Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 05/05/13
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1132 AM MDT FRI MAY 3 2013
.UPDATE...
ISSUED AT 853 AM MDT FRI MAY 3 2013
UPDATED FORECAST TO TAKE DOWN THE FREEZE WARNING FOR THE REMAINDER
OF THIS MORNING AS TEMPERATURES CONTINUE TO RISE ABOVE FREEZING.
THERE IS STILL THE POTENTIAL FOR ANOTHER FROST OR FREEZE AGAIN
TONIGHT SO CURRENT FREEZE WATCH FOR TONIGHT WILL REMAIN IN EFFECT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 300 AM MDT FRI MAY 3 2013
CURRENTLY...CLEAR SKIES WITH NORTHERLY FLOW ALOFT AS THE UPPER
TROUGH SITS TO THE EAST OF COLORADO OVER KS AND NE...AS PER LATEST
SATELLITE IMAGERY AND H5 RAP ANALYSIS. WIDESPREAD BELOW FREEZING
TEMPS FOR THE EASTERN CO PLAINS AS OF 3 AM.
TODAY AND TONIGHT...NOT A LOT TO ADD TO THE ONGOING FORECAST PACKAGE
IN THE SHORT TERM. THE UPPER TROUGH TO THE EAST IS EXPECTED TO
STRENGTHEN AS IT EJECTS TO THE SE AWAY FROM CO...RELAXING THE WINDS
ALOFT FOR THE STATE. SUNNY TO MOSTLY SUNNY SKIES ARE EXPECTED
TODAY...WITH A NICE REBOUND FOR TEMPS INTO THE UPPER 50S TO MID 60S
FOR MOST LOCATIONS TODAY. LIGHT WINDS AND CLEAR SKIES TONIGHT WILL
PRODUCE ONE MORE NIGHT AND SUB-FREEZING TEMPS...AND CURRENT FREEZE
WATCH LOOKS GOOD. DECIDED TO HOLD OFF ON UPGRADING AT THIS
TIME...AND TO AVOID CONFUSION OPTED TO LET CURRENT WARNING RUN THE
COURSE...THEN AT EXPIRATION THE WATCH CAN BE UPGRADED. MOORE
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 300 AM MDT FRI MAY 3 2013
...WETTER PATTERN POSSIBLE THIS PERIOD...
SIMULATIONS IN RATHER GOOD AGREEMENT GIVEN THE RATHER WEAK FLOW
REGIME WHICH WILL BE OVER THE WESTERN PART OF THE CONUS THIS
PERIOD. AT THE BEGINNING OF THIS PD (SAT 12Z)...A WELL ESTABLISHED
CUTOFF LOW WILL BE LOCATED IN THE VICINITY OF MISSOURI WHILE A
WEAKER CLOSED LOW WILL BE DEVELOPING OVER THE S IDAHO REGION. WEAK
RIDGING AND OVERALL WEAK MIDLVL FLOW WILL BE OVER THE FCST AREA.
AS THE WEEKEND PROGRESSES...THE LOW OVER MISSOURI WILL SLOWLY MOVE
EAST WHILE THE UPPER LOW OVER IDAHO RETROGRADES OVER N CALIF. THIS
WILL ALLOW FOR A SMALL MIDLVL RIDGE TO BUILD OVER THE FCST AREA.
GIVEN THIS PATTERN...I EXPECT IT WILL BE MAINLY DRY OVER THE
REGION. A FEW SCTD AFTERNOON AND EVENING TSRA WILL BE POSSIBLE
OVER THE CONTDVD AND AN ISOLATED STORM OR TWO WILL BE POSSIBLE
OVER THE S MTNS/PIKES PEAK REGION. DAYTIME TEMPS WILL BE PLEASANT
WITH MAINLY 60S ACROSS THE PLAINS AND VALLEYS.
DURING THE MONDAY TIMEFRAME...A SHORTWAVE WILL EJECT OUT OF THE
CALIF LOW AND MOVE ACROSS THE REGION. I EXPECT WE WILL SEE
INCREASING CHANCES OF SHOWER OVER THE MTNS WITH ISOLATED SHOWERS
BECOMING POSSIBLE OVER THE PLAINS LATE IN THE DAY. MAX TEMPS MONDAY
WILL BE A FEW DEGREES WARMER THAN THE WEEKENDS HIGHS. SHEAR WILL BE
INCREASING MONDAY (ALTHOUGH NOT ALL THAT STRONG)...SO WE MAY SEE A
BIT MORE ORGANIZED CONVECTION ON THIS DAY ON THE PLAINS.
TUESDAY...CALIF LOW STARTS TO MOVE EAST AND SIMULATIONS HINT AT A
DRY SLOT AFFECTING THE S TIER OF THE CWA. THIS SHOULD BRING A
DECREASING THREAT OF SHOWERS TO THE REGION AND ALLOW FOR TEMPS TO
RISE INTO THE MID 70S ACROSS THE PLAINS WITH 60S VALLEYS.
WEDNESDAY IS WHEN THE MAIN LOW MOVES OVER THE STATE...AND THIS IS
THE DAY WE SHOULD SEE THE MOST ACTIVE WX. THERE IS NOT MUCH COLD AIR
WITH THIS SYSTEM SO ALL PRECIP (EXCEPT OVER THE HIGHEST TRRN) SHOULD
BE LIQUID. SHEAR IS FCST TO BE RATHER IMPRESSIVE (ESPECIALLY GFS) OVER
THE FAR E PLAINS AND IT IS POSSIBLE WE MAY SEE OUR FIRST SEVERE WX
THREAT OVER THE FCST AREA. THERE WILL ALSO BE A GOOD CHANCE OF
PRECIP OVER THE ENTIRE AREA GIVEN THE EXPECTED INSTABILITY AND
FORCING. FOR NOW I HAVE POPS IN THE 20-40% RANGE...BUT THESE VALUES
MAY NEED TO BE INCREASED IF MODELS CONTINUE TO SHOW THIS SCENARIO.
MAX TEMPS THIS DAY WILL BE COOLER GIVEN THE LIKELY INCREASED CLOUD
COVER OVER THE FCST AREA.
WED NITE THROUGH THU THE WEAK UPPER LOW MOVES VERY LITTLE AND WE
SHOULD SEE A CONTINUED THREAT OF MUCH NEED PRECIP OVER THE FCST
AREA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1122 AM MDT FRI MAY 3 2013
VFR CONDITIONS ARE EXPECTED AT KPUB...KCOS...AND KALS THROUGH 18Z
SATURDAY WITH ONLY A FEW HIGH CLOUDS MOVING ACROSS SOUTHEASTERN
COLORADO BY 20Z. -PJC
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
FREEZE WATCH FROM LATE TONIGHT THROUGH SATURDAY MORNING FOR
COZ084>089-093>099.
&&
$$
UPDATE...KT
SHORT TERM...MOORE
LONG TERM...HODANISH
AVIATION...PJC
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1018 AM MDT FRI MAY 3 2013
.UPDATE...
&&
.SHORT TERM...ONGOING FORECASTS LOOK ON TRACK. HIGH PRESSURE WILL
CONTINUE TO BUILD ACROSS COLORADO DESPITE THE NORTHERLY FLOW
ALOFT. WARMUP TO CONTINUE WITH HIGHS ACROSS NORTHEAST COLORADO
AROUND 60 DEGREES. EXPECTED FORECAST HIGHS MAY NEED TO BE
INCREASED A FEW DEGREES AS CURRENT TEMPERATURES ALREADY IN THE
40S ACROSS PLAINS. SOME INCREASE IN HIGH LEVEL CLOUDS AND WEAK
NORTHERLY SURGE MAY SLOW WARMUP. WILL SEE HOW THINGS TRANSPIRE
BEFORE MAKING ANY ADJUSTMENTS.
.AVIATION...CURRENT TAF TRENDS LOOK REASONABLE. WEAK NORTHERLY SURGE
STILL EXPECTED AROUND 18Z...AS NOTED BY LATEST RAP AND HRRR...WITH
THE TREND TOWARD EASTERLY BY 00Z THEN SOUTHEAST DURING THE EVENING.
VFR...
&&
.HYDROLOGY...
&&
.PREV DISCUSSION... /ISSUED 406 AM MDT FRI MAY 3 2013/
SHORT TERM...NORTHERLY FLOW ALOFT WILL PREVAIL TODAY AS AN UPPER
LEVEL LOW SPINS OVER THE CENTRAL AND SOUTHERN PLAINS. FLOW ALOFT
WILL NORTHWESTERLY AS A RIDGE STARTS TO FORM DUE TO A TROUGH MOVING
SOUTHWEST ACROSS THE NORTHERN ROCKIES.
FOR TODAY...AIRMASS CONTINUES TO RECOVER FROM THE COLD BLAST A
COUPLE OF DAYS AGO. HIGHS WILL BE NEAR 60 DEGREES ACROSS NORTHEAST
COLORADO. NORTH TO NORTHEAST WINDS WILL DEVELOP THIS AFTERNOON AS A
SURFACE HIGH RESIDES OVER THE NORTHERN PLAINS. AS THIS HIGH SINKS
SOUTH OVERNIGHT...IT WILL PUSH SLIGHTLY COOLER AIR INTO THE AREA FOR
SATURDAY. BECAUSE OF THIS SURFACE HIGH SINKING SOUTH...THE NORMAL
SOUTHERLY DRAINAGE WINDS WILL HAVE A HARD TIME DEVELOPING TONIGHT.
OVERNIGHT LOWS WILL CONTINUE TO BE ON THE COOL SIDE FOR THIS TIME OF
YEAR WITH READINGS AROUND 32 DEGREES.
LONG TERM...CONTORTED JET STREAM PATTERN TAKES SHAPE OVER THE WRN
CONUS OVER THE WEEKEND. BY SATURDAY...100+ KT JET DIVING SOUTH OUT
OF WESTERN CANADA CARVES OUT A STRONG POSITIVELY TILTED UPPER LEVEL
TROUGH OVER THE PACIFIC NORTHWEST/NORTHERN ROCKIES. AS THIS IS GOING
ON...NEARLY ZONAL FLOW ALOFT SETS UP OVER COLORADO WITH A SHORTWAVE
RIDGE FORMING TO OUR SOUTH. MEANWHILE POST-FRONTAL EAST-NORTHEAST
LOW-LEVEL FLOW COUPLED WITH DIURNAL HEATING APPEARS TO PRODUCE LOW
TOP CONVECTION OVER AND NEAR THE FRONT RANGE MTNS SATURDAY
AFTERNOON. ANY PRECIP SHOULD BE LIGHT ACCORDING TO THE NAM AND GFS
AND MOST OF THAT CONFINED TO THE HIGHER ELEVATIONS. BY SATURDAY
EVENING COULD SEE SOME ENHANCEMENT IN THIS PRECIP WITH LOWERING
CLOUD BASES GENERALLY ALONG AND WEST OF THE FRONT RANGE...WITH A
WEAK MID-LEVEL DISTURBANCE MOVING UP FROM THE FOUR CORNERS. GFS IS A
BIT MORE AMBITIOUS WITH ITS MOISTURE PROFILE AND THE AMOUNT OF
PRECIP IT PRODUCES. STILL...PRECIP AMOUNTS SHOULD BE ON THE LOW
SIDE. EXCEPT FOR A FEW SHOWERS DRIFTING OVR THE I-25 URBAN CORRIDOR
DURING THE EVENING...DO NOT SEE ANY PRECIP FARTHER OUT ON THE
PLAINS.
ON SUNDAY...AS THE UPPER RIDGE TO OUR SOUTH CONTINUES TO AMPLIFY
..SO DOES THE SOUTHWEST FLOW CARRYING MID AND HIGH LEVEL MOISTURE
UP FROM THE DESERT SOUTHWEST. THIS INCREASE IN FLOW IS IN RESPONSE
TO THE STRONG JET SPINNING UP A DEEP CUTOFF LOW OFF THE CALIFORNIA
COAST. THE SHIFT TO A MORE SOUTHERLY FLOW ALOFT AND A SOUTHEASTERLY
LOW LEVEL FLOW ON THE PLAINS HELPS TO DRAWS MORE LOW AND MID-LEVEL
MOISTURE UP INTO THE AREA RESULTING IN MORE CLOUDS MAINLY AT AND
ABOVE MTN TOP LEVEL AND A SLIGHTLY BETTER CHANCE OF WETTING PRECIP
FOR THE HIGH COUNTRY...AS WELL AS A SLIGHT CHANCE OF RAIN SHOWERS
FOR THE URBAN CORRIDOR AND PALMER DIVIDE AREAS BY EVENING.
TEMPERATURES IN THE 50S ON THE PLAIN SATURDAY ARE EXPECTED TO THE
LOWER 60S ON SUNDAY. HIGH COUNTRY TEMPERATURE ABOUT THE SAME BOTH
DAYS..IN THE 40S AND LOWER 50S. CLOUD COVER AND COOL TEMPERATURES
WILL KEEP SNOWMELT RUNOFF IN THE HIGH COUNTRY IN CHECK.
BY MONDAY...MODELS SHOW A ZONAL JET STREAM SNAKING ALONG THE U.S.
MEXICO BORDER WITH COLORADO UNDER A MUCH WEAKER DIFLUENT SOUTHWEST
FLOW ALOFT. LOW-LEVEL FLOW EAST OF THE MTNS REMAINS SOUTHEASTERLY.
THROUGH THE DAY MODELS INDICATE YET ANOTHER EVEN STRONGER SHORTWAVE
TROUGH ROTATING UP FROM THE SOUTHWEST WITHIN THE BROAD CIRCULATION
AROUND THE WEST COAST CUTOFF LOW. WOULD EXPECT TO SEE SHOWERS ON THE
INCREASE IN THE HIGH COUNTRY FROM SOUTH TO NORTH ON MONDAY AS THE
SHORTWAVE TROUGH SWINGS NORTHWARD ACROSS THE REGION. SNOW LEVEL
SHOULD REMAIN FAIRLY HIGH POSSIBLY UP AROUND 10500 OR 11000 FT WITH
WARM ADVECTION. BY AFTERNOON WITH STEEP MID-LEVEL LAPSE RATES...
ISOLATED T-STORMS ALSO A POSSIBILITY OVER THE HIGH TERRAIN. LATEST
GUIDANCE SHOWS THE SHORT WAVE ENERGY AND MOISTURE PASSING OVER THE
NORTHEAST PLAINS DURING THE EVENING. NOT SURE ABOUT ANY THUNDER. LOW
POPS LOOK GOOD THERE. TEMPERATURES ON MONDAY WARM 1-2 DEG C FROM THE
DAY BEFORE.
TUESDAY AND BEYOND...PERIOD STARTS OUT DRY TUESDAY MORNING WITH WEAK
DOWNWARD MOTION IN THE WAKE OF PASSING SHORTWAVE. FROM
THERE...MODELS SHOW A GENERAL INCREASE IN MOISTURE AND LARGE SCALE
LIFT WITH THE WEST COAST CYCLONE FINALLY MAKING ITS MOVE INLAND
ACROSS THE GREAT BASIN. MODELS EVOLVE THIS CLOSED LOW INTO A BROAD
LOW PRESSURE TROUGH WHICH SLOWLY MIGRATES EASTWARD ACROSS THE CENTRAL
AND SOUTHERN ROCKY MTN REGIONS MIDWEEK. THIS WOULD KEEP TEMPERATURE
AT OR BELOW AVERAGE AND THE WEATHER UNSETTLED WITH A CHANCE OF
SHOWERS STARTING TUESDAY AFTERNOON OUT THROUGH THURSDAY. AT THIS
TIME...TEMPERATURES APPEAR TOO WARM FOR ANY SNOW AT LOWER
ELEVATIONS.
AVIATION...VFR CONDITIONS WILL PREVAIL THROUGH TONIGHT. NORMAL
LIGHT SOUTHERLY DRAINAGE WINDS AT KDEN AND KAPA WILL BECOME LIGHT
AFTER SUNRISE. BY 18Z...NORTH TO NORTHEAST WINDS WILL DEVELOP AT
SPEEDS LESS THAN 15 KNOTS. LIGHT WINDS ARE EXPECT TO REDEVELOP
TONIGHT.
HYDROLOGY...NO CONCERNS.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...D-L
LONG TERM....BAKER
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS PUEBLO CO
856 AM MDT FRI MAY 3 2013
.UPDATE...
ISSUED AT 853 AM MDT FRI MAY 3 2013
UPDATED FORECAST TO TAKE DOWN THE FREEZE WARNING FOR THE REMAINDER
OF THIS MORNING AS TEMPERATURES CONTINUE TO RISE ABOVE FREEZING.
THERE IS STILL THE POTENTIAL FOR ANOTHER FROST OR FREEZE AGAIN
TONIGHT SO CURRENT FREEZE WATCH FOR TONIGHT WILL REMAIN IN EFFECT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 300 AM MDT FRI MAY 3 2013
CURRENTLY...CLEAR SKIES WITH NORTHERLY FLOW ALOFT AS THE UPPER
TROUGH SITS TO THE EAST OF COLORADO OVER KS AND NE...AS PER LATEST
SATELLITE IMAGERY AND H5 RAP ANALYSIS. WIDESPREAD BELOW FREEZING
TEMPS FOR THE EASTERN CO PLAINS AS OF 3 AM.
TODAY AND TONIGHT...NOT A LOT TO ADD TO THE ONGOING FORECAST PACKAGE
IN THE SHORT TERM. THE UPPER TROUGH TO THE EAST IS EXPECTED TO
STRENGTHEN AS IT EJECTS TO THE SE AWAY FROM CO...RELAXING THE WINDS
ALOFT FOR THE STATE. SUNNY TO MOSTLY SUNNY SKIES ARE EXPECTED
TODAY...WITH A NICE REBOUND FOR TEMPS INTO THE UPPER 50S TO MID 60S
FOR MOST LOCATIONS TODAY. LIGHT WINDS AND CLEAR SKIES TONIGHT WILL
PRODUCE ONE MORE NIGHT AND SUB-FREEZING TEMPS...AND CURRENT FREEZE
WATCH LOOKS GOOD. DECIDED TO HOLD OFF ON UPGRADING AT THIS
TIME...AND TO AVOID CONFUSION OPTED TO LET CURRENT WARNING RUN THE
COURSE...THEN AT EXPIRATION THE WATCH CAN BE UPGRADED. MOORE
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 300 AM MDT FRI MAY 3 2013
...WETTER PATTERN POSSIBLE THIS PERIOD...
SIMULATIONS IN RATHER GOOD AGREEMENT GIVEN THE RATHER WEAK FLOW
REGIME WHICH WILL BE OVER THE WESTERN PART OF THE CONUS THIS
PERIOD. AT THE BEGINNING OF THIS PD (SAT 12Z)...A WELL ESTABLISHED
CUTOFF LOW WILL BE LOCATED IN THE VICINITY OF MISSOURI WHILE A
WEAKER CLOSED LOW WILL BE DEVELOPING OVER THE S IDAHO REGION. WEAK
RIDGING AND OVERALL WEAK MIDLVL FLOW WILL BE OVER THE FCST AREA.
AS THE WEEKEND PROGRESSES...THE LOW OVER MISSOURI WILL SLOWLY MOVE
EAST WHILE THE UPPER LOW OVER IDAHO RETROGRADES OVER N CALIF. THIS
WILL ALLOW FOR A SMALL MIDLVL RIDGE TO BUILD OVER THE FCST AREA.
GIVEN THIS PATTERN...I EXPECT IT WILL BE MAINLY DRY OVER THE
REGION. A FEW SCTD AFTERNOON AND EVENING TSRA WILL BE POSSIBLE
OVER THE CONTDVD AND AN ISOLATED STORM OR TWO WILL BE POSSIBLE
OVER THE S MTNS/PIKES PEAK REGION. DAYTIME TEMPS WILL BE PLEASANT
WITH MAINLY 60S ACROSS THE PLAINS AND VALLEYS.
DURING THE MONDAY TIMEFRAME...A SHORTWAVE WILL EJECT OUT OF THE
CALIF LOW AND MOVE ACROSS THE REGION. I EXPECT WE WILL SEE
INCREASING CHANCES OF SHOWER OVER THE MTNS WITH ISOLATED SHOWERS
BECOMING POSSIBLE OVER THE PLAINS LATE IN THE DAY. MAX TEMPS MONDAY
WILL BE A FEW DEGREES WARMER THAN THE WEEKENDS HIGHS. SHEAR WILL BE
INCREASING MONDAY (ALTHOUGH NOT ALL THAT STRONG)...SO WE MAY SEE A
BIT MORE ORGANIZED CONVECTION ON THIS DAY ON THE PLAINS.
TUESDAY...CALIF LOW STARTS TO MOVE EAST AND SIMULATIONS HINT AT A
DRY SLOT AFFECTING THE S TIER OF THE CWA. THIS SHOULD BRING A
DECREASING THREAT OF SHOWERS TO THE REGION AND ALLOW FOR TEMPS TO
RISE INTO THE MID 70S ACROSS THE PLAINS WITH 60S VALLEYS.
WEDNESDAY IS WHEN THE MAIN LOW MOVES OVER THE STATE...AND THIS IS
THE DAY WE SHOULD SEE THE MOST ACTIVE WX. THERE IS NOT MUCH COLD AIR
WITH THIS SYSTEM SO ALL PRECIP (EXCEPT OVER THE HIGHEST TRRN) SHOULD
BE LIQUID. SHEAR IS FCST TO BE RATHER IMPRESSIVE (ESPECIALLY GFS) OVER
THE FAR E PLAINS AND IT IS POSSIBLE WE MAY SEE OUR FIRST SEVERE WX
THREAT OVER THE FCST AREA. THERE WILL ALSO BE A GOOD CHANCE OF
PRECIP OVER THE ENTIRE AREA GIVEN THE EXPECTED INSTABILITY AND
FORCING. FOR NOW I HAVE POPS IN THE 20-40% RANGE...BUT THESE VALUES
MAY NEED TO BE INCREASED IF MODELS CONTINUE TO SHOW THIS SCENARIO.
MAX TEMPS THIS DAY WILL BE COOLER GIVEN THE LIKELY INCREASED CLOUD
COVER OVER THE FCST AREA.
WED NITE THROUGH THU THE WEAK UPPER LOW MOVES VERY LITTLE AND WE
SHOULD SEE A CONTINUED THREAT OF MUCH NEED PRECIP OVER THE FCST
AREA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 300 AM MDT FRI MAY 3 2013
VFR CONDITIONS ARE FORECAST FOR THE THREE MAIN TAF SITES OF
KCOS...KPUB AND KALS FOR THE NEXT 24 HRS.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
FREEZE WATCH FROM LATE TONIGHT THROUGH SATURDAY MORNING FOR
COZ084>089-093>099.
FREEZE WARNING UNTIL 9 AM MDT THIS MORNING FOR COZ083>089-
093>099.
&&
$$
UPDATE...KT
SHORT TERM...MOORE
LONG TERM...HODANISH
AVIATION...MOORE
AREA FORECAST DISCUSSION
NWS PUEBLO CO
321 AM MDT FRI MAY 3 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 300 AM MDT FRI MAY 3 2013
CURRENTLY...CLEAR SKIES WITH NORTHERLY FLOW ALOFT AS THE UPPER
TROUGH SITS TO THE EAST OF COLORADO OVER KS AND NE...AS PER LATEST
SATELLITE IMAGERY AND H5 RAP ANALYSIS. WIDESPREAD BELOW FREEZING
TEMPS FOR THE EASTERN CO PLAINS AS OF 3 AM.
TODAY AND TONIGHT...NOT A LOT TO ADD TO THE ONGOING FORECAST PACKAGE
IN THE SHORT TERM. THE UPPER TROUGH TO THE EAST IS EXPECTED TO
STRENGTHEN AS IT EJECTS TO THE SE AWAY FROM CO...RELAXING THE WINDS
ALOFT FOR THE STATE. SUNNY TO MOSTLY SUNNY SKIES ARE EXPECTED
TODAY...WITH A NICE REBOUND FOR TEMPS INTO THE UPPER 50S TO MID 60S
FOR MOST LOCATIONS TODAY. LIGHT WINDS AND CLEAR SKIES TONIGHT WILL
PRODUCE ONE MORE NIGHT AND SUB-FREEZING TEMPS...AND CURRENT FREEZE
WATCH LOOKS GOOD. DECIDED TO HOLD OFF ON UPGRADING AT THIS
TIME...AND TO AVOID CONFUSION OPTED TO LET CURRENT WARNING RUN THE
COURSE...THEN AT EXPIRATION THE WATCH CAN BE UPGRADED. MOORE
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 300 AM MDT FRI MAY 3 2013
...WETTER PATTERN POSSIBLE THIS PERIOD...
SIMULATIONS IN RATHER GOOD AGREEMENT GIVEN THE RATHER WEAK FLOW
REGIME WHICH WILL BE OVER THE WESTERN PART OF THE CONUS THIS
PERIOD. AT THE BEGINNING OF THIS PD (SAT 12Z)...A WELL ESTABLISHED
CUTOFF LOW WILL BE LOCATED IN THE VICINITY OF MISSOURI WHILE A
WEAKER CLOSED LOW WILL BE DEVELOPING OVER THE S IDAHO REGION. WEAK
RIDGING AND OVERALL WEAK MIDLVL FLOW WILL BE OVER THE FCST AREA.
AS THE WEEKEND PROGRESSES...THE LOW OVER MISSOURI WILL SLOWLY MOVE
EAST WHILE THE UPPER LOW OVER IDAHO RETROGRADES OVER N CALIF. THIS
WILL ALLOW FOR A SMALL MIDLVL RIDGE TO BUILD OVER THE FCST AREA.
GIVEN THIS PATTERN...I EXPECT IT WILL BE MAINLY DRY OVER THE
REGION. A FEW SCTD AFTERNOON AND EVENING TSRA WILL BE POSSIBLE
OVER THE CONTDVD AND AN ISOLATED STORM OR TWO WILL BE POSSIBLE
OVER THE S MTNS/PIKES PEAK REGION. DAYTIME TEMPS WILL BE PLEASANT
WITH MAINLY 60S ACROSS THE PLAINS AND VALLEYS.
DURING THE MONDAY TIMEFRAME...A SHORTWAVE WILL EJECT OUT OF THE
CALIF LOW AND MOVE ACROSS THE REGION. I EXPECT WE WILL SEE
INCREASING CHANCES OF SHOWER OVER THE MTNS WITH ISOLATED SHOWERS
BECOMING POSSIBLE OVER THE PLAINS LATE IN THE DAY. MAX TEMPS MONDAY
WILL BE A FEW DEGREES WARMER THAN THE WEEKENDS HIGHS. SHEAR WILL BE
INCREASING MONDAY (ALTHOUGH NOT ALL THAT STRONG)...SO WE MAY SEE A
BIT MORE ORGANIZED CONVECTION ON THIS DAY ON THE PLAINS.
TUESDAY...CALIF LOW STARTS TO MOVE EAST AND SIMULATIONS HINT AT A
DRY SLOT AFFECTING THE S TIER OF THE CWA. THIS SHOULD BRING A
DECREASING THREAT OF SHOWERS TO THE REGION AND ALLOW FOR TEMPS TO
RISE INTO THE MID 70S ACROSS THE PLAINS WITH 60S VALLEYS.
WEDNESDAY IS WHEN THE MAIN LOW MOVES OVER THE STATE...AND THIS IS
THE DAY WE SHOULD SEE THE MOST ACTIVE WX. THERE IS NOT MUCH COLD AIR
WITH THIS SYSTEM SO ALL PRECIP (EXCEPT OVER THE HIGHEST TRRN) SHOULD
BE LIQUID. SHEAR IS FCST TO BE RATHER IMPRESSIVE (ESPECIALLY GFS) OVER
THE FAR E PLAINS AND IT IS POSSIBLE WE MAY SEE OUR FIRST SEVERE WX
THREAT OVER THE FCST AREA. THERE WILL ALSO BE A GOOD CHANCE OF
PRECIP OVER THE ENTIRE AREA GIVEN THE EXPECTED INSTABILITY AND
FORCING. FOR NOW I HAVE POPS IN THE 20-40% RANGE...BUT THESE VALUES
MAY NEED TO BE INCREASED IF MODELS CONTINUE TO SHOW THIS SCENARIO.
MAX TEMPS THIS DAY WILL BE COOLER GIVEN THE LIKELY INCREASED CLOUD
COVER OVER THE FCST AREA.
WED NITE THROUGH THU THE WEAK UPPER LOW MOVES VERY LITTLE AND WE
SHOULD SEE A CONTINUED THREAT OF MUCH NEED PRECIP OVER THE FCST
AREA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 300 AM MDT FRI MAY 3 2013
VFR CONDITIONS ARE FORECAST FOR THE THREE MAIN TAF SITES OF
KCOS...KPUB AND KALS FOR THE NEXT 24 HRS.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
FREEZE WATCH FROM LATE TONIGHT THROUGH SATURDAY MORNING FOR
COZ084>089-093>099.
FREEZE WARNING UNTIL 9 AM MDT THIS MORNING FOR COZ083>089-
093>099.
&&
$$
SHORT TERM...MOORE
LONG TERM...HODANISH
AVIATION...MOORE
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
937 PM EDT Sat May 4 2013
.NEAR TERM [Rest of Tonight]...
Updated at: 930 PM EDT
The low-level cloud cover and light rain / drizzle appears to be
lingering in the eastern half of our forecast area longer than the
models have been indicating. Most of the MOS guidance is far too low
with PoPs as some of the bands of light rain showers have produced
several hundredths of an inch of rain in an hour. Therefore, the
forecast overnight was weighted toward the CAM (convection-allowing
models) guidance, and the locally-derived PoPs from those models.
Cross sections of NAM and RUC fields from DTS-SAV show the sloped
frontogenetic circulation in the low levels (surface to 800mb)
gradually shifting east with time overnight. Therefore, PoPs and
cloud cover were gradually decreased from west to east. The expected
stratus lingering through 12z in the far east should lead to warmer
low temperatures than MOS is indicating, especially east of 40J-ABY.
Lows were nudged up a bit in those locations.
&&
.SHORT TERM [Sunday through Monday]...
The anomalous upper level low will steadily spin through the heart
of the Southeast through the period. The low will provide plenty
of forcing for showers both Sunday and Monday as impulses
translate around the base of the low. The main limiting factor
will be the dry air in the lower levels which will likely keep any
rainfall rather light. Regardless, the wet pattern will continue
until the upper low spirals out of the region sometime on Monday
night. Aside from the continuing shower activity, temperatures
will run 10, to even 15 degrees below average for some locations.
Advancing clouds and rain will keep temperatures in check
tomorrow, with a lower 70s to upper 70s northwest to southeast
gradient in place. Overnight, lows will dip into the upper 40s in
the wake of the showers. Monday will be the coldest afternoon as
we are forecast to mix into the upper cold pool. Expect
temperatures to remain around 70 degrees throughout Florida, and
in the middle 60s across Georgia and Alabama, where clouds and
rain will linger much of the day. With rain lingering into the
night, overnight lows won`t be quite as cool, with around 50
degrees expected to the northwest, and up to 60 degrees across the
southeast Big Bend of Florida.
&&
.LONG TERM [Monday Night through Friday]...
In the wake of the upper low, we will dry out an warm up quite a
bit. No major weather systems are forecast to impact the local
area, and temperatures will warm to seasonal averages by mid week.
&&
.AVIATION [through 00z Monday]...
