO ND TO SD. IN FACT...THE
PRECIP SHIELD ALONG THE COLD CONVEYOR BELT ACTUALLY EXTENDS ALL
THE WAY FROM WYOMING TO MICHIGAN...AND THUNDERSTORMS ALONG THE
COLD FRONT EXTEND FROM MICHIGAN TO TEXAS. NOT A SMALL SYSTEM BY
ANY MEANS.
THE FORECAST AREA WILL FIND ITSELF IN THE DRY SLOT MOST OF THE DAY
TODAY AND ALSO TONIGHT TO SOME DEGREE. HOWEVER SOME DRIZZLE IS
POSSIBLE AND THE CLOUDS SHOULD LARGELY STAY IN TACT. THE OCCLUDED
BOUNDARY ISN`T GOING ANYWHERE...ESPECIALLY FOR CENTRAL MN/WI.
SOUTHERN PORTIONS OF THE FORECAST AREA /THAT`S RIGHT...SOUTHERN/
ARE CLOSER TO THE COLDER AND DRIER AIR...SO THERE IS A BETTER
CHANCE OF AT LEAST PARTIAL CLEARING TODAY IN SOUTHERN MN. MUCH
COLDER AIR ALOFT ARRIVES TONIGHT...SO THE STRATUS WON`T BE FAR
BEHIND EVEN IF THERE IS CLEARING DURING THE DAY TODAY. THE 00-06Z
GUIDANCE IS TOO FAR SOUTH WITH THE DEFORMATION PRECIP BAND THIS
MORNING...AS THE FORECAST AREA IS VIRTUALLY PRECIP FREE. IT`S ALSO
NOT DEEP ENOUGH WITH THE SURFACE LOW. TRIED TO KEEP THE POPS TODAY
ON THE OUTER EDGES OF THE FORECAST AREA TO COUNTER THIS AND ALSO
TO STAY CLOSE TO SURROUND FORECAST OFFICES. OTHERWISE...WINDS WILL
FALL OFF AS THE LOW SLOWLY FILLS AND MOVES OVERHEAD. IF THE CLOUDS
CLEAR ANYWHERE TONIGHT...FOG COULD BE A PROBLEM...TOOK THE SIDE OF
LOW STRATUS FOR NOW. NEAR STEADY TEMPERATURE TODAY SO MADE LITTLE
ADJUSTMENT TO THE PREVIOUS FORECAST. WE ADJUSTED DEWPOINTS BY
KEEPING SLIGHTLY HIGHER VALUES NEAR THE FRONT AND COOLER VALUES
CLOSER TO THE DRY SLOT.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 342 AM CDT SAT OCT 5 2013
THE SFC LOW FROM THE POTENT/DEEP SYSTEM AFFECTING THE REGION WILL
SHIFT INTO WI BY DAYBREAK SUN MRNG WHILE THE LOW PRES CENTER ALOFT
WILL SHIFT SE INTO NRN IA. AS THESE TWO LOWS MOVE EAST IN TANDEM
SLOWLY DURG THE DAY ON SUN...THE DRY SLOT OVER MUCH OF THE AREA
WILL FILL BACK IN WITH DEEPER MOISTURE WRAPPING AROUND THE UPPER
LEVEL LOW. COLD ALOFT COMBINED WITH LOW LEVEL WINDS SHIFTING TO A
MORE NLY DIRECTION WILL AID IN KEEPING LOW CLOUDS IN PLACE FOR
MUCH OF THE DAY...ALONG WITH A DRIZZLE/RAIN SCENARIO FOR SENSIBLE
WX. THE UPPER LOW WILL SHIFT ESE INTO CENTRAL IL BY MON
MRNG...DRAGGING MUCH OF THE MOISTURE WITH IT BUT THERE WILL STILL
BE A CHC FOR LINGERING SHOWERS IN WRN WI ON MON WHILE SRN/CENTRAL
MN STARTS TO CLEAR OUT. CONDS WILL GRADUALLY IMPROVE DURG THE DAY
ON MON AS HIGH PRES FROM SW CANADA DROPS IN. DESPITE THE COOL
ORIGIN OF THIS AIRMASS...IT WILL BE QUICKLY MODIFIED BY AN UPPER
LEVEL RIDGE THAT WITH INCRG H5 HEIGHTS WILL SPELL A WARMING TREND
ALONG WITH A PROLONGED DRYING-OUT PERIOD FOR THE AREA. DRY WX IS
FORECAST MON THRU THU WITH HIGHS RISING BACK INTO THE MID 70S.
MODELS CONTINUE TO ADVERTISE ANOTHER POTENT SYNOPTIC-SCALE LOW
PRES SYSTEM TO DEVELOP IN THE LEE OF THE ROCKIES THU NIGHT INTO
FRI MORNING...WITH IT QUICKLY MOVG NEWD INTO THE DAKOTAS FRI. THIS
MAY ALLOW FOR SOME MID-TO-LATE DAY SHWRS/TSTMS OVER WRN MN ON FRI
AS THIS SYSTEM ADVANCES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1239 PM CDT SAT OCT 5 2013
LOW CONFIDENCE WITH CIG FORECAST IN TAFS. DRYING ASSOCIATED WITH
OCCLUDED LOW OVER SE SODAK HAS BEEN SLOWLY SPREADING NORTH/EAST.
THE RAP ALONG WITH THE GFS/NAM TAKES VFR CONDITIONS ACROSS ALL
TERMINALS FOR A TIME. THERE IS LOTS OF DISAGREEMENT WITH WHEN MVFR
CIGS WILL DROP BACK SOUTH AND EAST THIS EVENING...WITH RAP BEING
THE MOST AGGRESSIVE WITH BRINGING MVFR OR LOWER CIGS BACK AND
THE GFS/NAM SIGNIFICANTLY SLOWER. THESE TAFS WERE WRITTEN MORE
TOWARD THE GFS/NAM IDEA FOR CIGS. CONFIDENCE INCREASING IN AN AREA
OF SHRA DEVELOPING SHORTLY FROM STC DOWN TO MKT ON EAST FOR THE
AFTERNOON. THE HRRR ALONG WITH THE HOPWRF HAVE BOTH BEEN DEPICTING
THIS ALL MORNING AND WITH MID LEVEL CLOUDS EXPANDING ON SATELLITE
ALONG WITH RETURNS SHOWING UP ON RADAR IN SOUTH CENTRAL MN...SIDED
CLOSELY WITH THE HRRR IN BRINGING PRECIP BACK TO ALL BUT RWF. THE
LOW OFF TO THE WEST WILL DRIFT ACROSS MN TONIGHT...WITH WINDS
BECOMING LIGHT AND VRB AS A RESULT. WITH THE LIGHT WINDS...
ANYWHERE THAT REMAINS RELATIVELY CLEAR TONIGHT WILL HAVE TO THREAT
FOR DENSE FOG. AT THE MOMENT...THE MOST LIKELY PLACE FOR THAT TO
HAPPEN WOULD BE OVER WRN WI.
KMSP...TOUGH TO PIN DOWN THE CIGS FOR THIS FORECAST...AS THE 12Z
NAM/GFS WOULD BOTH INDICATE THAT CIGS WILL REMAIN VFR UNTIL LATE
SUNDAY AFTERNOON. CONFIDENCE HIGH IN ANOTHER ROUND OF SHOWERS
MOVING ACROSS THE FIELD BETWEEN 20Z AND 01Z PER THE HRRR AND
HOPWRF...THOUGH CONFIDENCE LOWER IN CIGS COMING BACK DOWN AS LOW
AS THEY ARE CURRENTLY FORECAST TO BE...MAY ONLY COME AS LOW AS 6K
FT WITH THE PRECIP. OPTIMISTIC CIG FORECAST TOMORROW BASED ON THE
GFS/NAM...BUT THE RAP SHOWS MVFR CIGS RETURNING TO MSP AROUND
09Z. IF THE CIGS DO COME IN BEFORE 12Z SUNDAY...THERE IS A GOOD
CHANCE THEY WILL COME IN BELOW 017.
/OUTLOOK FOR KMSP/
MON...VFR...MVFR POSSIBLE EARLY. WINDS NW 5-10 KT.
TUE...VFR. WINDS S 15G25 KT.
WED...VFR. WINDS SSE 10-15 KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
UPDATE...MPG
SHORT TERM...CLF
LONG TERM...JPC
AVIATION...MPG
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1232 PM CDT SAT OCT 5 2013
.UPDATE...
ISSUED AT 1232 PM CDT SAT OCT 5 2013
UPDATED FOR AVIATION DISCUSSION.
UPDATE ISSUED AT 1029 AM CDT SAT OCT 5 2013
THE SURFACE LOW WAS LOCATED IN SOUTHEAST SOUTH DAKOTA AS OF 15Z
WITH AN OCCLUDED FRONT EXTENDING FROM THIS LOW ACROSS PORTIONS OF
S-C MINNESOTA INTO FAR SOUTHWEST WISCONSIN. 925MB BOUNDARY IS IN
NEARLY THE SAME LOCATION WITH HIGHER THETA-E AIR NORTH AND EAST OF THE
BOUNDARY. THIS FRONT MARKED A CLEARING LINE WITH DRY CONDITIONS
BEHIND IT OVER MUCH OF SOUTHERN MINNESOTA. LIGHT RAIN/DRIZZLE
CONTINUED OVER PORTIONS OF THE NORTHLAND THIS MORNING...BUT WASN`T
REAL WIDESPREAD. WE TRIMMED BACK SOME ON POPS THROUGH MID
AFTERNOON BUT MAY HAVE TO FURTHER AS SEVERAL OBSERVATIONS WERE NOT
REPORTING ANY RAIN AS OF 15Z. WE DO EXPECT AN INCREASE IN COVERAGE
LATER THIS AFTERNOON AS THE STACKED LOW PRESSURE SYSTEM MOVES
FURTHER EAST. THE LATEST HRRR WAS DOING A DECENT JOB DEPICTING THE
LIGHT RAIN THIS MORNING AND SHOWS COVERAGE INCREASING QUITE A BIT
MID TO LATE AFTERNOON ACROSS THE SOUTHERN THIRD...THEN FURTHER
NORTH THIS EVENING. THE 12Z NAM SUPPORTS THE HRRR BUT STILL MAY BE
OVERDONE WITH IT`S QPF. AREAS OF DRIZZLE WILL ALSO OCCUR AROUND
LAKE SUPERIOR. WE CONTINUE TO MONITOR RADAR TRENDS AND LATEST
MODEL OUTPUT AND ADJUST AS NEEDED.
IT REMAINS WINDY AROUND LAKE SUPERIOR...ESPECIALLY FROM SILVER BAY
TO THE TWIN PORTS AND ALONG THE BAYFIELD PENINSULA. KDLH WAS
GUSTING TO 42 MPH AS OF THE 1008 AM OBSERVATION AND TO 46 MPH ON
PARK POINT. WE`LL KEEP THE WIND ADVISORY GOING AS IS FOR NOW. WE
MAY NEED TO EXTEND IT FOR THE TWIN PORTS AREA TO TWO HARBORS/SILVER
BAY. THE WIND WASN`T AS STRONG ACROSS BAYFIELD/ASHLAND COUNTIES
BUT SOME HIGHER GUSTS WILL REMAIN POSSIBLE THERE AS WELL.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 410 AM CDT SAT OCT 5 2013
AT 4 AM...RAIN CONTINUED TO MOVE NORTHWARD ACROSS THE CWA. THE
MASSIVE LOW PRESSURE SYSTEM WAS LOCATED IN CENTRAL SOUTH
DAKOTA...WITH AN OCCLUDED FRONT STRETCHING EASTWARD THROUGH SW MN.
TEMPERATURES AT 4 AM WERE GENERALLY IN THE MID TO UPPER 40S NORTH
AND LOWER TO MIDDLE 50S SOUTH. STRONG WINDS CONTINUED NEAR LAKE
SUPERIOR...WITH KDYT AND KDLH STILL GUSTING ABOVE 40 MPH. THE RAIN
HAD DIMINISHED CONSIDERABLY ACROSS THE SOUTHERN THIRD OF THE CWA
BUT CONTINUED FROM THE TWIN PORTS NORTHWARD.
THE MAIN FOCUS FOR TODAY THROUGH SUNDAY IS THE EXTENT AND TIMING
OF VARIOUS WAVES OF PRECIPITATION. THE NAM AND THE NSSL AND NCEP
WRF RUNS SEEM TO HAVE A DECENT HANDLE ON THE SITUATION. THEY ALL
BRING A REPRIEVE IN THE RAIN TO THE SOUTHERN CWA...BEFORE
INCREASING AGAIN THIS AFTERNOON. DESPITE SOME BREAKS IN THE
PRECIPITATION...THERE SHOULD BE AREAS OF DRIZZLE AS WELL. WILL
CONTINUE WITH HIGH POPS. A LITTLE CONCERNED WE MAY NEED TO
EVENTUALLY PULL BACK ON POPS IN THE SOUTH...BUT KEPT THEM HIGH DUE
TO THE POTENTIAL FOR DRIZZLE.
RAIN SHOULD BECOME WIDESPREAD AGAIN TONIGHT...AS SURFACE LOW
PRESSURE RE-FORMS OVER WISCONSIN. FOR THAT REASON...WILL CONTINUE
WITH HIGH POPS TONIGHT...AND THEN GRADUALLY DECREASE IN PLACE AS
THE LOW STARTS TO FALL APART ON SUNDAY. WILL CONTINUE POPS
THROUGHOUT THE DAY THOUGH...AS THERE SHOULD BE SOME LINGERING
PRECIPITATION.
WILL CONTINUE WITH THE WIND ADVISORY FOR TODAY DUE TO THE STRONG
EASTERLY WINDS COMING OFF LAKE SUPERIOR.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 410 AM CDT SAT OCT 5 2013
ANOMALOUS SFC/MID LVL LOW WILL DRIFT EAST OF REGION BE EARLY MONDAY
AS SPLIT FLOW IN WESTERLIES ALLOWS NRN BRANCH TO DEEPEN OVER REGION.
PRECIP WILL GRADUALLY DIMINISH OVER THE ERN CWA AS CYCLONIC
CIRCULATION LOOSENS ITS GRIP MONDAY. MDLS AGREE THAT A RELATIVELY
QUIET DRY WEATHER PATTERN WILL COMMENCE TUESDAY AND PERSIST THROUGH
THE WEEK. SYNOPTIC PATTERN WILL FEATURE A DEVELOPING LARGE AMPLITUDE
UPPER TROF OVER CALIFORNIA WITH A BROAD UPPER RIDGE ACROSS THE NRN
PLAINS AND THE WRN GT LAKES. A SFC TROUGH WILL BEGIN TO FORM OVER
THE PLAINS AND EXTEND NORTH INTO NWRN MN BY WED EVENING. ALTHOUGH A
WARM ADVECTION REGIME WILL BECOME MORE PRONOUNCED ACROSS THE CWA AT
THIS TIME IT APPEARS THE MORE FAVORABLE LIFT WILL OCCUR TO THE WEST
OF THE REGION THROUGH THURSDAY. CONFIDENCE LOWERS BY FRIDAY AS TO
HOW FAR EAST THE EJECTING MID LVL SYSTEM WILL TRACK DUE TO
DOWNSTREAM UPPER RIDGE OVER MS RIVER VALLEY. WILL KEEP MAINLY DRY
OVER ALL OF CWA THROUGH FRIDAY BEFORE ALLOWING POPS TO RENTER THE
CWA FRIDAY NIGHT. TEMPS WILL RISE ABOVE CLIMO MOST OF THE WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1232 PM CDT SAT OCT 5 2013
IFR AND MVFR CIGS/VSBYS WILL PERSIST THROUGH TODAY AND MOST OF
TONIGHT BEFORE GRADUAL IMPROVEMENT IS SEEN BY LATE SUNDAY MORNING
ACROSS THE WRN TERMINALS. LIGHT SCATTERED RAIN SHOWERS ARE
EXPECTED THIS AFTERNOON WITH MORE WIDESPREAD HEAVIER SHOWERS
POSSIBLE THIS EVENING...AFTER 23/00Z...LASTING THROUGH 05/06Z.
VSBYS WILL LOWER IN THE STRONGER SHOWERS...WITH POSSIBLY PATCHY
FOG AROUND DLH AND HYR TONIGHT. GUSTY NE WINDS WILL SLOWLY
DIMINISH IN INTENSITY AND BACK TO THE NORTH TONIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 49 47 51 41 / 80 80 60 20
INL 47 39 54 38 / 70 50 40 10
BRD 54 46 53 40 / 80 80 60 20
HYR 57 44 59 41 / 80 80 50 30
ASX 55 49 57 44 / 80 80 60 40
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WIND ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR MNZ020-037.
WI...WIND ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR WIZ001-002.
LS...GALE WARNING UNTIL 10 PM CDT THIS EVENING FOR LSZ141>147.
SMALL CRAFT ADVISORY UNTIL 4 AM CDT SUNDAY FOR LSZ121-140-148.
&&
$$
SHORT TERM...DAP
LONG TERM...CANNON
AVIATION...BJT
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1236 PM CDT SAT OCT 5 2013
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 350 AM CDT SAT OCT 5 2013
THE MSAS SHOWS THE SFC LOW NEARLY STATIONARY THIS MORNING ACROSS
SCNTL SD. THE LOW IS IN THE PROCESS OF DOING A LOOP. THIS
AFTERNOON IT WILL DRIFT EAST AT 5 MPH INTO SERN SD AND THIS IS
CONSISTENT WITH THE MOTION OF THE 500 MB LOW AT JUST 6 KT.
VERY SLOW STORM MOTIONS OF THIS TYPE...5 MPH...OFTEN PRODUCE HIGH
WIND EVENTS IN THE CNTL PLAINS. THE GFS...ECM AND RAP SHOW
SUSTAINED WINDS INCREASING TO AROUND 40 MPH ACROSS NCNTL NEB THIS
AFTERNOON WITH GUSTS TO 58 MPH IN THE RAP AND HRRR MODELS. THE
NAM KEEPS THE GUSTS BELOW 58 MPH THIS AFTN. MEANWHILE THE MET
GUIDANCE SHOWS NO HIGH WIND EVENT AT ALL WHILE THE MAV GUIDANCE
FAVORS SWRN NEB. THE MULTI LAYER WINDS IN THE RAP MODEL FROM
H850MB TO H700MB KEEP WINDS AT 60 KTS OR LESS AND THIS IS
CONSISTENT WITH A HIGH END WIND ADVISORY WITH A FEW GUSTS TO 58
MPH.
THUS THERE IS A SPLIT IN THE MODEL DATA. A HIGH END WIND ADVISORY
EVENT WOULD APPEAR TO BE THE MOST LIKELY SOLN INDICATED BY THE
MODELS BUT LOCAL STUDIES SUGGEST A HIGH WIND EVENT WOULD UNFOLD
THIS AFTERNOON. A WIND ADVISORY WILL CONTINUE TODAY ACROSS ALL
AREAS EXCEPT WHERE THE WINTER STORM WARNING IS IN EFFECT.
WINTER STORM CONDITIONS ARE LIKELY ONGOING ACROSS NRN SHERIDAN
AND WRN CHERRY COUNTIES THIS MORNING. THE RADAR MAY BE
OVERSHOOTING THE DENDRITIC LAYER. THE ELLSWORTH NEDOR CAM IS
QUIET WHILE THE RUSHVILLE CAM CONTINUES TO SHOW SNOW AND BLOWING
SNOW WITH VISIBILITY AROUND 2 MILES OR SO. THE 08Z KIEN OB SHOWS
1/2 MILE VISIBILITY WITH A VERTICAL VISIBILITY OF JUST 500 FEET.
THE REST OF THE NEDOR CAMS ARE DARK SO WE WILL HAVE TO WAIT FOR
SUNRISE TO GET A BETTER ANALYSIS OF THE SITUATION ACROSS NW NEB.
THE WINTER STORM WARNING WILL CONTINUE UNTIL 18Z AS FORECAST.
GIVEN THE UPPER LOW HAS STALLED ACROSS THE CNTL PLAINS...THE
MODEL CONSENSUS SHOWS WRAPAROUND RAIN AND SNOW TODAY THROUGH
SUNDAY MORNING. THE UPPER LEVEL LOW IS EXPECTED TO CONTINUE
MOVING SLOWLY EAST SOUTHEAST INTO SRN IOWA BY LATE SUNDAY
AFTERNOON. A MULTI MODEL CONSENSUS WAS USED FOR POPS TONIGHT AND
SUNDAY. THE RAP MODEL WAS USED EXCLUSIVELY FOR THE TODAY PERIOD.
NONE OF THE MODELS ARE SHOWING VERY HEAVY QPF AND SNOW TOTALS OF
2 INCHES OR LESS ARE EXPECTED BASED ON THAT OUTPUT. THERE IS SOME
UNCERTAINTY WITH THIS FORECAST AS THE 850 MB MOISTURE TRANSPORT
IS STILL QUITE STRONG ACROSS THE NRN PLAINS AND OCCASIONAL
LIGHTNING STRIKES ARE STILL SHOWING UP AT 08Z. THE NAM WHICH
APPEARS TO HAVE THE BEST HANDLE THE MASSIVE QPF ASSOCIATED WITH
THIS STORM GENERALLY KEEPS QPF LESS THAN 0.10 INCHES IN ANY 3
HOUR PERIOD ACROSS NRN NEB.
OTHERWISE...HIGHS TODAY RISE INTO THE 30S AND 40S ACCORDING TO A
BLEND OF BIAS CORRECTED AND DETERMINISTIC DATA. THE MODELS ARE
FORECASTING LOWS IN THE MID 20S TONIGHT ACROSS THE SNOW FIELD
ACROSS NWRN NEB WITH LOWER 30S ELSEWHERE. IF THE WRN HALF OF THE
FORECAST AREA CLEARS OUT TONIGHT AS INDICATED IN THE MODELS THEN
THESE LOWS COULD BE 5 OR MORE DEGREES COLDER. HIGHS SUNDAY RISE
INTO THE 40S ACROSS THE SNOW COVERED NORTHWEST WITH 50S AND 60S
ELSEWHERE.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 350 AM CDT SAT OCT 5 2013
BY SUNDAY NIGHT THE LOW PRESSURE SYSTEM WILL HAVE PUSHED TOWARDS
THE MID MISS RVR VALLEY AND THE WRAP AROUND MOISTURE WILL HAVE
SHIFTED INTO EASTERN NEB. MEANWHILE AN UPPER LEVEL RIDGE WILL
BUILD ACROSS THE WEST...AS THE NEXT TROUGH PUSHES ACROSS
NORTHEASTERN PACIFIC OCEAN.
MONDAY THROUGH THURSDAY THE PACIFIC TROUGH WILL DIG TOWARDS THE
DESERT SOUTHWEST WHILE THE UPPER RIDGE SHIFTS EAST ACROSS THE
PLAINS. AT THE SFC HIGH PRESSURE WILL DOMINATE THE PLAINS THROUGH
MUCH OF THE WEEK. THUS EXPECT MILD CONDITIONS WITH 70S AND A FEW
MID/UPPER 60S ACROSS THE NW ZONES WHERE SOME INFLUENCE FROM THE
HEAVY SNOW PACK IS LIKELY TO LIMIT THE HEATING. ONCE THE SNOW
MELTS...COULD SEE MORE WIDESPREAD HIGHS INTO THE 70S ACROSS THE
NW. WITH THE WARM AIR MASS...EXPECT SEASONALLY WARM
LOWS...GENERALLY IN THE 40S SPOTTED WITH A FEW UPPER 30S.
LATE THURSDAY INTO FRIDAY THE LOW OVER THE SW WILL BEGIN TO EJECT
ONTO THE NORTHERN PLAINS. MODELS IN FAIR AGREEMENT...CONSIDERING
6/7 DAYS OUT...WITH A TRACK OF THE UPPER LOW ACROSS THE CENTRAL
ROCKIES AND INTO S DAKOTA. THE MODELS CONTINUE TO TRACK THE LOW TO
THE NE...INTO CANADA OVER THE WEEKEND. AS THE LOW PUSHES ONTO THE
ROCKIES...GOOD MOISTURE TRANSPORT WITH S WINDS EXPECTED ACROSS THE
AREA. POPS ARE NEEDED FOR THURSDAY INTO FRIDAY...HOWEVER PENDING
THE TRACK AND THE DRY SLOT...CONCERNED AMOUNTS MAY NOT AMOUNT TO
TOO MUCH OVER PART OF THE CWA. THUS WILL HOLD POPS IN THE SLIGHT
CHANCE AND LOWER CHANCE CATEGORY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1229 PM CDT SAT OCT 5 2013
STRONG LOW PRESSURE SYSTEM SLOWLY MOVING THROUGH THE NORTHERN
PLAINS WILL CONTINUE TO IMPACT THE AVIATION FORECAST IN WESTERN
AND NORTH CENTRAL NEBRASKA THROUGH SUNDAY MORNING. SNOW SQUALLS
WILL MOVE THROUGH KVTN DURING THE AFTERNOON AND BRING VSBYS DOWN
TO 2SM OR LESS AT TIMES. SNOW SHOWER ACTIVITY WILL BEGIN TO TAPER
OFF THIS EVENING AND OVERNIGHT. NO SNOW SHOWERS ARE ANTICIPATED TO
REACH KLBF...HOWEVER CIGS WILL HOVER AT OR JUST ABOVE MVFR LEVELS
THROUGH THE AFTERNOON.
GUSTY WINDS NORTHWEST WINDS WILL REMAIN THROUGH THE TAF PERIOD.
STRONGEST WINDS GUSTING TO 35 TO 40 KTS ARE EXPECTED THIS
AFTERNOON AND EARLY EVENING. WINDS WILL BEGIN TO RELAX AFTER 00Z
WITH WIND GUSTS OF 20 TO 25 KTS EXPECTED BY SUNDAY MORNING.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 7 PM CDT /6 PM MDT/ THIS EVENING FOR
NEZ006>010-022>029-035>038-056>059-069>071.
WINTER WEATHER ADVISORY UNTIL 7 PM CDT /6 PM MDT/ THIS EVENING
FOR NEZ004-005-094.
&&
$$
SHORT TERM...CDC
LONG TERM...MASEK
AVIATION...MARTIN
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
255 PM EDT SAT OCT 5 2013
.SYNOPSIS...
A STATIONARY FRONT WILL REMAIN OVER THE REGION THROUGH TONIGHT
THEN LIFT NORTH AS A WARM FRONT ON SUNDAY. THIS WILL KEEP OUR
WEATHER UNSETTLED THROUGH THE WEEKEND WITH SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS, PRIMARILY DURING THE DAYLIGHT HOURS.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
1155 AM UPDATE...CURRENT SFC ANALYSIS SHOWS STATIONARY FRONT
SLIGHTLY FURTHER SOUTH THEN YESTERDAY. ATTM IT STRETCHES ACROSS
THE SOUTHERN TIER OF NYS THEN DROPS SOUTHEAST INTO THE POCONOS.
CONVECTION OVER THE NRN FINGER LAKES REGION HAS ALMOST DISSIPATED
AS IT ENCOUNTERED A FAIRLY STABLE AIRMASS WELL NORTH OF THE
BOUNDARY. SATELLITE SHOWS STRATUS BEGINNING TO MIX OUT OVER NE PA
AND THE SOUTHERN TIER. THESE LOCATIONS WILL SEE SOME SUNNY BREAKS
THIS AFTERNOON WITH THE WYOMING VALLEY LIKELY TO SEE THE MOST
SUNSHINE. MODELS CONTINUE TO SUGGEST A WEAK SHORT WAVE WILL MOVE
ALONG THE BOUNDARY LATER THIS AFTERNOON AND INTO THE EARLY EVENING.
CURRENT POPS LOOK REASONABLE WITH ONLY MINOR ADJUSTMENTS. ISOLATED
THUNDER IS STILL POSSIBLE LATER TODAY ALONG AND SOUTH OF THE SFC
FEATURE.
915 AM UPDATE...LOCAL RADAR SHOWS A CLUSTER OF SHOWERS WITH
EMBEDDED ISOLATED THUNDER MOVING INTO THE FINGER LAKES REGION.
BASED ON CURRENT MOVEMENT AND HRRR OUTPUT THIS CLUSTER WILL MOVE
ACROSS THE FINGER LAKES REGION AND INTO THE NRN CWA THROUGH LATE
MORNING. INCREASED POPS IN THE ABOVE MENTIONED AREAS AND INCLUDED
ISOLATED T EXCEPT FAR NRN CWA WHERE MODEL SOUNDINGS INDICATE NO
INSTABILITY. REST OF FORECAST IN GOOD SHAPE.
620 AM UPDATE...
TEMPS HV STAYED UP IN THE 60S UNDER EXTENSIVE STRATUS AND FOG
DECK. EXPECT PATCHY DENSE FOG WL CONTINUE THRU 14Z ALONG WITH
ISOLD SHOWERS WITH STATIONARY FRONT LURKING ACRS THE AREA. AREA OF
SHOWERS MVG INTO NIAGARA FRONTIER AHD OF S/WV MAY MV INTO WRN
CNTYS TWD 12Z. KEPT SLGT CHC POPS IN ALL NIGHT FOR CNTRL CNTYS AND
EXPECT POPS TO INCRS IN CVRG ACRS TWIN TIERS TWD LATE MRNG. THUS
NO CHGS NEEDED AT THIS TIME OTHER THAN T/TD GRIDS TO COME MORE
INTO LINE WITH REALITY.
PREV DISCUSSION BLO...
330 AM UPDATE...
WMFNT IS CURRENTLY STRETCHED FM SFC LOW NR PIERRE SD ALONG THE I-90
CORRIDOR TO BTWN KBUF AND KERI AND ALONG NY/PA BORDER. DO NOT EXPECT
MUCH IN THE WAY OF MVMNT TDA AS 1028MB HIPRES RMNS LOCKED ACRS ERN
CANADA AND CLOSED LOW JUST CREEPS ALONG, ROUGHLY 100 MILES IN 12
HRS, AS IT WAITS FOR AN UPSTREAM KICKER.
AS FOR TDA`S FCST EXPECT ISOLD/SCTD CONVECTION AS WMFNT RMNS OVR
AREA. ISOLD SHOWERS EXPECTED UNTIL ABOUT NOON TDA AS ANY EMBEDDED
S/WVS MAY KICK SOMETHING OFF WITH FRONTAL BNDRY IN AREA. HWVR AFT
ABOUT 16Z INSTABILITY LOOKS TO NOSE INTO REGION MAINLY ALONG BNDRY
WITH CAPES BTWN 200-400 J/KG AND K-INDICES APPCHG 35. EXPECT
CONVECTION AFT THIS TIME ACRS THE SRN TIER/SUSQ REGION, THEN SOUTH
INTO NEPA AFT 18Z. NRN CNTYS EXPECTED TO BE SOCKED IN WITH LOCLDS
ALL DAY NORTH OF THE BNDRY SIMILAR TO YDA. THUS HV NOT ADDED ANY
THUNDER INTO ZONES ALONG AND NORTH OF THE NY THRUWAY AT THIS TIME.
SKIES EXPECTED TO RMN CLDY ACRS NRN AREAS WITH SOME SUN POSSIBLY
BREAKING OUT BRIEFLY ACRS THE SOUTH. EXPECT AFTN MAXES SIMILAR TO
YDA WITH HIGHS ARND 80 ACRS WRN AND SRN ZONES AND ONLY INTO THE 60S
OVR NE CNTYS.
FNT WL BEGIN LIFTING NORTH SAT NGT AS HIPRES BUILDS INTO THE
CANADIAN MARITIMES AND SRLY WINDS INCRS. EXPECT SLGT/CHC SHOWERS
THRU THE OVRNGT ACRS CWA, INCRSG TO LKLY TWD SUN MRNG ACRS NRN ZONES
AS EJECTING WV FM UPSTREAM CLOSED LOW RIDES ALONG FRONTAL BNDRY AND
INITIATES CONVECTION.
OVRNGT LOWS FOR SUN MRNG WL LKLY RMN ARND NRML VALUES (L/M 60S) FOR
HIGHS THIS TIME OF YR, NOT EVEN CLOSE TO NORMAL LOWS.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
330 AM UPDATE...
CWA WL BE IN WM SECTOR ON SUNDAY WITH SCTD CONVECTION EXPECTED OFF
AND ON THROUGHOUT THE DAY AS ANY SUBTLE WVS THAT CAN MV THRU WL
GENERATE CHCS FOR SHRA/TSRA. FOR NOW, HV NOT MADE MANY CHGS DUE TO
UNSETTLED PATTERN AND DIFFICULTY RESOLVING ANY TRIGGERS.
AREA RMNS IN WARM SECTOR ON SUN NGT AND CAN EXPECT JUST CHC SHOWERS
THRU 12Z MON SO HV DROPPED POPS TO JUST 30% AT THIS TIME FOR THE PD.
WARM AND HUMID CONDS WL CONT THRU MON MRNG WITH TEMPS AND TDS IN THE
U50S/L60S.
MOISTURE FM TROPICAL STORM KAREN PROGGED BY GFS TO WORK UP INTO AREA
MON NGT. HWVR, THIS WL ALL DEPEND ON HOW MUCH H5 SYSTEM SLOWS DOWN
AND IF FRONTAL BNDRY CAN HOLD OFF ENUF TO BRING MOISTURE INTO AREA.
AS OF NOW WITH PW VALUES INCRSG TO BTWN 1.5 AND 1.75 INCHES ON MON
NGT EXPECTED 12-HR QPF VALUES FM HPC WL AVG ARND 1 INCH THRU THE END
OF THE SHORT TERM. FROPA LOOKS TO HV SLOWED DOWN ENUF TO OCCUR AT
THE VRY TAIL END OF THE SHORT TERM.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
240 PM EDT UPDATE...
A MUCH DRIER WEATHER PATTERN IS EXPECTED IN THE EXTENDED THAN IN
THE NEAR TERM. THE UPPR LVL TROUGH THAT WILL BRING SHOWERS AND
THUNDERSTORMS OVER THE NEXT COUPLE OF DAYS WILL PUSH OUT OF THE
AREA TUESDAY/TUESDAY NIGHT. IN ITS WAKE AN UPPER AND LOWER LVL
RIDGE WILL BUILD INTO THE REGION. THERE WILL STILL BE A SLIGHT
CHANCE FOR SHOWERS ON TUESDAY/TUESDAY NIGHT FROM LINGERING
MOISTURE OF KAREN BUT WILL DIMINISH QUICKLY THEREAFTER. WENT
CLOSELY WITH WPC GUIDANCE AND KEPT THE FORECAST DRY AS CHANCES FOR
RAIN ARE VERY MINIMAL THROUGH THE EXTENDED. HIGH TEMPS STARTING
WED THROUGH SAT WILL BE MUCH COOLER AS WELL... WITH HIGHS
REMAINING IN THE MID TO UPPER 60S EVEN THOUGH CLOUD COVERAGE WILL
BE FOR THE MOST PART PARTLY CLOUDY. THESE TEMPS WILL BE CLOSER TO
THE SEASONABLE NORM BUT ARE STILL ABOVE AVERAGE. COOLER TEMPS ARE
AHEAD.