Updated at: 930 PM EDT
Skies have cleared at KDHN and KECP, well behind a slow-moving cold
front. KABY, KTLH, and KVLD will continue with IFR cigs and MVFR vis
(-RA/BR) this evening, but we expect clearing at KTLH around 06 UTC.
KABY and KVLD will not clear until Sunday morning. Strong winds will
develop Sunday afternoon as a strong mid tropospheric jet max rounds
the base of a large, deep-layer low pressure system. W-WSW winds of
15 KT (gusts of 25-30 KT) are likely. Widely scattered SHRA are
possible, but should not have much impact to ops.
&&
.MARINE...
Ongoing advisory conditions will continue through at least Monday
morning as the disturbed pattern is forecast to bring a few
fronts across our Gulf of Mexico waters. Cautionary conditions
will then take over until Tuesday, when higher pressure and weaker
gradients spread over the northern Gulf.
&&
.FIRE WEATHER...
Drier air will move into the area for Sunday and Monday, but red
flag conditions are not expected. However, mixing heights, transport
winds, and dispersions are expected to be high on both days.
&&
.HYDROLOGY...
With only light rain anticipated through mid week, do not expect
any meaningful river or creek rises for the foreseeable future.
All area rivers will remain below action stage, except the
Apalachicola River at Blountstown which will bounce in and out of
action stage over the next several days.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 46 77 48 71 56 / 40 30 10 20 20
Panama City 53 72 53 68 60 / 0 30 10 20 10
Dothan 43 71 46 68 50 / 10 30 20 40 20
Albany 47 74 47 68 52 / 90 30 20 40 30
Valdosta 54 76 48 70 55 / 90 20 10 30 30
Cross City 55 78 50 71 59 / 40 10 10 20 20
Apalachicola 52 73 52 68 61 / 10 30 10 20 20
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AL...None.
GM...Small Craft Advisory until 8 AM EDT Monday for Gulf of Mexico
waters from Destin to the Suwannee River, out to 60 NM.
&&
$$
NEAR TERM...Lamers
SHORT TERM...Harrigan
LONG TERM...Harrigan
AVIATION...Fournier
MARINE...Harrigan
FIRE WEATHER...DVD
HYDROLOGY...Harrigan
AREA FORECAST DISCUSSION...UPDATED
NWS MIAMI FL
234 AM EDT FRI MAY 3 2013
.AVIATION...
PATCHY TO DENSE FOG HAS DEVELOPED OVER THE INTERIOR AREAS OF SOUTH
FLORIDA THIS MORNING. THE FOG COULD MOVE INTO THE TAF SITES OF
KTMB...KAPF...KFXE...AND KMIA BETWEEN 09Z AND 12Z THIS MORNING. SO
HAVE LOWER THE VIS AND CEILING INTO THE MVFR CONDITIONS FOR THE
FOG. REST OF THE TAF SITES SHOULD REMAIN IN THE VFR CONDITIONS
THROUGH THE EARLY MORNING HOURS OF TODAY. HOWEVER...KPBI TAF SITE
COULD SEE SOME SHOWERS THROUGH THE EARLY MORNING HOURS OF TODAY.
SO HAVE PUT IN VCSH FOR THIS SITE.
THE WINDS WILL BE MAINLY FROM THE WEST DIRECTION AT SPEEDS OF 5
KNOTS OR LESS AT THE EAST COAST TAF SITES THROUGH THIS
MORNING...EXCEPT KPBI WHERE THE WINDS WILL BE SWINGING FROM A
NORTHEAST DIRECTION TO A NORTHWEST DIRECTION AT 5 MPH OR LESS AND
AT KAPF WHERE THE WINDS WILL BE LIGHT AND VARIABLE.
ALL OF THE TAF SITES SHOULD SEE SHOWERS BETWEEN 11Z AND 17Z BEFORE
A CHANCE OF THUNDERSTORMS RETURN BETWEEN 17Z AND 00Z. SO HAVE PUT
IN VCSH FOR ALL OF THE TAF SITES FOR THE MORNING HOURS AND VCTS
FOR THE AFTERNOON HOURS FOR TODAY. THE WINDS WILL ALSO REMAIN IN A
WESTERLY DIRECTION FOR THE DAY HOURS TODAY AROUND 10 KNOTS. AT
THIS TIME WILL LEAVE THE CEILING AND VIS IN THE VFR CONDITIONS FOR
THE DAY HOURS TODAY...DUE TO THE UNCERTAIN TIMING OF THE SHOWERS
AND THUNDERSTORMS AFFECTING THE TAF SITES.
&&
.AVIATION...54/BNB
.PREV DISCUSSION... /ISSUED 959 PM EDT THU MAY 2 2013/
UPDATE...
A CLEARING TREND CONTINUES ACROSS THE REGION WITH HEAVY SHOWERS
AND THUNDERSTORMS EXITING THE LOCAL ATLANTIC WATERS TO THE EAST.
HOWEVER...THERE IS STILL A STILL A CHANCE OF ADDITIONAL SHOWERS AND
ISOLATED THUNDERSTORMS OVERNIGHT. THE OOZ SOUNDING INDICATED STEEP
LOW LEVEL LAPSE RATES AND THERE IS A SURFACE TROUGH DEVELOPING IN
THE EASTERN GULF WITH DEEPER LAYERED TROPICAL MOISTURE STILL
LINGERING ACROSS THE REGION. SOME OF THE MESOSCALE MODEL GUIDANCE
ALSO INDICATED POSSIBLE CONVECTION RETURNING TO THE ATLANTIC
WATERS AND PORTIONS OF EASTERN SOUTH FLORIDA TONIGHT.
&&
60
PREV DISCUSSION... /ISSUED 747 PM EDT THU MAY 2 2013/
AVIATION...
BULK OF PRECIPITATION HAS MOVED OFFSHORE IN ASSOCIATION WITH
MESOSCALE LOW PRESSURE AREA, OR MESOLOW, WHICH MOVED ACROSS SOUTH
FLORIDA THIS AFTERNOON. LEFTOVER MID/HIGH CLOUDS WILL MOVE THROUGH
THE AREA BY 04Z WITH ONLY SCT CLOUDS AND VFR CONDITIONS OVERNIGHT.
THE MESOLOW IS OFF THE SE FLORIDA COAST AS OF 00Z AND IS LIKELY
CAUSING A TEMPORARY INCREASE IN NE WINDS TO 20-30 KNOTS ALONG THE
EAST COAST. THESE WINDS SHOULD DECREASE LATER THIS EVENING AS THE
LOW MOVES FARTHER OFFSHORE AND THE LARGE SCALE GRADIENT FLOW TAKES
OVER. WINDS SHIFT TO SW ACROSS ALL OF SOUTH FLORIDA ON FRIDAY AS
MAIN SFC LOW MOVES ACROSS THE AREA. SCATTERED TSTMS WILL RETURN TO
THE AREA ON FRIDAY WITH VCTS INCLUDED AT ALL SITES. /MOLLEDA
&&
PREV DISCUSSION... /ISSUED 501 PM EDT THU MAY 2 2013/
UPDATE...
A SMALL CRAFT ADVISORY IS IN EFFECT FROM 2 AM THIS MORNING TO 200
PM FRIDAY FOR THE ATLANTIC WATERS TO THE EAST OF PALM BEACH COUNTY. THE
COMBINATION OF WINDS FORECAST TO INCREASE TO THE 16 TO 21 KNOT
RANGE AND A SMALL LONG PERIOD SWELL WILL RESULT IN SEAS TO NEAR 7
FEET MAINLY EXPECTED TO THE EAST OF PALM BEACH COUNTY.
60
PREV DISCUSSION... /ISSUED 324 PM EDT THU MAY 2 2013/
DISCUSSION...
WIDESPREAD SHOWERS AND THUNDERSTORMS HAVE MOVED ACROSS SOUTH
FLORIDA TODAY. A WELL DEVELOPED MCS/MCV WAS MOVING ACROSS SOUTH
FLORIDA THIS AFTERNOON...AND SOME STORMS HAVE SHOWN ROTATION.
THERE WERE REPORTS OF DAMAGE FROM A STORM IN BOCA RATON EARLIER
THIS AFTERNOON AS WELL. SEVERE STREET FLOODING WAS REPORTED IN THE
BOCA RATON AND DELRAY BEACH AREAS...WHERE OVER 7.5 INCHES OF RAIN
HAS FALLEN.
A SURFACE BOUNDARY APPEARED TO BE DRIFTING SOUTH AND IT WAS
LOCATED ACROSS BROWARD COUNTY THIS AFTERNOON...AND LOCALLY HEAVY
RAIN AND FLOODING WILL BE POSSIBLE ACROSS BROWARD AND MIAMI DADE
COUNTY THROUGH THIS EVENING. AN UPPER LEVEL LOW ACROSS THE
NORTHEASTERN GULF WILL CONTINUE TO SLIDE SOUTHEAST AND OPEN INTO A
TROUGH OVERNIGHT AS IT MOVES INTO THE FLORIDA PENINSULA. UPPER
LEVEL DIVERGENCE FROM THIS UPPER LOW MAY HELP STORMS CONTINUE INTO
THE EVENING BEFORE DIMINISHING. THE HRRR SHOWS SHOWERS
DISSIPATING AFTER 00Z THIS EVENING.
SURFACE LOW PRESSURE IS EXPECTED TO DEVELOP ACROSS THE EASTERN
GULF OF MEXICO AND MOVE OVER SOUTH FLORIDA ON FRIDAY. THIS
WILL ALLOW THE STEERING FLOW OVER SOUTH FLORIDA TO REMAIN LIGHT
FROM A SOUTH TO SOUTHWEST DIRECTION KEEPING THE DEEP TROPICAL
MOISTURE IN PLACE. SO SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS ARE EXPECTED ACROSS THE REGION AGAIN ON FRIDAY. THE
EMPHASIS WILL BE FOR THE EAST COAST AND NORTHEAST COAST WHERE THE
BEST LOW LEVEL CONVERGENCE AND THE SURFACE BOUNDARY WILL BE
FOUND...ALONG WITH UPPER LEVEL FORCING ASSOCIATED WITH THE UPPER
LEVEL FLOW.
THE 500 MB TEMPS ON FRIDAY SHOULD BE A LITTLE BIT WARMER THAN
TODAY...DUE TO THE UPPER LEVEL LOW DISSIPATING OVER THE NORTHEAST
GULF OF MEXICO. HOWEVER...ANY STORMS THAT DO AFFECT SOUTH FLORIDA
TONIGHT INTO FRIDAY WILL BE CAPABLE OF PRODUCING HEAVY RAINFALL.
THE LOW WILL CONTINUE TO MOVE EAST OVER SOUTH FLORIDA ON SATURDAY
BEFORE MOVING INTO THE WESTERN ATLANTIC WATERS ON SUNDAY. SLIGHTLY
DRIER CONDITIONS ARE EXPECTED ON SATURDAY...BUT RAIN CHANCES WILL
CONTINUE FOR THE NORTHERN TWO-THIRDS OF THE REGION. MUCH DRIER
AIR WILL WORK INTO THE AREA FROM THE WEST ON SUNDAY.
FOR EARLY TO MIDDLE OF NEXT WEEK...A MID TO UPPER LEVEL LOW WILL
DEVELOP OVER THE TENNESSEE VALLEY AND MOVE SLOWLY EAST TOWARDS THE
MID ATLANTIC STATES. THIS WILL ALLOW FOR DRIER WEATHER TO CONTINUE
TO WORK INTO SOUTH FLORIDA FROM THE WEST. SO THE WEATHER SHOULD
REMAIN DRY OVER SOUTH FLORIDA FOR THE EARLY TO MIDDLE PART OF NEXT
WEEK.
AVIATION...
LIGHT TO MODERATE RAIN WILL CONTINUE AT KAPF AND KPBI THROUGH
ABOUT 21-22Z. VERY HEAVY RAIN AND THUNDERSTORMS WILL CONTINUE FOR
THE REST OF THE EAST COAST TAF SITES...WHERE IFR CONDITIONS MAY
OCCUR. RAIN IS EXPECTED TO BEGIN DIMINISHING AFTER 04-06Z
TONIGHT...WITH IMPROVING CONDITIONS. STORMS WILL BE POSSIBLE AGAIN
BEGINNING LATE MORNING ON FRIDAY. WINDS WILL BE VARIABLE THE REST
OF THIS AFTERNOON WITH GUSTY WINDS POSSIBLE. LIGHT AND VARIABLE
WINDS ARE EXPECTED AFTER MIDNIGHT. WITH LOW PRESSURE MOVING OVER
SOUTH FLORIDA...WESTERLY WINDS ARE EXPECTED ON FRIDAY.
MARINE...
THE WINDS OVER SOUTH FLORIDA TODAY INTO FRIDAY WILL BE FROM THE
SOUTH TO SOUTHEAST DIRECTION AT 10 KNOTS OR LESS...BEFORE SLOWLY
SWINGING TO A NORTHWEST DIRECTION BY LATE THIS WEEKEND AND
INCREASING SPEEDS TO 10 TO 15 KNOTS. AT THE SAME TIME...A SMALL
NORTHEAST SWELL OF 1 TO 3 FEET WILL CONTINUE TO AFFECT THE
ATLANTIC WATERS OF SOUTH FLORIDA LATE THIS WEEK INTO THIS
WEEKEND. THESE CONDITIONS WILL ALLOW FOR THE ATLANTIC SEAS TO
REMAIN BELOW 6 FEET TODAY INTO THIS WEEKEND...EXCEPT FOR THE PALM
BEACH WATERS WHERE THE SEAS COULD BUILD TO 6 FEET THIS WEEKEND.
FOR THE GULF SIDE...THE SEAS WILL REMAIN BELOW 6 FEET TODAY INTO
THIS WEEKEND. THE ONLY EXCEPTION IS THE OFFSHORE GULF WATERS WHERE
THE SEAS COULD BUILD TO 6 FEET BY THIS WEEKEND.
FIRE WEATHER...
DEEP TROPICAL MOISTURE WILL REMAIN OVER THE REGION ON FRIDAY WITH
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS. SLIGHTLY DRIER
AIR WILL BEGIN TO MOVE INTO THE REGION ON SATURDAY...WITH LESSER
RAIN CHANCES.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 69 87 67 85 / 40 30 20 20
FORT LAUDERDALE 73 88 69 85 / 30 20 20 20
MIAMI 72 87 69 86 / 30 10 10 20
NAPLES 68 87 66 82 / 20 20 10 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...DENSE FOG ADVISORY UNTIL 9 AM EDT THIS MORNING FOR FAR SOUTH
MIAMI DADE-GLADES-HENDRY-INLAND BROWARD-INLAND COLLIER-
INLAND MIAMI DADE-INLAND PALM BEACH-MAINLAND MONROE.
AM...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 2 PM EDT THIS
AFTERNOON FOR COASTAL WATERS FROM JUPITER INLET TO
DEERFIELD BEACH, FL OUT 20 NM-WATERS FROM JUPITER INLET TO
DEERFIELD BEACH, FL EXTENDING FROM 20 NM TO 60 NM.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...13/SI
AVIATION/RADAR...54/BNB
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1052 AM EDT FRI MAY 3 2013
.UPDATE...
THE AVIATION SECTION HAS BEEN BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 345 AM EDT FRI MAY 3 2013
RAIN CHANCES WILL INCREASE ACROSS THE REGION THROUGH SUNDAY AS AN
UPPER LOW CUTS OFF OVER THE SOUTHERN PLAINS TODAY...THEN STRENGTHENS
AND DRIFTS SOUTHEAST INTO THE LOWER MISSISSIPPI VALLEY BY SUNDAY.
THE UPPER LOW WILL MOVE THROUGH THE CAROLINAS EARLY NEXT WEEK AND
OFF THE MID ATLANTIC COAST BY WEDNESDAY. HIGH PRESSURE WILL
REESTABLISH ACROSS THE OHIO VALLEY WITH WARMER DRIER WEATHER
RETURNING BY MIDWEEK.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 945 AM EDT FRI MAY 3 2013
MINOR TWEAKS MADE TO GRIDS...MAINLY SKY COVER...RAIN CHANCES AND
TEMPERATURES BASED ON SATELLITE...RADAR AND CURRENT CONDITIONS.
A COLD FRONT HAS PUSHED INTO THE NORTHWEST PART OF OUR FORECAST
AREA. HOWEVER ALL MODELS BACK IT WEST INTO ILLINOIS THIS AFTERNOON
AS LOW PRESSURE DEVELOPS OVER THE MID MISSISSIPPI VALLEY. WILL
LOWER TEMPERATURES A DEGREE OR TWO NORTHWEST AND FAR WEST FOR THIS
AFTERNOON. PREVIOUS NEAR TERM DISCUSSION FOLLOWS...
ABUNDANCE OF MID AND HIGH LEVEL CLOUD COVER ACROSS CENTRAL INDIANA
EARLY THIS MORNING. DEEPER MOISTURE NEAR AND WEST OF A QUASI-
STATIONARY FRONTAL BOUNDARY NOW DRAPED ACROSS THE WABASH VALLEY
SOUTHWEST INTO THE MISSISSIPPI RIVER VALLEY. TEMPERATURES WERE IN
THE 60S OVER MUCH OF THE FORECAST AREA AT 07Z...WITH THE EXCEPTION
OF UPPER 40S AND 50S OVER THE FAR NORTHWEST WHICH HAD SLIPPED BEHIND
THE FRONT.
FOCUS FOR TODAY WILL BE ON THE LOCATION OF THE FRONT AND POTENTIAL
FOR CONVECTIVE DEVELOPMENT ACROSS CENTRAL INDIANA. UPPER TROUGH
CONTINUING TO AMPLIFY OVER THE CENTRAL PLAINS THIS MORNING AND AS
ENERGY ALOFT DIVES INTO THE TROUGH TODAY EXPECT IT TO AMPLIFY AND
STRENGTHEN FURTHER...EVENTUALLY CUTTING OFF OVER SOUTHWEST MISSOURI
BY THIS EVENING. AT THE SURFACE...NEARLY STATIONARY BOUNDARY OVER
EXTREME WESTERN FORECAST AREA LIKELY TO MOVE LITTLE THROUGH THE
MORNING BEFORE RETROGRADING BACK TO THE WEST INTO ILLINOIS THIS
AFTERNOON AS THE UPPER LOW DEEPENS. SURFACE LOW PRESSURE CURRENTLY
DEVELOPING OVER NORTHERN MISSISSIPPI EARLY THIS MORNING WILL LIFT
NORTH THEN NORTHWEST ALONG THE BOUNDARY AND SHOULD BE NEAR KSTL BY
THIS EVENING.
REMAIN UNIMPRESSED IN POTENTIAL FOR WIDESPREAD RAINFALL FOR CENTRAL
INDIANA TODAY AS BULK OF THE DEEPEST MOISTURE WILL REMAIN CONFINED
ALONG AND TO THE WEST OF THE LOCATION OF THE BOUNDARY ALL DAY.
PREDOMINANT SOUTHEASTERLY LOW LEVEL FLOW WILL MAINTAIN SOME DEGREE
OF DRY AIR THROUGH THE BOUNDARY LAYER ACROSS MUCH OF THE REGION. LOW
LEVEL CONVERGENCE AND ISENTROPIC LIFT WILL REMAIN FOCUSED TO THE
SOUTHWEST OF THE FORECAST AREA TODAY AS A LOW LEVEL JET LIFTS INTO
THE MID MISSISSIPPI VALLEY. PRESENCE OF A FEW MID LEVEL VORT LOBES
ROTATING UP INTO THE REGION FROM THE SOUTH AND WEAK INSTABILITY LOOK
TO BE THE MAIN CATALYSTS FOR CONVECTIVE DEVELOPMENT TODAY. WILL
CARRY LIKELY POPS IN THE WABASH VALLEY THIS MORNING IN THE VICINITY
OF THE BOUNDARY AND CHANCE POPS ELSEWHERE. LOW/MID LEVEL LAPSE RATES
BRIEFLY INCREASE THIS AFTERNOON AND ALONG WITH THE INSTABILITY
PRESENT...SHOULD BE ENOUGH TO GENERATE SCATTERED LOW TOPPED
CONVECTION.
TEMPS...LOW LEVEL THERMALS ARE SUPPORTIVE OF MOS GUIDANCE TODAY WITH
HIGHS WARMING INTO THE 70S.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
ISSUED AT 345 AM EDT FRI MAY 3 2013
FORECAST CHALLENGES FOCUS ON POTENTIAL FOR RAIN AS THE UPPER LOW
TRACKS FROM THE OZARKS E/SE INTO THE SOUTHEAST STATES BY SUNDAY
NIGHT. OP GFS/GGEM/ECMWF ALL IN EXCELLENT AGREEMENT ON TRACK AND
STRENGTH OF THE UPPER LOW THROUGH THE SHORT TERM WITH THE 00Z NAM
BECOMING A SLOW OUTLIER BY SUNDAY.
AFOREMENTIONED SURFACE LOW WILL GET PULLED AWAY FROM THE REGION
TONIGHT AND SATURDAY BY THE UPPER LOW...WITH THE FRONTAL BOUNDARY
BECOMING STRETCHED AND EVENTUALLY WASHING OUT ACROSS THE LOWER OHIO
VALLEY BY LATE WEEKEND AS THE UPPER LOW MOVES INTO MISSISSIPPI. BEST
CHANCES FOR WIDESPREAD RAINFALL TO IMPACT CENTRAL INDIANA WILL COME
SATURDAY INTO EARLY SUNDAY AS DEEPER MOISTURE PIVOTS BACK NORTH INTO
THE SOUTHERN HALF OF THE FORECAST AREA AND COMBINES WITH A PERIOD OF
ISENTROPIC LIFT AND STRONG CONVERGENCE AT THE NOSE OF THE LOW LEVEL
JET. AN AXIS OF MID LEVEL DEFORMATION ALSO COMES INTO PLAY ON
SATURDAY AND ALIGNS JUST NORTH OF THE LOW LEVEL JET. CONFIDENCE IS
HIGHEST IN HEAVIER RAINFALL IMPACTING THE LOWER WABASH VALLEY
SATURDAY AND SATURDAY NIGHT...GRADUALLY DIMINISHING IN COVERAGE AND
INTENSITY GOING NORTH/EAST ACROSS THE FORECAST AREA FURTHER AWAY
FROM THE DEEPER PLUME OF MOISTURE AND BETTER FORCING. COULD SEE 1.5
TO 2 INCHES OF RAINFALL BY THE END OF THE WEEKEND OVER THE LOWER
WABASH VALLEY...DROPPING TO A HALF INCH OR LESS ALONG AND NORTH/EAST
OF INTERSTATE 74. WILL KEEP THUNDER MENTION OUT THROUGH THE PERIOD
AS POOR LAPSE RATES AND LITTLE TO NO INSTABILITY OVER THE OHIO
VALLEY.
WILL CARRY LIKELY POPS OVER SOUTHERN COUNTIES WITH DECREASING POPS
FURTHER NORTH/EAST. PRESENCE OF SUBSIDENCE AND DRIER AIR
TRANSPORTING INTO THE LOWER GREAT LAKES FROM THE EAST WILL LIKELY
CREATE A SHARP CUTOFF TO THE NORTHERN EXTENT OF THE PRECIP SHIELD.
VERY DISTINCT POSSIBILITY THAT NORTHEAST COUNTIES SEE LITTLE TO NO
RAINFALL TONIGHT THROUGH SUNDAY...ESPECIALLY IF MODEL TRENDS
CONTINUE WITH THE MORE SOUTHERN TRACK TO THE UPPER LOW OVER THE
WEEKEND. PRECIP COVERAGE WILL DIMINISH SUNDAY NIGHT AS DRIER AIR
WRAPS AROUND THE BACK SIDE OF THE UPPER LOW AND INTO THE REGION.
TEMPS...LEANED TOWARDS COOLER MAVMOS GUIDANCE ACROSS MUCH OF THE
AREA FOR HIGHS SATURDAY. DID UNDERCUT TEMPS HOWEVER OVER THE LOWER
WABASH VALLEY WITH EXPECTATION OF RAINFALL AND CLOUDS. UNDERCUT MOS
OVER ENTIRE FORECAST AREA SUNDAY AS SIMILAR BOUNDARY LAYER TEMPS TO
SATURDAY AND PRESENCE OF CLOUDS/RAIN SHOULD KEEP HIGHS A COUPLE
DEGREES COOLER THAN GUIDANCE. WENT A DEGREE OR TWO WARMER ON LOWS
TONIGHT AND SAT NIGHT AND NEAR MOS SUNDAY NIGHT.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
ISSUED AT 345 AM EDT FRI MAY 3 2013
RAIN SHOWERS AND ISOLATED THUNDERSTORMS ACROSS THE SOUTHERN COUNTIES
WILL BE POSSIBLE EARLY IN THE EXTENDED PERIOD AS A BROAD UPPER LEVEL
LOW CONTINUES TO AFFECT CENTRAL INDIANA. THE GFS AND EURO ARE IN
DECENT AGREEMENT WITH THE TRACK OF THE SYSTEM...TAKING THE UPPER LOW
OVER THE SOUTHEAST U.S. AND AN ACCOMPANYING SURFACE LOW OVER THE
TENNESSEE VALLEY. MODELS START TO DIFFER THOUGH ON THURSDAY AS THE
EURO BRINGS ANOTHER UPPER LEVEL LOW OVER THE UPPER MIDWEST...AND THE
GFS SHOWS RIDGING. FOR NOW...WILL STICK WITH LATEST INITIALIZATION
WHICH INCREASES POPS FROM WEST TO EAST STARTING THURSDAY AFTERNOON.
IN REGARD TO TEMPS...WAS ABLE TO CONTINUE WITH ALLBLEND...EXCEPT FOR
MONDAY/S HIGHS WHICH NEEDED ADJUSTING DOWN DUE TO CLOUD COVER OVER
THE SOUTH.
&&
.AVIATION /DISCUSSION FOR THE 03/1500Z TAF ISSUANCE/...
UPDATED TO REMOVE -TSRA FROM KHUF THIS AFTERNOON AND REPLACE WITH
VCTS...AND ALSO PUSHED BACK VCTS BY A BIT AT THE SITES BASED ON RAP
AND HRRR OUTPUT. PREVIOUS DISCUSSION FOLLOWS...
ISSUED AT 1052 AM EDT FRI MAY 3 2013
SCATTERED TO NUMEROUS SHOWERS AND ISOLATED THUNDERSTORMS /MAINLY
THIS AFTERNOON/ WILL IMPACT TAF SITES FOR DURATION OF TAF PERIOD AS
A STATIONARY BOUNDARY REMAINS DRAPED OVER WESTERN PORTIONS OF
CENTRAL INDIANA. NONETHELESS...ANTICIPATE VFR CONDITIONS TO BE THE
PREVAILING FLIGHT CATEGORY WITH ONLY BRIEF DETERIORATION TO MVFR AT
TIMES WITH HEAVIER SHOWERS/STORMS. THUNDERSTORMS SHOULD TAPER OFF
WITH LOSS OF DAYTIME HEATING...SO ONLY CARRIED MENTION OF RAIN AFTER
SAT 00Z. WINDS WILL BE SOUTHEASTERLY AT 8 TO 14 KTS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...RYAN/JH
SHORT TERM...RYAN
LONG TERM....TDUD
AVIATION...TDUD/CP
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
110 AM EDT FRI MAY 3 2013
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
ISSUED AT 332 PM EDT THU MAY 2 2013
AN UPPER TROUGH OF LOW PRESSURE OVER THE GREAT PLAINS WILL DEEPEN
INTO A CLOSED UPPER LOW AND TRACK INTO THE MID MISSISSIPPI VALLEY BY
SATURDAY AND ACROSS TENNESSEE AND THE DEEP SOUTH SUNDAY AND MONDAY.
IT WILL MOVE OFF THE MID ATLANTIC COAST BY THE MIDDLE OF NEXT WEEK
AND HIGH PRESSURE WILL REBUILD ACROSS OUR REGION. THIS SYSTEM WILL
BRING INCREASING CHANCE OF SHOWERS NEXT FEW DAYS...ESPECIALLY WEST
AND SOUTH.
&&
.NEAR TERM /REST OF TONIGHT/...
ISSUED AT 1007 PM EDT THU MAY 2 2013
MAIN CHANGE OVER THE LAST SEVERAL UPDATES HAS BEEN TO TAILOR BACK
POPS...ESPECIALLY ACROSS THE WESTERN COUNTIES WHERE ONLY A FEW
ISOLATED THUNDERSTORMS ARE MOVING THROUGH. BELIEVE HRRR HAS THE
BEST HANDLE ON POPS TONIGHT INTO FRIDAY AND LEANED TOWARD THIS
GUIDANCE. AT THIS RATE BULK OF PRECIP WILL NOT REACH CENTRAL
INDIANA UNTIL AT LEAST LATE MORNING FRIDAY...IF NOT LATER.
PREVIOUS DISC FOLLOWS...
RADAR HAS SHOWN AND INCREASE TO SHOWERS AND THUNDERSTORMS ACROSS
ILLINOIS THIS AFTERNOON AS CAPES HAVE BEEN RUNNING FROM 1500 TO 2000
J/KG. SOME OF THESE MAY SPREAD INTO FAR WESTERN SECTIONS THIS
EVENING AS AIRMASS IS SOMEWHAT UNSTABLE THERE. FATHER EAST WILL
DOWNPLAY RAIN CHANCES SOME AS MODELS HAVE TENDED TO BE TOO QUICK IN
SPREADING RAIN EAST TOO MUCH. LAPS SHOWS CAPES FROM INDY AND
EASTWARD NO MORE THAN 200 J/KG AND SOME OF THE PREVIOUS MODELS
INDICATED THAT IT COULD BE RAINING MUCH OF TODAY HERE AS WELL.
FOR NOW WILL MENTION HIGH CHANCE POPS FAR WEST...AND SLIGHT CHANCES
FROM INDY AND WESTWARD LATER TONIGHT. WHILE MOST EASTERN AREAS
SHOULD REMAIN DRY. OVERNIGHT LOWS WILL BE IN THE UPPER 50S TO LOWER
60S WHICH IS CLOSE TO PERSISTENCE.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
ISSUED AT 332 PM EDT THU MAY 2 2013
FORECAST FOCUS CONTINUES TO BE ON RAIN CHANCES FRIDAY...AND OVER THE
WEEKEND. MODELS DEEPEN THE UPPER TROUGH OVER THE PLAINS INTO A
CLOSED UPPER LOW AND TRACK IT TOWARDS SOUTHERN TENNESSEE AND
NORTHERN MISSISSIPPI. MODELS HAVE TRENDED A LITTLE FARTHER SOUTH
WITH THE TRACK...ESPECIALLY THE GFS. AS A RESULT...IT LOOKS LIKE THE
HEAVIEST RAINS WILL BE ACROSS OUR SOUTH AND ANY RAIN THAT MAKES IT
INTO OUR NORTHEAST WILL BE LIGHT.
ON FRIDAY WILL MENTION LIKELY POPS...FAR WEST...CHANCE POPS
ELSEWHERE...BUT DRY OR SLIGHT CHANCE POPS FAR EAST. WENT CLOSER TO
SLIGHTLY WARMER MET TEMPERATURES EAST AS THERE WILL STILL BE SOME
SUN.