&
.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
140 PM EDT UPDATE...
A VERY CHALLENGING FORECAST IS IN STORE FOR THE NEXT 24 HOURS AS A
WARM FRONT LIFTS NORTH FROM THE BORDER OF PA TO NORTHERN NY.
CURRENTLY ACROSS THE REGION A VERY DENSE MVFR STRATUS DECKS LIES
ACROSS MUCH OF CENTRAL NY. DUE TO HEATING FROM THE SUN...WE DO
EXPECT THESE CLOUDS TO LIFT BRIEFLY TO VFR THIS AFTERNOON/EVENING.
CONFIDENCE IS NOT HIGH ON THE TIMING OF THE TRANSITION. THERE IS A
CHANCE FOR LIGHT RAIN SHOWERS THIS AFTERNOON...BUT WITHOUT STRONG
UPPER FORCING DECIDED TO KEEP OUT OF TAFS DUE TO UNCERTAINTY OF
LOCATION. THE OVERALL CHANCE FOR RAIN SHOWERS WILL INCREASE AFTER
00Z TONIGHT AS THE DRAPED WARM FRONT MOVES NORTH. THE BEST CHANCES
FOR RAIN ARE AT KRME... KITH... AND KSYR. THESE SHOWERS MAY PERSIST
WELL INTO THE AFTERNOON ON SUNDAY AND EXPECT THESE SHOWERS TO BE
FUEL ALTERNATE CIGS AND VISBYS.
OUTLOOK...
SUNDAY THROUGH THURSDAY...AN UNSETTLED PERIOD...WITH SCATTERED
TO WIDESPREAD SHOWERS ANTICIPATED...ALG WITH THE LIKELIHOOD OF
RESTRICTIVE CONDS FROM TIME TO TIME.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...PVN
NEAR TERM...PVN/RRM
SHORT TERM...PVN
LONG TERM...KAH
AVIATION...KAH
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
158 PM EDT SAT OCT 5 2013
.SYNOPSIS...
A STATIONARY FRONT WILL REMAIN OVER THE REGION THROUGH TONIGHT
THEN LIFT NORTH AS A WARM FRONT ON SUNDAY. THIS WILL KEEP OUR
WEATHER UNSETTLED THROUGH THE WEEKEND WITH SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS, PRIMARILY DURING THE DAYLIGHT HOURS.
&&
.NEAR TERM /THROUGH TONIGHT/...
1155 AM UPDATE...CURRENT SFC ANALYSIS SHOWS STATIONARY FRONT
SLIGHTLY FURTHER SOUTH THEN YESTERDAY. ATTM IT STRETCHES ACROSS
THE SOUTHERN TIER OF NYS THEN DROPS SOUTHEAST INTO THE POCONOS.
CONVECTION OVER THE NRN FINGER LAKES REGION HAS ALMOST DISSIPATED
AS IT ENCOUNTERED A FAIRLY STABLE AIRMASS WELL NORTH OF THE
BOUNDARY. SATELLITE SHOWS STRATUS BEGINNING TO MIX OUT OVER NE PA
AND THE SOUTHERN TIER. THESE LOCATIONS WILL SEE SOME SUNNY BREAKS
THIS AFTERNOON WITH THE WYOMING VALLEY LIKELY TO SEE THE MOST
SUNSHINE. MODELS CONTINUE TO SUGGEST A WEAK SHORT WAVE WILL MOVE
ALONG THE BOUNDARY LATER THIS AFTERNOON AND INTO THE EARLY EVENING.
CURRENT POPS LOOK REASONABLE WITH ONLY MINOR ADJUSTMENTS. ISOLATED
THUNDER IS STILL POSSIBLE LATER TODAY ALONG AND SOUTH OF THE SFC
FEATURE.
915 AM UPDATE...LOCAL RADAR SHOWS A CLUSTER OF SHOWERS WITH
EMBEDDED ISOLATED THUNDER MOVING INTO THE FINGER LAKES REGION.
BASED ON CURRENT MOVEMENT AND HRRR OUTPUT THIS CLUSTER WILL MOVE
ACROSS THE FINGER LAKES REGION AND INTO THE NRN CWA THROUGH LATE
MORNING. INCREASED POPS IN THE ABOVE MENTIONED AREAS AND INCLUDED
ISOLATED T EXCEPT FAR NRN CWA WHERE MODEL SOUNDINGS INDICATE NO
INSTABILITY. REST OF FORECAST IN GOOD SHAPE.
620 AM UPDATE...
TEMPS HV STAYED UP IN THE 60S UNDER EXTENSIVE STRATUS AND FOG
DECK. EXPECT PATCHY DENSE FOG WL CONTINUE THRU 14Z ALONG WITH
ISOLD SHOWERS WITH STATIONARY FRONT LURKING ACRS THE AREA. AREA OF
SHOWERS MVG INTO NIAGARA FRONTIER AHD OF S/WV MAY MV INTO WRN
CNTYS TWD 12Z. KEPT SLGT CHC POPS IN ALL NIGHT FOR CNTRL CNTYS AND
EXPECT POPS TO INCRS IN CVRG ACRS TWIN TIERS TWD LATE MRNG. THUS
NO CHGS NEEDED AT THIS TIME OTHER THAN T/TD GRIDS TO COME MORE
INTO LINE WITH REALITY.
PREV DISCUSSION BLO...
330 AM UPDATE...
WMFNT IS CURRENTLY STRETCHED FM SFC LOW NR PIERRE SD ALONG THE I-90
CORRIDOR TO BTWN KBUF AND KERI AND ALONG NY/PA BORDER. DO NOT EXPECT
MUCH IN THE WAY OF MVMNT TDA AS 1028MB HIPRES RMNS LOCKED ACRS ERN
CANADA AND CLOSED LOW JUST CREEPS ALONG, ROUGHLY 100 MILES IN 12
HRS, AS IT WAITS FOR AN UPSTREAM KICKER.
AS FOR TDA`S FCST EXPECT ISOLD/SCTD CONVECTION AS WMFNT RMNS OVR
AREA. ISOLD SHOWERS EXPECTED UNTIL ABOUT NOON TDA AS ANY EMBEDDED
S/WVS MAY KICK SOMETHING OFF WITH FRONTAL BNDRY IN AREA. HWVR AFT
ABOUT 16Z INSTABILITY LOOKS TO NOSE INTO REGION MAINLY ALONG BNDRY
WITH CAPES BTWN 200-400 J/KG AND K-INDICES APPCHG 35. EXPECT
CONVECTION AFT THIS TIME ACRS THE SRN TIER/SUSQ REGION, THEN SOUTH
INTO NEPA AFT 18Z. NRN CNTYS EXPECTED TO BE SOCKED IN WITH LOCLDS
ALL DAY NORTH OF THE BNDRY SIMILAR TO YDA. THUS HV NOT ADDED ANY
THUNDER INTO ZONES ALONG AND NORTH OF THE NY THRUWAY AT THIS TIME.
SKIES EXPECTED TO RMN CLDY ACRS NRN AREAS WITH SOME SUN POSSIBLY
BREAKING OUT BRIEFLY ACRS THE SOUTH. EXPECT AFTN MAXES SIMILAR TO
YDA WITH HIGHS ARND 80 ACRS WRN AND SRN ZONES AND ONLY INTO THE 60S
OVR NE CNTYS.
FNT WL BEGIN LIFTING NORTH SAT NGT AS HIPRES BUILDS INTO THE
CANADIAN MARITIMES AND SRLY WINDS INCRS. EXPECT SLGT/CHC SHOWERS
THRU THE OVRNGT ACRS CWA, INCRSG TO LKLY TWD SUN MRNG ACRS NRN ZONES
AS EJECTING WV FM UPSTREAM CLOSED LOW RIDES ALONG FRONTAL BNDRY AND
INITIATES CONVECTION.
OVRNGT LOWS FOR SUN MRNG WL LKLY RMN ARND NRML VALUES (L/M 60S) FOR
HIGHS THIS TIME OF YR, NOT EVEN CLOSE TO NORMAL LOWS.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
330 AM UPDATE...
CWA WL BE IN WM SECTOR ON SUNDAY WITH SCTD CONVECTION EXPECTED OFF
AND ON THROUGHOUT THE DAY AS ANY SUBTLE WVS THAT CAN MV THRU WL
GENERATE CHCS FOR SHRA/TSRA. FOR NOW, HV NOT MADE MANY CHGS DUE TO
UNSETTLED PATTERN AND DIFFICULTY RESOLVING ANY TRIGGERS.
AREA RMNS IN WARM SECTOR ON SUN NGT AND CAN EXPECT JUST CHC SHOWERS
THRU 12Z MON SO HV DROPPED POPS TO JUST 30% AT THIS TIME FOR THE PD.
WARM AND HUMID CONDS WL CONT THRU MON MRNG WITH TEMPS AND TDS IN THE
U50S/L60S.
MOISTURE FM TROPICAL STORM KAREN PROGGED BY GFS TO WORK UP INTO AREA
MON NGT. HWVR, THIS WL ALL DEPEND ON HOW MUCH H5 SYSTEM SLOWS DOWN
AND IF FRONTAL BNDRY CAN HOLD OFF ENUF TO BRING MOISTURE INTO AREA.
AS OF NOW WITH PW VALUES INCRSG TO BTWN 1.5 AND 1.75 INCHES ON MON
NGT EXPECTED 12-HR QPF VALUES FM HPC WL AVG ARND 1 INCH THRU THE END
OF THE SHORT TERM. FROPA LOOKS TO HV SLOWED DOWN ENUF TO OCCUR AT
THE VRY TAIL END OF THE SHORT TERM.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
345 AM UPDATE...
MED RNG GRIDS UPDATED WITH 00Z WPC GDNC (BLENDED WITH SOME GFS/MOS
DATA) TO REFLECT A SLOWER MVMNT OF THE UPR LOW...WITH AN EXTENSION OF
CHC POPS INTO MID WEEK AND MORE IN THE WAY OF CLDS DUE TO THIS
SYSTEM. PREV BLO...
2 PM UPDATE...
MAIN INTEREST IN THE LONG TERM FORECAST WILL BE THE POTENTIAL FOR
HEAVY RAIN MONDAY NIGHT. THE MAIN WEATHER PLAYERS WILL BE AN UPPER
LEVEL LOW NOW OVER SE WYOMING...AND ASSOCIATED COLD FRONT OVER THE
CENTRAL PLAINS. AS THESE FEATURES MOVE EAST THE SOUTHERLY FLOW OF
AIR AHEAD OF THEM WILL TRANSPORT MOISTURE...SOME OF IT WILL BE
WHATS LEFT OF TS KAREN...NORTHWARD INTO OUR AREA. WITH HIGH
VARIANCE IN THE MODELS JUST 24 HOURS AGO...THE 12Z NAM AND GFS ARE
FAIRLY SIMILAR IN SHOWING AN AREA OF STEADY RAIN ALONG AND AHEAD
OF THE COLD FRONT MOVING INTO OUR AREA MONDAY EVENING. BOTH THE
GFS AND WPC GUIDANCE SHOW A GENERAL 1" TO 2" RAIN ACROSS THE AREA
MONDAY NIGHT...WITH ISOLATED HIGHER AMOUNTS POSSIBLE. WITH OUR
RECENT STRETCH OF DRY WEATHER AND THE PROGRESSIVE NATURE OF THE
FRONT (RAIN FALLING IN 12 HOURS OR LESS)...WIDESPREAD PROBLEMS ARE
NOT EXPECTED AT THIS EARLY JUNCTURE. IN FACT FOR MOST THIS WILL BE
A WELCOME BENEFICIAL FALL RAIN.
LATER TUESDAY AND BEYOND...THE GFS IS NOW THE SLOWEST WITH THE
UPPER LEVEL LOW MOVING OVER OUR AREA AND KEEPING US
CLOUDY/UNSETTLED FOR ONE MORE DAY. WILL LEAN WITH WPC GUIDANCE
DRYING US OUT BY TUESDAY NIGHT. HIGH PRESSURE CONTROLS THE REST OF
THE PERIOD WITH QUIET WEATHER EXPECTED.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
140 PM EDT UPDATE...
A VERY CHALLENGING FORECAST IS IN STORE FOR THE NEXT 24 HOURS AS A
WARM FRONT LIFTS NORTH FROM THE BORDER OF PA TO NORTHERN NY.
CURRENTLY ACROSS THE REGION A VERY DENSE MVFR STRATUS DECKS LIES
ACROSS MUCH OF CENTRAL NY. DUE TO HEATING FROM THE SUN...WE DO
EXPECT THESE CLOUDS TO LIFT BRIEFLY TO VFR THIS AFTERNOON/EVENING.
CONFIDENCE IS NOT HIGH ON THE TIMING OF THE TRANSITION. THERE IS A
CHANCE FOR LIGHT RAIN SHOWERS THIS AFTERNOON...BUT WITHOUT STRONG
UPPER FORCING DECIDED TO KEEP OUT OF TAFS DUE TO UNCERTAINTY OF
LOCATION. THE OVERALL CHANCE FOR RAIN SHOWERS WILL INCREASE AFTER
00Z TONIGHT AS THE DRAPED WARM FRONT MOVES NORTH. THE BEST CHANCES
FOR RAIN ARE AT KRME... KITH... AND KSYR. THESE SHOWERS MAY PERSIST
WELL INTO THE AFTERNOON ON SUNDAY AND EXPECT THESE SHOWERS TO BE
FUEL ALTERNATE CIGS AND VISBYS.
OUTLOOK...
SUNDAY THROUGH THURSDAY...AN UNSETTLED PERIOD...WITH SCATTERED
TO WIDESPREAD SHOWERS ANTICIPATED...ALG WITH THE LIKELIHOOD OF
RESTRICTIVE CONDS FROM TIME TO TIME.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...PVN
NEAR TERM...PVN/RRM
SHORT TERM...PVN
LONG TERM...
AVIATION...KAH
AREA FORECAST DISCUSSION
NWS RALEIGH NC
155 PM EDT SAT OCT 5 2013
.SYNOPSIS...
HIGH PRESSURE OVER THE REGION WILL MOVE SLOWLY EAST AND OFF SHORE OF
THE CAROLINA COAST TONIGHT AND SUNDAY. WEAK LOW PRESSURE...AND
MOISTURE STREAMING AWAY FROM KAREN...WILL MOVE NORTHEAST ALONG A
COLD FRONT THAT WILL CROSS THE CAROLINAS ON MONDAY.
&&
.NEAR TERM /TODAY AND TONIGHT/...
AS OF 1000 AM SATURDAY...
SURFACE RIDGE REMAINS IN PLACE OVER CENTRAL NORTH CAROLINA...AND
THE MORNING UPPER-AIR ANALYSIS SHOWED THE RIDGE AXIS ALOFT JUST TO
OUR WEST. MORNING AMDAR SOUNDINGS AS WELL AS THE SOUNDING FROM KGSO
NOTED WARMING ALOFT AROUND 600MB OVER THE LAST 24 HOURS...
REPRESENTING STRONG CAPPING. THE LATEST RAP SHOWS THE RIDGE ALOFT
BUILDING EAST OVERHEAD DURING THE AFTERNOON...WITH GOOD SUBSIDENCE
AND LITTLE OR NO MIXED-LAYER CAPE IN THE LOWEST KM. MORNING
SOUNDINGS AND THE KRAX VAD WIND PROFILE NOTED A FAIRLY DEEP...BUT
LIGHT...NORTHERLY COMPONENT TO THE WIND WHICH SHOULD VEER DURING THE
DAY BASED ON THE LATEST RAP AND MOS GUIDANCE. MAIN CHANGES...ALL
MINOR...TO THE FORECAST FOR THE AFTERNOON WERE TO MODIFY THE
DIRECTION OF THE LIGHT WIND INTO THE MID-AFTERNOON HOURS...AND NOTE
JUST A FEW MORE CLOUDS WITH SOME MOSTLY THIN CIRRUS WORKING ITS WAY
EAST OF THE RIDGE AXIS ALOFT. 1000-850MB THICKNESSES FROM THE KGSO
12Z SOUNDING COMBINED WITH THE FORECAST MAXIMUM VALUE OF THAT
PARAMETER THIS AFTERNOON GIVES MAXES IN LINE WITH THE FORECAST.
LOWS TONIGHT WILL BE SIMILAR TO THIS MORNING...IN THE LOWER/MID
60S...COOLEST IN RURAL AND LOW-LYING AREAS. EXPECT AREAS OF FOG
AGAIN TONIGHT UNDER A MAINLY CLEAR SKY...LIGHT WIND...AND SURFACE
DEW POINTS LATE AT NIGHT 60 TO 65.
&&
.SHORT TERM /SUNDAY AND SUNDAY NIGHT/...
AS OF 345 AM SATURDAY...
AN IMPRESSIVE UPPER LEVEL LOW CENTERED OVER THE UPPER MIDWEST THIS
MORNING WILL TRACK INTO THE CENTRAL MS RIVER VALLEY SUN INTO SUN
NIGHT...WHILE ADDITIONAL SHORTWAVE ENERGY (OVER THE 4-CORNERS REGION
THIS MORNING) DIGS SOUTHEAST THROUGH THE LOWER MIDWEST INTO THE
LOWER MS RIVER VALLEY ALONG THE SOUTHERN PERIPHERY OF THE UPPER LOW.
ADDITIONALLY...TROPICAL CYCLONE KAREN IS EXPECTED TO TRACK SLOWLY
NORTH TOWARD THE GULF COAST ON SUN...MOVING ASHORE SOMEWHERE IN THE
DEEP SOUTH SUN NIGHT. IN THE LOWER LEVELS...A COLD FRONT ASSOC/W AN
OCCLUDED SFC LOW ATTENDANT THE UPPER LEVEL LOW WILL TRACK EAST INTO
THE TN/OH VALLEY ON SUN...APPROACHING THE SOUTHERN APPALACHIANS SUN
NIGHT.
PER THE 00Z GUIDANCE...SOUTHERLY RETURN FLOW AND LOW-LEVEL WARM
ADVECTION WILL NOT SIGNIFICANTLY STRENGTHEN UNTIL SUN NIGHT...AND
THE AIRMASS ON SUNDAY IS EXPECTED TO BE VERY SIMILAR TO TODAY WITH A
PRONOUNCED MID-LEVEL CAP AND MEAGER DIURNAL DESTABILIZATION (AT
BEST). FORCING FOR ASCENT WILL LARGELY BE ABSENT OVER CENTRAL
NC...CONFINED TO THE SEABREEZE OVER THE COASTAL CAROLINAS AND SMALL
AMPLITUDE DISTURBANCES IN STRENGTHENING SW FLOW ALOFT OVER FAR
WESTERN PORTIONS OF THE STATE DURING THE AFT/EVE. AS A RESULT...WILL
CONTINUE TO INDICATE A DRY FCST ON SUN. A RAPID INCREASE IN
LOW-LEVEL MOISTURE ASSOC/W STRENGTHENING SOUTHERLY FLOW WILL OCCUR
SUN NIGHT AND MON MORNING...WITH ASCENT INCREASING IN THE FORM OF
LOW-LEVEL WARM ADVECTION AND DPVA ASSOC/W SMALL AMPLITUDE
DISTURBANCES IN SW FLOW ALOFT. ALL OF THE 00Z GUIDANCE INDICATES
MEASURABLE PRECIP IN THE WESTERN PIEDMONT BY 12Z MON...AND THIS
SEEMS CONSISTENT WITH THE AFOREMENTIONED DISCUSSION. WILL INDICATE
PRECIP CHANCES INCREASING FROM THE WEST AFTER MIDNIGHT...RANGING
FROM 60-80% IN THE FAR WESTERN PIEDMONT TO ~20% ALONG THE I-95
CORRIDOR. EAST OF I-95...FORCING FOR ASCENT WILL BE MUCH WEAKER AND
PRECIP CHANCES WILL LARGELY BE TIED TO SHOWER ACTIVITY MOVING INLAND
FROM THE ATLANTIC IN ASSOC/W ONSHORE FLOW. AS A RESULT...WILL
INDICATE A DRY FCST IN THE FAR NE COASTAL PLAIN WITH A SLIGHT CHANCE
SOUTH OF HWY 64 IN THE SE COASTAL PLAIN.
THICKNESSES WILL BE SLIGHTLY LOWER (PERHAPS 5-10M) THAN TODAY.
THIS...ALONG WITH INCREASING CLOUD COVER DURING THE AFTERNOON SHOULD
RESULT IN HIGHS A FEW DEGREES COOLER THAN TODAY IN THE MID 80S
(84-88F)...COOLEST IN THE WESTERN PIEDMONT. LOWS SUN NIGHT WILL BE
TEMPERED BY CLOUD COVER AND A LIGHT SOUTHERLY BREEZE...IN THE UPPER
60S TO NEAR 70F IN THE SOUTH. -VINCENT
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 300 AM SATURDAY...
THE LATEST INFORMATION FROM THE NHC CONCERNING "KAREN" CONTINUES TO
DOWNGRADE THE TROPICAL SYSTEM. IT HAS BEEN DESCRIBED AS ALREADY
BEING `DECAPITATED" BY ONE FORECASTER - DUE TO STRONGER WINDS ALOFT.
THEREFORE... THE CONFIDENCE OF WHETHER ANY REMNANTS OF `KAREN" WILL
BE LEFT TO BRING INDIRECT IMPACTS (RAIN, SEVERE THREAT) FOR CENTRAL
NC BY EARLY NEXT WEEK HAS LOWERED.
ON A MORE CONFIDENT NOTE... A MID/UPPER LEVEL TROUGH IS FORECAST TO
BE APPROACHING THE APPALACHIANS MONDAY... THEN SWING ACROSS OUR
REGION TUE AND TUE NIGHT. THE MAIN UPPER DYNAMICS ARE FORECAST TO
PUSH FROM THE MIDWEST TO THE GREAT LAKES. HOWEVER... MOISTURE IS
EXPECTED TO SURGE NORTHWARD ALONG THE EASTERN SEABOARD BRINGING
WIDESPREAD SHOWERS AND ISOLATED THUNDERSTORMS ALONG THE COLD FRONT.
IF THE REMNANT LOW PRESSURE OF `KAREN` TRACKS NE INTO NC AS SOME OF
THE MODELS STILL SUGGEST... THERE CAN STILL BE ENHANCED RAINFALL FOR
12-24 HOURS. OTHERWISE... THIS WOULD BE A TYPICAL RAINFALL EVENT
ASSOCIATED WITH A MID-LATITUDE TROUGH EARLY NEXT WEEK.
ONCE THE TROUGH PASSES... CLEARING AND COOLER CONDITIONS ARE
EXPECTED MID THROUGH LATE WEEK. LOWS 50-55. HIGHS 70-75.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 155 PM SATURDAY...
THE 18Z VALID TAF FORECAST WILL BASICALLY BE PERSISTENCE...WITH
SOME AFTERNOON CU DIMINISHING LEAVING A FEW CIRRUS STREAMING ATOP
THE RIDGE AXIS. LIGHT WINDS...MOSTLY LIGHT SOUTH...WITH DEW POINTS
IN THE LOWER TO MID 60S LATE TONIGHT SHOULD RESULT IN AREAS OF FOG
ONCE AGAIN. THE HIGHEST PROBABILITIES OF FOG CONTINUE TO BE TOWARD
KFAY AND KRWI...LESSER TOWARD THE NORTHWEST. THE TAFS NOTE LOCAL
MVFR VISIBILITY TOWARD KGSO AND KINT...LOCAL IFR VISIBILITY AT
KRDU...AND RELATIVELY LOWER VISIBILITIES AT KFAY AND KRWI LATE
TONIGHT INTO EARLY SUNDAY. WITH MIXING SUNDAY MORNING...A MORE
NOTICEABLE SOUTHERLY WIND SHOULD DEVELOP WITH SURFACE SPEEDS
AVERAGING JUST UNDER 10KT BY THE END OF THE 18Z VALID TAF PERIOD.
BEYOND THE 18Z VALID TAF PERIOD...VFR CONDITIONS PERSIST UNTIL JUST
AFTER MIDNIGHT SUNDAY NIGHT INTO MONDAY MORNING. MOISTURE STREAMING
NORTH INTO THE CAROLINAS FROM THE GULF AHEAD OF A COLD FRONT LIKELY
RESULTS IN CONDITIONS BECOMING SUB-VFR WITH AT LEAST NUMEROUS
SHOWERS DEVELOPING. SOUTH WINDS SUNDAY NIGHT INCREASE ALOFT TO 30KT
BY 2000FT AS THE SURFACE GRADIENT INCREASES AHEAD OF THE FRONT. BY
TUESDAY...AVIATION CONDITIONS ARE EXPECTED TO IMPROVE TO
PREDOMINANTLY VFR IN NORTHEAST FLOW BEHIND THE FRONT. THESE
CONDITIONS CONTINUE THROUGH THURSDAY...WITH ONLY A SMALL PROBABILITY
OF LOW CLOUDS IN A LOW-LEVEL NORTHEAST FLOW LATE WEDNESDAY NIGHT
INTO THURSDAY MORNING.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SEC/DJF
NEAR TERM...DJF/VINCENT
SHORT TERM...VINCENT
LONG TERM...BADGETT
AVIATION...DJF
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
146 PM EDT SAT OCT 5 2013
.SYNOPSIS...
SOUTHWEST FLOW OF WARM...MUGGY AIR CONTINUES INTO SUNDAY. COLD FRONT
BRINGS SHOWERS ALONG WITH SOME STORMS LATE SUNDAY INTO MONDAY.
UPPER LOW PULLS OUT MIDWEEK...YIELDING TO HIGH PRESSURE LATE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...
A FEW SMALL WAVES EMBEDDED WITHIN THE UPPER RIDGE HAVE SPARKED
SOME CONVECTION OVER THE OHIO VALLEY THIS MORNING...BUT THIS IS
NOT ABLE TO GET MUCH IN TERMS OF VERTICAL EXTENT. HAD TO DRAG THE
POPS A LITTLE FURTHER TO THE SOUTHEAST...BUT LEFT THEM OUT OF CRW.
WILL REASSESS WHEN THE NEW MODELS ARE IN. HRRR HAS BEEN VALUABLE
THIS MORNING.
PREVIOUS DISCUSSION...
SUMMER REPRISE CONTINUES. ALTOCU THIS MORNING AIDS IN ERADICATING
THE DENSE VALLEY FOG OF EARLY MORNING...OR HOLDS IT IN IF IT
SURVIVES DAWN....AND CU THIS AFTERNOON IN VERY WARM AND HUMID SW
FLOW AS UPPER RIDGE MOVES E ACROSS AREA. WEAK RIPPLES IN THE UPPER
LEVEL SW FLOW ONCE THE RIDGE GOES BY COULD GRAZE NW PORTION OF AREA
WITH CONVECTION MIDDAY TODAY INTO THIS EVENING.
FLOW GOES MORE SOUTHERLY TONIGHT...SO CONVECTION ASSOCIATED WITH
RIPPLES IN FLOW WILL SHIFT N OF THE AREA WHILE THAT ASSOCIATED WITH
COLD FRONT TO THE W REMAINS W OF THE AREA THROUGH 12Z SUN. ALTOCU
LIMITED TO THE W. BOUNDARY LATER FLOW SHOULD PRECLUDE DENSE VALLEY
FOG SAVE FOR THE DEEPER VALLEYS OF EASTERN WV LATE TONIGHT.
ROLLED WITH BIAS CORRECTED ADJMET AND BIAS CORRECTED ALL BLEND
TOGETHER WITH PREVIOUS FOR HIGHS TODAY WITH ADJMAV BEING TOO HIGH.
LOWER TO MID 80S LOWLANDS IS 5-10F BELOW RECORD HIGHS. DID BLEND IN
BIAS CORRECTED ADJMAV FOR LOWS TONIGHT...A TICK OR SO HIGHER THAN
PREVIOUS ON RIDGE/HILL TOPS.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
UNSETTLED WEATHER IN THE SHORT TERM PERIOD. RATHER WARM AND HUMID
DAY ON TAP SUNDAY...AS UPPER LOW ACROSS CENTRAL U.S. DIGS SOUTH AND
EAST...CAUSING FLOW TO BACK...AND SLOWING THE PROGRESSION OF THE
COLD FRONT AND ASSOCIATED PRECIPITATION INTO THE CWA. STILL
EXPECTING SOME DECENT RAINFALL TOTALS...AS LLJ AIDS IN MOISTURE
TRANSPORT TO THE REGION...WITH PW VALUES EXPECTED TO RISE TO 1.6 TO
1.7 INCHES. AS WITH PREVIOUS FORECASTER...WILL LEAVE A MENTION OF
WATER PROBLEMS OUT OF THE HWO DUE TO RECENT DRY SPELL...AND OVERALL
PROGRESSIVE NATURE OF THE SYSTEM. IN ADDITION...AT THIS POINT...SPC
HAS ISSUED ONLY A SEE TEXT AREA FOR THE CWA...AS CLOUD COVER...AND
OVERALL LACK OF INSTABILITY SHOULD HOPEFULLY LIMIT THE SEVERE
POTENTIAL ACROSS THE REGION. STILL...EXPECTING SOME RATHER GUSTY
CONDITIONS ASSOCIATED WITH FRONTAL PASSAGE...SET TO TAKE PLACE ON
MONDAY...PARTICULARLY ACROSS HIGHER ELEVATIONS. HOWEVER...THIS WILL
NEED TO BE MONITORED AS MODELS ARE INDICATING STRONG FORCING WITH
THE FRONT. MODELS CONTINUE TO INDICATE THAT REMNANTS OF KAREN WILL
REMAIN FAR ENOUGH TO THE EAST OF THE AREA...THAT THE CWA WILL SEE
LITTLE TO NO EFFECT.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
LOOKING AT UPR RIDGE TO BUILD ACROSS EASTERN CONUS IN THE EXTENDED
WITH STALLED SFC FRONT LINGERING ALONG E COAST. SEASONABLE TEMPS
DURING THE DAY AND COOL NIGHTS ON TAP.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
CONVECTION EXPECTED OVER THE OHIO VALLEY AGAIN TODAY...WITH
ISOLATED CHANCES IN THE MOUNTAINS. ONLY HAVE VCTS IN THE PKB AREA
GIVEN THE CURRENT SET OF POP GRIDS IN PLACE...WHERE THESE VALUES
ARE THE HIGHEST. A FEW SHOWERS MAY LINGER AROUND HTS AS WELL...BUT
THE BULK OF THE ACTIVITY SHOULD REMAIN CLOSER TO ILN/CMH/ZZV.
DID NOT GO WITH MUCH FOG TONIGHT AS RH PROGS HAVE DEPTH OF THE
MOISTURE EXTENDING THROUGH 550MB...ALLUDING TO CLOUD COVER IN
PLACE. EKN MAY GET LIFR LATE TONIGHT WHERE THE CLOUD COVER IS NOT
EXPECTED TO BE AS PROMINENT.
WITH THE FRONTAL SYSTEM GETTING CLOSER...WILL SEE SURFACE FLOW
AROUND 10KTS OUT OF THE SOUTHWEST SUNDAY. AIR FLOW OFF THE SURFACE
WILL BE HIGHER WITH THE APPROACH OF THE LOW LEVEL JET. TRI
STATE/SOUTHEAST OHIO LOCATIONS COULD SEE 40-50KTS OFF THE SURFACE
AT AROUND 5KFT...ALSO OUT OF THE SOUTHWEST.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z SUNDAY...
FORECAST CONFIDENCE: MEDIUM TO HIGH.
ALTERNATE SCENARIOS: MAY NEED VCSH AT HTS THIS AFTERNOON. BRIEF
RAIN IS POSSIBLE AT BOTH PKB/HTS. EKN MAY NOT FOG TONIGHT.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
EDT 1HRLY 10 11 12 13 14 15 16 17 18 19 20 21
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY L H H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 18Z SUNDAY...
IFR POSSIBLE ALONG COLD FRONT...MOVING W TO E...SUN NT INTO
MON...AND IN POST-RAIN FOG/STRATUS TUE MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...TRM/SL
NEAR TERM...TRM/26
SHORT TERM...SL
LONG TERM...30
AVIATION...26
AREA FORECAST DISCUSSION
NWS TULSA OK
326 PM CDT SAT OCT 5 2013
.DISCUSSION...
BAND OF ONGOING CONVECTION IS ALIGNED ALONG THE 850MB FRONT...AND
GIVEN THE LATEST RUC PROJECTIONS...THIS BOUNDARY WILL BE ACROSS
FAR WESTERN AR INTO EXTREME SE OK BY 00Z AND PUSHING EASTWARD. ANY
EVENING PRECIP WILL BE CONFINED TO THIS ZONE BEFORE PUSHING
FURTHER EASTWARD AND CLEAR OF THE FORECAST AREA. SKIES WILL
CONTINUE TO CLEAR FROM NW TO SE AND ALLOW FOR A COOL SUNDAY MORNING.
BREEZY NORTHWEST WINDS WILL DEVELOP SUNDAY WHILE TEMPERATURES
REMAIN BELOW SEASONAL NORMALS. WINDS WILL DROP OFF AROUND SUNSET
AND ALLOW TEMPS TO FALL QUICKLY. A SEVERAL DAY WARMING TREND
COMMENCES MONDAY WITH TEMPS RETURNING TO ABOVE NORMAL READINGS BY
MID WEEK. THE WARM AND DRY WEATHER WILL PREVAIL INTO THE WEEKEND
WHEN THE NEXT STORM SYSTEM PUSHES INTO THE PLAINS. WILL INTRODUCE
LOW PRECIP CHANCES FOR NEXT WEEKEND PENDING THE EVOLUTION OF THIS
SYSTEM.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 46 70 45 75 / 0 0 0 0
FSM 46 71 46 75 / 20 0 0 0
MLC 43 72 43 77 / 10 0 0 0
BVO 40 69 40 75 / 0 10 0 0
FYV 41 65 39 70 / 10 0 0 0
BYV 43 63 44 69 / 30 0 0 0
MKO 42 70 42 75 / 10 0 0 0
MIO 42 66 42 72 / 0 10 0 0
F10 43 71 44 76 / 0 0 0 0
HHW 47 76 44 79 / 30 0 0 0
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
LONG TERM....07
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
628 PM EDT SAT OCT 5 2013
.SYNOPSIS...
A WARM FRONT ACROSS SOUTHERN NEW YORK WILL SLOWLY LIFT NORTHWARD
THROUGH THE WEEKEND...AS A MATURE LOW PRESSURE SYSTEM MOVES EAST
FROM THE NORTH-CENTRAL PLAINS THROUGH THE MIDWEST/OHIO VALLEY.