THERE WILL BE BETTER CHANCES OF SHOWERS OVER THE WEEKEND CENTRAL AND
SOUTH AS THE UPPER LOW MOVES A LITTLE CLOSER. WENT WITH LIKELY POPS
FROM INDY AND SOUTH AND WEST AND CHANCE POPS ELSEWHERE. WENT CLOSE
TO A MOS BLEND ON TEMPERATURES. HIGH TEMPERATURES COULD BE A LITTLE
WARMER ACROSS OUR NORTHEAST...BECAUSE PRECIPITATION THERE WILL BE
SCATTERED AT BEST.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
ISSUED AT 335 AM EDT THU MAY 2 2013
ENSEMBLES ARE SHOWING BETTER AGREEMENT ON A LARGE UPPER LOW SLOWLY
PASSING ACROSS THE TENNESSEE VALLEY FROM WEST TO EAST DURING THE
LONG TERM. SURFACE LOWS ARE STILL SHOWING QUITE A BIT OF SCATTER
SUNDAY NIGHT BUT SEEM TO COME INTO BETTER AGREEMENT BY MONDAY NIGHT
ON A LOCATION SOUTHEAST OF INDIANA AND MOVING FURTHER EAST AND AWAY
FROM THE AREA BY MIDDAY TUESDAY. THIS SHOULD ALLOW FOR POPS TO DROP
TO SLIGHT CHANCE OR LESS FROM MONDAY NIGHT ON. DURING THE DAYS SOME
INSTABILITY MAKES ITS WAY INTO THE SOUTHERN COUNTIES SO INCLUDED A
SLIGHT CHANCE OF THUNDER AT THAT TIME. SUNDAY NIGHT AND MONDAY THERE
IS SUFFICIENT FORCING FROM THE PROXIMITY OF THE UPPER AND SURFACE
LOWS TO JUSTIFY HIGH CHANCE POPS ACROSS THE SOUTH WITH LOWER CHANCES
AS YOU HEAD NORTH. FOR TEMPERATURES GENERALLY WENT WITH
ALLBLEND...WITH A SLIGHT ADJUSTMENT DOWN FOR HIGHS ON MONDAY WITH
THE UPPER LOW TO THE SOUTH AND MOSTLY CLOUDY SKIES.
&&
.AVIATION /DISCUSSION FOR THE 03/06Z TAFS/...
ISSUED AT 107 AM EDT FRI MAY 3 2013
MAINLY VFR THROUGH THE PERIOD OUTSIDE OF SHOWERS/THUNDERSTORMS.
BOUNDARY IS NEARLY STATIONARY JUST TO OUR NORTHWEST/WEST WITH WEAK
LOW PRESSURE ALONG IT. THIS BOUNDARY SERVED AS FOCUS FOR SCATTERED
CONVECTIVE DEVELOPMENT TO OUR WEST YESTERDAY AFTERNOON WITH SLOW AND
ERRATIC STORM MOTIONS IN AN UNSTABLE BUT VERY WEAKLY SHEARED
ENVIRONMENT. WITH LOSS OF HEATING...INTENSITY OF STORMS HAS BEEN
STEADILY DIMINISHING...ONLY SHOWERS LIKELY TO REMAIN BY ISSUANCE
TIME NEAR HUF/LAF...SO WILL CARRY VCSH THERE.
OVERNIGHT IN GENERAL EXPECTING JUST AN INCREASE IN CLOUD COVER. WINDS
WILL BECOME LESS THAN 10KT AT IND...LIGHT AND VARIABLE AT THE
OUTLYING SITES.
WILL CONTINUE WITH VCTS/CB MENTION TOMORROW AS THIS BOUNDARY SHOULD
MAKE SOME VERY SLOW EASTWARD PROGRESS. WINDS WILL BE 8-12KT TOMORROW
OUT OF THE SOUTHEAST.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...JH
NEAR TERM...JH/SMF
SHORT TERM...JH
LONG TERM....CP
AVIATION...NIELD
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1232 AM CDT FRI MAY 3 2013
.SYNOPSIS...
ISSUED AT 351 PM CDT THU MAY 2 2013
12Z UA ANALYSIS HAS 850MB LOWS ALONG THE KS/MO BORDER AND ANOTHER IN
WESTERN OKLAHOMA. A VERY STRONG 850MB THERMAL GRADIENT RAN FROM
MN/WI DOWN TO OKLAHOMA AND WEST TEXAS. SATELLITE TRENDS THROUGH MID
AFTERNOON SHOW THE LOW CLOUDS MAKING SLOW PROGRESS EASTWARD. RADAR
SHOWS THE MAIN RAIN SHIELD OVER CENTRAL AND NORTHEAST IOWA WITH
SCATTERED CONVECTION ACROSS ILLINOIS AND EASTERN IOWA.
18Z SFC ANALYSIS HAS WEAK LOWS FROM LOWER MICHIGAN BACK INTO
NORTHEAST ARKANSAS WITH THE FRONT CONNECTING ALL THE LOWS. DEW
POINTS ACROSS THE PLAINS AND PARTS OF THE UPPER MIDWEST WERE IN THE
20S AND 30S WITH 40S AND HIGHER FROM THE GREAT LAKES INTO THE LOWER
MISSISSIPPI VALLEY.
08
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 351 PM CDT THU MAY 2 2013
VERY DIFFICULT FCST. REFER TO THE CLIMATE SECTION FOR INFORMATION
REGARDING MAY SNOW FOR SOME LOCATIONS.
THE TRENDS WITH THE MODELS IS COLDER. THE MAIN PRECIPITATION SHIELD
IS ALONG AND BEHIND THE 850MB FRONT. THE RAP AND WRF TRENDS HAVE
THIS FRONT SLOWLY MOVING EAST TONIGHT. THUS RAIN WILL SLOWLY BREAK
OUT AND INCREASE IN AREAL COVERAGE DURING THE EVENING HOURS.
WBZ TEMPERATURES AND ACTUAL OBSERVATIONS SHOW TREMENDOUS EVAPORATIVE
COOLING WILL OCCUR ACROSS THE FAR NORTHWEST AND WESTERN PARTS OF THE
CWFA TONIGHT. FCST SOUNDINGS INDICATE RAIN BECOMING MIXED WITH AND
THEN CHANGING OVER TO SLEET/SNOW MIXTURE. THE OVERALL FORCING AND
WAA ALOFT IS SIGNIFICANT SO THERE WILL LIKELY BE ACCUMULATIONS ON
GRASSY SURFACES EVEN THOUGH THE GROUND IS QUITE WARM.
THEREFORE...WINTER WEATHER ADVISORIES HAVE BEEN RAISED FOR THE
WESTERN TWO ROWS OF COUNTIES FROM HWY 92 ON NORTH.
BUCHANAN...BENTON...IOWA...AND KEOKUK COUNTIES HAVE THE BEST CHANCE
AT SEEING POTENTIALLY HISTORIC SNOWFALL FOR MAY. THE HIGHEST
SNOWFALL AMOUNTS WILL BE IN THE WESTERN PARTS OF THESE COUNTIES.
SNOW/SLEET AMOUNTS THERE COULD RANGE FROM 1 TO 4 INCHES.
FURTHER EAST...ACROSS DELAWARE...LINN...JOHNSON...AND WASHINGTON
COUNTIES THE CHANGE OVER TO SLEET WILL OCCUR DURING THE EVENING. IN
THIS AREA MORE SLEET THAN SNOW IS EXPECTED WITH THE HIGHER AMOUNTS
IN THE WESTERN PARTS OF THESE COUNTIES. SNOW/SLEET AMOUNTS IN THIS
AREA COULD RANGE FROM A DUSTING TO 1 INCH.
THE OVERALL LARGE PICTURE SUGGESTS THE POTENTIAL FOR SOME SLEET AS
FAR EAST AS A DUBUQUE IOWA TO KAHOKA MISSOURI LINE DUE TO
EVAPORATIVE COOLING. IN THIS AREA ONLY TRACE AMOUNTS ARE EXPECTED.
ROUGHLY ALONG AND EAST OF THE MISSISSIPPI...SHOWERS WILL GIVE WAY TO
A WIDESPREAD RAIN AS THE WAA INCREASES.
FRIDAY...THE SNOW/SLEET MIXTURE IN THE FAR NORTHWEST/WEST PARTS OF
THE CWFA WILL CHANGE BACK TO ALL RAIN AS WARM AIR ALOFT MOVES INTO
THE AREA. ACROSS THE EASTERN CWFA THE OVERALL FORCING INCREASES AS A
SFC WAVE MOVES UP FROM THE SOUTH. ALTHOUGH NOT INCLUDED IN THE
FORECAST...THE LIFT TOOL SUGGESTS POSSIBLY SOME ISOLATED THUNDER
OVER THE FAR SOUTHEAST AND EASTERN PARTS OF THE CWFA AS STRONG
CONVERGENCE MOVES ALONG A THETA E GRADIENT.
08
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 351 PM CDT THU MAY 2 2013
RECORD COLD RAIN...SLEET...SNOW EVENT MAIN CHALLENGE THIS FORECAST.
OVERVIEW...INITIALIZATION AND VERIFICATION GOOD WITH MAIN ISSUE THE
PHASING OF LATENT HEAT RELEASE AND STRONG EVAPORATIVE COOLING TO
DETERMINE WHAT FAR WESTERN SECTIONS RECEIVE SLEET AND SNOW TONIGHT.
VERIFICATION AT 18Z SUPPORTS FORCING AND THERMAL FIELDS OF 12Z NAM-
WRF AND HI-RES ECMWF. THIS SUPPORTS SOME ACCUMULATIONS OF SNOW AND
QUITE A BIT OF SLEET FAR WEST SECTIONS. HEAVY RAIN AND FORCING
TOOLS SUGGEST MOST OF AREA TO PICK UP 1.5 TO LOCALLY AROUND 2.5
INCHES OF TOTAL PRECIPITATION NEXT 2-3 DAYS WITH MOST FALLING
FRIDAY AND FRIDAY NIGHT. STRATIFORM NATURE AND AMOUNTS OVER LONGER
TIME PERIOD SUPPORT MINOR RIVER ISSUES ON SOME RIVERS.
FRIDAY NIGHT...KEPT CATEGORICAL POPS WITH DEEPLY OCCLUDING AND
MATURING RAIN OF UPPER LOW TO DEPOSIT MOSTLY 1/3 TO 2/3 OF AN INCH
WITH HEAVIEST OVER SW 1/2 TO 2/3 OF AREAL TEMPERATURES WITH MILDER
AIR FROM EAST TO ALLOW TEMPERATURES TO BE NEARLY STEADY WITH LOWER
50S EAST TO MID/UPPER 40S FAR WEST.
SATURDAY AND SUNDAY...MINOR CHANGES MADE. CONSIDERABLE CLOUDS WITH
PERIODS OF LIGHT RAIN SATURDAY AND SATURDAY AND VERY LIGHT RAIN
SUNDAY. A QUARTER INCH OR LESS ON SATURDAY MOST LOCATIONS WITH
SPOTTY VERY LIGHT AMOUNTS SUNDAY. TEMPERATURES COOL WITH MOSTLY
LOWER TO MIDDLE 60S AND MINS SATURDAY NIGHT IN THE MID/UPPER 40S.
NICHOLS
DAYS 4 THROUGH 7...SUNDAY NIGHT THROUGH THURSDAY...
SUNDAY NIGHT THROUGH MONDAY NIGHT THE DEEP UPPER LOW GRADUALLY
SHIFTS SOUTHEAST...AND A SURFACE RIDGE BUILDS INTO THE AREA TO CAUSE
OUR SCATTERED SHOWERS TO SLOWLY DIMINISH IN COVERAGE...SO THAT BY
MONDAY NIGHT WE SHOULD BE COMPLETELY DRY. TEMPERATURES TO REMAIN
BELOW NORMAL WITH LOWS IN THE 40S. MONDAY HIGHS ARE CURRENTLY
FORECAST TO RISE INTO THE UPPER 60S...BUT IT TOO MUCH CLOUD COVER IS
LINGERING WILL HAVE TO LOWER THESE VALUES.
TUESDAY AND TUESDAY NIGHT THE SURFACE RIDGE SLOWLY SHIFTS EAST
ACROSS THE AREA...PRODUCING MAINLY DRY CONDITIONS AND GRADUALLY
WARMING TEMPERATURES. AM CARRYING SOME DAYTIME SLIGHT CHANCE POPS
IN THE SOUTHWEST CLOSEST TO THE LINGERING PLUME OF MOISTURE WHERE WE
MIGHT GET SOME DIURNALLY DRIVEN SHOWERS. HIGHS TUESDAY SHOULD GET
APPROACH 70 WITH 850MB TEMPERATURES GRADUALLY WARMING AS WELL.
TUESDAY NIGHT MINS TO MODERATE TO AROUND 50.
WEDNESDAY AND THURSDAY QUITE A BIT OF UNCERTAINTY RE-ENTERS THE
FORECAST. WE WILL BE IN A SPLIT FLOW WITH A NORTHERN STREAM MAINLY
AFFECTING SOUTHERN CANADA AND THE FAR NORTHERN CONUS...AND THE
SOUTHERN STREAM MAINLY AFFECTING THE SOUTHERN CONUS. MODELS ARE
DIVERGING IN THE HANDLING OF A SHORTWAVE THAT MOVES THROUGH THE
NORTHERN STREAM...AND HOW MUCH IT PHASES WITH A CUT OFF LOW IN THE
SOUTHERN STREAM OVER THE SOUTHWEST CONUS. THE ECMWF IS FASTER AND
IS PHASING IT MORE...AND DRAGGING MORE MOISTURE UP INTO THE
AREA...PRODUCING PRECIPITATION BEGINNING WEDNESDAY NIGHT. THE GFS
IS SLOWER AND PHASES IT LESS...AND DOES NOT BRING PRECIPITATION INTO
THE AREA UNTIL THURSDAY NIGHT. THUS...WHILE I AM CARRYING SOME
SLIGHT CHANCE POPS BEGINNING ON WEDNESDAY...THESE ARE MORE FOR A
CONTINUATION OF THE DIURNAL SHOWERS DURING THE DAY WITH THE
GRADUALLY INCREASING MOISTURE. AM BRINGING IN SOME LOW CHANCE POPS
FOR THURSDAY IN ASSOCIATION WITH THE NEW SHORTWAVE. TEMPERATURES TO
CONTINUE TO WARM THROUGH AT LEAST WEDNESDAY NIGHT...WITH HIGHS ON
WEDNESDAY INTO THE LOWER 70S. THURSDAY STILL FAIRLY WARM IN THE
FORECAST BUT THIS MAY NEED TO BE LOWERED IF PRECIPITATION MOVES INTO
THE AREA SOONER.
LE
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1230 AM CDT FRI MAY 3 2013
AN AREA OF RAIN SHOWERS CONTINUES TO DEVELOP AND SPREAD NORTH
AFFECTING EASTERN IOWA AND WESTERN ILLINOIS. THE RAIN CONTINUES TO
INCREASE IN COVERAGE AND PERIODS OF RAIN ARE EXPECTED THROUGHOUT
FRIDAY AS THE UPPER LEVEL SYSTEM MOVES INTO THE REGION. JUST A BIT
FURTHER WEST A MIX OF WINTRY PRECIPITATION HAS BEEN REPORTED WITH
SOME SLEET AND SNOW...AND LIGHT FREEZING RAIN AS FAR EAST AS KCID. THE
MAIN BAND OF SNOW CONTINUES TO EDGE EAST FROM CENTRAL IOWA.
HOWEVER THE WINTRY PRECIPITATION IS EXPECTED TO REMAIN WEST OF
KDBQ. A RETURN TO LIQUID PRECIPITATION IS THEN FORECAST AS WARMER
TEMPERATURES WORK BACK IN FROM EAST TO WEST BY MID FRIDAY MORNING.
MAINLY IFR CONDITIONS ARE EXPECTED WITH POTENTIAL FOR LIFR
CONDITIONS AT TIMES THROUGH FRIDAY.
STOFLET
&&
.CLIMATE...
ISSUED AT 351 PM CDT THU MAY 2 2013
MAY SNOWFALL IN IOWA IS RARE.
A VERY QUICK LOOK BACK AT PAST WEATHER RECORDS SUGGESTS THAT THE
LAST TIME A FAIRLY WIDESPREAD SNOW OCCURRED IN MAY ACROSS IOWA WAS
IN 1966. BELOW IS WHEN MEASURABLE SNOW AND/OR SLEET FELL IN MAY
FOR SELECTED SITES.
CEDAR RAPIDS #1 (MARION)...
0.2 INCHES 05/01/1997 FELL AS SLEET
0.3 INCHES 05/11/1966
DUBUQUE IOWA...
3.1 INCHES 05/01/1966
1.0 INCHES 05/07-08/1960
IOWA CITY WWTP...
0.2 INCHES 05/05/1944
MOLINE ILLINOIS...
0.3 INCHES ON 05/03/1935
TRACE ON 05/06/1989
TRACE ON 05/22/1917*
* LATEST RECORDED SNOWFALL ON RECORD
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...WINTER WEATHER ADVISORY UNTIL 10 AM CDT THIS MORNING FOR BENTON-
BUCHANAN-IOWA-KEOKUK.
WINTER WEATHER ADVISORY UNTIL 8 AM CDT THIS MORNING FOR DELAWARE-
JOHNSON-LINN-WASHINGTON.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...08
SHORT TERM...08
LONG TERM...NICHOLS/LE
AVIATION...STOFLET
CLIMATE...08
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
107 PM EDT FRI MAY 03 2013
...Updated Aviation Discussion...
.Forecast Update...
Issued at 1155 AM EDT Fri May 3 2013
12Z Models continue to advertise a sharp cutoff in precipitation on
the northeast side of the large band of rain expected to setup as
the upper low now over the Central Plains starts travelling
southeast. Have begun to trim pops over the northeast forecast area,
including a tweak downward for the Louisville area for tomorrow.
Pops over the south still look pretty solid. Given the slow-moving
nature of the line across our forecast area combined with heavy
rains that fell earlier, as well as ensemble guidance indicating
rivers across the south likely will go to flood stage, have decided
to go ahead and issue a flood watch across south central Kentucky.
Issued at 905 AM EDT Fri May 3 2013
Atmosphere much less capped than yesterday, as seen from the earlier
showers we had over the northwest forecast area this morning. The
limiting factor will be dry air over the east. The ARW and NMM
versions of the WRF as well as the latest RAP all have a band of
showers and storms forming at the edge of this dry air, which would
be along the I-65 corridor, later this afternoon.
As for the more steady rains coming in, models are fine tuning where
the band will set up and move (slowly). There looks to be a sharp
cutoff over the northeast, and the heaviest rains look to fall where
we`ve had plenty of rain already in the last month. Given that
earlier rain we may have to go with a flood watch across south
central Kentucky and will decide after seeing the 12Z model data.
Issued at 520 AM EDT Fri May 3 2013
Did a quick update to increase PoPs a bit across our western
sections due to the batch of showers moving northward through
southwestern Indiana. Also have some isolated showers that have
popped up on the east side of I-65 as well, so have also expanded
PoPs a little further east.
&&
.Short Term (Now through Saturday)...
Issued at 324 AM EDT Fri May 3 2013
In the near term, partly to mostly cloudy skies are expected to
persist across the region. Early morning radar imagery shows a few
isolated showers moving northward across our western CWA...mainly
west of I-65. We expect the isolated showers to continue through
the remainder of the early morning hours west of I-65. Temperatures
remained quite mild with readings in the upper 50s in the southeast
sections with lower 60s elsewhere. Temperatures will probably drop
another 1-2 degrees before hitting their overnight minimums.
Stalled out boundary out to our west is forecast to make very slow
progress eastward today, mainly staying out near the Mississippi
river. Southeasterly winds will pick up today as the pressure
gradient increases across the region. Plenty of clouds are expected
across the western half of the region today with a little less in
the east. Moisture plume out ahead of the slow moving boundary will
help generate waves of showers mainly to our west. Previous
forecast has a very good handle here with isolated-scattered showers
and possibly a thunderstorm or two mainly west of I-65 during the
afternoon hours. Current data still supports this, so only some
minor tweaks to the grids were made here. Temperatures this
afternoon will warm into the mid-upper 70s with the highest temps
out across the east where the veil of clouds is expected to be a bit
thinner.
By tonight, the frontal boundary out to the west is forecast to
start making some eastward progress as the deep closed low out over
the Plains gets more organized and deepens. Rain showers will be
most concentrated out across our western sections and then
overspread much of central Kentucky by sunrise Saturday. Light
southeasterly flow and plenty of cloud cover will result in mild
overnight minimum temperatures with readings cooling into the
mid-upper 50s.
Saturday, by all accounts, will be cloudy and wet across the region
as the surface frontal boundary occludes across the region. Band of
showers over western Kentucky is expected to gradually spread
eastward across the central part of the state throughout the day.
The rain will generally be light to moderate, but could be a little
heavy at times especially across southern Kentucky. Instability is
virtually not existent so not expecting much in the way of thunder.
However, with the good moisture fetch off the SW Atlantic, training
of rain showers looks increasingly likely which could lay down
around an inch of rain in some spots by Saturday evening. The
clouds and precipitation will keep temperatures down on Saturday
with highs only warming into the upper 50s.
.Long Term (Saturday Night through Thursday)...
Issued at 300 AM EDT Fri May 3 2013
The well advertised cutoff upper level low will be over Arkansas at
the beginning of the long term. This low will slowly swing across
the southeastern CONUS and into northern GA by Monday morning. It
will then work its way up the Atlantic coast through mid week.
The fetch of moisture off the Atlantic will continue to wrap around
the northern side of the low as it slides south of the forecast area
through the end of the weekend. Moderate rain will continue across
much of the area Saturday night through Sunday. Through this time
period an rainfall totals look to range from half an inch across
portions of the Bluegrass and southern Indiana to an inch south of
the Bluegrass Parkway. Some minor flooding will be possible on area
rivers with this rain. For more information refer to the hydrology
discussion below.
Rain chances will continue off and on through the first half of the
work week. However, these will become more diurnal in nature as the
low moves up the coast. A few thunderstorms will be possible with
this activity, especially if the sun is able to break out at all.
Thursday finally looks to be dry under ridging aloft.
Temperatures will remain on the cool side Sunday with highs only in
the lower 60s. However we will see a warming trend through the week.
By Thursday high temperatures should be back into the upper 70s with
lows in the mid to upper 50s.
&&
.Aviation (18Z TAF Issuance)...
Issued at 105 PM EDT Fri May 3 2013
Stalled frontal boundary remains out to our west, but we should
start to see some movement this period, as a developing upper low
over the Central Plains drifts southeast into Arkansas tonight. We
may see an isolated storm this afternoon, as moisture starts to
increase ahead of this system. However coverage looks isolated
enough to leave out of each of the terminals for now. High-res
models continue to show some storms along a NW/SE-oriented band near
KSDF later this afternoon, but would prefer to wait and see
development before adding to the TAFs. More solid rain chances will
start, first at KBWG late tonight then at KSDF Saturday morning.
Have enough confidence in at least MVFR conditions as we get deeper
into the moisture, so put these in 6-7 hours after the showery
activity starts.
&&
.Hydrology...
Issued at 300 PM EDT Thu May 2 2013
An upper air disturbance is forecast to move across the region this
weekend. This will result in moderate to heavy rainfall over
southern Kentucky. Between Friday afternoon and Sunday morning
between one and inch inches could fall with the heaviest amounts
near Bowling Green.
This area recently had minor flooding and this new rain could result
in a new round of flooding in the middle of the Green River Basin.
Residents with livestock or equipment in flood prone areas should
watch water levels closely this weekend.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...FLOOD WATCH FROM SATURDAY MORNING THROUGH SUNDAY EVENING FOR
KYZ026-027-061>066-070>078-081-082.
$$
Updates..........RJS
Short Term.......MJ
Long Term........EER
Aviation.........RJS
Hydrology........CMC
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1158 AM EDT FRI MAY 03 2013
.Forecast Update...
Issued at 1155 AM EDT Fri May 3 2013
12Z Models continue to advertise a sharp cutoff in precipitation on
the northeast side of the large band of rain expected to setup as
the upper low now over the Central Plains starts travelling
southeast. Have begun to trim pops over the northeast forecast area,
including a tweak downward for the Louisville area for tomorrow.
Pops over the south still look pretty solid. Given the slow-moving
nature of the line across our forecast area combined with heavy
rains that fell earlier, as well as ensemble guidance indicating
rivers across the south likely will go to flood stage, have decided
to go ahead and issue a flood watch across south central Kentucky.
Issued at 905 AM EDT Fri May 3 2013
Atmosphere much less capped than yesterday, as seen from the earlier
showers we had over the northwest forecast area this morning. The
limiting factor will be dry air over the east. The ARW and NMM
versions of the WRF as well as the latest RAP all have a band of
showers and storms forming at the edge of this dry air, which would
be along the I-65 corridor, later this afternoon.
As for the more steady rains coming in, models are fine tuning where
the band will set up and move (slowly). There looks to be a sharp
cutoff over the northeast, and the heaviest rains look to fall where
we`ve had plenty of rain already in the last month. Given that
earlier rain we may have to go with a flood watch across south
central Kentucky and will decide after seeing the 12Z model data.
Issued at 520 AM EDT Fri May 3 2013
Did a quick update to increase PoPs a bit across our western
sections due to the batch of showers moving northward through
southwestern Indiana. Also have some isolated showers that have
popped up on the east side of I-65 as well, so have also expanded
PoPs a little further east.
&&
.Short Term (Now through Saturday)...
Issued at 324 AM EDT Fri May 3 2013
In the near term, partly to mostly cloudy skies are expected to
persist across the region. Early morning radar imagery shows a few
isolated showers moving northward across our western CWA...mainly
west of I-65. We expect the isolated showers to continue through
the remainder of the early morning hours west of I-65. Temperatures
remained quite mild with readings in the upper 50s in the southeast
sections with lower 60s elsewhere. Temperatures will probably drop
another 1-2 degrees before hitting their overnight minimums.
Stalled out boundary out to our west is forecast to make very slow
progress eastward today, mainly staying out near the Mississippi
river. Southeasterly winds will pick up today as the pressure
gradient increases across the region. Plenty of clouds are expected
across the western half of the region today with a little less in
the east. Moisture plume out ahead of the slow moving boundary will
help generate waves of showers mainly to our west. Previous
forecast has a very good handle here with isolated-scattered showers
and possibly a thunderstorm or two mainly west of I-65 during the
afternoon hours. Current data still supports this, so only some
minor tweaks to the grids were made here. Temperatures this
afternoon will warm into the mid-upper 70s with the highest temps
out across the east where the veil of clouds is expected to be a bit
thinner.
By tonight, the frontal boundary out to the west is forecast to
start making some eastward progress as the deep closed low out over
the Plains gets more organized and deepens. Rain showers will be
most concentrated out across our western sections and then
overspread much of central Kentucky by sunrise Saturday. Light
southeasterly flow and plenty of cloud cover will result in mild
overnight minimum temperatures with readings cooling into the
mid-upper 50s.
Saturday, by all accounts, will be cloudy and wet across the region
as the surface frontal boundary occludes across the region. Band of
showers over western Kentucky is expected to gradually spread
eastward across the central part of the state throughout the day.
The rain will generally be light to moderate, but could be a little
heavy at times especially across southern Kentucky. Instability is
virtually not existent so not expecting much in the way of thunder.
However, with the good moisture fetch off the SW Atlantic, training
of rain showers looks increasingly likely which could lay down
around an inch of rain in some spots by Saturday evening. The
clouds and precipitation will keep temperatures down on Saturday
with highs only warming into the upper 50s.
.Long Term (Saturday Night through Thursday)...
Issued at 300 AM EDT Fri May 3 2013
The well advertised cutoff upper level low will be over Arkansas at
the beginning of the long term. This low will slowly swing across
the southeastern CONUS and into northern GA by Monday morning. It
will then work its way up the Atlantic coast through mid week.
The fetch of moisture off the Atlantic will continue to wrap around
the northern side of the low as it slides south of the forecast area
through the end of the weekend. Moderate rain will continue across
much of the area Saturday night through Sunday. Through this time
period an rainfall totals look to range from half an inch across
portions of the Bluegrass and southern Indiana to an inch south of
the Bluegrass Parkway. Some minor flooding will be possible on area
rivers with this rain. For more information refer to the hydrology
discussion below.
Rain chances will continue off and on through the first half of the
work week. However, these will become more diurnal in nature as the
low moves up the coast. A few thunderstorms will be possible with
this activity, especially if the sun is able to break out at all.
Thursday finally looks to be dry under ridging aloft.
Temperatures will remain on the cool side Sunday with highs only in
the lower 60s. However we will see a warming trend through the week.
By Thursday high temperatures should be back into the upper 70s with
lows in the mid to upper 50s.
&&
.Aviation (12Z TAF Issuance)...
Issued at 643 AM EDT Fri May 3 2013
Nearly stationary frontal boundary out near the MS river will remain
out to our west throughout the day. VFR conditions are expected at
all the terminals today with southeast winds picking up during the
mid-morning hours. The pressure gradient is expected to increase as
a deep upper low continues to strengthen over the Plains. Southeast
winds of 10-15 mph with gusts up to 20 mph will be possible later
this afternoon.
A few waves of low pressure will move up along the frontal boundary
producing a few rounds of showers later today. The vast majority of
this activity will stay west of KBWG and KSDF this afternoon.
Coverage still looks rather sparse enough to preclude mention in
this TAF forecast at the moment.
&&
.Hydrology...
Issued at 300 PM EDT Thu May 2 2013
An upper air disturbance is forecast to move across the region this
weekend. This will result in moderate to heavy rainfall over
southern Kentucky. Between Friday afternoon and Sunday morning
between one and inch inches could fall with the heaviest amounts
near Bowling Green.
This area recently had minor flooding and this new rain could result
in a new round of flooding in the middle of the Green River Basin.
Residents with livestock or equipment in flood prone areas should
watch water levels closely this weekend.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...FLOOD WATCH FROM SATURDAY MORNING THROUGH SUNDAY EVENING FOR
KYZ026-027-061>066-070>078-081-082.
$$
Updates..........MJ/RJS
Short Term.......MJ
Long Term........EER
Aviation.........MJ
Hydrology........CMC
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
908 AM EDT FRI MAY 03 2013
.Forecast Update...
Issued at 905 AM EDT Fri May 3 2013
Atmosphere much less capped than yesterday, as seen from the earlier
showers we had over the northwest forecast area this morning. The
limiting factor will be dry air over the east. The ARW and NMM
versions of the WRF as well as the latest RAP all have a band of
showers and storms forming at the edge of this dry air, which would
be along the I-65 corridor, later this afternoon.
As for the more steady rains coming in, models are fine tuning where
the band will set up and move (slowly). There looks to be a sharp
cutoff over the northeast, and the heaviest rains look to fall where
we`ve had plenty of rain already in the last month. Given that
earlier rain we may have to go with a flood watch across south
central Kentucky and will decide after seeing the 12Z model data.
Issued at 520 AM EDT Fri May 3 2013
Did a quick update to increase PoPs a bit across our western
sections due to the batch of showers moving northward through
southwestern Indiana. Also have some isolated showers that have
popped up on the east side of I-65 as well, so have also expanded
PoPs a little further east.
&&
.Short Term (Now through Saturday)...