THE TRAILING COLD FRONT WILL SLOW ITS EASTWARD PROGRESS AS IT
CROSSES THE APPALACHIANS...INTERACTING WITH THE REMNANTS OF
TROPICAL STORM KAREN. THE DEEP CLOSED UPPER LOW MOVING THROUGH
THE OHIO VALLEY WILL DRAW ABUNDANT MOISTURE NORTHWARD ALONG THE
NORTH-SOUTH COLD FRONT AND LIKELY PRODUCE GENEROUS RAINFALL
AMOUNTS ACROSS CENTRAL PENNSYLVANIA MONDAY INTO TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
18Z RADAR LOOP SHOWS ISOLD-SCT CONVECTION DEVELOPING ACRS WRN AND
CNTRL PA. LG SCALE FORCING IS FAIRLY NEBULOUS AS THE AREA IS
STILL LARGELY UNDER THE INFLUENCE OF AN UPPER LEVEL RIDGE CENTERED
OVER THE SE STATES. DEWPOINTS IN THE 60S AND UNSEASONABLY WARM
AFTN TEMPS IN THE MID 70S-80S IS RESULTING IN SUFFICIENT
INSTABILITY WITH RUC ML CAPES BTWN 500-1000 J/KG. SHORTWAVES
LIFTING NEWD FROM THE OH VLY MAY ALLOW FOR SOME MORE ORGANIZED
CLUSTERS OF STORMS OVER NW PA. SFC WARM FRONT DRAPED NEAR THE PA/NY
BORDER MAY PROVIDE SOME FOCUS BUT OVERALL EXPECT SOMEWHAT
DISORGANIZED CVRG TO CONVECTIVE ACTIVITY. ADDNL SHORTWAVE ENERGY
CRESTING THE UPPER RIDGE MAY CONTINUE TO PRODUCE SCT SHOWERS INTO
TONIGHT...MAINLY OVER THE NRN TIER ZONES INVOF THE WARM FRONTAL
ZONE. HOWEVER INSTABILITY SHOULD DECREASE AFTER DARK SO CVRG MAY
BE LIMITED. EXPECT LOWS TO AGAIN BE VERY MILD/MUGGY FOR THIS TIME
OF YEAR...HOLDING IN THE 60S OVERNIGHT IN MOST PLACES. AREAS OF
FOG AND LOW STRATUS SHOULD DEVELOP AND PERSIST INTO EARLY SUNDAY
MORNING.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
CONSENSUS SHORT-RANGE DATA CONTINUES TO FAVOR THE NRN ZONES WITH
THE HIGHEST POPS DURING THE DAY ON SUNDAY...NEAR THE WAVY
Q-STNRY/WARM FRONTAL BOUNDARY. A LIGHT LLVL NELY AGEO WIND/ESE SFC
WIND MAY KEEP CLOUDS ENTRENCHED OVER THE NERN 1/2 TO 1/3 OF THE
CWA THRU THE A.M. HOURS IN SOMEWHAT OF A CAD SFC PATTERN. AN
INCREASING SLY GRADIENT FLOW SHOULD PUSH THE BOUNDARY /AND ASSOCD
LOWER CLOUDS/ NWD DURING THE AFTN. THIS MAKES FOR A TRICKY TEMP
FCST WITH POTENTIAL FOR READINGS TO SOAR WELL INTO THE 80S
/PERHAPS 90F NEAR THE MD LINE/ IN THE WARM SECTOR. PLAYED THE
MIDDLE GROUND FOR NOW USING A CONS MODEL BLEND...IN AN ATTEMPT TO
MITIGATE A POTENTIALLY LARGE MAX T BUST.
SUN NGT FOCUS WILL SHIFT TO DEEP CYCLONE CROSSING THE MIDWEST
STATES AND ITS ASSOCD COLD FRONT. GUIDANCE CONTINUES TO DISPLAY
SOME VARIABILITY WITH THE CLOSED H5 LOW...OWING TO SOME DEGREE OF
INFLUENCE TIED TO A SHORTWAVE IN CENTRAL CANADA BRUSHING ACROSS
THE TOP OF THE MATURE CYCLONE. SPACING BTWN THE TWO SYSTEMS FAVORS
A CONS APPROACH BETWEEN THE NON-NCEP SOLUTIONS LIKE THE 00Z ECMWF
WHICH QUICKLY PHASE THE ENERGY...AND THEIR RESPECTIVE NCEP
COUNTERPARTS WHICH MAINTAIN A CLOSED CYCLONE FOR A LONGER
DURATION. THESE MODEL DIFFS LEAD TO TIMING/PLACEMENT DIFFS WITH
THE COLD FRONT AND QPF AXIS...AS REMNANT TROPICAL MSTR IS DRAWN
NWD ALONG THE N-S FRONTAL ZONE. BY 12Z MON...THE GFS/EC AND HPC
SEEM TO AGREE ON A QPF AXIS CENTERED ALONG THE PA/OH BORDER. THE
MAIN RAIN EVENT FOR CENTRAL PA LOOKS TO BE DURING THE DAY MONDAY
INTO MONDAY NIGHT.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
CURRENT 12Z RUNS STAY CONSISTENT IN TIMING THROUGH 06Z MONDAY.
AFTER THAT PERIOD THE MODELS BEGIN TO DIVERGE IN TIMING...POSITION
AND INTENSIFICATION. THE LATEST NAM SEEMS TO BE THE SLOWEST
SOLUTION AND STALLS THE LARGE UPPER LEVEL LOWS PROGRESSION...WITH
PASSAGE THROUGH PA EARLY TUESDAY. THE CANADIAN...EC AND GFS MOVE
THE SYSTEM THROUGH 6 TO 12 HOURS FASTER. THE EC MOVES THE
STRONGEST FORCING TO THE NORTH...AND POSITIVELY TILTS THE TROUGH
AS MOVES EASTWARD. THE GFS AND CMC DEEPEN THE TROUGH AS SUCH MADE
A TIMING CHANGE TO THE PASSAGE OF THE FRONT...DELAYING IT BY 6-12
HRS...IN LINE WITH THE TREND IN THE MDLS OVER THE LAST 24 HRS.
THIS ALSO PREDICATED A NUDGE UPWARD IN THE MAXES FOR MONDAY. A
CONSENSUS OF MDL PROG QPF THROUGH THE RAINY PERIOD YIELDS 1 TO 2
INCH AMOUNTS OVER MUCH OF THE AREA...WITH THE HIGHEST AMOUNTS IN
THE LOWER SUSQ VALLEY. THIS SEEMS REASONABLE WITH THE MERGING OF
MOISTURE FROM KAREN AND THE COLD FRONT. THE RECENT LACK OF
RAINFALL SHOULD ALLOW ALL THAT TO BE HANDLED EASILY.
HOWEVER...TROPICAL MOISTURE CAN PILE UP QUICKLY AND UNDER-
ESTIMATION IS POSSIBLE AT THIS RANGE. AS THE FRONT MOVES OVER THE
MOUNTAINS LATE MORNING ON MONDAY...THERE IS A GOOD CHANCE FOR
SCATTERED THUNDERSTORMS ALONG THE BOUNDARY. ALSO EXPECT PERIODS OF
HEAVY RAINFALL AT AND BEHIND THE FRONT...MONDAY AFTERNOON AND
EARLY EVENING.
SPC HAS REMOVED THE SLIGHT RISK...THOUGH WITH THE HEAVY RAINFALL AND
CONVECTION...WHICH SHOULD BE LOW TOPPED...CANNOT RULE OUT GUSTY WINDS
ALONG THE FRONT.
AFTER THE RAIN EXITS THE REGION BY TUESDAY MORNING...A RETURN TO
RIDGING FOR THE MIDDLE AND END OF THE WEEK WITH DRY AND CONTINUED
MILD CONDITIONS.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
MAINLY VFR CONDS WITH LIGHT/VARIABLE WIND WILL CONTINUE THIS
EVENING...THOUGH ISOLATED SHOWERS DRIFTING EAST ACROSS THE REGION
COULD BRING A BRIEF BOUT OF MVFR CONDITIONS. WILL CONTINUE WITH THE
MENTION OF VCSH AT MOST TAF SITES THROUGH 03Z-04Z...AND EVEN A TEMPO
FOR HIGH END IFR CONDITIONS AT KJST BETWEEN 00-02Z...AS A CLUSTER OF
TSRA /CURRENTLY INVOF KPIT/ TRACKS EWD AT 20-25KTS.
CONVECTION WILL WANE DURING THE LATE EVENING WITH THE LOSS OF
HEATING AND LACK OF ANY SIGNIFICANT LLVL BOUNDARY.
CLEARING SKIES...A CALM WIND AND PLENTY OF LOW LVL MOISTURE WILL SET
THE STAGE FOR REDEVELOPMENT OF FOG AND LOW STRATUS LATER TONIGHT.
EXPECT MVFR TO IFR /LOCAL LIFR/ RESTRICTIONS TO PERSIST INTO SUNDAY
MORNING. LOW CLOUDS COULD LINGER OVER THE ERN TERMINALS THRU SUNDAY
MORNING...AS WARM FRONT PIVOTS OVER ZNY SECTOR.
OUTLOOK...
MON...RAIN/LOW CIGS POSSIBLE.
TUE...AM RAIN/LOW CIGS POSSIBLE EAST.
WED-THR...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...DANGELO/CERU
AVIATION...LAMBERT/STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
405 PM EDT SAT OCT 5 2013
.SYNOPSIS...
A WARM FRONT ACROSS SOUTHERN NEW YORK WILL SLOWLY LIFT NORTHWARD
THROUGH THE WEEKEND...AS A MATURE LOW PRESSURE SYSTEM MOVES EAST
FROM THE NORTH-CENTRAL PLAINS THROUGH THE MIDWEST/OHIO VALLEY.
THE TRAILING COLD FRONT WILL SLOW ITS EASTWARD PROGRESS AS IT
CROSSES THE APPALACHIANS...INTERACTING WITH THE REMNANTS OF
TROPICAL STORM KAREN. THE DEEP CLOSED UPPER LOW MOVING THROUGH
THE OHIO VALLEY WILL DRAW ABUNDANT MOISTURE NORTHWARD ALONG THE
NORTH-SOUTH COLD FRONT AND LIKELY PRODUCE GENEROUS RAINFALL
AMOUNTS ACROSS CENTRAL PENNSYLVANIA MONDAY INTO TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
18Z RADAR LOOP SHOWS ISOLD-SCT CONVECTION DEVELOPING ACRS WRN AND
CNTRL PA. LG SCALE FORCING IS FAIRLY NEBULOUS AS THE AREA IS
STILL LARGELY UNDER THE INFLUENCE OF AN UPPER LEVEL RIDGE CENTERED
OVER THE SE STATES. DEWPOINTS IN THE 60S AND UNSEASONABLY WARM
AFTN TEMPS IN THE MID 70S-80S IS RESULTING IN SUFFICIENT
INSTABILITY WITH RUC ML CAPES BTWN 500-1000 J/KG. SHORTWAVES
LIFTING NEWD FROM THE OH VLY MAY ALLOW FOR SOME MORE ORGANIZED
CLUSTERS OF STORMS OVER NW PA. SFC WARM FRONT DRAPED NEAR THE PA/NY
BORDER MAY PROVIDE SOME FOCUS BUT OVERALL EXPECT SOMEWHAT
DISORGANIZED CVRG TO CONVECTIVE ACTIVITY. ADDNL SHORTWAVE ENERGY
CRESTING THE UPPER RIDGE MAY CONTINUE TO PRODUCE SCT SHOWERS INTO
TONIGHT...MAINLY OVER THE NRN TIER ZONES INVOF THE WARM FRONTAL
ZONE. HOWEVER INSTABILITY SHOULD DECREASE AFTER DARK SO CVRG MAY
BE LIMITED. EXPECT LOWS TO AGAIN BE VERY MILD/MUGGY FOR THIS TIME
OF YEAR...HOLDING IN THE 60S OVERNIGHT IN MOST PLACES. AREAS OF
FOG AND LOW STRATUS SHOULD DEVELOP AND PERSIST INTO EARLY SUNDAY
MORNING.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
CONSENSUS SHORT-RANGE DATA CONTINUES TO FAVOR THE NRN ZONES WITH
THE HIGHEST POPS DURING THE DAY ON SUNDAY...NEAR THE WAVY
Q-STNRY/WARM FRONTAL BOUNDARY. A LIGHT LLVL NELY AGEO WIND/ESE SFC
WIND MAY KEEP CLOUDS ENTRENCHED OVER THE NERN 1/2 TO 1/3 OF THE
CWA THRU THE A.M. HOURS IN SOMEWHAT OF A CAD SFC PATTERN. AN
INCREASING SLY GRADIENT FLOW SHOULD PUSH THE BOUNDARY /AND ASSOCD
LOWER CLOUDS/ NWD DURING THE AFTN. THIS MAKES FOR A TRICKY TEMP
FCST WITH POTENTIAL FOR READINGS TO SOAR WELL INTO THE 80S
/PERHAPS 90F NEAR THE MD LINE/ IN THE WARM SECTOR. PLAYED THE
MIDDLE GROUND FOR NOW USING A CONS MODEL BLEND...IN AN ATTEMPT TO
MITIGATE A POTENTIALLY LARGE MAX T BUST.
SUN NGT FOCUS WILL SHIFT TO DEEP CYCLONE CROSSING THE MIDWEST
STATES AND ITS ASSOCD COLD FRONT. GUIDANCE CONTINUES TO DISPLAY
SOME VARIABILITY WITH THE CLOSED H5 LOW...OWING TO SOME DEGREE OF
INFLUENCE TIED TO A SHORTWAVE IN CENTRAL CANADA BRUSHING ACROSS
THE TOP OF THE MATURE CYCLONE. SPACING BTWN THE TWO SYSTEMS FAVORS
A CONS APPROACH BETWEEN THE NON-NCEP SOLUTIONS LIKE THE 00Z ECMWF
WHICH QUICKLY PHASE THE ENERGY...AND THEIR RESPECTIVE NCEP
COUNTERPARTS WHICH MAINTAIN A CLOSED CYCLONE FOR A LONGER
DURATION. THESE MODEL DIFFS LEAD TO TIMING/PLACEMENT DIFFS WITH
THE COLD FRONT AND QPF AXIS...AS REMNANT TROPICAL MSTR IS DRAWN
NWD ALONG THE N-S FRONTAL ZONE. BY 12Z MON...THE GFS/EC AND HPC
SEEM TO AGREE ON A QPF AXIS CENTERED ALONG THE PA/OH BORDER. THE
MAIN RAIN EVENT FOR CENTRAL PA LOOKS TO BE DURING THE DAY MONDAY
INTO MONDAY NIGHT.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
CURRENT 12Z RUNS STAY CONSISTENT IN TIMING THROUGH 06Z MONDAY.
AFTER THAT PERIOD THE MODELS BEGIN TO DIVERGE IN TIMING...POSITION
AND INTESIFICATION. THE LATEST NAM SEEMS TO BE THE SLOWEST
SOLUTION AND STALLS THE LARGE UPPER LEVEL LOWS PROGRESSION...WITH
PASSAGE THROUGH PA EARLY TUESDAY. THE CANADIAN...EC AND GFS MOVE
THE SYSTEM THROUGH 6 TO 12 HOURS FASTER. THE EC MOVES THE
STRONGEST FORCING TO THE NORTH...AND POSITIVELY TILTS THE TROUGH
AS MOVES EASTWARD. THE GFS AND CMC DEEPEN THE TROUGH AS SUCH MADE
A TIMING CHANGE TO THE PASSAGE OF THE FRONT...DELAYING IT BY 6-12
HRS...IN LINE WITH THE TREND IN THE MDLS OVER THE LAST 24 HRS.
THIS ALSO PREDICATED A NUDGE UPWARD IN THE MAXES FOR MONDAY. A
CONSENSUS OF MDL PROG QPF THROUGH THE RAINY PERIOD YIELDS 1 TO 2
INCH AMOUNTS OVER MUCH OF THE AREA...WITH THE HIGHEST AMOUNTS IN
THE LOWER SUSQ VALLEY. THIS SEEMS REASONABLE WITH THE MERGING OF
MOISTURE FROM KAREN AND THE COLD FRONT. THE RECENT LACK OF
RAINFALL SHOULD ALLOW ALL THAT TO BE HANDLED EASILY.
HOWEVER...TROPICAL MOISTURE CAN PILE UP QUICKLY AND UNDER-
ESTIMATION IS POSSIBLE AT THIS RANGE. AS THE FRONT MOVES OVER THE
MOUNTAINS LATE MORNING ON MONDAY...THERE IS A GOOD CHANCE FOR
SCATTERED THUNDERSTORMS ALONG THE BOUNDARY. ALSO EXPECT PERIODS OF
HEAVY RAINFALL AT AND BEHIND THE FRONT...MONDAY AFTERNOON AND
EARLY EVENING.
SPC HAS REMOVED THE SLIGHT RISK...THOUGH WITH THE HEAVY RAINFALL
AND CONVECTION...WHICH SHOULD BE LOW TOPPED...CANNOT RULE OUT GUSTY WINDS
ALONG THE FRONT.