Issued at 324 AM EDT Fri May 3 2013
In the near term, partly to mostly cloudy skies are expected to
persist across the region. Early morning radar imagery shows a few
isolated showers moving northward across our western CWA...mainly
west of I-65. We expect the isolated showers to continue through
the remainder of the early morning hours west of I-65. Temperatures
remained quite mild with readings in the upper 50s in the southeast
sections with lower 60s elsewhere. Temperatures will probably drop
another 1-2 degrees before hitting their overnight minimums.
Stalled out boundary out to our west is forecast to make very slow
progress eastward today, mainly staying out near the Mississippi
river. Southeasterly winds will pick up today as the pressure
gradient increases across the region. Plenty of clouds are expected
across the western half of the region today with a little less in
the east. Moisture plume out ahead of the slow moving boundary will
help generate waves of showers mainly to our west. Previous
forecast has a very good handle here with isolated-scattered showers
and possibly a thunderstorm or two mainly west of I-65 during the
afternoon hours. Current data still supports this, so only some
minor tweaks to the grids were made here. Temperatures this
afternoon will warm into the mid-upper 70s with the highest temps
out across the east where the veil of clouds is expected to be a bit
thinner.
By tonight, the frontal boundary out to the west is forecast to
start making some eastward progress as the deep closed low out over
the Plains gets more organized and deepens. Rain showers will be
most concentrated out across our western sections and then
overspread much of central Kentucky by sunrise Saturday. Light
southeasterly flow and plenty of cloud cover will result in mild
overnight minimum temperatures with readings cooling into the
mid-upper 50s.
Saturday, by all accounts, will be cloudy and wet across the region
as the surface frontal boundary occludes across the region. Band of
showers over western Kentucky is expected to gradually spread
eastward across the central part of the state throughout the day.
The rain will generally be light to moderate, but could be a little
heavy at times especially across southern Kentucky. Instability is
virtually not existent so not expecting much in the way of thunder.
However, with the good moisture fetch off the SW Atlantic, training
of rain showers looks increasingly likely which could lay down
around an inch of rain in some spots by Saturday evening. The
clouds and precipitation will keep temperatures down on Saturday
with highs only warming into the upper 50s.
.Long Term (Saturday Night through Thursday)...
Issued at 300 AM EDT Fri May 3 2013
The well advertised cutoff upper level low will be over Arkansas at
the beginning of the long term. This low will slowly swing across
the southeastern CONUS and into northern GA by Monday morning. It
will then work its way up the Atlantic coast through mid week.
The fetch of moisture off the Atlantic will continue to wrap around
the northern side of the low as it slides south of the forecast area
through the end of the weekend. Moderate rain will continue across
much of the area Saturday night through Sunday. Through this time
period an rainfall totals look to range from half an inch across
portions of the Bluegrass and southern Indiana to an inch south of
the Bluegrass Parkway. Some minor flooding will be possible on area
rivers with this rain. For more information refer to the hydrology
discussion below.
Rain chances will continue off and on through the first half of the
work week. However, these will become more diurnal in nature as the
low moves up the coast. A few thunderstorms will be possible with
this activity, especially if the sun is able to break out at all.
Thursday finally looks to be dry under ridging aloft.
Temperatures will remain on the cool side Sunday with highs only in
the lower 60s. However we will see a warming trend through the week.
By Thursday high temperatures should be back into the upper 70s with
lows in the mid to upper 50s.
&&
.Aviation (12Z TAF Issuance)...
Issued at 643 AM EDT Fri May 3 2013
Nearly stationary frontal boundary out near the MS river will remain
out to our west throughout the day. VFR conditions are expected at
all the terminals today with southeast winds picking up during the
mid-morning hours. The pressure gradient is expected to increase as
a deep upper low continues to strengthen over the Plains. Southeast
winds of 10-15 mph with gusts up to 20 mph will be possible later
this afternoon.
A few waves of low pressure will move up along the frontal boundary
producing a few rounds of showers later today. The vast majority of
this activity will stay west of KBWG and KSDF this afternoon.
Coverage still looks rather sparse enough to preclude mention in
this TAF forecast at the moment.
&&
.Hydrology...
Issued at 300 PM EDT Thu May 2 2013
An upper air disturbance is forecast to move across the region this
weekend. This will result in moderate to heavy rainfall over
southern Kentucky. Between Friday afternoon and Sunday morning
between one and inch inches could fall with the heaviest amounts
near Bowling Green.
This area recently had minor flooding and this new rain could result
in a new round of flooding in the middle of the Green River Basin.
Residents with livestock or equipment in flood prone areas should
watch water levels closely this weekend.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Updates..........MJ/RJS
Short Term.......MJ
Long Term........EER
Aviation.........MJ
Hydrology........CMC
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
700 PM EDT FRI MAY 3 2013
.SYNOPSIS...
ISSUED AT 329 PM EDT FRI MAY 3 2013
UNSEASONABLY WARM TEMPERATURES WILL PERSIST THROUGH THE WEEKEND INTO
EARLY NEXT WORK WEEK. EAST WINDS WILL KEEP TEMPERATURES WARM ALL
THE WAY TO THE LAKE SHORE. THE NEXT GOOD CHANCES FOR RAIN DO NOT
ARRIVE UNTIL WEDNESDAY NIGHT INTO THURSDAY.
&&
.UPDATE...
ISSUED AT 522 PM EDT FRI MAY 3 2013
I UPDATED THE GRIDS TO BETTER MATCH THE TEMP/DEW POINT GRADIENT
NEAR US-31 OVER THE NEXT FEW HOURS. I ALSO USING A COMBINATION OF
THE HRRR 19Z AND RAP MODEL UPDATED THE POP/WEATHER GRIDS TO SHOW
THE SHOWERS LIFTING OUT TO THE NORTHWEST OVER THE NEXT FEW HOURS.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 329 PM EDT FRI MAY 3 2013
CONVECTION HAS RECENTLY DEVELOPED ALONG THE INVERTED TROUGH/LAKE
BREEZE BOUNDARY IN A REGION OF BETTER INSTABILITY CENTERED MAINLY
SOUTH OF MUSKEGON. EXPECT A RAPID DECREASE IN ACTIVITY AGAIN THIS
EVENING WITH A LOSS OF INSOLATION.
AFTER THIS EVENING...DRY CONDITIONS WITH EAST WINDS WILL PERSIST
THROUGH THE WEEKEND. THIS IS A WARM AND DRY PATTERN SO WENT ABOVE
GUIDANCE TEMPERATURES...ESPECIALLY ALONG THE LAKESHORE WHICH CAN
WARM SIGNIFICANTLY WITH THIS TYPE OF PATTERN WHERE SLIGHT
DOWNSLOPING COMES INTO PLAY.
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 342 PM EDT FRI MAY 3 2013
HAVE A DRY FORECAST FROM MONDAY THROUGH WEDNESDAY NIGHT AS THE LOW
OVER THE SOUTHEAST U.S. AIDES IN KEEPING A RIDGE OVER THE GREAT
LAKES. DRY AND WARM WEATHER IS FORECAST TO CONTINUE WITH HIGHS NEAR
70 OR INTO THE LOWER 70S EACH DAY NEXT WEEK. THE NEXT CHANCE FOR
PRECIPITATION COMES OUT ON THURSDAY WHEN AN UPPER SHORTWAVE TROUGH
IS PROGD TO SLIP THROUGH THE AREA. GIVEN UPPER LOWS SITUATED OVER
THE LOWER 48 AND THE SHORTWAVE IS ON THE SOUTHERN EDGE OF THE
WESTERLIES...CONFIDENCE IS LOWER IN ITS PLACEMENT AT DAY 6 IN THE
FORECAST.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 700 PM EDT FRI MAY 3 2013
VFR CIGS WILL PREVAIL THROUGH SATURDAY. AS THE SYSTEM MOVES SOUTH
OF MICHIGAN TONIGHT THROUGH SATURDAY THE IMPACT FOR SOUTHWEST
MICHIGAN IS DEEP SOUTHEAST WINDS AND CEILING WELL ABOVE 10000 FT
AGL.
THE SHOWERS NEAR THE LAKE SHORE LATE THIS AFTERNOON HAVE ALREADY
MOVED OUT OVER THE LAKE TO THE NORTHWEST OF MUSKEGON AND ARE NOT
EXPECTED TO COME BACK.
&&
.MARINE...
ISSUED AT 329 PM EDT FRI MAY 3 2013
NO CHANGES TO THE FORECAST PLANNED AT THIS TIME. AFTER WINDS AND
WAVES
SUBSIDE THIS EVENING...GENERALLY LIGHT OFFSHORE WINDS WILL PRECLUDE
THE NEED FOR HEADLINES.
&&
.FIRE WEATHER...
ISSUED AT 329 PM EDT FRI MAY 3 2013
WITH EASTERLY WINDS OVER THE WEEKEND...WE ARE IN A FAVORABLE SETUP
FOR
WARM AND DRY CONDITIONS. THE LATEST PLANNING FORECAST ISSUANCE BRINGS
SOME AREAS CLOSER TO RED FLAG WARNING CRITERIA. TEMPERATURE AND
HUMIDITY THRESHOLDS WILL BE SOMETHING TO CLOSELY WATCH OVER THE
NEXT COUPLE DAYS. HOWEVER...WIND SPEEDS SHOULD ALSO BE DECREASING
FROM SATURDAY TO SUNDAY.
&&
.HYDROLOGY...
ISSUED AT 329 PM EDT FRI MAY 3 2013
NO CONCERNS DUE TO LITTLE OR NO EXPECTED PRECIPITATION OVER THE
NEXT SEVERAL DAYS.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...WDM
SYNOPSIS...TJT
SHORT TERM...TJT
LONG TERM...DUKE
AVIATION...WDM
FIRE WEATHER...TJT
HYDROLOGY...TJT
MARINE...TJT
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
524 PM EDT FRI MAY 3 2013
.SYNOPSIS...
ISSUED AT 329 PM EDT FRI MAY 3 2013
UNSEASONABLY WARM TEMPERATURES WILL PERSIST THROUGH THE WEEKEND INTO
EARLY NEXT WORK WEEK. EAST WINDS WILL KEEP TEMPERATURES WARM ALL
THE WAY TO THE LAKE SHORE. THE NEXT GOOD CHANCES FOR RAIN DO NOT
ARRIVE UNTIL WEDNESDAY NIGHT INTO THURSDAY.
&&
.UPDATE...
ISSUED AT 522 PM EDT FRI MAY 3 2013
I UPDATED THE GRIDS TO BETTER MATCH THE TEMP/DEW POINT GRADIENT
NEAR US-31 OVER THE NEXT FEW HOURS. I ALSO USING A COMBINATION OF
THE HRRR 19Z AND RAP MODEL UPDATED THE POP/WEATHER GRIDS TO SHOW
THE SHOWERS LIFTING OUT TO THE NORTHWEST OVER THE NEXT FEW HOURS.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 329 PM EDT FRI MAY 3 2013
CONVECTION HAS RECENTLY DEVELOPED ALONG THE INVERTED TROUGH/LAKE
BREEZE BOUNDARY IN A REGION OF BETTER INSTABILITY CENTERED MAINLY
SOUTH OF MUSKEGON. EXPECT A RAPID DECREASE IN ACTIVITY AGAIN THIS
EVENING WITH A LOSS OF INSOLATION.
AFTER THIS EVENING...DRY CONDITIONS WITH EAST WINDS WILL PERSIST
THROUGH THE WEEKEND. THIS IS A WARM AND DRY PATTERN SO WENT ABOVE
GUIDANCE TEMPERATURES...ESPECIALLY ALONG THE LAKESHORE WHICH CAN
WARM SIGNIFICANTLY WITH THIS TYPE OF PATTERN WHERE SLIGHT
DOWNSLOPING COMES INTO PLAY.
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 342 PM EDT FRI MAY 3 2013
HAVE A DRY FORECAST FROM MONDAY THROUGH WEDNESDAY NIGHT AS THE LOW
OVER THE SOUTHEAST U.S. AIDES IN KEEPING A RIDGE OVER THE GREAT
LAKES. DRY AND WARM WEATHER IS FORECAST TO CONTINUE WITH HIGHS NEAR
70 OR INTO THE LOWER 70S EACH DAY NEXT WEEK. THE NEXT CHANCE FOR
PRECIPITATION COMES OUT ON THURSDAY WHEN AN UPPER SHORTWAVE TROUGH
IS PROGD TO SLIP THROUGH THE AREA. GIVEN UPPER LOWS SITUATED OVER
THE LOWER 48 AND THE SHORTWAVE IS ON THE SOUTHERN EDGE OF THE
WESTERLIES...CONFIDENCE IS LOWER IN ITS PLACEMENT AT DAY 6 IN THE
FORECAST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 245 PM EDT FRI MAY 3 2013
EXPECTING VFR CONDITIONS THE NEXT 24 HOURS...AS SOUTHWEST LOWER
MICHIGAN REMAINS ON THE PERIPHERY OF AN UPPER LOW TO OUR
SOUTHWEST. CEILINGS BETWEEN 5000-8000FT CAN BE EXPECTED THIS
AFTERNOON AND EVENING AS CUMULUS CLOUDS BUBBLE UP IN THE HEAT OF
THE DAY. HAVE INCLUDED VCSH AT KMKG...KGRR AND KAZO FROM 21Z
THROUGH 04Z. THE HIGH BASED CUMULUS SHOULD DISSIPATE TOWARDS
MIDNIGHT...WITH CLOUDS AT OR ABOVE 10000FT TONIGHT INTO SATURDAY
MORNING. WIND DIRECTION WILL BE SOUTHEAST FOR THE MOST PART
OUTSIDE OF A LAKE BREEZE THAT PUSHES SLIGHTLY INLAND THIS
AFTERNOON.
&&
.MARINE...
ISSUED AT 329 PM EDT FRI MAY 3 2013
NO CHANGES TO THE FORECAST PLANNED AT THIS TIME. AFTER WINDS AND
WAVES
SUBSIDE THIS EVENING...GENERALLY LIGHT OFFSHORE WINDS WILL PRECLUDE
THE NEED FOR HEADLINES.
&&
.FIRE WEATHER...
ISSUED AT 329 PM EDT FRI MAY 3 2013
WITH EASTERLY WINDS OVER THE WEEKEND...WE ARE IN A FAVORABLE SETUP
FOR
WARM AND DRY CONDITIONS. THE LATEST PLANNING FORECAST ISSUANCE BRINGS
SOME AREAS CLOSER TO RED FLAG WARNING CRITERIA. TEMPERATURE AND
HUMIDITY THRESHOLDS WILL BE SOMETHING TO CLOSELY WATCH OVER THE
NEXT COUPLE DAYS. HOWEVER...WIND SPEEDS SHOULD ALSO BE DECREASING
FROM SATURDAY TO SUNDAY.
&&
.HYDROLOGY...
ISSUED AT 329 PM EDT FRI MAY 3 2013
NO CONCERNS DUE TO LITTLE OR NO EXPECTED PRECIPITATION OVER THE
NEXT SEVERAL DAYS.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...WDM
SYNOPSIS...TJT
SHORT TERM...TJT
LONG TERM...DUKE
AVIATION...DUKE
FIRE WEATHER...TJT
HYDROLOGY...TJT
MARINE...TJT
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
418 PM EDT FRI MAY 3 2013
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 418 PM EDT FRI MAY 3 2013
UPPER TROUGH CONTINUES TO SPLIT APART NEXT 24 HRS WITH UPPER LOW
FOCUSING OVER CNTRL MISSISSIPPI RIVER VALLEY. REGIONAL RADAR SHOWS
SWATH OF MAINLY RAIN FROM ILLINOIS INTO WISCONISN AND INTO WESTERN
UPR MICHIGAN AND INTO MINNESOTA ARROWHEAD. THIS PRECIP IS SUPPORTED
BY PERSISTENT H85-H7 FRONTOGENESIS AND RIGHT ENTRANCE REGION FROM
UPPER JET OVER ONTARIO. BOTH FEATURES ARE FORECAST TO DIMINISH INTO
SATURDAY AS UPPER LOW TO THE SOUTH BECOMES DOMINANT UPPER LEVEL
FEATURE.
ANALYSIS FROM RUC AND NAM INDICATING WARM LAYER IS WELL ABOVE 0C
SUGGESTS PTYPE OVER WESTERN UPR MICHIGAN SHOULD BE RAIN BUT REPORTS
FROM GOGEBIC INTO SOUTHERN HOUGHTON COUNTY SHOW IT IS NOT WITH LGT
SNOW OCCURRING. THESE AREAS LINE UP WELL WITH SUB ZERO 950-900MB
TEMPS SO KEPT MENTION OF SLEET/SNOW OVER FAR WESTERN UPR MICHIGAN
THROUGH EARLY MORNING HOURS BEFORE SHALLOWER COLD TEMPS WARM ABOVE
0C. OTHERWISE...RAIN WILL BE DOMINANT PTYPE ACROSS REST OF
CWA...MORE SCATTERED IN THE EASTERN HALF OF CWA. KEPT A MENTION OF
FZRA OVER INLAND WESTERN THIRD OF CWA. SINCE MAJORITY OF PRECIP WILL
OCCUR OVER WESTERN CWA AND SINCE THERE IS GOING TO BE CONTINUING
FZRA/SLEET/SNOW...CHANGING TO RAIN/FREEZING RAIN...OPTED TO KEEP
WINTER WEATHER ADVY OUT FOR GOGEBIC AND ONTONAGON COUNTIES THROUGH
12Z SATURDAY. COULD SEE SIMILAR PYTPE THIS EVENING FARTHER EAST
ACROSS KEWEENAW...BUT BASED ON UPSTREAM RADAR TRENDS AND BLEND OF
SHORT TERM MODELS...THINK THESE AREAS WILL MISS OUT ON HEAVIER QPF
AND BETTER CHANCE OF SLEET/ICE ACCUMS.
IMPROVING WEATHER ON SATURDAY...HOPEFULLY. LINGERING DIVERGENCE
ALOFT MAY STILL BRING SOME LGT RAIN OVER WEST AND NORTHWEST CWA.
SHOULD STAY DRY OVER THE EAST HALF. SIMILAR TO LAST COUPLE DAYS
SHOULD BE A WIDE TEMPERATURE RANGE FROM WEST TO EAST. BASED ON FCST
H85 TEMPS AND CLEARER SKIES EXPECTED...THINKING EASTERN INTERIOR
CWA MAY REACH MID 60S TO LOWER 70S. COOLER NORTH FLOW KEEPS WEST AND
CNTRL COOLER...BUT STILL A BIT WARMER THAN RECENT TEMPERATURES.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 418 PM EDT FRI MAY 3 2013
NAM SHOWS A CLOSED 500 MB LOW OVER NORTHERN CA AND ANOTHER OVER
NORTHERN ARKANSAS WITH A 500 MB RIDGE OVER THE LOWER GREAT LAKES.
THE 500 MB PATTERN OVER THE EAST HALF OF THE U.S. IS AN OMEGA BLOCK
00Z SUN AND DOES NOT MOVE MUCH ON SUNDAY EXCEPT TO TRY TO FORM A REX
BLOCK WITH THE LOW MOVING SLOWLY EAST UNDERNEATH THE RIDGE. THE REX
BLOCK THEN GETS ESTABLISHED ON MON. THIS FORECAST PERIOD FEATURES
DEEPER MOISTURE OVER THE WEST HALF OF THE CWA GRADUALLY DECREASING.
WILL KEEP SLIGHT CHANCE POPS OVER THE FAR WESTERN CWA SAT NIGHT WITH
THIS MOVING FURTHER WEST WITH TIME ON SUN. PCPN SHOULD BE ALL RAIN
BY THAT TIME. TEMPERATURES CONTINUE THE SLOW WARMING TREND WITH TIME
AND DRY WEATHER COMES IN FOR SUN INTO MON. DID NOT MAKE TOO MANY
CHANGES TO THE GOING FORECAST FOR TEMPERATURES EXCEPT DID LOWER LOWS
A BIT WITH THE COLDER MOS GUIDANCE FOR SAT NIGHT AND SUN NIGHT.
IN THE EXTENDED...ECMWF AND GFS SHOW A CLOSED 500 MB LOW OVER THE
SOUTHEAST U.S. 12Z TUE. THINGS GET INTERESTING OVER THE NORTHERN
PLAINS. 12Z TUE...ECMWF HAS A CLOSED 500 MB LOW NEAR SISSETON SD AND
THE GFS HAS A 500 MB RIDGE THERE INSTEAD. THIS DIFFERENCE CARRIES
INTO 12Z WED WITH THE ECMWF CONTINUING ITS SOLUTION OF A TROUGH IN
THE UPPER MISSISSIPPI VALLEY WITH THE 06Z GFS HAVING A CLOSED 500 MB
LOW OVER MISSOURI WHILE THE 00Z GFS STILL MAINTAINING A RIDGE OVER
THE CORNBELT. THE ECMWF TAKES THE TROUGH INTO THE UPPER GREAT LAKES
12Z THU WITH THE GFS MAINTAINING A FLAT 500 MB RIDGE OVER THE AREA.
THE 500 MB RIDGE GETS FLATTENED BY 12Z FRI WITH A BROAD 500 MB
TROUGH AND THE WESTERLIES GETTING PUSHED SOUTH INTO THE AREA.
CONFIDENCE REMAINS LOW WITH THIS EXTENDED FORECAST DUE TO THE 2 VERY
DIFFERENT MODEL SOLUTIONS. LOOKS DRY THROUGH TUE NIGHT BEFORE A COLD
FRONT HEADS SOUTH OUT OF CANADA AND BRINGS WITH IT A SLIGHT CHANCE
TO LOW CHANCE FOR PCPN WED INTO FRI. TEMPERATURES CONTINUE TO SLOWLY
WARM AND GO TO NEAR NORMAL BY THE END OF THE PERIOD. THE COLD FRONT
MOVES THROUGH WED NIGHT AND SLOWLY PUSHES SOUTH OF THE AREA THEN FOR
THU INTO FRI.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 149 PM EDT FRI MAY 3 2013
CIGS REMAIN FAIRLY SIMILAR THROUGH THE TAF PERIOD AS LOW LEVEL
MOISTURE IS ABUNDANT. BASED ON UPSTREAM RADAR AND OBSERVATION
TRENDS...STILL DECENT CHANCE OF SEEING ADDITIONAL PRECIP AT IWD BY
THIS EVENING...PROBABLY IN THE FORM OF FZRA/FZDZ. BETTER CHANCE FOR
PRECIP AT SAW...SCT SHOWERS...WILL BE AROUND SUNSET. THERE WILL BE
BETTER CHANCE OF DZ/FZDZ BY THIS EVENING AND THROUGH THE NIGHT AT CMX.
HAVE WENT WITH A RETURN TO IFR VSBY AT SAW LATER THIS EVENING THROUGH
DAYBREAK SATURDAY GIVEN PERSISTENT UPSLOPE FLOW AND SUBSIDENCE
INVERSION SETTING UP LATER TONIGHT.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 418 PM EDT FRI MAY 3 2013
NO GALES SEEN DURING THIS FORECAST PERIOD. THE STRONGEST WINDS IN
THE PERIOD ARE THIS AFTERNOON WITH NORTHEAST WINDS BELOW 25 KNOTS. A
HIGH PRESSURE RIDGE SETTLES IN AND KEEPS STRONG SYSTEMS AWAY FROM
THE AREA.
&&
.HYDROLOGY...
ISSUED AT 418 PM EDT FRI MAY 3 2013
STURGEON RIVER AT ALSTON AND CHASSELL...THE MICHIGAMME RIVER AROUND
WITCH LAKE...AND THE PAINT RIVER NEAR CRYSTAL FALLS WILL REMAIN
CONCERNS INTO AT LEAST EARLY NEXT WEEK...BUT OTHERWISE RIVER LEVELS
CONTINUE TO COME DOWN. ACTUALLY...MICHIGAMME MAY REMAIN A CONCERN
THROUGH MOST OF NEXT WEEK. DECENT AMOUNT OF WATER EQUIVALENT HAS
OCCURRED LAST TWO DAYS OVER WESTERN CWA...VCNTY OF IRONWOOD TO
ONTONAGON...OVER 2 INCHES OVER FAR WESTERN GOGEBIC COUNTY. WILL HAVE
TO ASSESS WHAT AFFECT THE PRECIP WILL HAVE WHEN COMBINED WITH
FURTHER MELTING OF ANY SUSTAINED SNOWPACK WHEN TEMPS WARM INTO THE
60-70S SUN INTO NEXT WEEK. SNOW WATER EQUIVALENT OF 8.8 INCHES IN
PAINESDALE ON THURSDAY WITH 24 INCHES OF SNOW DEPTH...SO THE OTTER
RIVER STILL HAS PLENTY OF SNOW IN THE HEADWATERS WHICH MAY CAUSE
ADDITIONAL PROBELMS AT CLLM4 IN THE COMING DAYS.
FOR COMPLETE DETAILS...SEE THE LATEST RIVER FLOOD WARNINGS AND
ADVISORIES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 8 AM EDT /7 AM CDT/ SATURDAY FOR
MIZ002-009.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...07
AVIATION...JLA
MARINE...07
HYDROLOGY...JLA
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
246 PM EDT FRI MAY 3 2013
.SYNOPSIS...
ISSUED AT 340 AM EDT FRI MAY 3 2013
IT WILL BE MILD TODAY WITH SCATTERED AFTERNOON SHOWERS AND A FEW
THUNDERSTORMS MAINLY WEST OF A LINE FROM KALAMAZOO TO GRAND RAPIDS
AND BIG RAPIDS. DRY AND MILD WEATHER IS ANTICIPATED THROUGH THE
WEEKEND AND FOR MOST OF NEXT WEEK.
&&
.UPDATE...
ISSUED AT 932 AM EDT FRI MAY 3 2013
UPDATED FORECAST TO ACCOUNT FOR RAIN SHOWERS CURRENTLY OVER FAR
SW CWA. HAVE GENERALLY RAISED POPS NEAR THE LAKESHORE INTO THE
AFTERNOON. LATEST HRRR GUIDANCE SUGGESTS THAT AREA OF PRECIPITATION
OVER CENTRAL IN WILL MOVE NORTH...REACHING OUR SOUTHERN CWA BY
THIS EVENING. WILL MONITOR THIS AND MAY BE RAISING POPS SOUTH OF
I-96 LATER TODAY IF THESE TRENDS CONTINUE.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY AFTERNOON)
ISSUED AT 340 AM EDT FRI MAY 3 2013
OUR PRIMARY SHORT TERM FCST CHALLENGE IS TO DETERMINE PROBABILITIES
FOR SCATTERED SHOWERS/TSTORMS TODAY. AS WAS THE CASE YESTERDAY
AFTERNOON WE EXPECT SFC CONVERGENCE FROM AN INVERTED SFC TROF AND
THE LAKE BREEZE TO TRIGGER DEVELOPMENT OF SHOWERS AND A FEW STORMS
THIS AFTERNOON... WITH THE RELATIVELY BEST CHC FOR THOSE WEST OF
US-131 AS SUGGESTED BY LATEST 00Z 4KM WRF-NMM SIM Z GUIDANCE. MAX
TEMPS WILL REACH THE LOW TO MID 70S EXCEPT SIGNIFICANTLY COOLER
RIGHT ALONG THE LAKE MI SHORELINE.
DRY AND SEASONABLY MILD WX IS THEN EXPECTED TONIGHT THROUGH SUNDAY
AS THE UPPER RIDGE AXIS TAKES HOLD AND UPPER LOW DRIFTS FURTHER SE
INTO THE SOUTHEASTERN UNITED STATES. MAX TEMPS THIS WEEKEND SHOULD
AGAIN REACH THE LOW TO MID 70S. THE EASTERLY WINDS WILL LIKELY NOT
BE STRONG ENOUGH TO PRECLUDE LAKE BREEZE DEVELOPMENT SATURDAY AND
SUNDAY... SO LOCATIONS RIGHT ALONG LAKE MI SHOULD AGAIN BE COOLER.
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 340 AM EDT FRI MAY 3 2013
LOOKS LIKE A QUIET WEATHER PATTERN IN THE EXTENDED AS THE UPPER LOW
TRACKS WELL SOUTH OF THE GREAT LAKES AND DRY EAST FLOW DOMINATES.
ADDED SLIGHT CHANCE POPS FOR THURSDAY AS WEAKER...NORTHERN CUT OFF
LOW FINALLY MOVES EAST AND OVER LOWER MICHIGAN. THIS SHOULD BE
MOISTURE STARVED SINCE IT HAS LITTLE OR NO GULF MOISTURE TO WORK
WITH.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 245 PM EDT FRI MAY 3 2013
EXPECTING VFR CONDITIONS THE NEXT 24 HOURS...AS SOUTHWEST LOWER
MICHIGAN REMAINS ON THE PERIPHERY OF AN UPPER LOW TO OUR
SOUTHWEST. CEILINGS BETWEEN 5000-8000FT CAN BE EXPECTED THIS
AFTERNOON AND EVENING AS CUMULUS CLOUDS BUBBLE UP IN THE HEAT OF
THE DAY. HAVE INCLUDED VCSH AT KMKG...KGRR AND KAZO FROM 21Z
THROUGH 04Z. THE HIGH BASED CUMULUS SHOULD DISSIPATE TOWARDS
MIDNIGHT...WITH CLOUDS AT OR ABOVE 10000FT TONIGHT INTO SATURDAY
MORNING. WIND DIRECTION WILL BE SOUTHEAST FOR THE MOST PART
OUTSIDE OF A LAKE BREEZE THAT PUSHES SLIGHTLY INLAND THIS
AFTERNOON.
&&
.MARINE...
ISSUED AT 340 AM EDT FRI MAY 3 2013
WE WILL ALLOW THE SCA TO EXPIRE EARLY THIS MORNING. WAVE HEIGHTS OF
2 TO 4 FEET ARE ANTICIPATED TODAY BUT WAVES AND WINDS WILL STAY BELOW
SCA CRITERIA. MINIMAL WAVE ACTION IS ANTICIPATED THIS WEEKEND WITH
OFFSHORE WINDS.
&&
.FIRE WEATHER...
ISSUED AT 340 AM EDT FRI MAY 3 2013
A FEW SHOWERS AND THUNDERSTORMS ARE EXPECTED TODAY. AFTER TODAY DRY
AND MILD WEATHER IS EXPECTED THIS WEEKEND THROUGH MOST OF NEXT WEEK
KEEPING FUEL MOISTURE RATHER LOW.
&&
.HYDROLOGY...
ISSUED AT 340 AM EDT FRI MAY 3 2013
ANY PRECIPITATION TODAY FROM SCATTERED SHOWERS AND A FEW STORMS WILL
BE QUITE LIGHT. DRY WEATHER IS EXPECTED THIS WEEKEND THROUGH MOST OF
NEXT WEEK. THEREFORE THERE ARE NO SIGNIFICANT HYDRO CONCERNS AT THIS
TIME THAT WOULD AFFECT MAINSTEM RIVERS.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...TJT
SYNOPSIS...LAURENS
SHORT TERM...LAURENS
LONG TERM...OSTUNO
AVIATION...DUKE
FIRE WEATHER...LAURENS
HYDROLOGY...LAURENS
MARINE...LAURENS
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
931 AM EDT FRI MAY 3 2013
.SYNOPSIS...
ISSUED AT 340 AM EDT FRI MAY 3 2013
IT WILL BE MILD TODAY WITH SCATTERED AFTERNOON SHOWERS AND A FEW
THUNDERSTORMS MAINLY WEST OF A LINE FROM KALAMAZOO TO GRAND RAPIDS
AND BIG RAPIDS. DRY AND MILD WEATHER IS ANTICIPATED THROUGH THE
WEEKEND AND FOR MOST OF NEXT WEEK.
&&
.UPDATE...
ISSUED AT 932 AM EDT FRI MAY 3 2013
UPDATED FORECAST TO ACCOUNT FOR RAIN SHOWERS CURRENTLY OVER FAR
SW CWA. HAVE GENERALLY RAISED POPS NEAR THE LAKESHORE INTO THE
AFTERNOON. LATEST HRRR GUIDANCE SUGGESTS THAT AREA OF PRECIPITATION
OVER CENTRAL IN WILL MOVE NORTH...REACHING OUR SOUTHERN CWA BY
THIS EVENING. WILL MONITOR THIS AND MAY BE RAISING POPS SOUTH OF
I-96 LATER TODAY IF THESE TRENDS CONTINUE.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY AFTERNOON)
ISSUED AT 340 AM EDT FRI MAY 3 2013
OUR PRIMARY SHORT TERM FCST CHALLENGE IS TO DETERMINE PROBABILITIES
FOR SCATTERED SHOWERS/TSTORMS TODAY. AS WAS THE CASE YESTERDAY
AFTERNOON WE EXPECT SFC CONVERGENCE FROM AN INVERTED SFC TROF AND
THE LAKE BREEZE TO TRIGGER DEVELOPMENT OF SHOWERS AND A FEW STORMS
THIS AFTERNOON... WITH THE RELATIVELY BEST CHC FOR THOSE WEST OF
US-131 AS SUGGESTED BY LATEST 00Z 4KM WRF-NMM SIM Z GUIDANCE. MAX
TEMPS WILL REACH THE LOW TO MID 70S EXCEPT SIGNIFICANTLY COOLER
RIGHT ALONG THE LAKE MI SHORELINE.
DRY AND SEASONABLY MILD WX IS THEN EXPECTED TONIGHT THROUGH SUNDAY
AS THE UPPER RIDGE AXIS TAKES HOLD AND UPPER LOW DRIFTS FURTHER SE
INTO THE SOUTHEASTERN UNITED STATES. MAX TEMPS THIS WEEKEND SHOULD
AGAIN REACH THE LOW TO MID 70S. THE EASTERLY WINDS WILL LIKELY NOT
BE STRONG ENOUGH TO PRECLUDE LAKE BREEZE DEVELOPMENT SATURDAY AND
SUNDAY... SO LOCATIONS RIGHT ALONG LAKE MI SHOULD AGAIN BE COOLER.
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 340 AM EDT FRI MAY 3 2013
LOOKS LIKE A QUIET WEATHER PATTERN IN THE EXTENDED AS THE UPPER LOW
TRACKS WELL SOUTH OF THE GREAT LAKES AND DRY EAST FLOW DOMINATES.
ADDED SLIGHT CHANCE POPS FOR THURSDAY AS WEAKER...NORTHERN CUT OFF
LOW FINALLY MOVES EAST AND OVER LOWER MICHIGAN. THIS SHOULD BE
MOISTURE STARVED SINCE IT HAS LITTLE OR NO GULF MOISTURE TO WORK
WITH.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 751 AM EDT FRI MAY 3 2013
VFR SHOULD PREVAIL MOST OF THE DAY BUT AREAS OF MVFR IN SHOWERS
AND THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON AND INTO THE
EVENING. LEFT THIS OUT OF THE FORECAST SINCE THE COVERAGE IS
EXPECTED TO BE LOW...BUT PROBABLY GREATER THAN YESTERDAY. WINDS
WILL BE AOB 10 KNOTS FROM THE EAST OR SOUTHEAST.
&&
.MARINE...
ISSUED AT 340 AM EDT FRI MAY 3 2013
WE WILL ALLOW THE SCA TO EXPIRE EARLY THIS MORNING. WAVE HEIGHTS OF
2 TO 4 FEET ARE ANTICIPATED TODAY BUT WAVES AND WINDS WILL STAY BELOW
SCA CRITERIA. MINIMAL WAVE ACTION IS ANTICIPATED THIS WEEKEND WITH
OFFSHORE WINDS.
&&
.FIRE WEATHER...
ISSUED AT 340 AM EDT FRI MAY 3 2013
A FEW SHOWERS AND THUNDERSTORMS ARE EXPECTED TODAY. AFTER TODAY DRY
AND MILD WEATHER IS EXPECTED THIS WEEKEND THROUGH MOST OF NEXT WEEK
KEEPING FUEL MOISTURE RATHER LOW.
&&
.HYDROLOGY...
ISSUED AT 340 AM EDT FRI MAY 3 2013
ANY PRECIPITATION TODAY FROM SCATTERED SHOWERS AND A FEW STORMS WILL
BE QUITE LIGHT. DRY WEATHER IS EXPECTED THIS WEEKEND THROUGH MOST OF
NEXT WEEK. THEREFORE THERE ARE NO SIGNIFICANT HYDRO CONCERNS AT THIS
TIME THAT WOULD AFFECT MAINSTEM RIVERS.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...TJT
SYNOPSIS...LAURENS
SHORT TERM...LAURENS
LONG TERM...OSTUNO
AVIATION...OSTUNO
FIRE WEATHER...LAURENS
HYDROLOGY...LAURENS
MARINE...LAURENS
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
730 PM CDT SAT MAY 4 2013
...UPDATED FOR 00Z AVIATION DISCUSSION...
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 341 PM CDT SAT MAY 4 2013
WARMER WEATHER WILL GRADUALLY MOVE IN ACROSS THE REGION OVER THE
NEXT FEW DAYS AND CONDITIONS BEGIN TO DRY OUT. BY THE MIDDLE OF THE
WEEK A SERIES OF UPPER LEVEL DISTURBANCES WILL BRING RETURNED
CHANCES FOR SHOWERS AND THUNDERSTORMS...ALONG WITH COOLER
TEMPERATURES.
EARLY AFTERNOON NORTH AMERICAN WATER VAPOR IMAGERY TOGETHER WITH
500MB HEIGHTS AND WINDS SHOWED THE CUTOFF LOW SPINNING OVER THE
OZARK MOUNTAINS...WITH A RIDGE LOCATED ALONG EACH COAST. AT THE
SURFACE A LOOSE PRESSURE GRADIENT WAS DRAPED ACROSS THE UPPER
MIDWEST BETWEEN A 1028 HIGH IN NORTH DAKOTA...AND A 1013 LOW IN
SOUTHERN MISSOURI WITH NORTHERLY WINDS OVER MINNESOTA AND
WISCONSIN. THE EXPANSIVE CLOUD SHIELD FROM THE AFOREMENTIONED
UPPER LEVEL LOW WAS BEGINNING TO SHOW SOME HOLES IN
WISCONSIN...AND THIS ALLOWED TEMPERATURES TO CLIMB INTO THE MID
70S WHERE THERE WAS NO SNOWPACK. HOWEVER...FARTHER WEST
TEMPERATURES WERE ONLY IN THE 40S WHERE THE DEEP SNOWPACK LINGERED
FROM THE PREVIOUS WINTER STORM. FARTHER WEST STILL IN NEAR THE
SD/MN BORDER TEMPERATURES WERE ONLY IN THE UPPER 30S ALONG WITH
THICKER CLOUDS AND LIGHT DRIZZLE ASSOCIATED WITH THE DEFORMATION
ZONE FROM THE DECAYING CYCLONE TO THE SOUTH. TONIGHT FORECAST
MODELS SHOW THE PRESSURE GRADIENT RELAXING...RESULTING IN
DECREASING WINDS. AS THE CLEARING TREND PROGRESSES WESTWARD
OVERNIGHT AREAS OF FOG ARE EXPECTED TO DEVELOP ALONG THE MN/WI
BORDER...WITH THE HIGHEST POTENTIAL FOR DENSE FOG ALONG AND EAST
OF A LINE FROM ALBERT LEA UP THROUGH RED WING AND RICE LAKE WI.
FORECAST SOUNDINGS SHOW A DEEP INVERSION WITH LOW LEVEL
MOISTURE...BUT FEEL THE WINDS ARE OVERDONE...SO THE FOG POTENTIAL
IS HIGHER THAN INDICATED. MEMBER 2 OF THE HOPWRF HAS A BETTER
HANDLE OF THE CLEARING TREND...AND SHOWS FOG DEVELOPMENT IN THIS
REGION AROUND 08Z. THE 16Z RUN OF THE HRRR SHOWS A SIMILAR TREND.
THEREFORE HAVE ISSUED A DENSE FOG ADVISORY OVERNIGHT. HIGH
TEMPERATURES ON SUNDAY WILL DEPEND ON HOW QUICKLY WE CAN MIX OUT
THE FOG. THIS WILL BE DIFFICULT TO DO WITH LIGHT WINDS AND WEAK
MECHANICAL MIXING...SO WILL HAVE TO DEPEND ON THE EARLY MAY SUN.
TEMPERATURES ACROSS THE WEST WILL BE 15 TO 20 DEGREES COOLER THAN
SNOW FREE AREAS OF WISCONSIN DUE TO CLOUD COVER.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 341 PM CDT SAT MAY 4 2013
SUNDAY NIGHT WILL HAVE ANOTHER FAVORABLE SETUP FOR FOG
DEVELOPMENT. ON MONDAY SURFACE TEMPERATURES WILL REBOUND TO NEAR
70 DEGREES...WITH WARMER TEMPS ON TUESDAY AS SOUTHERLY FLOW
INCREASES AHEAD OF THE NEXT WEAK UPPER LEVEL WAVE. USED A MIX DOWN
TOOL TO FORECAST HIGH TEMPERATURES...AND INCREASED THEM A FEW
DEGREES ABOVE THE PREVIOUS FORECAST...ESPECIALLY IN FAR WESTERN
MINNESOTA. THIS WAVE IS FORECAST TO BRING A CHANCE FOR SHOWERS AND
THUNDERSTORMS WEDNESDAY. THE SEVERE WEATHER THREAT IS VERY
LOW...WITH SMALL DEEP LAYER SHEAR AND ONLY 500J/KG OF MLCAPE.
UNSETTLED WEATHER WILL CONTINUE THROUGH THE END OF THE WEEK. LOW
POPS AND SLIGHTLY COOLER TEMPERATURES WILL BE FOCUSED ALONG A WARM
FRONT THAT IS FORECAST TO STALL OUT ACROSS THE REGION...AS
PERIODIC SHORTWAVES MOVING ACROSS THE UPPER MIDWEST.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY AFTERNOON) ISSUED AT
1230 PM CDT SAT MAY 4 2013
WELL ADVERTISED CUT OFF 50H LOW WILL CONTINUE TO SLOWLY TREK FROM
ARKANSAS INTO ALABAMA BY SUN/18Z. EJECTION OF THIS FEATURE HAS
PRETTY MUCH ELIMINATED MOST CHANCES FOR RAINFALL ACROSS ALL TAF
SITES. QUITE A FEW LARGE AREAS OF CLEAR TO SCT SKY CONDITIONS
NOTED OVER EAST CENTRAL MN AND MOST OF WI. IFR CIGS AT KAXN
...KSTC AND KRWF WILL TRANSITION BACK TO VFR CONDITIONS BY 03Z.
MODELS ARE WAY TOO PESSIMISTIC ON MVFR CIGS THROUGH AT LEAST FIRST
6 TO 8 HOURS OF FORECAST...ALTHOUGH NAM GUIDANCE CLOSER TO ACTUAL
CONDITIONS. WITH THAT SAID DECIDED BEST OPTION WAS TO REINTRODUCE
LOW END MVFR CIGS AT MOST AIRPORTS AFT 09Z ASSOCIATED WITH FOG
FORMATION IN LIEU OF LIGHTENING N WIND REGIME AND COPIOUS RESIDUAL
MOISTURE LEVELS. IFR VSBY FOG SHOULD DEVELOP OVER MOST TAF SITES WITH
WORST VSBYS...LIFR...ANTICIPATED AT KEAU AND KRNH...A REFLECTION OF
RECENT HEAVY SNOWFALL EVENT. KU-RULE INDICATING FAIRLY QUICK
DISINTEGRATION OF STRATOCU DECK BY 14Z MOST LOCALES. SHORT WINDOW
OF SCT CONDITIONS FROM KSTC-KMSP EAST...AS COLD AIR ALOFT COMBINES
WITH SFC HEATING INITIATING NEW VFR STRATO-CU DECK BY LATE MORNING.
KU-RULE CONFIRMS THIS ASSUMPTION...AND BACKS UP SCT CONDITIONS THROUGH
MOST OF THE DAYLIGHT HOURS AT KAXN AND KRWF. LIGHT NORTHERLY WINDS
WILL CONTINUE THROUGH END OF PD. SHOULD EXPECT SCT CONDITIONS SUNDAY
NIGHT...WITH VERY POSSIBLE IFR-LOW END FOG CONDITIONS DEVELOPING AGAIN
LATE SUNDAY NIGHT.
KMSP...
ANTICIPATE WEAK NORTHERLY WIND COMPONENT THROUGH END OF PERIOD.
HIGH LEVEL CIRRUS WILL GIVE WAY TO LOWERING MID AND THEN STRATO
CU DECK BY 07Z. RADIATIONAL COOLING...SLACKENING WIND REGIME
AND PLENTY OF RESIDUAL MOISTURE SHOULD EQUAL AT LEAST IFR VSBYS
AND POSSIBLE SHORT PERIOD LIFR BETWEEN 09 AND 12Z. MVFR TO LOW
END MVFR CIGS WILL FOLLOW SUIT WITH FOG INITIATION. STRATO-CU
DECK SHOULD BREAK UP BY 14Z...AS NVA CONTINUES TO PLOW INTO
REGION FROM WESTERN WI. STILL ENOUGH COLD AIR ALOFT TO INITIATED
VFR STRATO CU RETURN BY LATE MORNING...WITH DISINTEGRATION
ANTICIPATED BY 22Z TIME FRAME AND THEN CLEARING SKIES FOR MUCH
OF SUNDAY NIGHT. ANOTHER GOOD CHANCE FOR MVFR FOG ANTICIPATED FOR
LATE SUNDAY NIGHT.
/OUTLOOK FOR KMSP/
MON...VFR CIGS. PERIOD OF MVFR CIGS 09Z-12Z. WINDS LIGHT/VARIABLE.
TUE...VFR. WINDS LIGHT/VARIABLE...BECOMING SOUTH 3-5 KTS TUE NIGHT.
WED...VFR. WIND SOUTH AT 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...DENSE FOG ADVISORY FROM 1 AM TO 10 AM CDT SUNDAY FOR MNZ078-085-
093.
WI...DENSE FOG ADVISORY FROM 1 AM TO 10 AM CDT SUNDAY FOR WIZ015-016-
023>028.
&&
$$
SHORT TERM...TRH
LONG TERM...JRB
AVIATION...AZ
AREA FORECAST DISCUSSION
NWS DULUTH MN
1243 PM CDT FRI MAY 3 2013
.AVIATION...18Z TAF ISSUANCE
PRECIPITATION IN VARIOUS FORMS WILL CONTINUE ACROSS THE
REGION THIS AFTERNOON...WEST OF A LINE FROM KINL THROUGH
KDLH...THEN SPREAD EAST INTO KBRD AFT 00Z. MOST OF THE
PRECIPITATION WILL BE SNOW AT FIRST...THEN CHANGE TO RAIN OR
FREEZING RAIN...DEPENDING ON SFC TEMPS...WHICH WILL HOVER AROUND
FREEZING. CIGS WILL BE MAINLY MVFR THROUGH 00Z THEN DROP TO IFR IN
THE MAIN RAIN AREAS.
&&
.PREV DISCUSSION... /ISSUED 1025 AM CDT FRI MAY 3 2013/
UPDATE...
HAVE EXTENDED THE WINTER WEATHER ADVISORY FOR FREEZING RAIN OVER
NORTHERN WISCONSIN /EXCEPT PRICE COUNTY/ THROUGH 1000 PM THIS
EVENING...POSSIBLY NEEDING TO BE EXTENDED FURTHER. THE 12Z
NAM/DLHWRF BOTH SHOW SFC TEMPS REMAIN BELOW FREEZING OVER THE
ADVISORY AREA THROUGH AT LEAST MIDNIGHT. MEANWHILE...AN S-SE H85
FLOW WILL CONTINUE TO WARM MID LEVELS THROUGH THE
DAY...DIMINISHING ANY LINGERING SNOW AND PROMOTING FREEZING RAIN
THIS AFTERNOON/TONIGHT.
HAVE INTRODUCED MENTION OF FREEZING RAIN TO MN ARROWHEAD ZONES
THIS AFTERNOON AND EVENING WHERE H80-H85 LAYER TEMPS WARM A FEW
DEGREES ABOVE 0 C...WHILE SFC READINGS REMAIN SUB-FREEZING. WE
WILL CLOSELY MONITOR THIS AREA FOR ICE ACCUM POTENTIAL...AND AN
ADVISORY MAY BE NEEDED THIS AFTERNOON/TONIGHT FOR LAKE COOK
COUNTIES.
PREV DISCUSSION... /ISSUED 408 AM CDT FRI MAY 3 2013/
.SHORT TERM...TODAY THROUGH SATURDAY.
AT 4 AM...IT WAS FAIRLY QUIET ACROSS THE NORTHLAND. THERE WAS SOME
LIGHT SNOW ACROSS NW WI...AND REPORTS JUST OUTSIDE OF THE CWA OF
SOME LIGHT FREEZING DRIZZLE. TEMPERATURES RANGED FROM THE 20S IN
NE MN TO AROUND 30 IN NW WI.
THE NEXT MAIN WAVE OF PRECIPITATION WAS QUICKLY STREAMING
NORTHWARD THROUGH THE PLAINS. WE SHOULD SEE AN INCREASE
THROUGHOUT THE MORNING ACROSS WESTERN WISCONSIN. DEFINITELY SOME
PTYPE ISSUES...AND A THOROUGH ASSESSMENT OF THE FORECAST SOUNDINGS
SHOW SOME PRETTY SIGNIFICANT DIFFERENCES AMONG THE MODELS. JUST A
FEW DEGREES DIFFERENCE IN THE WARM LAYER WILL MEAN A CHANGE FROM
FREEZING RAIN OR RAIN...TO SLEET AND/OR SNOW.
FOR TODAY...HAVE RAISED POPS A BIT THROUGHOUT THE DAY...FIRST WITH
LIKELY POPS IN THE EASTERN 1/3 OF THE CWA...AND THEN SPREADING IT
NORTHWARD AND WESTWARD AS THE MORNING WEARS ON. NAM BUFR SOUNDINGS
AND THE HRRR FORECAST PTYPE INDICATE THAT A MIXTURE COULD LAST
INTO THE AFTERNOON...AND THERE MAY BE SOME SLEET AS WELL.
FORECAST LAYER THICKNESS VALUES ALSO INDICATE SOME POTENTIAL FOR
THIS TO LAST INTO THE AFTERNOON AND EVEN TONIGHT. WILL EXTEND THE
ADVISORY TIME THROUGH NOON WITH THE CAVEAT THAT SOME AREAS MAY
NEED TO BE EXTENDED INTO THE AFTERNOON.
HAVE INCREASED POPS CONSIDERABLY TONIGHT AND ON SATURDAY...WITH
GENERALLY RAIN DURING THE EVENING AND RAIN AND/OR FREEZING RAIN
AFTER MIDNIGHT. IN GENERAL...WE SHOULD SEE MAINLY RAIN ON
SATURDAY. TEMPS WILL BE TRICKY DUE TO THE CLOUDS AND EXPECTED
PRECIPITATION.
.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY.
A TROUGH OF LOW PRESSURE AND BAROCLINIC ZONE IS EVIDENT SATURDAY
NIGHT...WEAKENING SUNDAY. THIS WILL LEAD TO A CHANCE FOR RAIN OVER
MUCH OF THE CWA SATURDAY NIGHT...DIMINISHING FROM NORTH TO SOUTH
SUNDAY. RIDGING WILL TAKE OVER MONDAY INTO MONDAY NIGHT AND LEAD TO
A DRY PERIOD.
CONFIDENCE DIMINISHES MONDAY NIGHT INTO AT LEAST MID WEEK...AS THE
ECMWF BRINGS IN A SHORTWAVE AND SUPPORTS THE CHANCE FOR SHOWERS
TUESDAY/WEDNESDAY. WE FOLLOWED CLOSER TO THIS SOLUTION DURING THAT
PERIOD.
THE MODELS THEN HAVE A FASTER WNW FLOW OVER FAR NORTHERN MN/SOUTHERN
CANADA BY LATE IN THE WEEK WITH A CONTINUED CHANCE FOR RAIN WITH
WEAK LOW PRESSURE AT THE SURFACE. WE HAVE POPS CONTINUING THROUGH
THE REST OF THE PERIOD...ALTHOUGH WERE NOT OVERLY IMPRESSED WITH THE
FORCING AND EXPECTED PRECIPITATION AMOUNTS.
TEMPERATURES WILL BE A BIT BELOW NORMAL SUNDAY...RISING INTO THE
SIXTIES MONDAY THROUGH THE END OF THE WEEK.
HYDROLOGY...
FLOOD WARNINGS CONTINUED FOR THE MISSISSIPPI RIVER AT AITKIN AND
FORT RIPLEY FOR MINOR FLOODING. WE DROPPED THE WARNING FOR THE
SAINT LOUIS RIVER IN SCANLON AS THERE IS A CLEAR LOWERING TREND.
A FLOOD WARNING REMAINS FOR CENTRAL AND SOUTHERN SAINT LOUIS
COUNTY AS THERE IS STILL FLOODING OCCURRING THERE WITH WATER OVER
SEVERAL ROADS ACCORDING TO THE SAINT LOUIS COUNTY HIGHWAY
DEPARTMENT. THE NUMBER OF CLOSED ROADS HAD DIMINISHED SINCE
YESTERDAY THOUGH. THERE IS STILL SNOW OVER NORTHERN
MINNESOTA...ESPECIALLY IN THE WOODS. COOLER TEMPS TODAY WILL SLOW
THE MELT...BUT TEMPS WILL START TO WARM THIS WEEKEND INTO NEXT
WEEK...KEEPING ELEVATED RIVERS/STREAMS.
WE CONTINUED THE WARNING ACROSS ASHLAND/IRON COUNTIES. THE
MONTREAL REMAINS HIGH...AND THE ASHLAND COUNTY COMMISSIONER
REPORTED SEVERAL ROADS UNDER WATER AS WELL. ALL THIS SNOW THAT HAS
RECENTLY FALLEN WILL START TO MELT THIS WEEKEND ALTHOUGH
TEMPERATURES WILL BE BELOW NORMAL UNTIL MONDAY/TUESDAY. THIS
SNOWFALL AS WELL AS SNOW THAT WAS ALREADY ON THE GROUND WILL KEEP
RIVERS AND STREAMS ELEVATED. THE BAD RIVER HAS FALLEN A COUPLE
FEET SINCE YESTERDAY...BUT COULD START TO RISE AGAIN AS THE SNOW
MELTS.
&&
.POINT TEMPS/POPS...
DLH 37 32 40 36 / 80 80 60 50
INL 47 29 51 33 / 10 10 10 10
BRD 49 34 45 38 / 10 50 60 40
HYR 33 32 44 34 / 90 90 60 30
ASX 34 32 39 33 / 90 90 60 40
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...WINTER WEATHER ADVISORY UNTIL 10 PM CDT THIS EVENING FOR
WIZ002>004-007-008.
LS...SMALL CRAFT ADVISORY UNTIL 1 AM CDT SATURDAY FOR LSZ121-143>148.
&&
$$
SHORT TERM...GRANING
LONG TERM....CLC
AVIATION...CLC
AREA FORECAST DISCUSSION
NWS DULUTH MN
1025 AM CDT FRI MAY 3 2013
.UPDATE...
HAVE EXTENDED THE WINTER WEATHER ADVISORY FOR FREEZING RAIN OVER
NORTHERN WISCONSIN /EXCEPT PRICE COUNTY/ THROUGH 1000 PM THIS
EVENING...POSSIBLY NEEDING TO BE EXTENDED FURTHER. THE 12Z
NAM/DLHWRF BOTH SHOW SFC TEMPS REMAIN BELOW FREEZING OVER THE
ADVISORY AREA THROUGH AT LEAST MIDNIGHT. MEANWHILE...AN S-SE H85
FLOW WILL CONTINUE TO WARM MID LEVELS THROUGH THE
DAY...DIMINISHING ANY LINGERING SNOW AND PROMOTING FREEZING RAIN
THIS AFTERNOON/TONIGHT.
HAVE INTRODUCED MENTION OF FREEZING RAIN TO MN ARROWHEAD ZONES
THIS AFTERNOON AND EVENING WHERE H80-H85 LAYER TEMPS WARM A FEW
DEGREES ABOVE 0 C...WHILE SFC READINGS REMAIN SUB-FREEZING. WE
WILL CLOSELY MONITOR THIS AREA FOR ICE ACCUM POTENTIAL...AND AN
ADVISORY MAY BE NEEDED THIS AFTERNOON/TONIGHT FOR LAKE COOK
COUNTIES.
&&
.PREV DISCUSSION... /ISSUED 644 AM CDT FRI MAY 3 2013/
AVIATION...12Z TAFS
WAA AND AN INVERTED TROUGH WERE CAUSING SNOW...WITH A WINTRY MIX IN
SPOTS OVER NORTHWEST WISCONSIN. MVFR WITH SOME SPOTTY IFR CEILINGS
COVERED NORTHWEST WISCONSIN. OVERALL...MVFR OR EVEN SOME IFR
CONDITIONS SHOULD SPREAD WEST AND NORTH THROUGH THE DAY INTO
TONIGHT. SNOW...OR A WINTRY MIX WILL ALSO SPREAD WEST AND NORTH
TODAY. BOUNDARY LAYER TEMPS WILL THEN WARM AND RAIN WILL BECOME
MORE WIDESPREAD. FREEZING RAIN WILL THEN BE POSSIBLE AGAIN LATER
TONIGHT AS SURFACE TEMPS COOL.
PREV DISCUSSION... /ISSUED 408 AM CDT FRI MAY 3 2013/
SHORT TERM...TODAY THROUGH SATURDAY.
AT 4 AM...IT WAS FAIRLY QUIET ACROSS THE NORTHLAND. THERE WAS SOME
LIGHT SNOW ACROSS NW WI...AND REPORTS JUST OUTSIDE OF THE CWA OF
SOME LIGHT FREEZING DRIZZLE. TEMPERATURES RANGED FROM THE 20S IN
NE MN TO AROUND 30 IN NW WI.
THE NEXT MAIN WAVE OF PRECIPITATION WAS QUICKLY STREAMING
NORTHWARD THROUGH THE PLAINS. WE SHOULD SEE AN INCREASE
THROUGHOUT THE MORNING ACROSS WESTERN WISCONSIN. DEFINITELY SOME
PTYPE ISSUES...AND A THOROUGH ASSESSMENT OF THE FORECAST SOUNDINGS
SHOW SOME PRETTY SIGNIFICANT DIFFERENCES AMONG THE MODELS. JUST A
FEW DEGREES DIFFERENCE IN THE WARM LAYER WILL MEAN A CHANGE FROM
FREEZING RAIN OR RAIN...TO SLEET AND/OR SNOW.
FOR TODAY...HAVE RAISED POPS A BIT THROUGHOUT THE DAY...FIRST WITH
LIKELY POPS IN THE EASTERN 1/3 OF THE CWA...AND THEN SPREADING IT
NORTHWARD AND WESTWARD AS THE MORNING WEARS ON. NAM BUFR SOUNDINGS
AND THE HRRR FORECAST PTYPE INDICATE THAT A MIXTURE COULD LAST
INTO THE AFTERNOON...AND THERE MAY BE SOME SLEET AS WELL.
FORECAST LAYER THICKNESS VALUES ALSO INDICATE SOME POTENTIAL FOR
THIS TO LAST INTO THE AFTERNOON AND EVEN TONIGHT. WILL EXTEND THE
ADVISORY TIME THROUGH NOON WITH THE CAVEAT THAT SOME AREAS MAY
NEED TO BE EXTENDED INTO THE AFTERNOON.
HAVE INCREASED POPS CONSIDERABLY TONIGHT AND ON SATURDAY...WITH
GENERALLY RAIN DURING THE EVENING AND RAIN AND/OR FREEZING RAIN
AFTER MIDNIGHT. IN GENERAL...WE SHOULD SEE MAINLY RAIN ON
SATURDAY. TEMPS WILL BE TRICKY DUE TO THE CLOUDS AND EXPECTED
PRECIPITATION.
LONG TERM...SATURDAY NIGHT THROUGH THURSDAY.
A TROUGH OF LOW PRESSURE AND BAROCLINIC ZONE IS EVIDENT SATURDAY
NIGHT...WEAKENING SUNDAY. THIS WILL LEAD TO A CHANCE FOR RAIN OVER
MUCH OF THE CWA SATURDAY NIGHT...DIMINISHING FROM NORTH TO SOUTH
SUNDAY. RIDGING WILL TAKE OVER MONDAY INTO MONDAY NIGHT AND LEAD TO
A DRY PERIOD.
CONFIDENCE DIMINISHES MONDAY NIGHT INTO AT LEAST MID WEEK...AS THE
ECMWF BRINGS IN A SHORTWAVE AND SUPPORTS THE CHANCE FOR SHOWERS
TUESDAY/WEDNESDAY. WE FOLLOWED CLOSER TO THIS SOLUTION DURING THAT
PERIOD.
THE MODELS THEN HAVE A FASTER WNW FLOW OVER FAR NORTHERN MN/SOUTHERN
CANADA BY LATE IN THE WEEK WITH A CONTINUED CHANCE FOR RAIN WITH
WEAK LOW PRESSURE AT THE SURFACE. WE HAVE POPS CONTINUING THROUGH
THE REST OF THE PERIOD...ALTHOUGH WERE NOT OVERLY IMPRESSED WITH THE
FORCING AND EXPECTED PRECIPITATION AMOUNTS.
TEMPERATURES WILL BE A BIT BELOW NORMAL SUNDAY...RISING INTO THE
SIXTIES MONDAY THROUGH THE END OF THE WEEK.
HYDROLOGY...
FLOOD WARNINGS CONTINUED FOR THE MISSISSIPPI RIVER AT AITKIN AND
FORT RIPLEY FOR MINOR FLOODING. WE DROPPED THE WARNING FOR THE
SAINT LOUIS RIVER IN SCANLON AS THERE IS A CLEAR LOWERING TREND.
A FLOOD WARNING REMAINS FOR CENTRAL AND SOUTHERN SAINT LOUIS
COUNTY AS THERE IS STILL FLOODING OCCURRING THERE WITH WATER OVER
SEVERAL ROADS ACCORDING TO THE SAINT LOUIS COUNTY HIGHWAY
DEPARTMENT. THE NUMBER OF CLOSED ROADS HAD DIMINISHED SINCE
YESTERDAY THOUGH. THERE IS STILL SNOW OVER NORTHERN
MINNESOTA...ESPECIALLY IN THE WOODS. COOLER TEMPS TODAY WILL SLOW
THE MELT...BUT TEMPS WILL START TO WARM THIS WEEKEND INTO NEXT
WEEK...KEEPING ELEVATED RIVERS/STREAMS.