AFTER THE RAIN EXITS THE REGION BY TUESDAY MORNING...A RETURN TO
RIDGING FOR THE MIDDLE AND END OF THE WEEK WITH DRY AND CONTINUED
MILD CONDITIONS.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
VFR CONDS CONTINUE THIS AFTN WITH SCT-BKN 3-5KFT MOD CUMULUS BASES
AND ISOLD/WDLY SCT CONVECTION DEVELOPING ACROSS THE AIRSPACE. BRIEF
RESTRICTIONS TO MVFR/IFR ARE POSSIBLE UNDER DIRECT HITS FROM
SHOWERS AND TSTMS. ADDED SOME VCSH MENTION BUT OVERALL CVRG IS
LIMITED. AMDS WILL NEED TO BE ISSUED FOR BRIEF SHRA/TSRA IMPACTS.
CONVECTION SHOULD WANE INTO THE EVE WITH THE LOSS OF INSTABILITY.
CLEARING SKIES...A CALM WIND AND PLENTY OF LOW LVL MOISTURE WILL
SET THE STAGE FOR REDEVELOPMENT OF FOG AND LOW STRATUS TONIGHT.
EXPECT MVFR TO IFR /LOCAL LIFR/ RESTRICTIONS TO PERSIST INTO
SUNDAY MORNING. LOW CLOUDS COULD LINGER OVER THE ERN TERMINALS
THRU SUNDAY MORNING...AS WARM FRONT PIVOTS OVER ZNY SECTOR.
OUTLOOK...
MON...RAIN/LOW CIGS POSSIBLE.
TUE...AM RAIN/LOW CIGS POSSIBLE EAST.
WED-THR...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...DANGELO/CERU
AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
258 PM EDT SAT OCT 5 2013
.SYNOPSIS...
A WARM FRONT ACROSS SOUTHERN NEW YORK WILL SLOWLY LIFT NORTHWARD
THROUGH THE WEEKEND...AS A MATURE LOW PRESSURE SYSTEM MOVES EAST
FROM THE NORTH-CENTRAL PLAINS THROUGH THE MIDWEST/OHIO VALLEY.
THE TRAILING COLD FRONT WILL SLOW ITS EASTWARD PROGRESS AS IT
CROSSES THE APPALACHIANS...INTERACTING WITH THE REMNANTS OF
TROPICAL STORM KAREN. THE DEEP CLOSED UPPER LOW MOVING THROUGH
THE OHIO VALLEY WILL DRAW ABUNDANT MOISTURE NORTHWARD ALONG THE
NORTH-SOUTH COLD FRONT AND LIKELY PRODUCE GENEROUS RAINFALL
AMOUNTS ACROSS CENTRAL PENNSYLVANIA MONDAY INTO TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
18Z RADAR LOOP SHOWS ISOLD-SCT CONVECTION DEVELOPING ACRS WRN AND
CNTRL PA. LG SCALE FORCING IS FAIRLY NEBULOUS AS THE AREA IS
STILL LARGELY UNDER THE INFLUENCE OF AN UPPER LEVEL RIDGE CENTERED
OVER THE SE STATES. DEWPOINTS IN THE 60S AND UNSEASONABLY WARM
AFTN TEMPS IN THE MID 70S-80S IS RESULTING IN SUFFICIENT
INSTABILITY WITH RUC ML CAPES BTWN 500-1000 J/KG. SHORTWAVES
LIFTING NEWD FROM THE OH VLY MAY ALLOW FOR SOME MORE ORGANIZED
CLUSTERS OF STORMS OVER NW PA. SFC WARM FRONT DRAPED NEAR THE PA/NY
BORDER MAY PROVIDE SOME FOCUS BUT OVERALL EXPECT SOMEWHAT
DISORGANIZED CVRG TO CONVECTIVE ACTIVITY. ADDNL SHORTWAVE ENERGY
CRESTING THE UPPER RIDGE MAY CONTINUE TO PRODUCE SCT SHOWERS INTO
TONIGHT...MAINLY OVER THE NRN TIER ZONES INVOF THE WARM FRONTAL
ZONE. HOWEVER INSTABILITY SHOULD DECREASE AFTER DARK SO CVRG MAY
BE LIMITED. EXPECT LOWS TO AGAIN BE VERY MILD/MUGGY FOR THIS TIME
OF YEAR...HOLDING IN THE 60S OVERNIGHT IN MOST PLACES. AREAS OF
FOG AND LOW STRATUS SHOULD DEVELOP AND PERSIST INTO EARLY SUNDAY
MORNING.
&&
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
CONSENSUS SHORT-RANGE DATA CONTINUES TO FAVOR THE NRN ZONES WITH
THE HIGHEST POPS DURING THE DAY ON SUNDAY...NEAR THE WAVY
Q-STNRY/WARM FRONTAL BOUNDARY. A LIGHT LLVL NELY AGEO WIND/ESE SFC
WIND MAY KEEP CLOUDS ENTRENCHED OVER THE NERN 1/2 TO 1/3 OF THE
CWA THRU THE A.M. HOURS IN SOMEWHAT OF A CAD SFC PATTERN. AN
INCREASING SLY GRADIENT FLOW SHOULD PUSH THE BOUNDARY /AND ASSOCD
LOWER CLOUDS/ NWD DURING THE AFTN. THIS MAKES FOR A TRICKY TEMP
FCST WITH POTENTIAL FOR READINGS TO SOAR WELL INTO THE 80S
/PERHAPS 90F NEAR THE MD LINE/ IN THE WARM SECTOR. PLAYED THE
MIDDLE GROUND FOR NOW USING A CONS MODEL BLEND...IN AN ATTEMPT TO
MITIGATE A POTENTIALLY LARGE MAX T BUST.
SUN NGT FOCUS WILL SHIFT TO DEEP CYCLONE CROSSING THE MIDWEST
STATES AND ITS ASSOCD COLD FRONT. GUIDANCE CONTINUES TO DISPLAY
SOME VARIABILITY WITH THE CLOSED H5 LOW...OWING TO SOME DEGREE OF
INFLUENCE TIED TO A SHORTWAVE IN CENTRAL CANADA BRUSHING ACROSS
THE TOP OF THE MATURE CYCLONE. SPACING BTWN THE TWO SYSTEMS FAVORS
A CONS APPROACH BETWEEN THE NON-NCEP SOLUTIONS LIKE THE 00Z ECMWF
WHICH QUICKLY PHASE THE ENERGY...AND THEIR RESPECTIVE NCEP
COUNTERPARTS WHICH MAINTAIN A CLOSED CYCLONE FOR A LONGER
DURATION. THESE MODEL DIFFS LEAD TO TIMING/PLACEMENT DIFFS WITH
THE COLD FRONT AND QPF AXIS...AS REMNANT TROPICAL MSTR IS DRAWN
NWD ALONG THE N-S FRONTAL ZONE. BY 12Z MON...THE GFS/EC AND HPC
SEEM TO AGREE ON A QPF AXIS CENTERED ALONG THE PA/OH BORDER. THE
MAIN RAIN EVENT FOR CENTRAL PA LOOKS TO BE DURING THE DAY MONDAY
INTO MONDAY NIGHT.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
MADE A TIMING TWEAK TO THE PASSAGE OF THE FRONT...DELAYING IT BY
6-12 HRS...IN LINE WITH THE TREND IN THE MDLS OVER THE LAST 24
HRS. THIS ALSO PREDICATED A NUDGE UPWARD IN THE MAXES FOR MONDAY.
A CONSENSUS OF MDL PROG QPF THROUGH THE RAINY PERIOD YIELDS 1 TO 2
INCH AMOUNTS OVER MUCH OF THE AREA. THIS SEEMS REASONABLE WITH THE
MERGING OF MOISTURE FROM KAREN AND THE COLD FRONT. THE RECENT LACK
OF RAINFALL SHOULD ALLOW ALL THAT TO BE HANDLED EASILY.
HOWEVER...TROPICAL MOISTURE CAN PILE UP QUICKLY AND UNDER-
ESTIMATION IS POSSIBLE AT THIS RANGE.
PREV DISC FOLLOWS...
MAIN FEATURE FOR THE LONG TERM WILL BE A CLOSED UPPER LOW THAT
SLOWLY MOVES FROM THE LOWER OHIO VALLEY TO THE ST. LAWRENCE VALLEY
BY EARLY WEEK. THIS FEATURE WILL HELP DRAW SOME OF THE MOISTURE
ASSOCIATED WITH TROPICAL STORM/DEPRESSION KAREN INTO THE AREA.
WHILE NOT A DIRECT HIT OVER THE REGION...EXPECT STORM TOTAL
AMOUNTS FROM LATE SUNDAY THROUGH TUESDAY TO BE IN THE 1 TO 1.5
INCH RANGE.
LATEST MODELS DELAY THE ARRIVAL OF THE LEADING AREA OF
PRECIPITATION/FRONTAL BOUNDARY TOWARD SUNDAY NIGHT. HAVE BACKED
OFF POPS FOR SUNDAY AFTERNOON AS A RESULT. THIS WILL KEEP MILD AIR
ACROSS THE REGION THROUGH THE WEEKEND.
AFTER THE RAIN EXITS THE REGION BY TUESDAY MORNING...A RETURN TO
RIDGING FOR THE MIDDLE AND END OF THE WEEK WITH DRY AND CONTINUED
MILD CONDITIONS.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
VFR CONDS CONTINUE THIS AFTN WITH SCT-BKN 3-5KFT MOD CUMULUS BASES
AND ISOLD/WDLY SCT CONVECTION DEVELOPING ACROSS THE AIRSPACE. BRIEF
RESTRICTIONS TO MVFR/IFR ARE POSSIBLE UNDER DIRECT HITS FROM
SHOWERS AND TSTMS. ADDED SOME VCSH MENTION BUT OVERALL CVRG IS
LIMITED. AMDS WILL NEED TO BE ISSUED FOR BRIEF SHRA/TSRA IMPACTS.
CONVECTION SHOULD WANE INTO THE EVE WITH THE LOSS OF INSTABILITY.
CLEARING SKIES...A CALM WIND AND PLENTY OF LOW LVL MOISTURE WILL
SET THE STAGE FOR REDEVELOPMENT OF FOG AND LOW STRATUS TONIGHT.
EXPECT MVFR TO IFR /LOCAL LIFR/ RESTRICTIONS TO PERSIST INTO
SUNDAY MORNING. LOW CLOUDS COULD LINGER OVER THE ERN TERMINALS
THRU SUNDAY MORNING...AS WARM FRONT PIVOTS OVER ZNY SECTOR.
OUTLOOK...
MON...RAIN/LOW CIGS POSSIBLE.
TUE...AM RAIN/LOW CIGS POSSIBLE EAST.
WED-THR...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...DANGELO/TYBURSKI
AVIATION...STEINBUGL
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
305 PM MDT SAT OCT 5 2013
.SHORT TERM...THIS EVENING THROUGH SUNDAY NIGHT
ISSUED AT 301 PM MDT SAT OCT 5 2013
THE STORM CONTINUES TO WIND DOWN SLOWLY FOR THE BLACK
HILLS REGION THIS AFTERNOON. A STRONG CLOSED LOW OVER EASTERN SOUTH
DAKOTA IS MAKING A LITTLE PROGRESS EASTWARD THIS AFTERNOON. THE
RESULT FOR THE WESTERN HALF OF THE STATE IS DECREASING SNOWFALL AND
WIND AS THE WEAKENING BAND OF PRECIPITATION AND STRONG WIND SHFTS
EASTWARD. THE 18Z HRRR SHOWS THE SURFACE LOW CENTER WEAKENING
RAPIDLY AND REFORMING OVER MINNESOTA DURING THE NEXT SEVERAL HOURS.
AS THE SYSTEM MOVES INTO CENTRAL SOUTH DAKOTA BOTH THE PRECIPITATION
RATE AND DURATION OF STRONG WINDS ARE EXPECTED TO DECREASE RESULTING
IN A LESS POTENT EVENT IN THOSE PARTS.
A MUCH WELCOME DAY OF BLUE SKIES AND SUNSHINE ARE IN STORE FOR
SUNDAY AS A TRANSITORY HIGH PRESSURE RIDGE SHIFTS INTO THE HIGH
PLAINS. GUIDANCE WARMING SEEMS A LITTLE TOO AGRESSIVE CONSIDERING
THE EXTENSIVE SNOWPACK WE`VE ACQUIRED SO TEMPS WERE TRIMMED DOWN A
BIT. THIS IS BETTER THAN A RAPID MELTOFF ANYWAY. WILL HAVE TO KEEP
AN EYE ON HOW THE STREAMS RESPOND OVER THE NEXT COUPLE OF DAYS. THE
MILD SUNNY WEATHER IS FORECAST TO CONTINUE MONDAY AS THE RIDGE
LINGERS OVER THE REGION.
&&
.LONG TERM...MONDAY THROUGH SATURDAY
ISSUED AT 301 PM MDT SAT OCT 5 2013
PROGRESSIVE LONG WAVE RIDGE BUILDS IN BEHIND THE RECORD-BREAKING
BLIZZARD... MOVING QUICKLY FROM NEAR 110W ON MON TO JUST E OF 100W
ON TUE AND TO 85W ON WED. AS IT DOES SO...A NEW LONG WAVE TROF IS
CARVED OUT IN THE WEST. GFS CONTINUES TREND OF LAST SEVERAL RUNS IN
SPLITTING OFF A NRN STREAM SHORT WAVE AND MOVING IT ACROSS WRN CAN
WHILE THE STRONGER PORTION OF THE WAVE DIGS S WARD INTO CA. BY 12Z
WED A CLOSED LOW IS SHOWN OVER NRN CA. THE DIGGING PROCESS IS
COMPLETED BY THU AT 12Z AND THE LOW IS FCST TO MOVE OUT TO THE
NE...PERHAPS TO SE SD BY 12Z SAT. THIS RUN OF GFS IS SLIGHTLY
FARTHER S AND E THAN YESTERDAY`S. WHILE THE TRACK IS REMINISCENT OF
OUR PRESENT STORM...1000 TO 500MB THICKNESSES ARE PRESENTLY FCST TO
BE WELL ABOVE SNOW RELATED VALUES AND THE UPPER LOW IS FAR LESS
INTENSE. BUT IT IS EARLY IN THE GAME.
ACCEPTED THE EXTENDED INIT TEMPS...THOUGH THEY ARE MUCH BELOW GFS
MOS GUIDANCE FOR WED AND THU. THINKING IS THAT THERE WILL STILL BE SOME
WET GROUND FROM THE HEAVY SNOW AND THAT THE STORM-FOLLOWING RIDGE IS
FCST TO MOVE E WARD SO QUICKLY THAT UPPER LEVEL COOLING WILL ALREADY
BE UNDERWAY AS THE TROF IN THE W INTENSIFIES AND APPROACHES THE AREA.
CLOUDS...POPS...AND PRECIP BROUGHT IN THU NIGHT INTO SAT IN LINE
WITH APPROACHING CLOSED LOW.
&&
.AVIATION...FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING
ISSUED AT 301 PM MDT SAT OCT 5 2013
FOR 12Z TAF ISSUANCE.
A WIDESPREAD AREA OF SNOW CONTINUES TO BLANKET THE AREA...AND VERY
STRONG NORTHWEST WINDS ARE PERSISTING. LIFR AND IFR CONDITIONS WILL
PREDOMINATE OVER WESTERN SD IN SNOW AND BLOWING SNOW THROUGH MID
MORNING SATURDAY. PRECIPITATION WILL END FROM THE WEST WITH IMPROVING
CEILINGS AND VISIBILITIES. BY SUNSET...EXPECT MOSTLY VFR CONDITIONS.
STRONG WINDS WILL DIMINISH VERY SLOWLY DURING THE AFTERNOON SATURDAY.
NO OBSERVATIONS HAVE BEEN AVAILABLE SINCE FRIDAY AFTERNOON FROM KRAP DUE TO
COMMUNICATIONS ISSUES.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WINTER STORM WARNING UNTIL 6 PM MDT THIS EVENING FOR SDZ044.
WINTER WEATHER ADVISORY UNTIL 7 PM CDT THIS EVENING FOR SDZ046-
047-049.
BLIZZARD WARNING UNTIL 6 PM MDT THIS EVENING FOR SDZ014-032-043.
WY...NONE.
&&
$$
SHORT TERM...CARPENTER
LONG TERM...BARBER
AVIATION...BARBER
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1154 AM CDT SAT OCT 5 2013
.AVIATION...
BASED ON CURRENT MVMT...FRONT SHOULD BE NEAR CLL AROUND 21Z...IAH
2Z & GLS 5Z. MODELS SHOWING SOME SPOTTY SHRA GENERALLY E OF HWY
288 & I-45 THRU THE DAY AND KEPT VCSHS IN TAFS. DID LOWER CIGS
OVERNIGHT IN THE WAKE OF THE FRONT INTO MVFR & HIGH IFR TERRITORY
AS SOME MOISTURE GETS TRAPPED BELOW SHARP INVERSION. WILL ALSO BE
KEEPING AN EYE ON THE POTENTIAL FOR SOME POST FRONTAL PRECIP
(WITH H85 FRONT LOOKING TO BE FOCUS) OVERNIGHT. MAJORITY OF MODELS
THAT DO SHOW THIS OCCURRING KEEP IT MOSTLY WEST AND EAST OF OUR
TERMINALS. WILL LEAVE MENTION OUT OF 18Z TAFS ATTM AND SEE HOW IT
PLAYS OUT. LOOK CIGS TO LIFT & CLEAR OUT FROM NW-SE FROM MID
MORNING THRU MID/LATE AFTN SUNDAY. 47
&&
.PREV DISCUSSION... /ISSUED 1021 AM CDT SAT OCT 5 2013/
THE COLD FRONT WAS PROGRESSING STEADILY ACROSS THE NORTHERN AND
CENTRAL PORTIONS OF THE STATE. UPDATED THE WIND SHIFT WITH THE
LATEST RAP FORECAST. A 12Z ANALYSIS SHOWED A SURFACE RIDGE OVER
THE TEXAS COASTAL AREAS WITH LOW-LEVEL MOISTURE STREAMING
NORTHWARD FROM THE GULF INTO AREAS MAINLY EAST OF FREEPORT. OVER
MOST OF THE FORECAST AREA THE AIR MASS WAS FAIRLY DRY AND CAPPED
AND EXPECT THAT MOST CONVECTION THIS AFTERNOON WILL BE CONFINED TO
THE EASTERN AND NORTHERN SET OF COUNTIES WHERE THE DEEPER MOISTURE
AND COOLER AIRMASS ALOFT RESIDES.
WILL UPDATE MAINLY FOR THE WINDS. OTHERWISE...THE REMAINDER OF THE
FORECAST LOOKS ON TARGET. 40
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 89 58 81 52 83 / 20 20 10 0 0
HOUSTON (IAH) 92 62 80 53 83 / 50 30 10 0 0
GALVESTON (GLS) 89 69 81 65 80 / 40 30 20 0 0
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 7 PM CDT THIS EVENING
FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE
MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM HIGH
ISLAND TO FREEPORT 20 TO 60 NM.
&&
$$
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
100 PM EDT SAT OCT 5 2013
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OVER THE REGION THROUGH TONIGHT. A LOW
PRESSURE SYSTEM TRACKING FROM THE CENTRAL PLAINS TO THE GREAT
LAKES WILL PUSH A STRONG COLD FRONT THROUGH THE AREA ON MONDAY.
THE LOW AND COLD FRONT WILL MOVE OFFSHORE BY TUESDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 945 AM EDT SATURDAY...
SHOULD BE A WARM...POTENTIALLY RECORD BREAKING DAY...ESPECIALLY AT
BLACKSBURG/BLUEFIELD (SEE CLIMATE SECTION BELOW)...AS HIGH
PRESSURE RESIDES OVERHEAD. FOG WILL BE LIFTING ACROSS THE
VALLEYS...BUT HAS HELD STRONG IN THE GREENBRIER VALLEY.
TEMPS STARTING TO RUN A COUPLE DEGREES WARMER OUT EAST THAN
CURRENT FORECAST...SO BUMPED UP HIGHS A COUPLE DEGREES...LOOKING
AT UPPER 70S TO LOWER 80S ACROSS THE HIGHER TERRAIN...TO MID TO
UPPER 80S VALLEYS AND POINTS EAST OF THE BLUE RIDGE.
PREVIOUS VALID DISCUSSION...
SURFACE HIGH PRESSURE AND A 500 MB RIDGE WILL REMAIN OVER THE
CENTRAL AND SOUTHERN APPALACHIANS THROUGH TONIGHT. LOCAL WRF AS
WELL AS HRRR AND LATEST RAP GUIDANCE SUGGEST THERE IS STILL A LOW
CHANCE OF SHOWERS THIS AFTERNOON...MAINLY NORTH OF I-64. ASIDE
FROM THE WEST TO SOUTHWEST UPSLOPE WINDS...LITTLE IN THE WAY OF
SHORT WAVES TO HELP TRIGGER ANY PRECIPITATION.
ANY SCATTERED TO BROKEN CU THAT DEVELOPS TODAY WILL DISSIPATE
THIS EVENING. USED A BLEND OF BIAS CORRECTED MAV/MET GUIDANCE FOR
OVERNIGHT LOWS.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 453 AM EDT SATURDAY...
MODELS REMAINING CONSISTENT WITH MOVING A COLD FRONT AND ASSOCIATED
SHOWERS INTO THE OHIO VALLEY ON SUNDAY. MODELS HAVE SLOWED DOWN THE
FRONTS MOVEMENT INTO THE AREA SUNDAY NIGHT AND ACROSS THE REGION
MONDAY/MONDAY NIGHT. THE SLOWER PROGRESSION OF THE FRONT IS DUE TO
UPPER LEVEL FORCING BECOMING DETACHED FROM THE LOW LEVEL BOUNDARY.
TROPICAL STORM KAREN OR REMNANTS OF...MAY ALSO PLAYING A PART IN
SLOWING THE FRONT DOWN TO A CRAWL AS IT CROSSES OVER THE AREA. BASED
ON THE 00Z MODEL TRENDS...LOWERED POPS INTO SUNDAY EVENING.
MEASURABLE RAIN BEGINS TO TRACK ACROSS THE SOUTHWEST EARLY MONDAY
MORNING...THEN SPREADS ACROSS THE REST OF THE MOUNTAINS AROUND
SUNRISE. RAIN CHANCES INCREASE EAST OF THE BLUE RIDGE TOWARD THE
AFTERNOON AND CONTINUES INTO THE EVENING. WITH A COLD FRONT
INTERACTING WITH TROPICAL MOISTURE...IT WAS A NO BRAINER TO INCREASE
POPS TO 100 PERCENT MONDAY. WITH THE FRONT BEING SLOWER...ALSO
INCREASED POPS MONDAY EVENING...TRENDING DOWN TUESDAY MORNING AS THE
FRONT TRACKS EAST.
WITH SHOWERS NOT DUE TO MOVE ACROSS THE PIEDMONT UNTIL THE
AFTERNOON...THERE MAY BE ENOUGH INSTABILITIES TO GENERATE A RUMBLE
OF THUNDER. IF ENOUGH INSTABILITIES IS PRESENT WHEN THE 850 JET
PASSES OVERHEAD...A STORM OR TWO MAY PRODUCE STRONG WINDS. FOR THE
MOST PART...THIS WILL BE A HYDRO EVENT. PWATS ON MONDAY APPROACH 2
INCHES WHICH IS CLOSE TO BEING 2 STANDARD DEVIATIONS ABOVE NORMAL.
RAINFALL AMOUNTS FROM SUNDAY NIGHT INTO MONDAY EVENING SHOULD RANGE
FROM 1 TO 2 INCHES. WITH THE RECENT DRY SPELL...THE FORECAST AREA
SHOULD NOT SEE ANY WIDESPREAD WATER PROBLEMS. LOCALIZE FLOODING IS
NOT OUT OF THE QUESTION IN POOR DRAINAGE AREAS...ESPECIALLY IF HIGH
RAINFALL RATES OR TRAINING OF STORMS PERSIST OVER AN AREA FOR
SEVERAL HOURS.
THE UPPER LEVEL RIDGE THAT BROUGHT WARMTH TO THE AREA ON SATURDAY
WILL BEGIN TO SLIDE OFF THE SOUTHEAST COAST ON SUNDAY. WITH THE
FRONT REMAINING WEST OF THE AREA FOR MOST OF SUNDAY...WARMER THAN
NORMAL TEMPERATURES WILL AGAIN COVER THE REGION. SUNDAY TEMPERATURES
WILL RANGE FROM THE LOW TO MID 80S ACROSS THE WEST TO MID TO UPPER
80S IN THE EAST. A DRAMATIC COOL DOWN COMES MONDAY WITH THE RAIN.
FORECASTED HIGH TEMPERATURES MONDAY WILL RANGE FROM THE MID 60S IN
THE WEST TO LOWER 70S ACROSS THE PIEDMONT.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 1215 PM EDT FRIDAY...
FORECAST EARLY IN THE PERIOD CENTERS AROUND THE FRONT/REMNANTS OF
KAREN AND THE UPPER TROUGH MOVING ACROSS THE GREAT
LAKES/NORTHEAST/MID ATLANTIC. THE LATEST GFS (12Z) CONTINUES TO BE
SLOWER...AND IS ACTUALLY SLOWER THAN THE 06Z RUN IN MOVING THE FRONT
OUT...WITH A STRONGER UPPER LOW...BUT IS FURTHER EAST WITH KAREN.
PER NHC/WPC...WILL BE LEANING TOWARD THE 00Z ECMWF AND THE PREVIOUS
FORECAST. THERE WILL STILL BE LINGERING SHOWERS ACROSS THE PIEDMONT
TUESDAY AND NOT OUT OF THE QUESTION THAT STRONG SUBSIDENCE BEHIND
THE DEPARTING TROPICAL SYSTEM MAY START TO DRY THINGS OUT FASTER.
FOR MID TO LATE WEEK...THE FORECAST MAINTAINS A CHALLENGE IN TERMS
OF SFC HIGH PRESSURE WEDGING SOUTH INTO OUR AREA...WHILE A RESIDUAL
UPPER TROUGH LINGERS OVER THE SOUTHEAST. QUESTION WILL BE WHERE
DEEPER MOISTURE RESIDES. WITH THE ECMWF THINK MOST OF THE CLOUD
COVER WILL BE HUGGING OUR SOUTHEAST CWA WITH MORE RESIDING ACROSS
THE SOUTHEAST...WHILE THE WESTERN CWA SEES MORE SUN DURING THE DAY.
TEMPERATURES GIVEN A LIGHT NE-E FLOW WILL BE CLOSER TO NORMAL...WITH
THE THREAT OF RAIN BEING LESS THAN 10 PERCENT.
&&
.AVIATION /18Z SATURDAY THROUGH WEDNESDAY/...
AS OF 100 PM EDT SATURDAY...
AXIS OF UPPER RIDGE WILL CROSS THE AREA AS WE BEGIN TO COME UNDER
THE INFLUENCE OF UPSTREAM SYSTEM APPROACHING FROM THE MIDWEST. THERE
WILL BE A LITTLE SHORT WAVE ENERGY MOVING THROUGH THE ARE EARLY IN
THE TAF PERIOD...BUT SIGNIFICANT MOISTURE IS LACKING AND CAPES ARE
MEAGER. WHILE AN ISOLATED SHOWER CAN NOT BE RULED OUT IT DOES NOT
WARRANT A MENTION IN THE TAFS. WILL GO WITH BKN VFR CIGS WEST AND
NORTH WITH JUST SCT EAST AND SOUTH.
EXPECTING MID/HIGH CLOUDS TO REMAIN MOSTLY TO OUR NORTH AND ALLOW
FOR DECENT RAD COOLING OVERNIGHT. THUS...EXPECTING KLWB/KBCB TO
FOG IN AGAIN TONIGHT BUT ONLY MVFR AT OTHER SITES. SHOULD STAY VFR
AT KBLF AS WINDS COME AROUND TO A SWLY DIRECTION TO PROHIBIT FOG.
.EXTENDED AVIATION...
LOOKS LIKE COLD FRONT APPROACHING FROM THE WEST WILL BE THE MAIN
PLAYER FOR OUR WEATHER SUNDAY NIGHT THROUGH MONDAY AS TROPICAL
SYSTEM REMAINS TO OUR SOUTH. AVIATION CONDITIONS WILL BE QUITE
POOR THIS PERIOD WITH RAIN...GUSTY WINDS...AND LIKELY IFR CONDITIONS.
HOWEVER...THINGS WILL IMPROVE CONSIDERABLY BEHIND THE FRONT
TUESDAY...AND THE REMAINDER OF THE WEEK LOOKS GOOD FOR AVIATION
WITH THE EXPECTATION OF DIURNAL FOG FORMATION.
&&
.CLIMATE...
RECORD HIGH TEMPS FOR SATURDAY.
ROANOKE 98/1941
LYNCHBURG 96/1941
DANVILLE 98/1951
BLACKSBURG 86/1954
BLUEFIELD 85/2007
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS/WP
NEAR TERM...AMS/WP
SHORT TERM...RCS
LONG TERM...JH/WP
AVIATION...MBS
CLIMATE...RCS
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1213 PM CDT SAT OCT 5 2013
.UPDATE...
THE WARM FRONT IS INCHING NORTHWARD THIS MORNING. DENSE FOG IN
SOUTHEAST WI IMPROVED TO 1 TO 2 MILES...WHILE SHEBOYGAN AND PORT
WASHINGTON REMAIN SOCKED IN WITH THE LIGHT SOUTHEAST FLOW OFF THE
LAKE ON THE NORTH SIDE OF THE WARM FRONT. DENSE FOG ADVISORY IN
EFFECT UNTIL MID AFTERNOON THERE.
STRENGTHENING LOW LEVEL JET AND MOISTURE CONVERGENCE WITH A VORT MAX
MOVING OUT OF EASTERN IOWA IS LEADING TO INCREASING SHOWER COVERAGE
IN SOUTH CENTRAL WISCONSIN LATE THIS MORNING. THESE SHOWERS WILL
EXPAND/PROGRESS EASTWARD THROUGH EARLY AFTERNOON. 1000 J/KG OF MU
CAPE ALLOWING FOR A FEW EMBEDDED THUNDERSTORMS. WATCHING THE MORE
DISCRETE CELLS IN NORTH CENTRAL IL FOR STRENGTHENING...AS THAT
REGION HAS HIGHER CAPE AND BULK SHEAR VALUES. THESE VALUES WILL
GRADUALLY MOVE INTO SOUTHERN WI...BUT FOG AND LOW CLOUDS OVER
SOUTHERN WI WILL SLOW IT DOWN. LATEST HRRR KEEPS THE FORECAST
REFLECTIVITY FOR MIDDAY RATHER LIGHT. HIGH PRECIPITABLE WATER VALUES
WILL LEAD TO EFFICIENT RAINFALL THOUGH...SO WILL NEED TO WATCH FOR
FLOODING POTENTIAL ESPECIALLY IN URBAN AREAS.
WATER VAPOR IMAGERY SHOWS A STRONGER SHORTWAVE DOWN IN MISSOURI THAT
IS NOW FORECAST TO MOVE THROUGH NORTHEAST IL AROUND 00Z ALONG THE
SURFACE FRONTAL TROUGH INSTEAD OF SOUTHEAST WI. HOWEVER...THE
SURFACE TROUGH WILL EXTEND BACK INTO WEST CENTRAL WI...SO WHILE THE
STRONGEST 500MB SHORTWAVE WILL BE ABSENT...THERE WILL STILL BE
SURFACE CONVERGENCE...MODERATE BULK SHEAR...UPPER DIVERGENCE AND
STRONG 700MB OMEGA OVER SOUTHERN WI AT 00Z TO ALLOW FOR THUNDERSTORMS.
ANOTHER ROUND OF WIDESPREAD CONVECTION IS EXPECTED WITH THIS
FEATURE...MOST LIKELY BETWEEN 05 PM AND 10 PM IN THE MKX FORECAST
AREA. THIS WILL BE THE PERIOD FOR HEAVIEST RAIN AND STRONGEST WIND
GUSTS AND BEST POTENTIAL FOR SEVERE GUSTS. UNIDIRECTIONAL WIND
THROUGH THE COLUMN WILL LEAD TO THUNDERSTORMS QUICKLY DEVELOPING
INTO LINE SEGMENTS.
&&
.AVIATION/18Z TAFS/...
FOG CONTINUES TO THIN EXCEPT TOWARD SHEBOYGAN AND PORT WASHINGTON
AHEAD OF THE WARM FRONT AND WITH THE INFLUENCE OF MARINE AIR. CIGS
WILL REMAIN IFR OR LOWER UNTIL SCATTERED SHOWERS WITH A FEW EMBEDDED
THUNDERSTORMS SPREAD ACROSS SOUTH CENTRAL AND SOUTHEAST WI THROUGH
EARLY AFTERNOON. ANOTHER ROUND OF WIDESPREAD CONVECTION WITH HEAVY
RAIN AND STRONG WIND GUSTS WILL IMPACT SOUTHERN WI BETWEEN 5 PM TO
10 PM.
CONVECTION WILL END FROM WEST TO EAST SOON AFTER MIDNIGHT AS
OCCLUDED FRONT SLIDES EAST OF AREA.
&&
.MARINE...
WILL CONTINUE DENSE FOG ADVY INTO THE EVENING AS WARM...MOIST AIR
CONTINUES TO MOVE ACROSS COOLER NEAR SHORE WATERS OF LAKE MI.
SCATTERED MORNING AND EARLY AFTN CONVECTION WL GIVE WAY TO A MORE
WIDESPREAD PERIOD LATER THIS AFTN AND EVE.
&&
.PREV DISCUSSION... /ISSUED 305 AM CDT SAT OCT 5 2013/
TODAY AND TONIGHT - CONFIDENCE...MEDIUM.
WL EXPAND DENSE FOG ADVY INTO MORE OF SOUTHEAST THROUGH THE EARLY
MORNING AND CONTINUE 14Z EXPIRATION. AS WARM FRONT IN NORTHERN IL
BEGINS TO SHIFT NWD...DENSE FOG SHOULD THIN THROUGH THE
MORNING...BUT NORTHERN AREAS MAY NEED TO BE EXTENDED A FEW HOURS.