WE CONTINUED THE WARNING ACROSS ASHLAND/IRON COUNTIES. THE
MONTREAL REMAINS HIGH...AND THE ASHLAND COUNTY COMMISSIONER
REPORTED SEVERAL ROADS UNDER WATER AS WELL. ALL THIS SNOW THAT HAS
RECENTLY FALLEN WILL START TO MELT THIS WEEKEND ALTHOUGH
TEMPERATURES WILL BE BELOW NORMAL UNTIL MONDAY/TUESDAY. THIS
SNOWFALL AS WELL AS SNOW THAT WAS ALREADY ON THE GROUND WILL KEEP
RIVERS AND STREAMS ELEVATED. THE BAD RIVER HAS FALLEN A COUPLE
FEET SINCE YESTERDAY...BUT COULD START TO RISE AGAIN AS THE SNOW
MELTS.
&&
.POINT TEMPS/POPS...
DLH 37 32 40 36 / 80 80 60 50
INL 47 29 51 33 / 10 20 10 10
BRD 49 34 45 38 / 10 60 60 40
HYR 33 32 44 34 / 90 80 60 30
ASX 34 32 39 33 / 90 80 60 40
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...WINTER WEATHER ADVISORY UNTIL 10 PM CDT THIS EVENING FOR
WIZ002>004-007-008.
WINTER WEATHER ADVISORY UNTIL NOON CDT TODAY FOR WIZ009.
LS...SMALL CRAFT ADVISORY UNTIL 1 AM CDT SATURDAY FOR LSZ121-143>148.
&&
$$
SHORT TERM...GRANING
AREA FORECAST DISCUSSION
NWS DULUTH MN
644 AM CDT FRI MAY 3 2013
.AVIATION...12Z TAFS
WAA AND AN INVERTED TROUGH WERE CAUSING SNOW...WITH A WINTRY MIX IN
SPOTS OVER NORTHWEST WISCONSIN. MVFR WITH SOME SPOTTY IFR CEILINGS
COVERED NORTHWEST WISCONSIN. OVERALL...MVFR OR EVEN SOME IFR
CONDITIONS SHOULD SPREAD WEST AND NORTH THROUGH THE DAY INTO
TONIGHT. SNOW...OR A WINTRY MIX WILL ALSO SPREAD WEST AND NORTH
TODAY. BOUNDARY LAYER TEMPS WILL THEN WARM AND RAIN WILL BECOME
MORE WIDESPREAD. FREEZING RAIN WILL THEN BE POSSIBLE AGAIN LATER
TONIGHT AS SURFACE TEMPS COOL.
&&
.PREV DISCUSSION... /ISSUED 408 AM CDT FRI MAY 3 2013/
SHORT TERM...TODAY THROUGH SATURDAY.
AT 4 AM...IT WAS FAIRLY QUIET ACROSS THE NORTHLAND. THERE WAS SOME
LIGHT SNOW ACROSS NW WI...AND REPORTS JUST OUTSIDE OF THE CWA OF
SOME LIGHT FREEZING DRIZZLE. TEMPERATURES RANGED FROM THE 20S IN
NE MN TO AROUND 30 IN NW WI.
THE NEXT MAIN WAVE OF PRECIPITATION WAS QUICKLY STREAMING
NORTHWARD THROUGH THE PLAINS. WE SHOULD SEE AN INCREASE
THROUGHOUT THE MORNING ACROSS WESTERN WISCONSIN. DEFINITELY SOME
PTYPE ISSUES...AND A THOROUGH ASSESSMENT OF THE FORECAST SOUNDINGS
SHOW SOME PRETTY SIGNIFICANT DIFFERENCES AMONG THE MODELS. JUST A
FEW DEGREES DIFFERENCE IN THE WARM LAYER WILL MEAN A CHANGE FROM
FREEZING RAIN OR RAIN...TO SLEET AND/OR SNOW.
FOR TODAY...HAVE RAISED POPS A BIT THROUGHOUT THE DAY...FIRST WITH
LIKELY POPS IN THE EASTERN 1/3 OF THE CWA...AND THEN SPREADING IT
NORTHWARD AND WESTWARD AS THE MORNING WEARS ON. NAM BUFR SOUNDINGS
AND THE HRRR FORECAST PTYPE INDICATE THAT A MIXTURE COULD LAST
INTO THE AFTERNOON...AND THERE MAY BE SOME SLEET AS WELL.
FORECAST LAYER THICKNESS VALUES ALSO INDICATE SOME POTENTIAL FOR
THIS TO LAST INTO THE AFTERNOON AND EVEN TONIGHT. WILL EXTEND THE
ADVISORY TIME THROUGH NOON WITH THE CAVEAT THAT SOME AREAS MAY
NEED TO BE EXTENDED INTO THE AFTERNOON.
HAVE INCREASED POPS CONSIDERABLY TONIGHT AND ON SATURDAY...WITH
GENERALLY RAIN DURING THE EVENING AND RAIN AND/OR FREEZING RAIN
AFTER MIDNIGHT. IN GENERAL...WE SHOULD SEE MAINLY RAIN ON
SATURDAY. TEMPS WILL BE TRICKY DUE TO THE CLOUDS AND EXPECTED
PRECIPITATION.
LONG TERM...SATURDAY NIGHT THROUGH THURSDAY.
A TROUGH OF LOW PRESSURE AND BAROCLINIC ZONE IS EVIDENT SATURDAY
NIGHT...WEAKENING SUNDAY. THIS WILL LEAD TO A CHANCE FOR RAIN OVER
MUCH OF THE CWA SATURDAY NIGHT...DIMINISHING FROM NORTH TO SOUTH
SUNDAY. RIDGING WILL TAKE OVER MONDAY INTO MONDAY NIGHT AND LEAD TO
A DRY PERIOD.
CONFIDENCE DIMINISHES MONDAY NIGHT INTO AT LEAST MID WEEK...AS THE
ECMWF BRINGS IN A SHORTWAVE AND SUPPORTS THE CHANCE FOR SHOWERS
TUESDAY/WEDNESDAY. WE FOLLOWED CLOSER TO THIS SOLUTION DURING THAT
PERIOD.
THE MODELS THEN HAVE A FASTER WNW FLOW OVER FAR NORTHERN MN/SOUTHERN
CANADA BY LATE IN THE WEEK WITH A CONTINUED CHANCE FOR RAIN WITH
WEAK LOW PRESSURE AT THE SURFACE. WE HAVE POPS CONTINUING THROUGH
THE REST OF THE PERIOD...ALTHOUGH WERE NOT OVERLY IMPRESSED WITH THE
FORCING AND EXPECTED PRECIPITATION AMOUNTS.
TEMPERATURES WILL BE A BIT BELOW NORMAL SUNDAY...RISING INTO THE
SIXTIES MONDAY THROUGH THE END OF THE WEEK.
HYDROLOGY...
FLOOD WARNINGS CONTINUED FOR THE MISSISSIPPI RIVER AT AITKIN AND
FORT RIPLEY FOR MINOR FLOODING. WE DROPPED THE WARNING FOR THE
SAINT LOUIS RIVER IN SCANLON AS THERE IS A CLEAR LOWERING TREND.
A FLOOD WARNING REMAINS FOR CENTRAL AND SOUTHERN SAINT LOUIS
COUNTY AS THERE IS STILL FLOODING OCCURRING THERE WITH WATER OVER
SEVERAL ROADS ACCORDING TO THE SAINT LOUIS COUNTY HIGHWAY
DEPARTMENT. THE NUMBER OF CLOSED ROADS HAD DIMINISHED SINCE
YESTERDAY THOUGH. THERE IS STILL SNOW OVER NORTHERN
MINNESOTA...ESPECIALLY IN THE WOODS. COOLER TEMPS TODAY WILL SLOW
THE MELT...BUT TEMPS WILL START TO WARM THIS WEEKEND INTO NEXT
WEEK...KEEPING ELEVATED RIVERS/STREAMS.
WE CONTINUED THE WARNING ACROSS ASHLAND/IRON COUNTIES. THE
MONTREAL REMAINS HIGH...AND THE ASHLAND COUNTY COMMISSIONER
REPORTED SEVERAL ROADS UNDER WATER AS WELL. ALL THIS SNOW THAT HAS
RECENTLY FALLEN WILL START TO MELT THIS WEEKEND ALTHOUGH
TEMPERATURES WILL BE BELOW NORMAL UNTIL MONDAY/TUESDAY. THIS
SNOWFALL AS WELL AS SNOW THAT WAS ALREADY ON THE GROUND WILL KEEP
RIVERS AND STREAMS ELEVATED. THE BAD RIVER HAS FALLEN A COUPLE
FEET SINCE YESTERDAY...BUT COULD START TO RISE AGAIN AS THE SNOW
MELTS.
&&
.POINT TEMPS/POPS...
DLH 40 32 40 36 / 40 80 60 50
INL 47 29 51 33 / 10 20 10 10
BRD 49 34 45 38 / 10 60 60 40
HYR 42 32 44 34 / 80 80 60 30
ASX 37 32 39 33 / 70 80 60 40
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...WINTER WEATHER ADVISORY UNTIL NOON CDT TODAY FOR WIZ002>004-
007>009.
LS...SMALL CRAFT ADVISORY UNTIL 1 AM CDT SATURDAY FOR LSZ121-143>148.
&&
$$
SHORT TERM...DAP
LONG TERM....MELDE
AVIATION...MELDE
AREA FORECAST DISCUSSION...CORRECTED
NWS DULUTH MN
408 AM CDT FRI MAY 3 2013
.SHORT TERM...TODAY THROUGH SATURDAY.
AT 4 AM...IT WAS FAIRLY QUIET ACROSS THE NORTHLAND. THERE WAS SOME
LIGHT SNOW ACROSS NW WI...AND REPORTS JUST OUTSIDE OF THE CWA OF
SOME LIGHT FREEZING DRIZZLE. TEMPERATURES RANGED FROM THE 20S IN
NE MN TO AROUND 30 IN NW WI.
THE NEXT MAIN WAVE OF PRECIPITATION WAS QUICKLY STREAMING
NORTHWARD THROUGH THE PLAINS. WE SHOULD SEE AN INCREASE
THROUGHOUT THE MORNING ACROSS WESTERN WISCONSIN. DEFINITELY SOME
PTYPE ISSUES...AND A THOROUGH ASSESSMENT OF THE FORECAST SOUNDINGS
SHOW SOME PRETTY SIGNIFICANT DIFFERENCES AMONG THE MODELS. JUST A
FEW DEGREES DIFFERENCE IN THE WARM LAYER WILL MEAN A CHANGE FROM
FREEZING RAIN OR RAIN...TO SLEET AND/OR SNOW.
FOR TODAY...HAVE RAISED POPS A BIT THROUGHOUT THE DAY...FIRST WITH
LIKELY POPS IN THE EASTERN 1/3 OF THE CWA...AND THEN SPREADING IT
NORTHWARD AND WESTWARD AS THE MORNING WEARS ON. NAM BUFR SOUNDINGS
AND THE HRRR FORECAST PTYPE INDICATE THAT A MIXTURE COULD LAST
INTO THE AFTERNOON...AND THERE MAY BE SOME SLEET AS WELL.
FORECAST LAYER THICKNESS VALUES ALSO INDICATE SOME POTENTIAL FOR
THIS TO LAST INTO THE AFTERNOON AND EVEN TONIGHT. WILL EXTEND THE
ADVISORY TIME THROUGH NOON WITH THE CAVEAT THAT SOME AREAS MAY
NEED TO BE EXTENDED INTO THE AFTERNOON.
HAVE INCREASED POPS CONSIDERABLY TONIGHT AND ON SATURDAY...WITH
GENERALLY RAIN DURING THE EVENING AND RAIN AND/OR FREEZING RAIN
AFTER MIDNIGHT. IN GENERAL...WE SHOULD SEE MAINLY RAIN ON
SATURDAY. TEMPS WILL BE TRICKY DUE TO THE CLOUDS AND EXPECTED
PRECIPITATION.
.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY.
A TROUGH OF LOW PRESSURE AND BAROCLINIC ZONE IS EVIDENT SATURDAY
NIGHT...WEAKENING SUNDAY. THIS WILL LEAD TO A CHANCE FOR RAIN OVER
MUCH OF THE CWA SATURDAY NIGHT...DIMINISHING FROM NORTH TO SOUTH
SUNDAY. RIDGING WILL TAKE OVER MONDAY INTO MONDAY NIGHT AND LEAD TO
A DRY PERIOD.
CONFIDENCE DIMINISHES MONDAY NIGHT INTO AT LEAST MID WEEK...AS THE
ECMWF BRINGS IN A SHORTWAVE AND SUPPORTS THE CHANCE FOR SHOWERS
TUESDAY/WEDNESDAY. WE FOLLOWED CLOSER TO THIS SOLUTION DURING THAT
PERIOD.
THE MODELS THEN HAVE A FASTER WNW FLOW OVER FAR NORTHERN MN/SOUTHERN
CANADA BY LATE IN THE WEEK WITH A CONTINUED CHANCE FOR RAIN WITH
WEAK LOW PRESSURE AT THE SURFACE. WE HAVE POPS CONTINUING THROUGH
THE REST OF THE PERIOD...ALTHOUGH WERE NOT OVERLY IMPRESSED WITH THE
FORCING AND EXPECTED PRECIPITATION AMOUNTS.
TEMPERATURES WILL BE A BIT BELOW NORMAL SUNDAY...RISING INTO THE
SIXTIES MONDAY THROUGH THE END OF THE WEEK.
&&
.AVIATION...06Z TAFS
A BAND OF PCPN OVER NW WISCONSIN THAT IS ASSOCIATED WITH A WINTER
STORM THAT HAS BEEN AFFECTING THE REGION SINCE LAST NIGHT WILL
CONTINUE THROUGH FRIDAY. THE SNOW WILL LIKELY TRANSITION TO A WINTRY
MIXTURE OF SNOW/SLEET/-FZRA LATE TONIGHT AND THEN TO -RA BY EARLY
FRIDAY AFTERNOON. WIDESPREAD IFR/MVFR CONDITIONS ACROSS NW WISCONSIN
WILL LIKELY CONTINUE THROUGH FRIDAY.
WIDESPREAD LOW VFR CIGS IN THE 3 TO 4 KFT RANGE WILL PREVAIL
ACROSS NE MINNESOTA THROUGH AT LEAST TONIGHT IF NOT FRIDAY. THERE
MAY BE TIMES WHERE KDLH/KHIB/KINL FLIRT WITH MVFR CIGS. THE PCPN AND
MVFR CIGS OVER NW WISCONSIN WILL LIKELY BEGIN TO MOVE INTO KDLH
TOMORROW MORNING OR AFTERNOON AS THE BAND OF PCPN SPREADS
WESTWARD...AND THEN INTO THE KBRD AND KHIB AREAS IN THE AFTERNOON OR
EVENING. BY THE TIME THE PCPN MOVES INTO KDLH...IT SHOULD MOSTLY BE
-RA.
&&
.HYDROLOGY...
FLOOD WARNINGS CONTINUED FOR THE MISSISSIPPI RIVER AT AITKIN AND
FORT RIPLEY FOR MINOR FLOODING. WE DROPPED THE WARNING FOR THE
SAINT LOUIS RIVER IN SCANLON AS THERE IS A CLEAR LOWERING TREND.
A FLOOD WARNING REMAINS FOR CENTRAL AND SOUTHERN SAINT LOUIS
COUNTY AS THERE IS STILL FLOODING OCCURRING THERE WITH WATER OVER
SEVERAL ROADS ACCORDING TO THE SAINT LOUIS COUNTY HIGHWAY
DEPARTMENT. THE NUMBER OF CLOSED ROADS HAD DIMINISHED SINCE
YESTERDAY THOUGH. THERE IS STILL SNOW OVER NORTHERN
MINNESOTA...ESPECIALLY IN THE WOODS. COOLER TEMPS TODAY WILL SLOW
THE MELT...BUT TEMPS WILL START TO WARM THIS WEEKEND INTO NEXT
WEEK...KEEPING ELEVATED RIVERS/STREAMS.
WE CONTINUED THE WARNING ACROSS ASHLAND/IRON COUNTIES. THE
MONTREAL REMAINS HIGH...AND THE ASHLAND COUNTY COMMISSIONER
REPORTED SEVERAL ROADS UNDER WATER AS WELL. ALL THIS SNOW THAT HAS
RECENTLY FALLEN WILL START TO MELT THIS WEEKEND ALTHOUGH
TEMPERATURES WILL BE BELOW NORMAL UNTIL MONDAY/TUESDAY. THIS
SNOWFALL AS WELL AS SNOW THAT WAS ALREADY ON THE GROUND WILL KEEP
RIVERS AND STREAMS ELEVATED. THE BAD RIVER HAS FALLEN A COUPLE
FEET SINCE YESTERDAY...BUT COULD START TO RISE AGAIN AS THE SNOW
MELTS.
&&
.POINT TEMPS/POPS...
DLH 40 32 40 36 / 40 80 60 50
INL 47 29 51 33 / 10 20 10 10
BRD 49 34 45 38 / 10 60 60 40
HYR 42 32 44 34 / 80 80 60 30
ASX 37 32 39 33 / 70 80 60 40
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...WINTER WEATHER ADVISORY UNTIL NOON CDT TODAY FOR WIZ002>004-
007>009.
LS...SMALL CRAFT ADVISORY UNTIL 1 AM CDT SATURDAY FOR LSZ143>146.
SMALL CRAFT ADVISORY UNTIL 1 AM CDT SATURDAY FOR LSZ121-147-148.
&&
$$
SHORT TERM...DAP
LONG TERM....MELDE
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS DULUTH MN
406 AM CDT FRI MAY 3 2013
.SHORT TERM...TODAY THROUGH WEDNESDAY.
AT 4 AM...IT WAS FAIRLY QUIET ACROSS THE NORTHLAND. THERE WAS SOME
LIGHT SNOW ACROSS NW WI...AND REPORTS JUST OUTSIDE OF THE CWA OF
SOME LIGHT FREEZING DRIZZLE. TEMPERATURES RANGED FROM THE 20S IN
NE MN TO AROUND 30 IN NW WI.
THE NEXT MAIN WAVE OF PRECIPITATION WAS QUICKLY STREAMING
NORTHWARD THROUGH THE PLAINS. WE SHOULD SEE AN INCREASE
THROUGHOUT THE MORNING ACROSS WESTERN WISCONSIN. DEFINITELY SOME
PTYPE ISSUES...AND A THOROUGH ASSESSMENT OF THE FORECAST SOUNDINGS
SHOW SOME PRETTY SIGNIFICANT DIFFERENCES AMONG THE MODELS. JUST A
FEW DEGREES DIFFERENCE IN THE WARM LAYER WILL MEAN A CHANGE FROM
FREEZING RAIN OR RAIN...TO SLEET AND/OR SNOW.
FOR TODAY...HAVE RAISED POPS A BIT THROUGHOUT THE DAY...FIRST WITH
LIKELY POPS IN THE EASTERN 1/3 OF THE CWA...AND THEN SPREADING IT
NORTHWARD AND WESTWARD AS THE MORNING WEARS ON. NAM BUFR SOUNDINGS
AND THE HRRR FORECAST PTYPE INDICATE THAT A MIXTURE COULD LAST
INTO THE AFTERNOON...AND THERE MAY BE SOME SLEET AS WELL.
FORECAST LAYER THICKNESS VALUES ALSO INDICATE SOME POTENTIAL FOR
THIS TO LAST INTO THE AFTERNOON AND EVEN TONIGHT. WILL EXTEND THE
ADVISORY TIME THROUGH NOON WITH THE CAVEAT THAT SOME AREAS MAY
NEED TO BE EXTENDED INTO THE AFTERNOON.
HAVE INCREASED POPS CONSIDERABLY TONIGHT AND ON SATURDAY...WITH
GENERALLY RAIN DURING THE EVENING AND RAIN AND/OR FREEZING RAIN
AFTER MIDNIGHT. IN GENERAL...WE SHOULD SEE MAINLY RAIN ON
SATURDAY. TEMPS WILL BE TRICKY DUE TO THE CLOUDS AND EXPECTED
PRECIPITATION.
.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY.
A TROUGH OF LOW PRESSURE AND BAROCLINIC ZONE IS EVIDENT SATURDAY
NIGHT...WEAKENING SUNDAY. THIS WILL LEAD TO A CHANCE FOR RAIN OVER
MUCH OF THE CWA SATURDAY NIGHT...DIMINISHING FROM NORTH TO SOUTH
SUNDAY. RIDGING WILL TAKE OVER MONDAY INTO MONDAY NIGHT AND LEAD TO
A DRY PERIOD.
CONFIDENCE DIMINISHES MONDAY NIGHT INTO AT LEAST MID WEEK...AS THE
ECMWF BRINGS IN A SHORTWAVE AND SUPPORTS THE CHANCE FOR SHOWERS
TUESDAY/WEDNESDAY. WE FOLLOWED CLOSER TO THIS SOLUTION DURING THAT
PERIOD.
THE MODELS THEN HAVE A FASTER WNW FLOW OVER FAR NORTHERN MN/SOUTHERN
CANADA BY LATE IN THE WEEK WITH A CONTINUED CHANCE FOR RAIN WITH
WEAK LOW PRESSURE AT THE SURFACE. WE HAVE POPS CONTINUING THROUGH
THE REST OF THE PERIOD...ALTHOUGH WERE NOT OVERLY IMPRESSED WITH THE
FORCING AND EXPECTED PRECIPITATION AMOUNTS.
TEMPERATURES WILL BE A BIT BELOW NORMAL SUNDAY...RISING INTO THE
SIXTIES MONDAY THROUGH THE END OF THE WEEK.
&&
.AVIATION...06Z TAFS
A BAND OF PCPN OVER NW WISCONSIN THAT IS ASSOCIATED WITH A WINTER
STORM THAT HAS BEEN AFFECTING THE REGION SINCE LAST NIGHT WILL
CONTINUE THROUGH FRIDAY. THE SNOW WILL LIKELY TRANSITION TO A WINTRY
MIXTURE OF SNOW/SLEET/-FZRA LATE TONIGHT AND THEN TO -RA BY EARLY
FRIDAY AFTERNOON. WIDESPREAD IFR/MVFR CONDITIONS ACROSS NW WISCONSIN
WILL LIKELY CONTINUE THROUGH FRIDAY.
WIDESPREAD LOW VFR CIGS IN THE 3 TO 4 KFT RANGE WILL PREVAIL
ACROSS NE MINNESOTA THROUGH AT LEAST TONIGHT IF NOT FRIDAY. THERE
MAY BE TIMES WHERE KDLH/KHIB/KINL FLIRT WITH MVFR CIGS. THE PCPN AND
MVFR CIGS OVER NW WISCONSIN WILL LIKELY BEGIN TO MOVE INTO KDLH
TOMORROW MORNING OR AFTERNOON AS THE BAND OF PCPN SPREADS
WESTWARD...AND THEN INTO THE KBRD AND KHIB AREAS IN THE AFTERNOON OR
EVENING. BY THE TIME THE PCPN MOVES INTO KDLH...IT SHOULD MOSTLY BE
-RA.
&&
.HYDROLOGY...
FLOOD WARNINGS CONTINUED FOR THE MISSISSIPPI RIVER AT AITKIN AND
FORT RIPLEY FOR MINOR FLOODING. WE DROPPED THE WARNING FOR THE
SAINT LOUIS RIVER IN SCANLON AS THERE IS A CLEAR LOWERING TREND.
A FLOOD WARNING REMAINS FOR CENTRAL AND SOUTHERN SAINT LOUIS
COUNTY AS THERE IS STILL FLOODING OCCURRING THERE WITH WATER OVER
SEVERAL ROADS ACCORDING TO THE SAINT LOUIS COUNTY HIGHWAY
DEPARTMENT. THE NUMBER OF CLOSED ROADS HAD DIMINISHED SINCE
YESTERDAY THOUGH. THERE IS STILL SNOW OVER NORTHERN
MINNESOTA...ESPECIALLY IN THE WOODS. COOLER TEMPS TODAY WILL SLOW
THE MELT...BUT TEMPS WILL START TO WARM THIS WEEKEND INTO NEXT
WEEK...KEEPING ELEVATED RIVERS/STREAMS.
WE CONTINUED THE WARNING ACROSS ASHLAND/IRON COUNTIES. THE
MONTREAL REMAINS HIGH...AND THE ASHLAND COUNTY COMMISSIONER
REPORTED SEVERAL ROADS UNDER WATER AS WELL. ALL THIS SNOW THAT HAS
RECENTLY FALLEN WILL START TO MELT THIS WEEKEND ALTHOUGH
TEMPERATURES WILL BE BELOW NORMAL UNTIL MONDAY/TUESDAY. THIS
SNOWFALL AS WELL AS SNOW THAT WAS ALREADY ON THE GROUND WILL KEEP
RIVERS AND STREAMS ELEVATED. THE BAD RIVER HAS FALLEN A COUPLE
FEET SINCE YESTERDAY...BUT COULD START TO RISE AGAIN AS THE SNOW
MELTS.
&&
.POINT TEMPS/POPS...
DLH 40 32 40 36 / 40 80 60 50
INL 47 29 51 33 / 10 20 10 10
BRD 49 34 45 38 / 10 60 60 40
HYR 42 32 44 34 / 80 80 60 30
ASX 37 32 39 33 / 70 80 60 40
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...WINTER WEATHER ADVISORY UNTIL NOON CDT TODAY FOR WIZ002>004-
007>009.
LS...SMALL CRAFT ADVISORY UNTIL 1 AM CDT SATURDAY FOR LSZ143>146.
SMALL CRAFT ADVISORY UNTIL 1 AM CDT SATURDAY FOR LSZ121-147-148.
&&
$$
SHORT TERM...DAP
LONG TERM....MELDE
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS DULUTH MN
1233 AM CDT FRI MAY 3 2013
.AVIATION...06Z TAFS
A BAND OF PCPN OVER NW WISCONSIN THAT IS ASSOCIATED WITH A WINTER
STORM THAT HAS BEEN AFFECTING THE REGION SINCE LAST NIGHT WILL
CONTINUE THROUGH FRIDAY. THE SNOW WILL LIKELY TRANSITION TO A WINTRY
MIXTURE OF SNOW/SLEET/-FZRA LATE TONIGHT AND THEN TO -RA BY EARLY
FRIDAY AFTERNOON. WIDESPREAD IFR/MVFR CONDITIONS ACROSS NW WISCONSIN
WILL LIKELY CONTINUE THROUGH FRIDAY.
WIDESPREAD LOW VFR CIGS IN THE 3 TO 4 KFT RANGE WILL PREVAIL
ACROSS NE MINNESOTA THROUGH AT LEAST TONIGHT IF NOT FRIDAY. THERE
MAY BE TIMES WHERE KDLH/KHIB/KINL FLIRT WITH MVFR CIGS. THE PCPN AND
MVFR CIGS OVER NW WISCONSIN WILL LIKELY BEGIN TO MOVE INTO KDLH
TOMORROW MORNING OR AFTERNOON AS THE BAND OF PCPN SPREADS
WESTWARD...AND THEN INTO THE KBRD AND KHIB AREAS IN THE AFTERNOON OR
EVENING. BY THE TIME THE PCPN MOVES INTO KDLH...IT SHOULD MOSTLY BE
-RA.
&&
.PREV DISCUSSION... /ISSUED 1003 PM CDT THU MAY 2 2013/
UPDATE...
LIGHT SNOW CONTINUES TO FALL ACROSS NW WISCONSIN THIS EVENING. I
UPDATED THE FORECAST THROUGH THE REST OF TONIGHT. THE SNOW WILL
LIKELY CONTINUE THROUGH THE REST OF THE NIGHT. THERE HAS BEEN A
LITTLE BIT OF A LULL THIS EVENING...BUT THE MODELS AND RADAR
SUGGEST THE SNOW/PCPN RATES MAY PICK UP A BIT AGAIN AFTER
MIDNIGHT. THE LATEST NAM12 SOUNDINGS AND HRRR MODEL RUNS SUGGESTED
THE FREEZING RAIN MIGHT NOT BEGIN TO MOVE INTO NW WISCONSIN UNTIL
VERY LATE TONIGHT...SO I DELAYED ITS ARRIVAL.
THE MAIN CHALLENGE WITH THIS UPDATE WAS TO DETERMINE IF THE WINTER
WEATHER HEADLINES ARE STILL GOOD. MUCH OF NW WISCONSIN STILL HAS A
WINTER STORM WARNING WHICH IS IN EFFECT THROUGH FRIDAY MORNING.
WHILE ONLY LIGHT TO MODERATE SNOW IS EXPECTED THROUGH FRIDAY
MORNING...THE THREAT OF FREEZING RAIN LATER TONIGHT AND FRIDAY
MORNING HAS ME LEANING ON MAINTAINING THE CURRENT HEADLINES. THERE
IS A CHANCE THAT SIGNIFICANTLY MORE FREEZING RAIN COULD FALL THAN
FORECASTED. I THINK IT WOULD BE BEST TO FIRST MONITOR THE CHANGE
OVER TO MIXED PCPN LATER TONIGHT BEFORE MAKING CHANGES. THE NIGHT
SHIFT CAN REEVALUATE WHETHER OR NOT TO CHANGE THE CURRENT WARNINGS
AND ADVISORIES.
PREV DISCUSSION... /ISSUED 719 PM CDT THU MAY 2 2013/
UPDATE...
IT CONTINUES TO SNOW ACROSS NW WISCONSIN EARLY THIS EVENING. IT
ALSO APPEARS TO BE SNOWING LIGHT OVER THE EASTERN ARROWHEAD OF
MINNESOTA...BUT LITTLE TO NO ADDITIONAL ACCUMULATION IS EXPECTED
THROUGH THE REMAINDER OF THE NIGHT. THEREFORE...I LET THE WINTER
WEATHER ADVISORY FOR SOUTHERN COOK COUNTY EXPIRE AS PLANNED. I LET
THE WINTER STORM WARNINGS AND ADVISORY FOR COUNTIES IN NW
WISCONSIN CONTINUE THROUGH TOMORROW MORNING DUE TO THE EXPECTED
ADDITIONAL SNOW AND POTENTIAL FREEZING RAIN. THE LATEST NAM12
SOUNDINGS AND HRRR MODEL RUNS SEEM TO INDICATE THE FREEZING RAIN
MIGHT NOT BEGIN TO MOVE INTO NW WISCONSIN UNTIL VERY LATE
TONIGHT...SO I MIGHT DELAY ITS TIMING IN THE FORECAST WITH A LATER
UPDATE LATER THIS EVENING.
PREV DISCUSSION... /ISSUED 620 PM CDT THU MAY 2 2013/
AVIATION.../00Z TAF ISSUANCE/
A BAND OF PCPN OVER NW WISCONSIN THAT IS ASSOCIATED WITH A WINTER
STORM THAT HAS BEEN AFFECTING THE REGION SINCE LAST NIGHT WILL
CONTINUE THROUGH FRIDAY. THE SNOW WILL LIKELY TRANSITION TO A
WINTRY MIXTURE OF SNOW/SLEET/-FZRA LATE TONIGHT AND THEN TO -RA BY
EARLY FRIDAY AFTERNOON. WIDESPREAD IFR/MVFR CONDITIONS ACROSS NW
WISCONSIN WILL LIKELY CONTINUE THROUGH FRIDAY. UNFORTUNATELY...THE
OBSERVATION EQUIPMENT AT KHYR IS INOPERABLE...SO I AM UNABLE TO
KNOW WHAT IS EXACTLY HAPPENING AT KHYR. I PROVIDED A BEST GUESS
FORECAST FOR KHYR THROUGH FRIDAY...AND I WILL NOT BE PLANNING TO
MAKE ANY AMENDMENTS FOR THIS SITE.
WIDESPREAD LOW VFR CIGS IN THE 3 TO 4 KFT RANGE WILL PREVAIL
ACROSS NE MINNESOTA THROUGH AT LEAST TONIGHT IF NOT FRIDAY. THERE
MAY BE TIMES WHERE KDLH/KHIB/KINL FLIRT WITH MVFR CIGS. THE PCPN AND
MVFR CIGS OVER NW WISCONSIN WILL LIKELY BEGIN TO MOVE INTO KDLH
TOMORROW MORNING OR AFTERNOON AS THE BAND OF PCPN SPREADS
WESTWARD. BY THE TIME THE PCPN MOVES INTO KDLH...IT SHOULD MOSTLY
BE -RA.
PREV DISCUSSION... /ISSUED 351 PM CDT THU MAY 2 2013/
SHORT TERM...THROUGH EARLY FRIDAY EVENING.
WHAT AN IMPRESSIVE EVENT SO FAR...WITH MAX SNOWFALL SO FAR OF 16
INCHES 8 MILES SOUTH OF HAYWARD AND IN ASHLAND. I THINK IT`S
LIKELY THERE WILL BE SOME HIGHER TOTALS THAT COME IN AS ADDITIONAL
REPORTS FILTER IN LATE THIS AFTERNOON OR EVENING.
OVERALL...SNOWFALL INTENSITY WAS DIMINISHING WITH MOST OBSERVATIONS
SHOWING VSBYS AT OR ABOVE THREE QUARTERS OF A MILE. A SPOTTER
REPORTED THE SNOW HAD ENDED FOR NOW IN OGEMA IN SOUTHERN PRICE
COUNTY. WARM AIR ADVECTION AND A TROUGH SHOULD CAUSE PRECIPITATION
TO EXPAND OVERNIGHT OVER NORTHWEST WISCONSIN...AND THE WARMER AIR
ALOFT MOVING IN SHOULD CAUSE A WINTRY MIX TO OCCUR BY LATE TONIGHT
OR FRIDAY MORNING OVER MOST AREAS OF OUR WISCONSIN CWA. HEADLINES
WERE A CHALLENGE OVERNIGHT...AND WE OPTED TO EXTEND THE WARNING
FOR ASHLAND/BAYFIELD/IRON/SAWYER AND PRICE COUNTIES...RATHER THAN
CHANGE IT OVER TO AN ADVISORY. WE DID CHANGE WASHBURN TO AN
ADVISORY...AS MUCH OF THAT COUNTY HAS NOT HAD MUCH ADDITIONAL
SNOWFALL. WE`LL RELAY ADDITIONAL SNOWFALL AND POSSIBLE LIGHT ICE
ACCUMULATIONS IN THE HWO/STATEMENTS/ZONES/GRAPHICAST. WE EXPECT
ANOTHER INCH OR TWO TONIGHT/FRIDAY MORNING...WITH THAT SAME AMOUNT
POSSIBLE THIS AFTERNOON INTO EARLY EVENING.
MODELS ARE IN DECENT AGREEMENT THROUGH THE PERIOD...AND FINALLY ARE IN
GOOD AGREEMENT WITH THE EVOLUTION OF THE UPPER TROUGH THAT WILL
CUT OFF A LOW IN THE CENTRAL PLAINS TONIGHT INTO FRIDAY. THE GFS
WAS MUCH CLOSER THAN THE ECMWF WITH THIS A COUPLE DAYS AGO.
WE DELAYED THE WESTWARD MENTION OF POPS ON FRIDAY AS THE MODELS
KEEP THE BULK OF THE PRECIP OVER NORTHWEST WISCONSIN. WE EXPECT A
TRANSITION TO MAINLY RAIN BY AFTERNOON AS WARMER TEMPS ALOFT
CONTINUE TO ADVECT WEST AND BOUNDARY LAYER TEMPS WARM ABOVE
FREEZING.
LONG TERM...FRIDAY NIGHT THROUGH THURSDAY.
MAIN FOCUS IN EXTENDED IS THREAT FOR FZRA FRIDAY NIGHT AS ANOTHER
ROUND OF RAIN LIFTS NORTH OVER THE REGION. AT THIS TIME...THERE IS A
POTENTIAL FOR SOME LIGHT ICE ACCUM IS OVER THE WIS ZONES...AS WELL
AS IN THE MN ARROWHEAD WHERE SFC TEMPS LOOK TO FALL BELOW FREEZING
AS THE MID LEVELS QUICKLY WARM THROUGH THE NIGHT. AN ONSHORE FLOW
WITH WATER TEMPS IN THE MID 30S SHOULD KEEP AREAS NEAR LAKE SUPERIOR
WARM ENOUGH FOR ALL RA.
A COLD CORE LOW IN THE SOUTHERN STREAM...BECOMES CUT-OFF OVER THE SE
CONUS THROUGH THE WEEKEND. A H85 TROUGH AND REGION OF FGEN EXTENDING
NORTH FROM THE LOW...ACROSS THE NORTHLAND...WILL BE THE FOCUS FOR
ONGOING RAIN FRIDAY NIGHT THROUGH SATURDAY NIGHT. THE LATEST NAM/GFS
BOTH SHOW PWATS INCREASING FROM THE SOUTHEAST FRIDAY
NIGHT...REACHING AROUND AN INCH OVER THE SRN HALF OF THE FA BY SAT
AFTRN. MUCH OF THE NORTHLAND CAN EXPECT RAINFALL TOTALS ON THE ORDER
OF A HALF TO ONE INCH...WITH LOCALLY HIGHER AMOUNTS.
HYDROLOGY...
FLOOD WARNINGS CONTINUED FOR THE MISSISSIPPI RIVER AT AITKIN AND
FORT RIPLEY FOR MINOR FLOODING. WE DROPPED THE WARNING FOR THE
SAINT LOUIS RIVER IN SCANLON AS THERE IS A CLEAR LOWERING TREND.
A FLOOD WARNING REMAINS FOR CENTRAL AND SOUTHERN SAINT LOUIS
COUNTY AS THERE IS STILL FLOODING OCCURRING THERE WITH WATER OVER
SEVERAL ROADS ACCORDING TO THE SAINT LOUIS COUNTY HIGHWAY
DEPARTMENT. THE NUMBER OF CLOSED ROADS HAD DIMINISHED SINCE
YESTERDAY THOUGH. THERE IS STILL SNOW OVER NORTHERN
MINNESOTA...ESPECIALLY IN THE WOODS. COOLER TEMPS TODAY INTO
FRIDAY WILL SLOW THE MELT...BUT TEMPS WILL START TO WARM THIS
WEEKEND INTO NEXT WEEK...KEEPING ELEVATED RIVERS/STREAMS.
WE CONTINUED THE WARNING ACROSS ASHLAND/IRON COUNTIES. THE
MONTREAL REMAINS HIGH...AND THE ASHLAND COUNTY COMMISSIONER
REPORTED SEVERAL ROADS UNDER WATER AS WELL. ALL THIS SNOW THAT HAS
RECENTLY FALLEN WILL START TO MELT THIS WEEKEND ALTHOUGH
TEMPERATURES WILL BE BELOW NORMAL UNTIL MONDAY/TUESDAY. THIS
SNOWFALL AS WELL AS SNOW THAT WAS ALREADY ON THE GROUND WILL KEEP
RIVERS AND STREAMS ELEVATED. THE BAD RIVER HAS FALLEN A COUPLE
FEET SINCE YESTERDAY...BUT COULD START TO RISE AGAIN AS THE SNOW
MELTS.
&&
.POINT TEMPS/POPS...
DLH 42 32 39 35 / 20 80 60 40
INL 48 29 50 32 / 0 10 10 20
BRD 48 34 44 37 / 10 50 60 40
HYR 40 32 43 33 / 70 80 60 30
ASX 37 32 38 33 / 70 80 60 30
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...WINTER STORM WARNING UNTIL 11 AM CDT THIS MORNING FOR WIZ002>004-
008-009.
WINTER WEATHER ADVISORY UNTIL 11 AM CDT THIS MORNING FOR WIZ007.
LS...SMALL CRAFT ADVISORY FROM 4 AM EARLY THIS MORNING TO 1 AM CDT
SATURDAY FOR LSZ144>146.
SMALL CRAFT ADVISORY UNTIL 1 AM CDT SATURDAY FOR LSZ121-147-148.
&&
$$
AVIATION...GROCHOCINSKI/MELDE
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
633 PM CDT SAT MAY 4 2013
.DISCUSSION...
HAVE MADE SEVERAL CHANGES TO THE OVERNIGHT FORECAST TO REFLECT
ONGOING TRENDS. TEMPERATURES ARE ALREADY IN THE LOW 40S...AND
THINK WE WILL SHED AT LEAST A COUPLE OF DEGREES YET TONIGHT. HAVE
REDUCED MIN TEMPS IN MOST LOCATIONS OVERNIGHT...ESPECIALLY IN THE
WEST/NORTHWEST CWA WHERE TEMPS ARE COOLEST. INCREASED SKY COVERAGE
TO 100 PERCENT EVERYWHERE THROUGH THE NIGHT...AS WE WILL BE LOCKED
IN STRATUS THROUGH THE REMAINDER OF THE NIGHT AS LOWER CEILINGS
INVADE FROM THE EAST. AS FAR AS PRECIPITATION...THOUGHT THE 18Z
NAM/12Z 4KM WRF/LATEST FEW RUNS OF RAP HAD A VERY GOOD HANDLE ON
THE CURRENT PRECIP DISTRIBUTION...WITH A NARROW BAND OF RAIN IN
NORTHEAST NEB AND A MORE ROBUST AREA OF SHOWERS IN EAST CENTRAL
IA. THOSE MODELS ERODE THE PRECIPITATION COVERAGE IN IA AS IT
SLIDES WESTWARD THROUGH THE NIGHT...LEAVING JUST A FEW SHOWERS BY
THE TIME IT REACHES WESTERN IA LATER TONIGHT. HAVE KEPT MOST OF
THE CWA FREE OF POPS OVERNIGHT...WITH A PATCHY DRIZZLE MENTION
UNDER WEAK LIFT AND ABUNDANT LOW-LEVEL MOISTURE. DID HOLD ONTO A
CHANCE POP IN THE NORTHWEST CWA EARLY THIS EVENING...AS THE BAND
OF SCATTERED COVERAGE MOVES ACROSS...AS WELL AS A CHANCE IN THE
EAST TONIGHT AS THE DISSIPATING AREAS OF SHOWERS REACH WESTERN IA.
MAYES
&&
.AVIATION...
00Z TAFS FOR KOMA...KLNK...AND KOFK.
IFR CONDITIONS ARE EXPECTED THIS EVENING AND TONIGHT...WITH
IMPROVING CONDITIONS BY SUNDAY AFTERNOON. IFR CEILINGS ARE ALREADY
OVER KOMA AND WILL OVERSPREAD KLNK/KOFK LATER THIS EVENING. MAY
SEE PATCHY DZ AT THE SITES TONIGHT...BUT WILL LIKELY KEEP MENTION
OUT UNLESS IT BECOMES MORE WIDESPREAD. DID INCLUDE MVFR VIS AT ALL
SITES OVERNIGHT. CEILINGS SHOULD LIFT TO MVFR BY MID-MORNING AND
TO VFR BY MIDDAY OR EARLY AFTERNOON. NORTH WINDS ARE EXPECTED TO
REMAIN AT OR BELOW 10KT THROUGH THE PERIOD.
MAYES
&&
.PREV DISCUSSION... /ISSUED 249 PM CDT SAT MAY 4 2013/
DISCUSSION...
LARGE CLOSED UPPER LOW CONTINUES TO SLOWLY SPIN ACROSS NORTHWESTERN
ARKANSAS...WITH MOISTURE CONTINUING TO MOVE FROM EAST TO WEST
THROUGH THE FORECAST AREA. FIRST WAVE MOVED IN LATE LAST NIGHT
THROUGH THIS MORNING...WHICH BROUGHT WIDESPREAD PRECIPITATION TO
THE FORECAST AREA...WHICH CONTINUES THIS AFTERNOON ALONG AND NORTH
OF I80...WHICH HAS MOSTLY BEEN RAIN ALTHOUGH A FEW SNOW FLAKES
WERE NOTED FROM TIME TO TIME. THIS FIRST BATCH OF VERY LIGHT
PRECIP WILL CONTINUE TO PUSH WEST NORTHWEST THROUGH THE NORTHERN
CWA EARLY THIS EVENING.
MEANWHILE...THE NEXT BATCH OF SIMILAR PRECIPITATION IS CURRENTLY
MOVING THROUGH THE MID MISSISSIPPI RIVER VALLEY AND SHOULD BEGIN
TO MOVE INTO OUR AREA BY VERY LATE THIS EVENING AND AFTER
MIDNIGHT. THERE WILL BE A DRY PERIOD IN BETWEEN THE FIRST AND
SECOND WAVES...AND ITS ENTIRELY POSSIBLE THAT PARTS OF SOUTHEAST
NEBRASKA COULD REMAIN DRY OVERNIGHT...BUT CLOUDY.
AS THE UPPER LOW CONTINUES TO DRIFT SLOWLY EAST SOUTHEAST THROUGH
THE DAY SUNDAY...OUR REGION IS LEFT IN A COL AREA WITH LINGERING
TRAPPED MOISTURE...WITH SCATTERED SHOWERS IN THE MORNING...WITH
DIMINISHING COVERAGE IN THE AFTERNOON...AND SHOULD BE OVER BY
SUNDAY EVENING AS WEAK RIDGING BUILDS IN ALOFT. MONDAY MORNING
WILL PROBABLY BE DRY...BUT LEFT IN A SLIGHT CHANCE OF SHOWERS
MONDAY AFTERNOON AS LAPSE RATES STEEPEN ALTHOUGH CYCLONIC FORCING
BY THAT TIME IS ALMOST NON EXIST.
FOR THE EXTENDED FORECAST...THE UPPER CLOSED LOW THAT EXISTS
ACROSS THE WEST COAST WILL CONTINUE TO DEEPEN AND MAY EVEN
RETROGRADE THROUGH MONDAY. MEANWHILE...THE FIRST PIECE OF THIS
SYSTEM MOVING INTO THE CALIFORNIA BAJA REGION TODAY APPEARS TO BE
MOVING THROUGH THE PLAINS BY TUESDAY/WEDNESDAY WHICH WILL BRING
MORE SHOWERS AND PROBABLY THUNDERSTORMS AS INSTABILITY INCREASES...
ALTHOUGH SIGNIFICANT LOW LEVEL MOISTURE IS NOT EXPECTED.
MEANWHILE...THE UPPER CLOSED LOW MOVES INTO THE CENTRAL ROCKIES
AND BEGINS EJECTING SMALL WAVES INTO ONTO THE PLAINS THROUGH THE
REMAINDER OF THE WEEK WHICH WILL BRING DAILY CHANCES FOR RAIN.
AGAIN...NOT THAT IT WILL BE A CONTINUOUSLY RAINY PERIOD...BUT IT
SHOULD DEFINITELY BE A MORE ACTIVE PERIOD. ALSO DURING THIS
TIME...A SUBTLE COOL FRONT APPEARS TO BE SETTLING SOUTHWARD
THROUGH THE AREA...TRANSITIONING WINDS FROM SOUTH EARLY IN THE
PERIOD TO EAST NORTHEAST BY FRIDAY AND SATURDAY.
DEWALD
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BUFFALO NY
135 PM EDT FRI MAY 3 2013
.SYNOPSIS...
HIGH PRESSURE CENTERED OVER NEW ENGLAND AND THE CANADIAN MARITIMES
WILL CONTINUE TO PROVIDE OUR REGION WITH BEAUTIFUL WEATHER THROUGH
THE WEEKEND INTO EARLY NEXT WEEK. TEMPERATURES DURING THAT STRETCH
WILL REMAIN ABOVE NORMAL WITH AFTERNOON HIGHS GENERALLY IN THE 70S.
LOOKING FURTHER DOWN THE ROAD...THERE IS LITTLE IF ANY CHANCE FOR
WIDESPREAD PRECIPITATION THROUGH NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
GORGEOUS SPRING WEATHER WILL BE FOUND ACROSS ALL OF WESTERN AND
NORTH CENTRAL NEW YORK THIS AFTERNOON AS HIGH PRESSURE OVER NEW
ENGLAND WILL KEEP A WEALTH OF SUNSHINE IN PLACE. IT WILL QUITE MILD
AS H85 TEMPS IN THE VCNTY OF 10C WILL SUPPORT MID AFTERNOON HIGHS IN
THE UPPER 70S ACROSS THE LAKE PLAINS...AS WELL AS IN THE GENESEE AND
SOUTHERN TIER VALLEYS. ONCE AGAIN...THE COOL SPOTS WILL BE NEAR LAKE
ONTARIO WHERE A LAKE BREEZE SHOULD KEEP READINGS IN THE 60S.
SPEAKING OF WHICH...THE KBUF RADAR IS ONCE AGAIN DOING A FINE JOB OF
ILLUMINATING THE LAKE BREEZE BOUNDARY OFF LAKE ONTARIO. AS OF 1730Z
THE FRONT WAS SLOWLY SETTLING SOUTH ACROSS THE SOUTHERN PORTIONS OF
NIAGARA AND ORLEANS COUNTIES AND EXTENDED TO JUST NORTH OF
ROCHESTER. THE HRRR SIMULATION IS HANDLING THIS THE BEST OF THE
FINER SCALE GUIDANCE PACKAGES. OTHERWISE...
THE HIGH AMPLITUDE OMEGA BLOCK RESPONSIBLE FOR THIS STRETCH OF FINE
WEATHER WILL GENERALLY REMAIN IN PLACE THROUGH SATURDAY...ALTHOUGH
DEEP CLOSED LOWS OVER THE SOUTHERN PLAINS AND EASTERN ATLANTIC WILL
PINCH OFF THE SRN PORTION OF THE BLOCKING RIDGE. WHILE THE CORE OF
THE HIGH WILL REMAIN IN PLACE OVER OUR REGION...THE AFOREMENTIONED
ERODING OF ITS SOUTHERN FLANK WILL ALLOW LOWER H85 TEMPS TO ADVECT
WESTWARD FROM THE COAST. AS A RESULT...H85 TEMPS WILL SETTLE TO
BETWEEN 6 AND 8C WHICH IN TURN WILL KEEP SATURDAYS HIGH TEMPS A BIT
LOWER (ABT 5 DEG F) THAN THOSE FROM THE PAST COUPLE DAYS.
IN TERMS OF LOW TEMPS TONIGHT...IT WILL ALSO BE A BIT COOLER WITH
MINS DROPPING BACK CLOSER TO TYPICAL ERLY MAY VALUES. TEMPS BY
DAYBREAK WILL RANGE FROM THE MID AND UPPER 30S IN THE SRN TIER
VALLEYS TO THE LOWER 50SALONG THE IAG ESCARPMENT FROM IAG TO ROC.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY/...
SURFACE HIGH PRESSURE WILL REMAIN ACROSS THE NORTHEASTERN STATES
THROUGH THE WEEKEND. THIS WILL KEEP AN EXTENDED PERIOD OF FAIR AND
WARM WEATHER ACROSS WESTERN NEW YORK.
SKIES SHOULD BE MOSTLY CLEAR FOR THE WEEKEND...OUTSIDE OF PERHAPS
SOME SCATTERED CUMULUS INLAND OF THE LAKE BREEZE.
850MB TEMPS AVERAGING AROUND +6C WILL YIELD AFTERNOON HIGH TEMPS A
LITTLE LESS WARM THAN THE RECENT PAST FEW DAYS. HIGHS WILL BE IN THE
LOWER TO MID 70S FOR MOST LOCATIONS...BUT A WELL DEVELOPED LAKE
BREEZE CIRCULATION WILL BRING COOLER LAKE AIR A LITTLE FARTHER
INLAND. THIS WILL BE ESPECIALLY TRUE ON SUNDAY WHEN A NORTHERLY WIND
DEVELOPS FOLLOWING WHAT APPEARS TO BE A WEAK AND VERY DRY BACKDOOR
FRONT.
LOW TEMPERATURES WILL ALSO BE MILD THROUGH THE PERIOD...WITH LOWS
AROUND 50 ON THE LAKE PLAINS OF WESTERN NY...WITH 40S ACROSS THE
INTERIOR AND EAST OF LAKE ONTARIO.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
THE FORECAST FOR NEXT WEEK CONTINUES TO DEPEND ON THE PROGRESSION OF
A CUT-OFF LOW. WHILE SOME DETAILS STILL REMAIN UNCERTAIN...MODEL
CONSENSUS HAS COME INTO BETTER AGREEMENT OVER THE PAST COUPLE RUNS.
EXPECT THE CLOSED LOW TO START THE WEEK ACROSS THE SOUTHEASTERN
STATES. CONSENSUS THEN LIFTS THE LOW NORTHWARD TO THE MID-ATLANTIC
STATES TOWARD MID-WEEK...AND THEN THE LOW WILL LIKELY SLIDE TO THE
EAST AND OFF THE ATLANTIC COAST THURSDAY. WHILE THERE IS STILL SOME
CHANCE THE LOW WILL REACH US...THE VAST MAJORITY OF GUIDANCE KEEPS
THE UPPER LOW TOO FAR SOUTH TO BRING ANY PRECIPITATION TO OUR REGION.
IF THIS CONSENSUS HOLDS...EXPECT ANOTHER WEEK OF NICE WEATHER WITH
ABOVE NORMAL TEMPERATURES. THERE MAY BE A BIT MORE CLOUD COVER AS A
RESULT OF THE UPPER LOW. HOWEVER...850 MB TEMPERATURES SHOULD
CONTINUE TO RUN AROUND +10C. THIS WOULD ALLOW DAYTIME HIGHS TO
CONTINUE TO CLIMB INTO THE 70S THROUGH THE END OF THE WEEK.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
HIGH PRESSURE WILL KEEP LIGHT WINDS AND VFR CONDITIONS IN PLACE
THROUGH AT LEAST SATURDAY.
THE ONLY REAL FORECAST CHALLENGE WILL BE TIMING OF THE LAKE BREEZE
BOUNDARY OFF LAKE ONTARIO...WHICH WILL DROP SOUTH OF IAG/BUF AND
ROCHESTER AFTER 19Z THIS AFTERNOON...AND AGAIN SATURDAY AFETRNOON.
OUTLOOK...
SUNDAY THROUGH WEDNESDAY...VFR.
&&
.MARINE...
HIGH PRESSURE DOMINATING THE NORTHEASTERN UNITED STATES WILL PERSIST
THROUGH THE WEEKEND WITH LIGHT SOUTHEASTERLY FLOW RESULTING IN
TRANQUIL CONDITIONS ON THE LAKES. LAKE BREEZES WILL SET UP IN THE
EACH AFTERNOON.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...RSH
NEAR TERM...RSH
SHORT TERM...WCH
LONG TERM...APFFEL
AVIATION...RSH
MARINE...TMA
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
106 AM EDT FRI MAY 3 2013
.SYNOPSIS...
STRONG HIGH PRESSURE WILL REMAIN ANCHORED NORTH OF THE REGION
TODAY THROUGH THE WEEKEND. AN APPROACHING LOW PRESSURE SYSTEM
WILL BRING UNSETTLED WEATHER TO THE CAROLINAS EARLY NEXT WEEK.
FAIR WEATHER IS EXPECTED TO FOLLOW THIS SYSTEM THROUGH THE MIDDLE
OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
AS OF 106 AM FRIDAY...BASED ON LATEST KLTX AND SURROUNDING 88DS AND
THE LATEST HRRR OUTPUT AND THE 00Z NAM...THE BULK OF THE PCPN IN THE
FORM OF STRATIFORM R- AND L- TO REMAIN OVER THE ADJACENT ATLANTIC
WATERS. A TRAJECTORY RUNNING FROM ENE TO WSW FROM THE CURRENT PCPN
OVER THE ATL WATERS...WILL BRUSH ACROSS THE COASTAL COUNTIES
OVERNIGHT. WILL THE SLIGHT CHANCE ALONG THE IMMEDIATE COAST FOR ANY
ONSHORE MOVEMENT.
LATEST NAM MODEL AND GFS MOS INDICATES A RANGE OF LOWS FROM LOW TO
MID 50S NE PORTIONS OF THE CWA TO MID AND UPPER 50S SOUTHERN
PORTIONS. DEWPOINTS ONLY A FEW TICKS BELOW TEMPS DURING THE
OVERNIGHT. NE WINDS TO STAY ACTIVE OVERNIGHT ALONG WITH INTERVALS OF
CLOUDS...THUS PREVENTING ANY FOG DEVELOPMENT. POCKETS OF DRIZZLE
ALONG THE IMMEDIATE COAST OVERNIGHT COULD TEMPORARILY BRING DOWN
VSBYS.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
AS OF 3 PM THURSDAY...MAIN FORECAST CHALLENGE IS THE POSSIBILITY
OF THE INTERVALS OF NUISANCE RAIN/DRIZZLE CONTINUING FOR THE NEXT
COUPLE OF DAYS. ALTHOUGH THERMAL PROFILES CONTINUE TO DRY
OUT...THE FACT THAT THE NATURE OF THE SHOWERS HAS BEEN AND IS VERY
SHALLOW. THIS ALMOST GOES WITHOUT SAYING WITH DRIZZLE. THE
GFS...NAM AS WELL AS SREF PLUME DIAGRAMS SHOW SMALL AREAS OF QPF
INDICATIVE OF THIS ACTIVITY CONTINUING THROUGH
SATURDAY...THEREFORE...I HAVE ADDED THIS TO THE FORECAST. TIMING
IS DIFFICULT BUT LEANED TOWARD THE NAM TO SHOW AN INCREMENTAL
DIFFERENCE WITH A SLIGHT INCREASE BOTH FRIDAY AND SATURDAY
MORNINGS. ONLY SMALL CHANGES TO TEMPERATURE FORECAST.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 3 PM THURSDAY...CLIMATOLOGICALLY UNUSUAL SETUP THROUGH MOST OF
THE PERIOD MAKING FOR SOME INTERESTING AND CHALLENGING FORECASTS.
DEEP CUTOFF UPPER LOW WILL APPROACH AND EVENTUALLY TRAVERSE THE
CAROLINAS...WHICH IS MUCH MORE TYPICAL OF WINTER OR MUCH EARLIER IN
THE SPRING. IT IS MORE THE ISOLATION FROM THE FLOW OF THIS FEATURE
RATHER THAN ITS UNUSUAL TIMING THAT MAKES THE FORECAST CHALLENGING
SINCE SUCH FEATURES ARE USUALLY POORLY HANDLED BY MODEL GUIDANCE.
THAT SAID THE MODELS HAVE COME INTO PRETTY GOOD AGREEMENT WITH THE
EVOLUTION OF THE PATTERN. THERE WILL STILL BE SOME FUTURE
REFINEMENTS IN THE TIMING POSSIBLE AND THE WEATHER ITSELF WILL BE
QUITE COMPLEX AS WE SHOULD GO THROUGH SOME DISTINCT REGIME CHANGES
THROUGH THE PERIOD. SUNDAY APPEARS TO BE THE LAST DAY IN THE
PRE FRONTAL FLOW AHEAD OF THE UPPER LOW. MOISTURE WILL BE RAPIDLY ON
THE RISE ESP ACCORDING TO THE RELATIVELY FASTER GFS. BEST FORCING IN
THE FORM OF MID LEVEL JETTING AND HEIGHT FALLS COME EITHER LATE
SUNDAY OR SUNDAY NIGHT INTO MONDAY AGAIN DEPENDING ON MODEL SOLN.
RAINFALL CHANCES AND QPF POTENTIAL ARE STARTING TO LOOK PRETTY GOOD
WITH SUCH STRONG FORCING AND DEEP ATLANTIC MOISTURE EXPECTED. THEN
THE SYNOPTIC SCALE DRY SLOT WILL MOVE ACROSS THE AREA SHUTTING OFF
THE RAINFALL FOR ABOUT A PERIOD. WE WILL THEN MOVE INTO A VERY
CONVECTIVE REGIME AS THE COLD POOL ALOFT CRAWLS ACROSS THE REGION.
RIGHT NOW BEST ESTIMATE IS THIS IS TUESDAY...WHICH COULD BE A BUSY
DAY WITH A RADAR SCOPE FULL OF SMALL HAIL PRODUCING SHALLOW TSTMS.
RAIN CHANCES WILL BE SMALLER FOR THE REMAINDER OF THE PERIOD AS THE
SLOW MOVING SYSTEM COULD STILL PLAGUE THE COASTAL CAROLINAS WITH
WRAP-AROUND MOISTURE.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 05Z...LIGHT PRECIPITATION IS AGAIN MOVING ONSHORE NEAR KILM
BUT THE MAJORITY IS REMAINING OFFSHORE. SCATTERED LOW CLOUDS 1-2K
ARE
INCREASING UPSTREAM OF THE COASTAL TERMINALS WITH CLOUDS EXPANDING
WEST FROM THE PRECIPITATION AREA ALONG THE COAST. CIGS AND VSBYS ARE
CURRENTLY VFR.
HIGH PRESSURE WILL CONTINUE ACROSS THE TERMINALS THIS TAF VALID
PERIOD RESULTING IN A CONTINUED MOIST ENE-E LOW-MID LEVEL FLOW.
THERE IS MODERATE CONFIDENCE MVFR CIGS WILL DEVELOP AS ADVERTISED IN
TAFS WITH THE LOWEST CONFIDENCE IN TIMING. CONFIDENCE HAS LOWERED
THAT IFR WILL OCCUR AT THE COASTAL TERMINALS...ALTHOUGH IF ANY LIGHT
RAIN OCCURS THERE COULD BE TEMPO PERIODS OF IFR. BEST CONFIDENCE OF
IFR REMAIN AT KFLO. MVFR CONDITIONS WILL BE LIKELY AT ALL TERMINALS
THROUGH THE MORNING HOURS. ALL MODELS SUGGEST INCREASING MID LEVEL
MOISTURE AFTER 12Z INITIALLY AT THE COASTAL TERMINALS. THIS
COULD INCREASE THE CHANCES OF PRECIPITATION. SOME OF THIS
PRECIPITATION COULD MOVE WEST TO THE INLAND TERMINALS BY AFTERNOON.
EXTENDED OUTLOOK...SLIGHT CHANCE OF SHOWERS ESPECIALLY COASTAL
TERMINALS THROUGH SUNDAY. IFR/MVFR EARLY SUNDAY WITH RAIN/ISOLATED
THUNDERSTORMS DEVELOPING SUNDAY EVENING PERSISTING THROUGH MONDAY.
MVFR/TEMPO IFR POSSIBLE. VFR/TEMPO MVFR WITH SCATTERED SHOWERS
TUESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 106 AM FRIDAY...SCA EXTENDED FOR ALL WATERS TO 6 PM
SATURDAY...MAY 4TH.