OTRW...WEAKER WARM AIR ADVECTION WL CARRY NMRS CONVECTION ACROSS WRN
CWA EARLY THIS MRNG...HOWEVER FOCUS OF WAA REMAINS OVER NRN HALF OF
WI EARLY. LOW LEVEL JET STRENGTHENS ONCE AGAIN AHEAD OF STRONG
UPPER LOW OVER NORTHERN PLAINS LATER THIS MRNG AND AFTERNOON ACROSS
NRN IL/SRN WI REGION. SFC LOW SLIGHTLY WWD POSITION AT 12Z COMPARED
TO EARLIER RUNS...AND 00Z NAM CONTINUES TO ADJUST ITS TIMING AND
POSITION TO MORE FAVORED GFS AND ECMWF. INCREASING SOUTH WINDS
AHEAD OF SFC LOW WL ALLOW WARM FRONT OVER NRN IL TO MOVE NWD ACROSS
PORTIONS OF SRN WI TODAY AS SURFACE OCCLUSION BEARS DOWN ON THE
AREA. OCCLUSION MAKES SLOW EWD PROGRESS TODAY...AND LOOKS LIKE IT
WILL EXIT ERN CWA AROUND 06Z. STRONGER LAYER Q-VECTOR CONVERGENCE
SPREADS IN THIS AFTN AND TNGT WITH OCCLUSION AND UPPER LEVEL SHORT
WAVE. MUCAPE CURRENTLY AROUND 500 J/KG EXPECTED TO INCREASE TO
1500-2000 J/KG LATER TODAY AHEAD OF OCCLUSION. NO PROBLEM WITH
AVAILABLE SHEAR FAVORING MULTICELLS AND SUPERCELLS MODE. IF LOW
CLOUDS CLEAR OUT IN TIME ACROSS PORTIONS OF THE CWA...SHEAR AND
INSTABILITY SHOULD BE ENOUGH TO TRIGGER STRONG TO SEVERE
CONVECTION. CAN NOT RULE OUT A TORNADO CONSIDERING STRENGTH OF
FORCING. PWAT REMAINS OVER 200 PERCENT OF NORMAL...SO IF EXPECTED
NORTH TO SOUTH LINE OF CONVECTION LINGERS OVER AREA...POTENTIAL FOR
FLASH FLOODING. WARM CLOUD DEPTH PRIOR TO AFTN CONVECTION OVER 11K
FEET. FORTUNATELY HEAVIEST RAINFALL OF THE PAST SEVERAL DAYS HAS
BEEN MOSTLY WEST AND SOUTH OF CWA.
WILL CONTINUE SMALLER THREAT FOR CONVECTION LATE TONIGHT IN ERN CWA
DUE TO LINGERING LOW LEVEL JET IN THE AREA.
SUNDAY - CONFIDENCE...MEDIUM
SLOW MOVING NEARLY STACKED LOW PROGGD TO TRAVERSE FROM WESTERN IOWA
INTO CNTRL IL THROUGH SUNDAY NIGHT. PLENTY OF DRY AIR WRAPPING
AROUND THIS SYSTEM WITH DRY SLOT ACRS MUCH OF WI. 850 COLD ADVECTION
FROM THE SOUTHWEST. SOME MODELS SHOW CLOSE TO ZERO CELSIUS TOWARDS
THE IL BORDER BY LATER SUNDAY NIGHT. THE NAM MODEL IS THE ONLY MODEL
TO DEVELOP SOME DEF ZONE PRECIP SUNDAY NIGHT WITH A BIT MORE 700 RH
ON THE NORTHERN SIDE OF THE SYSTEM THAN THE OTHER MODELS. SURFACE
TROUGH AXIS EXTENDS ACROSS NRN AND WRN WI SO GIVEN THE PROGGD
PLACEMENT OF DRY RH AND QPF...WILL REMOVE POPS FOR SUNDAY BUT LEAVE
THEM IN FOR SUNDAY NIGHT.
MONDAY - CONFIDENCE...MEDIUM
MODEL CONSENSUS IS TO MOVE LOW FROM CNTRL IL INTO NE IN. BROAD 850
MILLIBAR CIRCULATION BECOMES CLOSED ACROSS LWR MI DURING THE
AFTERNOON. SURFACE/850 TROUGH EXTENDS FROM THE LWR MI LOW INTO
CNTRL/SRN WI ENHANCING LOW LEVEL FORCING. IN ADDITION TO THE RIPPLES
WRAPPING WEST AND SOUTHWEST AROUND THE PERIPHERY OF THE UPPER LOW
CENTER. SO WILL HAVE CHANCE POPS FOR SHRA IN THIS PATTERN. THE 00Z
ECMWF HAS THROWN A BIT OF A WRENCH INTO THINGS BY COMING IN WITH A
MUCH MORE PROGRESSIVE SOLUTION HOWEVER GIVEN THE CURRENT LOCATION
AND STRUCTURE OF THIS SYSTEM WOULD APPEAR THAT LEANING TOWARDS A
SLOWER SOLUTION HAS MORE CREDENCE AT THIS POINT. WILL NOT JUMP ON
THIS NEW ECMWF DEVELOPMENT YET ESP WITH THE NAM/GFS/GEM ALL SHOWING
A SLOWER LOOK.
TUESDAY - CONFIDENCE...MEDIUM
LOW PLODS INTO THE EASTERN GREAT LAKES WITH CYCLONIC FLOW ON THE
WESTERN SIDE STILL LINGERING INTO EASTERN WI. ALLBLEND HAS SOME
SLIGHT POPS IN THE EAST AND FOR NOW THIS IS FINE. WITH THE FASTER
00Z ECMWF WAS TEMPTED TO PULL THIS POP BUT AFTER COORD WITH LOT/GRB
WAS DECIDED TO LEAVE THIS AS IS FOR NOW AND STICK WITH THE CONSENSUS.
APPEARS INFLUENCE OF THE UPPER CIRCULATION GETS FAR ENOUGH AWAY WITH
SURFACE RIDGING BUILDING IN FOR THE AFTERNOON.
WEDNESDAY THROUGH FRIDAY - CONFIDENCE...MEDIUM
SURFACE/850 HIGH CENTERED OVER THE AREA ON WEDNESDAY. WITH A SHIFT
TO THE EAST ON THURSDAY AND FRIDAY...THIS SETS UP A RETURN SOUTHERLY
FLOW WHICH BRINGS MILDER 925 TEMPS INTO THE AREA.
AVIATION/12Z TAFS/...AREAS OF DENSE FOG WILL GRADUALLY THIN THIS
MORNING AS WINDS INCREASE AS WARM FRONT IN NRN IL ADVANCES NORTH.
CIGS MAY EVEN INCREASE TO VFR FOR A TIME BEFORE NMRS CONVECTION
SPREADS IN LATE MRNG AND AFTN. CONVECTION SHOULD END OVERNIGHT WRN
AREAS AS OCCLUDED FRONT SLIDES EAST OF AREA.
MARINE...WL CONTINUE DENSE FOG ADVY INTO THE AFTN AS WARM...MOIST AIR
CONTINUES TO MOVE ACROSS COOLER NEAR SHORE WATERS OF LAKE MI.
SCATTERED MORNING AND EARLY AFTN CONVECTION WL GIVE WAY TO A MORE
WIDESPREAD PERIOD LATER THIS AFTN AND EVE.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...DENSE FOG ADVISORY UNTIL 3 PM CDT THIS AFTERNOON FOR WIZ052-060.
LM...DENSE FOG ADVISORY UNTIL 10 PM CDT THIS EVENING FOR LMZ643>646.
&&
$$
UPDATE...MRC
TODAY/TONIGHT AND AVIATION/MARINE...MBK
SUNDAY THROUGH FRIDAY...COLLAR
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1150 AM CDT SAT OCT 5 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 413 AM CDT SAT OCT 5 2013
MOST EFFORT THIS FORECAST SHIFT WAS PUT TOWARD GETTING THE NEXT 24
HOURS AS ACCURATE AS POSSIBLE. SCREAMING MESSAGE IS THE SLOWER
EASTWARD PROGRESSION OF THE FRONT AND INSTABILITY...MAKING FOR A
BIT HIGHER SEVERE WEATHER CHANCE IN WI TODAY.
WATER VAPOR SHOWING THE MONSTER LOW THAT BROUGHT 25-45 INCHES OF
SNOW TO SD OVER CENTRAL SD AT 08Z AND NEARLY STATIONARY. OCCLUDED
FRONT CURRENTLY POSITIONED FROM KRWF TO KCCY...WHERE THE TRIPLE
POINT IS LOCATED. THE WARM FRONT EXTENDS EAST FROM NEAR KCCY TO
THE DELLS IN WI...WITH THE SURFACE COLD FRONT RUNNING SOUTH FROM
KCCY. THIS WARM FRONT IS THE LEADING EDGE OF THE HIGHER DEWPOINT
AIR...MIDDLE 60S...AND THE ENERGY FOR THIS AFTERNOONS STORMS. THE
OVERNIGHT CONVECTION HAS NOW PASSED OFF TO THE EAST...AND WITH IT
THE FLASH FLOOD THREAT.
EVALUATING THE 04.00Z MODEL GUIDANCE...THE TREND IS SLOWER WITH
THE NORTHEAST PROGRESSION OF THE OCCLUDED/COLD FRONT. THIS ALLOWS
MORE OF THE FORECAST AREA IN WI TO BE PRE-FRONTAL AND IN THE WARM
SECTOR FOR A HIGHER PROBABILITY OF SEVERE WEATHER. AS THE DAY
PROGRESSES...QVECTOR CONVERGENCE WILL INCREASE AS A SHORTWAVE
TROUGH IN COLORADO ROTATES AROUND THE LARGER SD TROUGH AND BEGINS
ITS EASTWARD PROGRESSION. AS THE FORCING BEGINS TO
INCREASE...NEAR/POST FRONTAL SHOWERS WILL LIKELY DEVELOP MUCH LIKE
SEEN ON RADAR ALONG I-35 EARLY THIS MORNING. ALSO...BETTER UPPER
LEVEL FORCING WILL BEGIN TO WORK TOWARD THE WARM SECTOR AND WORK
WITH 0-2KM THETA-E CONVERGENCE ALONG THE FRONT. INSTABILITY IN THE
WARM SECTOR WILL HIGHLY DEPEND ON THE EXTENT OF THE SHOWERS AND
CLOUDS OVER WI...HOWEVER BECAUSE THE DEWPOINTS ARE ALREADY MIDDLE
60S...AT LEAST MARGINAL INSTABILITY WILL BE PRESENT BY 18Z. MUCAPES
AROUND 1000-1500 J/KG LOOK TO BE A GOOD ESTIMATE ON AFTERNOON
CAPE...POSSIBLY HIGHER WITH MORE CLOUD BREAKS.
WIND SHEAR LOOKS TO INCREASE TODAY BUT RIGHT ON THE COLD/OCCLUDED
FRONTAL BOUNDARY...TO MAKE IT A MARGINAL SUPERCELL DAY WITH
MULTI-CELLS ALSO PRESENT. THE 05.06Z NAM AND 05.07Z RAP BOTH SUGGEST
NEAR 40 KTS OF 0-6KM SHEAR...CERTAINLY ENOUGH FOR SUPERCELLS. THE
05.07Z RAP MIXES ALL THE PRE-FRONTAL SURFACE WINDS TO SOUTHERLY. THE
05.06Z NAM AND LATEST HRRR RUNS ARE VERY AGREEABLE THAT THE WARM
FRONT WILL SHIFT NORTH TO ABOUT BLACK RIVER FALLS WI TODAY...VERY
CLOSE TO THE SPC DAY 1 NORTHERN EXTENT OF THE SLIGHT RISK. EASTERLY
FLOW IS FOUND NORTH OF THE WARM FRONT...WHICH EXTENDS TO THE EAST
TOWARD KGRB...SO A GOOD CONVERGENT BOUNDARY. WHILE TORNADO
PROBABILITIES DONT LOOK HIGH...THE TRIPLE POINT AREA AND ALONG THAT
WARM FRONT THIS AFTERNOON WILL BE A FOCAL POINT.
OTHERWISE...DAMAGING WIND SEGMENTS OR LARGE HAIL ARE THE MAIN
THREATS FROM THE STORMS IN WI. NORTH OF THE WARM FRONT...LOW-LEVEL
INVERTED CONDITIONS AND ELEVATED STORMS ARE FAVORED...HEAVY RAIN IS
THE MAIN THREAT...WITH AN ISOLATED HAIL STORM POSSIBLE. THE FRONT
SHOULD SHIFT EAST OF THE FORECAST AREA BY EARLY EVENING WITH STRONG
DEWPOINT DECREASES. THUS...THE MAIN SEVERE WEATHER THREAT LOOKS TO
BE ABOUT 1 PM TO 5 PM.
BY TONIGHT...THE NE AND EASTERNMOST FORECAST AREA MAY STILL HAVE
SOME RAIN REMAINING. HAVE SLOWED THAT SLIGHTLY FROM THE PREVIOUS
FORECAST. A DECREASING TREND OCCURS THROUGH THE EVENING AS WEATHER
SHIFTS EAST.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 413 AM CDT SAT OCT 5 2013
THE LATEST MODEL CONSENSUS IS TO NOW KEEP THE DEFORMATION
ASSOCIATED WITH THE CYCLONIC MOIST FLOW WRAPPING AROUND THE LOW TO
THE WEST-NORTHWEST ON SATURDAY. THIS IS HIGHLY DEPENDENT ON THE
TRACK OF THE LOW WHICH IS A BIT FURTHER SOUTH IN THE LATEST
GUIDANCE. IN ANY CASE...CHANGES WERE MADE TO SUNDAY TO TRY AND DRY
IT OUT WITH THE RAIN SHOWERS JUST WEST OF THE AREA. ALTHOUGH THE
CONSENSUS OF THE MODELS IS TO BRING THAT BAND INTO THE FORECAST
AREA FOR MONDAY NOW...THE LATEST 05.00Z ECMWF IS MUCH MORE
PROGRESSIVE AND RAPIDLY SHIFTS THE SHOWERS EAST. HAVE A SMALL
CHANCE OF SHOWERS TO ADDRESS THAT SITUATION.
THE REMAINDER OF THE PERIOD IS DOMINATED BY DRY WEATHER UNDER
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1150 AM CDT SAT OCT 5 2013
FRONTAL BOUNDARY WILL CONTINUE TO ROTATE NORTHEAST ACROSS THE REGION
THIS AFTERNOON. ITS ALREADY CLEARED KRST...AND WILL DO SO AT KLSE BY
MID-AFTERNOON. COULD BE A BRIEF SWITCH TO WESTERLY WINDS FOR AN HOUR
OR TWO...THEN SHIFT BACK TO MORE SOUTH-SOUTHWEST. AN UPPER LEVEL
SHORTWAVE MOVING IN FROM THE SOUTHWEST WILL WORK ON THE FRONT TO
SPAWN SCT SHRA/TS NEAR THE SFC FRONT...AND THIS ACTIVITY COULD
IMPACT THE TAF SITES FOR A FEW HOURS THIS AFTERNOON.
SKIES SHOULD CLEAR THIS EVENING AS DRY AIR WRAPS INTO THE STORM
SYSTEM...PER LATEST SATELLITE IMAGERY. MASS OF MVFR/IFR CIGS
ASSOCIATED WITH THE MAIN SFC LOW WITH THE SYSTEM...CURRENTLY ACROSS
SD. THE LOW WILL MOVE EAST/NORTHEAST TONIGHT...BRINGING THE CLOUD
SHIELD IN NEAR 12Z. NUMERICAL GUIDANCE SUGGEST ONLY VFR CIGS BY THAT
TIME...BUT HARD TO ARGUE WITH SFC OBS/SATELLITE...PLUS RH FIELDS
SUPPORT LOWER CIGS. WILL BRING IN SOME MVFR CIGS FOR SUN MORNING.
ANOTHER FORECAST CONSIDERATION IS THE POTENTIAL FOR FOG...ESPECIALLY
IN THE RIVER VALLEYS. WITH EXPECTED CLEARING TONIGHT...THE SFC
PRESSURE GRADIENT BECOMING BAGGY - THUS LIGHT WINDS...AND RECENT
RAINS TO MOISTEN THE BOUNDARY LAYER...IT COULD BE FAVORABLE FOR SUB
1SM AT KLSE. HOW LONG IT STAYS CLEAR WILL PROBABLY BE THE BIGGEST
FACTOR...AND A LOT OF UNCERTAINTY HERE. WILL ADD BCFG FOR NOW.
&&
.HYDROLOGY...
ISSUED AT 413 AM CDT SAT OCT 5 2013
CONCERNING THE FLASH FLOOD WATCH...WITH CURRENT CONVECTION EAST
OF THE AREA...MAIN THREAT HAS DIMINISHED. AS AFTERNOON CONVECTION
INCREASES...IT SHOULD BE AFFECTING AREAS THAT HAVE HAD LESS RAIN
OVERALL THAN THOSE WEST OF THE MISS RIVER. AREAS EAST OF THE MISS
RIVER CAN TAKE ANOTHER 1-2 INCHES...ESPECIALLY SWRN WI. THERE IS A
SMALL PROBABILITY OF LOCALIZED FLASH FLOODING TODAY IN THE CENTRAL
WI CORRIDOR IN THE PRE-FRONTAL AIR MASS WHICH WILL STILL HAVE 1.25
TO 1.75 INCH PRECIPITABLE WATER VALUES. RAIN RATES ARE EXPECTED TO
BE HIGH...PROBABLY 2 TO 3 INCH PER HOUR SHOULD CAPE DEVELOP AS
FORECAST. THE SLOW MOVEMENT OF THE FRONT DOES GIVE SOME CONCERN
FOR FLOODING SO WILL ISSUE ANOTHER HYDROLOGICAL DISCUSSION FOR
THAT AREA AND CANCEL THE FLASH FLOOD WATCH.
THERE ARE SOME RIVER RESPONSES CURRENTLY OCCURRING. MONITORING THE
ROOT RIVER BASIN AND THE UPPER IOWA RIVERS BOTH HAVE RESPONSES.
ALSO THE WHITEWATER RIVER MIDDLE FORK THAT RUNS THROUGH WHITEWATER
STATE PARK IS RISING. AT THIS TIME THESE WILL APPROACH FLOOD STAGE
BUT IT IS BELIEVED THEY WILL NOT REACH IT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BAUMGARDT
LONG TERM....BAUMGARDT
HYDROLOGY....BAUMGARDT
AVIATION.....RIECK