PERSISTENCE THE WORD HERE FOR WINDS. CURRENT NE WINDS BASICALLY
REMAIN AT THESE SPEEDS FOR THE OVERNIGHT PERIOD. OF NOTE...HRRR
AND NAM INDICATE A MORE EASTERLY WIND DIRECTION AND 3 TO 5 KT
SUSTAINED HIER SPEEDS FOR THE ADJACENT OFFSHORE WATERS. THIS WILL
LIKELY HAVE IMPLICATIONS ON SIGNIFICANT SEAS
OVERNIGHT...ESPECIALLY THE OUTER WATERS OFF THE CAPES...FEAR AND
ROMAIN. OVERALL...HAVE INCREASED SIGNIFICANT SEAS BY 1
FOOT...HIGHEST AT 8 FT...ACROSS ALL WATERS...AND WOULD NOT BE
SURPRISED TO OBSERVE 2 FT HIER...HIGHEST AT 9 FT...MAINLY ACROSS
THE OUTER WATERS 15 TO 20 NM OUT FROM THE CAPES. AVERAGE PERIODS
OVERNIGHT WILL RUN 5 TO 6 SECONDS.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 PM THURSDAY...PERSISTENT NORTHEAST FLOW CONTINUES THROUGH
THE PERIOD. THERE MAY BE A LITTLE VEERING VERY LATE IN THE PERIOD
TO MORE OF A EASTERLY FLOW BUT OVERALL...THE NE FLOW WILL BE THE
STORY. STRONGEST WINDS WILL OCCUR FRIDAY WITH A FEW AREAS ACROSS
THE OUTER WATERS POSSIBLY EXCEEDING 25 KNOTS. FOR NOW THINK THESE
SPEEDS WILL BE LIMITED IN DURATION TO KEEP GALE CONSIDERATION IN
CHECK. SEAS WILL REMAIN RUGGED THROUGH THE PERIOD AND WILL ALMOST
CERTAINLY SEE THE SMALL CRAFT ADVISORY CONTINUE.
LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 3 PM THURSDAY...FAIRLY COMPLEX AND ACTIVE WEATHER EXPECTED FOR
MOST OF THE PERIOD ESPECIALLY EARLY ON. A DEEPLY CUTOFF UPPER SYSTEM
WILL APPROACH FROM THE WEST ON SUNDAY WITH A COLD FRONT ALONG ITS
LEADING EDGE. ONSHORE/EASTERLY FLOW WILL GET PINCHED BY THIS
APPROACHING BOUNDARY AS HIGH PRESSURE NOSED INTO THE CAROLINAS TRIES
TO HOLD ITS GROUND. AT SOME POINT THERE SHOULD BE SOME PRETTY SHARP
VEERING AS THE HIGH LOSES GROUND TO THE APPROACHING FRONT...AND THIS
IS PROBABLY THE MOST UNCERTAIN PART OF THE FORECAST. SOUTHERLY FLOW
SHOULD OVERSPREAD BY MONDAY WITH ADDITIONAL VEERING DUE TO THE
CYCLONIC CURVATURE OF THE ISOBARS COMING ACROSS THE CAROLINAS MONDAY
NIGHT INTO TUESDAY. ALL OF THE CHANGING OF THE WIND DIRECTION
THROUGH THE PERIOD SHOULD KEEP WAVE FACES RATHER STEEP AND PERIODS
SHORT MAKING FOR CHOPPY CONDITIONS. WHETHER OR NOT ANY CAUTIONARY
HEADLINES OR EVEN ADVISORIES ARE NEEDED TO TO WAVE HEIGHTS IS VERY
UNCERTAIN BUT WIND SPEEDS WILL REMAIN SHY OF EITHER.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT SATURDAY FOR AMZ250-252-
254-256.
&&
$$
NEAR TERM...DCH/MJC
SHORT TERM...SHK
LONG TERM...MBB
AVIATION...MRR/MJC
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
714 PM CDT SAT MAY 4 2013
.UPDATE...
ISSUED AT 711 PM CDT SAT MAY 4 2013
FCST ON TRACK PRETTY GOOD. DID ADJUST CURRENT TEMPS A BIT AS TEMPS
IN FAR EAST NEVER GOT OUT OF THE 30S. OTHERWISE MOVED RAIN AREA A
TAD FURTHER WEST AND WENT 80-90 BACK TO FORMAN-CENTRAL CASS CO-
CROOKSTON TO BAUDETTE AS RAIN HAS MADE IT THAT FAR WEST. DONT
THINK IT WILL MAKE IT MUCH FARTHER WEST. WENT CATEGORICAL IN THIS
BAND THROUGH 09Z THEN BACKED OFF AS DRIER AIR WORKS IN FROM THE
NORTHWEST AFTER THAT TIME.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 342 PM CDT SAT MAY 4 2013
MAIN CHALLENGE FOR THIS FORECAST PACKAGE WILL BE PCPN. LATEST
ANALYSIS SHOWS UPPER LOW OVER NRN ARKANSAS. EXPECT SLOWER CHANGES TO
THE LOCAL WEATHER OVER THE NEXT FEW DAYS AS THE OVERALL PATTERN
SHOWS A REX BLOCK OVER WRN CONUS AND ANOTHER BLOCK OVER THE EAST
COAST.
MODELS INITIALIZED WELL AND AND OPTED FOR A BLENDED SOLN. FOR TODAY
AND TONIGHT...MAIN QUESTION IS WHERE AREA OF PCPN WILL SETTLE.
REGIONAL RADAR SHOWS BAND OF PCPN MOVING NORTH INTO WEST CENTRAL AND
NW MINNESOTA. HRRR AND RAP MODELS IN GENERAL AGREEMENT ON PLACEMENT
OF PCPN AND EXPECT MOST PCPN AMOUNTS WILL BE UNDER A QUARTER INCH
OVER THE NEXT 24 HOURS. THE 300K ISENTROPIC ANALYSIS SHOWS SOME
DECENT LIFT AND EXPECTING AN 850MB BAROCLINIC ZONE TO SET UP.
HOWEVER...CONDENSATION PRESSURE DEFICITS WEAK SO FOR NOW WILL ONLY
KEEP LIKELY POPS IN THAT AREA. FOR SUNDAY...LOOKING FOR THE
BAROCLINIC ZONE TO SLOWLY SLIDE SOUTHEAST AND WILL SEE THE END OF
PCPN. OTHERWISE...LOOKING FOR DRIER WEATHER GOING INTO MONDAY.
EXTENSIVE CLOUD COVER WILL KEEP TEMPERATURES A BIT LOWER TODAY
INTO SUNDAY WHEN THE UPPER RIDGE BEGINS SLIDE OVER THE AREA AND A
WARMING TREND BEGINS.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 342 PM CDT SAT MAY 4 2013
12 UTC GFS/ECMWF SHOW THE FORECAST AREA IN POORLY DEFINED SPLIT FLOW
MID-WEEK...TRANSITIONING TO NORTHWEST FLOW ALOFT FRIDAY NIGHT INTO
SATURDAY WITH A STRONG CANADIAN COLD FRONT. PRECIPITATION CHANCES
THROUGH FRIDAY WILL DEPEND ON EVOLUTION OF A WEAK CUT-OFF LOW ACROSS
THE SOUTHERN ROCKIES. MOST MODELS PAINT MOST QPF ACROSS THE CENTRAL
PLAINS...BUT SOME DOES MAKE IT FARTHER NORTH. WITH THESE CUT-OFF
LOWS NOT A LOT OF CONFIDENCE...SO WILL KEEP ALL BLEND 20-40 POPS FOR
MOST OF THE WEEK. HOWEVER...THERE SHOULD BE MORE DRY PERIODS THAN
WET. WILL ALSO LIMIT THUNDER MENTION AS INSTABILITY APPEARS TO BE
MINIMAL AT THIS TIME. TEMPERATURES WILL BE ON THE WARM-SIDE OF THE
MOST RECENT THERMAL REGIME WITH HIGHS IN THE 60S AND LOWS MAINLY IN
THE 40S. IT DOES APPEAR CONDITIONS WILL COOL ON SATURDAY WITH
PASSAGE OF THE FRONT FRIDAY NIGHT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 711 PM CDT SAT MAY 4 2013
QUESTION OVERNIGHT IS CEILINGS. BEMIDJI HANGING AROUND IFR CIGS
WITH LIGHT RAIN/DRIZZLE AND I THINK A GOOD CHANCE TO GO IFR CIGS
AFTER DARK THROUGH THE OVERNIGHT. FARGO-THIEF RIVER RIVER CIGS
HOLDING THAT MVFR-VFR THRESHOLD AND WILL MAINTAIN THAT RANGE
THROUGH THE NIGHT. GFK-DVL WILL REMAIN VFR...HIGH END STRATOCU IN
GFK AND CIRRUS AT DVL. ALL AREAS WILL SEE NORTHEAST WINDS
DIMINISH TO UNDER 10 KTS.
&&
.HYDROLOGY...
ISSUED AT 1258 PM CDT SAT MAY 4 2013
THE BROAD CREST WAVE OF SNOWMELT RUNOFF IS APPROACHING THE
DRAYTON AREA THIS WEEKEND WITH A CREST EXPECTED NEAR 40 FEET.
THE CREST WAVE WILL MOVE INTO THE PEMBINA REGION TOWARD THE END OF
NEXT WEEK WITH A FORECAST NEAR 48.5 FEET...JUST UNDER MAJOR FLOOD
STAGE. A SECOND ROUND OF RUNOFF IS EXPECTED ALONG THE PEMBINA RIVER
WITH ADDITIONAL RISES FORECAST AT WALHALLA AND NECHE THIS NEXT WEEK.
ELSEWHERE RIVERS CONTINUE TO RECEDE AS NO NEW RUNOFF IS OCCURRING
WITH THE DRY WEATHER OVER THE PAST WEEK.
AREAL FLOODING...WILL KEEP THE NORTH DAKOTA WARNINGS GOING AS
OVERLAND FLOODING CONTINUES TO CAUSE ISSUES AND ROAD CLOSURES. AS
FOR THE BELTRAMI AND CLEARWATER COUNTIES WILL CANCEL AFTER
CONFIRMING WITH COUNTY OFFICIALS THAT OVERLAND WATER HAS
DIMINISHED DRAMATICALLY.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...RIDDLE
SHORT TERM...HOPKINS
LONG TERM...ROGERS
AVIATION...RIDDLE
HYDROLOGY...JK
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
950 AM EDT FRI MAY 3 2013
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OVER NEW ENGLAND THROUGH THE WEEKEND
THEN BEGIN TO WEAKEN EARLY NEXT WEEK. LOW PRESSURE EXTENDING UP
THE MISSISSIPPI VALLEY TO LAKE MICHIGAN WILL REMAIN STATIONARY
INTO SATURDAY THEN SLOWLY MOVE EAST THROUGH THE LOWER TENNESSEE
VALLEY.
&&
.NEAR TERM /THROUGH TONIGHT/...
ONLY MINOR CHANGES PLANNED FOR THE FORECAST. THE 12Z SOUNDINGS SHOW
A SHARP GRADIENT IN MOISTURE ACROSS THE REGION WITH PRECIP WATER AT
PIT ONLY .13 INCH TO .82 INCH AT ILN. THE HRRR ACKNOWLEDGES THIS
DRY AIR OVER THE CENTRAL APPALACHIANS AND ADVECTS IT NORTHWESTWARD
ACROSS THE EASTERN 2/3 OF THE FORECAST AREA THIS AFTERNOON. WILL
LOWER DEWPOINTS IN THE 30S AND RAISE MAX TEMPERATURES A FEW
DEGREES TO SUPPORT THE 12Z SOUNDING AT PIT.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
THE SHORT TERM FORECAST DEPENDS ON THE EVOLUTION OF THE UPPER LOW
AS IT FORMS TODAY IN THE AR/MO REGION. CURRENT GFS/NAM/SREF RUNS
FAIRLY AGREEABLE IN KEEPING THE LOW IN AR THROUGH SATURDAY NIGHT
BEFORE DRIVING IT SLOWLY EAST ACROSS AL AND GA. MEANWHILE HIGH
PRESSURE ALOFT AND AT THE SURFACE WILL EXTEND INTO THE AREA FROM
THE E/NE WITH DRY AIR CONTINUING TO MOVE ACROSS THE AREA. BASED ON
THIS KEPT THE FORECAST DRY THROUGH THE ENTIRE SHORT TERM PERIOD
WITH FAIR SKIES EXPECTED MUCH OF THE TIME. TEMPS SHOULD REMAIN
SEASONAL TO A FEW DEGREES ABOVE.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
ONLY DAY THAT HAS ANY CHANCE OF PRECIPITATION IS TUESDAY...AND THAT
MAY NOT PAN OUT. MORE CONSISTENCY WITH MODELS MAINTAINING HIGH
PRESSURE OVER THE AREA AND SHIFTING THE CUTOFF LOW EAST ACROSS THE
TN VALLEY. CLOUD SHIELD WILL LIKELY REACH TO THE LOCAL AREA...BUT
SHOWERS MAY NOT. WILL CONTINUE THE LOW PRECIP CHANCES...WITH NO
PRECIP MENTIONED FOR WEDNESDAY AND THURSDAY. TEMPERATURES SLIGHTLY
ABOVE NORMAL.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS WILL CONTINUE THROUGH TONIGHT. MOST LOCATIONS WILL
ONLY SEE VARIABLE AMOUNTS OF HIGH LEVEL CLOUD COVER. EXPECT SE
WINDS TO CONTINUE WITH SOME GUSTS AROUND 20 KNOTS FOR MOST
LOCATIONS BY FRIDAY AFTERNOON. LAKE BREEZE POSSIBLE AT KERI...NOT
AS LIKELY FOR KCLE. NO CHANGES.
.OUTLOOK...NON-VFR CONDITIONS POSSIBLE BY MONDAY.
&&
.MARINE...
HIGH PRESSURE TO THE EAST OF THE LAKE WILL CONTINUE TO BLOCK THE
ADVANCEMENT OF LOW PRESSURE ACROSS THE WESTERN LAKES/MIDWEST. THAT
SYSTEM WILL EVENTUALLY PASS SOUTH OF LAKE ERIE...LIKELY ACROSS THE
TN VALLEY EARLY NEXT WEEK. THIS WILL LEAVE HIGH PRESSURE AS THE MAIN
INFLUENCE FOR LAKE ERIE. CAN EXPECT DAILY ONSHORE/LAKE BREEZE FLOW
FOR MOST OF THE AFTERNOONS...THE SOUTHEAST FLOW AT NIGHT BECOMING
MORE NORTHEASTERLY. BY MIDWEEK HIGH PRESSURE BUILDS OVER THE WESTERN
LAKES AND THE FLOW ACROSS LAKE ERIE WILL BECOME MORE NORTHERLY...BUT
STILL REMAIN LIGHT.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TK
NEAR TERM...LAPLANTE
SHORT TERM...TK
LONG TERM...OUDEMAN
AVIATION...OUDEMAN
MARINE...OUDEMAN
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
832 PM CDT SAT MAY 4 2013
.UPDATE...
LATEST RADAR IMAGERY SHOWS LIGHT TO MODERATE RAIN SHIELD REMAINS
ACROSS EASTERN ZONES...GENERALLY ALONG AND EAST OF A LINE FROM
GALLATIN TO MANCHESTER. WEST OF THAT LINE...SCATTERED TO NUMEROUS
LIGHT TO OCCASIONALLY MODERATE SHOWERS HAVE DEVELOPED WESTWARD TO
NEAR A CLARKSVILLE TO PULASKI LINE. LOCATIONS REMAIN DRY TO THE
WEST OF THERE...BUT LIGHT SHOWERS HAVE BEGUN SPREADING ACROSS THE
TENNESSEE RIVER IN THE PAST HOUR IN ASSOCIATION WITH THE
APPROACHING UPPER LOW. TEMPERATURES REMAIN UNUSUALLY COLD AND
WIDELY VARIABLE AT THIS HOUR...WITH LOW 50S ON THE PLATEAU...MID
TO UPPER 40S IN THE CENTRAL CWA...AND LOW 50S IN THE SOUTHWEST.
HAVE MADE SEVERAL ADJUSTMENTS TO GRIDS/ZONES BASED ON LATEST OBS
AND RADAR TRENDS. RAISED POPS ACROSS THE WEST WHERE LIGHT RAIN IS
SPREADING EASTWARD WITH UPPER LOW...AND EXTENDED LIKELY POPS
FURTHER TO THE WEST TO NEAR A CLARKSVILLE/PULASKI LINE. LATEST
HRRR RUNS INDICATE CURRENT SHOWER ACTIVITY ALONG THE I-65 CORRIDOR
WILL CONTINUE THIS EVENING THEN DISSIPATE OVERNIGHT AS DRIER AIR
AROUND CIRCULATION OF UPPER LOW SHIFTS EASTWARD. AS THIS
OCCURS...HRRR INDICATES PRECIPITATION INTENSITIES WITHIN RAIN
SHIELD WILL STRENGTHEN OVERNIGHT AS SURFACE TROUGH DEEPENS AND
UPPER LOW APPROACHES...LEADING TO AN INCREASE IN RAINFALL RATES
IN THE FLOOD WATCH AREA. AS MENTIONED PREVIOUSLY...OF PARTICULAR
CONCERN WILL BE THE SOUTHERN PLATEAU COUNTIES OF VAN
BUREN...WHITE...CUMBERLAND...AND PUTNAM WHERE HIGHEST MOISTURE
TRANSPORT WILL BE FOCUSED AND OROGRAPHIC LIFT IN THE 2000-3000 FT
TERRAIN ENHANCES PRECIPITATION. THE CROSSVILLE ASOS HAS RECEIVED
1.31 INCHES OF RAIN AS OF 7 PM...AND ANOTHER 1 TO 1.5 INCHES IS
POSSIBLE THROUGH MIDNIGHT IN THE FLOOD WATCH AREA. STORM TOTAL
AMOUNTS THROUGH SUNDAY FROM 2 TO POTENTIALLY 4 INCHES STILL APPEAR
REASONABLE IN EASTERN ZONES AND NO CHANGES ARE PLANNED TO THE
FLOOD WATCH.
SHAMBURGER
&&
.PREV DISCUSSION... /ISSUED 646 PM CDT SAT MAY 4 2013/
UPDATE...FOR 00Z AVIATION FORECAST
AVIATION...
POOR FLYING CONDITIONS TO CONTINUE ACROSS THE MID STATE NEXT 24
HOURS AS UPPER LOW CURRENTLY SPINNING OVER CENTRAL ARKANSAS KEEPS
A MOISTURE PLUME STREAMING INTO TENNESSEE. SHORT RANGE MODELS HAVE
GOOD HANDLE ON RAINFALL WITH THE HEAVIEST TO FALL ALONG THE
CENTRAL AND SOUTHERN PLATEAU COUNTIES WHERE RAINFALL WILL BECOME
HEAVY OVERNIGHT. RAIN WILL CONTINUE ON SUNDAY. HAVE FORECASTED
LOW IFR CEILINGS AT CROSSVILLE IN THE OVERNIGHT ALONG WITH HEAVY
RAINFALL. ALSO EXPECT LOW IFR CEILINGS AT NASHVILLE BUT WITH LIGHT
RANIFALL.
BOYD
PREV DISCUSSION... /ISSUED 613 PM CDT SAT MAY 4 2013/
MESOSCALE UPDATE...
LATEST RADAR IMAGERY SHOWS MAIN AXIS OF MODERATE TO OCCASIONALLY
HEAVY RAIN NOW OVER THE UPPER CUMBERLAND REGION...GENERALLY EAST
OF A LINE FROM LAFAYETTE TO ALTAMONT. LATEST HRRR MODEL RUNS
INDICATE THIS MAIN RAIN BAND WILL REMAIN IN PLACE FOR ANOTHER 12
TO 18 HOURS AS A SURFACE TROUGH OF LOW PRESSURE ARCING SOUTHEAST
TO NORTHWEST REMAIN IN PLACE AND DEEPENS WITH THE UPPER LOW
APPROACHING FROM THE WEST. OBS FROM THE CROSSVILLE ASOS INDICATE
RAINFALL RATES OF 0.10 TO 0.25 INCHES PER HOUR ARE OCCURRING IN
THE HEAVIEST RAIN AREAS...WITH 1 TO 2 INCHES OF RAINFALL POSSIBLE
JUST THROUGH MIDNIGHT. HEAVIEST RAIN TOTALS ARE EXPECTED TO BE ON
THE SOUTHERN PLATEAU ACROSS VAN BUREN...WHITE...AND CUMBERLAND
COUNTIES WHERE OROGRAPHIC ENHANCEMENT FROM THE HIGHER TERRAIN
SQUEEZES OUT ADDITIONAL MOISTURE. FLOODING WILL BECOME AN
INCREASING CONCERN IN THIS AREA AS WE CONTINUE THROUGH THE NIGHT
AND ESPECIALLY ON SUNDAY.
SHAMBURGER
PREV DISCUSSION... /ISSUED 340 PM CDT SAT MAY 4 2013/
DISCUSSION...
PRECIP CLEARING LINE HAS BEEN MAKING A SLOW EASTWARD MOVEMENT TODAY.
AT 2PM THE CLEARING LINE WAS ROUGHLY ORIENTED PARALLEL TO I-65. THIS
EASTWARD PROGRESSION MAY CONTINUE FOR A FEW MORE HOURS BUT WILL
LIKELY STALL BY EVENING.
CURRENTLY UPPER LEVEL LOW IS LOCATED OVER NRN AR WITH A SLOW ESE
MOVEMENT. 2 SFC TROUGH ARE AT WORK WITH ONE LOCATED ALONG THE MS
RIVER AND ANOTHER INVERTED VERSION OF A SFC TROUGH EXTENDING
NORTHWARD THROUGH GA INTO EASTERN TN. AS THE UPPER LOW CONTINUES
MOVING EASTWARD...INTENSIFICATION ALONG THE STATIONARY INVERTED
TROUGH IS EXPECTED. THERE MAY EVEN BE A BIT OF RETROGRADE MOVEMENT
WITH THE INVERTED TROUGH AS IT STRENGTHENS. SO FAR OMEGA RETURNS
HAVE BEEN MARGINALLY IMPRESSIVE OVER EASTERN PORTIONS OF THE MID
STATE WHERE THE RAIN IS ONGOING. TONIGHT HOWEVER...THE STRENGTHENING
INVERTED TROUGH WILL TRANSLATE INTO GREATER FORCING AND THE RAINFALL
INTENSITY LEVELS WILL PICK UP. THUS...THOUGH I WILL LIKELY BE
CUTTING A FEW MORE CENTRAL COUNTIES FROM THE FLOOD WATCH...THE
EASTERN THIRD OF OUR CWA(PLATEAU AND ADJACENT COUNTIES) ARE STILL
VERY MUCH UNDER THE GUN. MODELS ARE ALL CONVERGING ON THE HEAVY
RAINFALL POTENTIAL EXTENDING NORTHWARD INTO OUR SOUTHERN PLATEAU IN
PARTICULAR. ADDITIVE RAINFALL ENHANCEMENT IS CLEARLY INDICATED WITH
HRRR DATA ALONG WITH A GENERAL MODEL QPF CONSENSUS.
AROUND 2 TO 3 INCHES OF ADDITIONAL RAINFALL WITH LOCALIZED AMOUNTS
OF 4 INCHES ARE STILL POSSIBLE ACROSS OUR SOUTHERN PLATEAU.
ELSEWHERE ACROSS THE WATCH AREA...WILL LEAN TOWARD AROUND 2 INCHES
OF ADDITIONAL RAINFALL BEING POSSIBLE BUT WILL REFRAIN FROM THE
EXTRA LOCALIZED WORDING.
CURRENT THINKING FOR THE WATCH AREA IS TO INCLUDE AREAS ALONG AND
EAST OF A LINE FROM MACON COUNTY TO COFFEE COUNTY. WILL KEEP THE
WATCH GOING UNTIL 7 PM SUNDAY NIGHT. ALTHOUGH THE HEAVIEST ACTIVITY
WILL MOVE EAST OF OUR COUNTIES BY 18Z...ITS GOOD TO KEEP THE WATCH
GOING FOR A FEW MORE HOURS AS FLOODING CAN OFTEN OCCUR HOURS AFTER
THE HEAVIER RAINFALL ENDS.
SHOWER ACTIVITY...THOUGH LESS INTENSE...TO PERSIST INTO SUNDAY NIGHT
AS THE UPPER LOW PASSES JUST TO OUR SOUTH. SOME SUNSHINE WILL RETURN
ON MONDAY ALONG WITH WARMER TEMPS.
IN THE EXT FCST...UPPER LOW WILL BE FAR ENOUGH EAST AND UPPER
RIDGING WILL COMMENCE BY MID WEEK. THIS WILL EQUATE TO WARMER AND
DRIER CONDITIONS. IN FACT...MAY GO POP FREE TUES NT INTO WED.
UPPER RIDGE WILL BEGIN TO FLATTEN BY THE END OF THE WEEK.
INSTABILITY PARAMETERS INDICATE INCREASE CAPES AND LOWERING CAP
STRENGTHS BEGINNING ON THU. A SFC FRONT WILL THEN MOVE CLOSER BY
FRIDAY AND SATURDAY AND THIS WILL ADD TO OUR SHOWER AND TSTM
CHANCES. EXT TEMPS WILL BE RUNNING ABOVE NORMAL FOR THE LAST HALF OF
THE EXTENDED...THU-SAT. WONT DEVIATE MUCH FROM MEX ADVICE.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH THROUGH SUNDAY EVENING FOR TNZ009>011-029>034-
063>066-077>080.
&&
$$
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
646 PM CDT SAT MAY 4 2013
.UPDATE...FOR 00Z AVIATION FORECAST
.AVIATION...
POOR FLYING CONDITIONS TO CONTINUE ACROSS THE MID STATE NEXT 24
HOURS AS UPPER LOW CURRENTLY SPINNING OVER CENTRAL ARKANSAS KEEPS
A MOISTURE PLUME STREAMING INTO TENNESSEE. SHORT RANGE MODELS HAVE
GOOD HANDLE ON RAINFALL WITH THE HEAVIEST TO FALL ALONG THE
CENTRAL AND SOUTHERN PLATEAU COUNTIES WHERE RAINFALL WILL BECOME
HEAVY OVERNIGHT. RAIN WILL CONTINUE ON SUNDAY. HAVE FORECASTED
LOW IFR CEILINGS AT CROSSVILLE IN THE OVERNIGHT ALONG WITH HEAVY
RAINFALL. ALSO EXPECT LOW IFR CEILINGS AT NASHVILLE BUT WITH LIGHT
RANIFALL.
BOYD
&&
.PREV DISCUSSION... /ISSUED 613 PM CDT SAT MAY 4 2013/
MESOSCALE UPDATE...
LATEST RADAR IMAGERY SHOWS MAIN AXIS OF MODERATE TO OCCASIONALLY
HEAVY RAIN NOW OVER THE UPPER CUMBERLAND REGION...GENERALLY EAST
OF A LINE FROM LAFAYETTE TO ALTAMONT. LATEST HRRR MODEL RUNS
INDICATE THIS MAIN RAIN BAND WILL REMAIN IN PLACE FOR ANOTHER 12
TO 18 HOURS AS A SURFACE TROUGH OF LOW PRESSURE ARCING SOUTHEAST
TO NORTHWEST REMAIN IN PLACE AND DEEPENS WITH THE UPPER LOW
APPROACHING FROM THE WEST. OBS FROM THE CROSSVILLE ASOS INDICATE
RAINFALL RATES OF 0.10 TO 0.25 INCHES PER HOUR ARE OCCURRING IN
THE HEAVIEST RAIN AREAS...WITH 1 TO 2 INCHES OF RAINFALL POSSIBLE
JUST THROUGH MIDNIGHT. HEAVIEST RAIN TOTALS ARE EXPECTED TO BE ON
THE SOUTHERN PLATEAU ACROSS VAN BUREN...WHITE...AND CUMBERLAND
COUNTIES WHERE OROGRAPHIC ENHANCEMENT FROM THE HIGHER TERRAIN
SQUEEZES OUT ADDITIONAL MOISTURE. FLOODING WILL BECOME AN
INCREASING CONCERN IN THIS AREA AS WE CONTINUE THROUGH THE NIGHT
AND ESPECIALLY ON SUNDAY.
SHAMBURGER
PREV DISCUSSION... /ISSUED 340 PM CDT SAT MAY 4 2013/
DISCUSSION...
PRECIP CLEARING LINE HAS BEEN MAKING A SLOW EASTWARD MOVEMENT TODAY.
AT 2PM THE CLEARING LINE WAS ROUGHLY ORIENTED PARALLEL TO I-65. THIS
EASTWARD PROGRESSION MAY CONTINUE FOR A FEW MORE HOURS BUT WILL
LIKELY STALL BY EVENING.
CURRENTLY UPPER LEVEL LOW IS LOCATED OVER NRN AR WITH A SLOW ESE
MOVEMENT. 2 SFC TROUGH ARE AT WORK WITH ONE LOCATED ALONG THE MS
RIVER AND ANOTHER INVERTED VERSION OF A SFC TROUGH EXTENDING
NORTHWARD THROUGH GA INTO EASTERN TN. AS THE UPPER LOW CONTINUES
MOVING EASTWARD...INTENSIFICATION ALONG THE STATIONARY INVERTED
TROUGH IS EXPECTED. THERE MAY EVEN BE A BIT OF RETROGRADE MOVEMENT
WITH THE INVERTED TROUGH AS IT STRENGTHENS. SO FAR OMEGA RETURNS
HAVE BEEN MARGINALLY IMPRESSIVE OVER EASTERN PORTIONS OF THE MID
STATE WHERE THE RAIN IS ONGOING. TONIGHT HOWEVER...THE STRENGTHENING
INVERTED TROUGH WILL TRANSLATE INTO GREATER FORCING AND THE RAINFALL
INTENSITY LEVELS WILL PICK UP. THUS...THOUGH I WILL LIKELY BE
CUTTING A FEW MORE CENTRAL COUNTIES FROM THE FLOOD WATCH...THE
EASTERN THIRD OF OUR CWA(PLATEAU AND ADJACENT COUNTIES) ARE STILL
VERY MUCH UNDER THE GUN. MODELS ARE ALL CONVERGING ON THE HEAVY
RAINFALL POTENTIAL EXTENDING NORTHWARD INTO OUR SOUTHERN PLATEAU IN
PARTICULAR. ADDITIVE RAINFALL ENHANCEMENT IS CLEARLY INDICATED WITH
HRRR DATA ALONG WITH A GENERAL MODEL QPF CONSENSUS.
AROUND 2 TO 3 INCHES OF ADDITIONAL RAINFALL WITH LOCALIZED AMOUNTS
OF 4 INCHES ARE STILL POSSIBLE ACROSS OUR SOUTHERN PLATEAU.
ELSEWHERE ACROSS THE WATCH AREA...WILL LEAN TOWARD AROUND 2 INCHES
OF ADDITIONAL RAINFALL BEING POSSIBLE BUT WILL REFRAIN FROM THE
EXTRA LOCALIZED WORDING.
CURRENT THINKING FOR THE WATCH AREA IS TO INCLUDE AREAS ALONG AND
EAST OF A LINE FROM MACON COUNTY TO COFFEE COUNTY. WILL KEEP THE
WATCH GOING UNTIL 7 PM SUNDAY NIGHT. ALTHOUGH THE HEAVIEST ACTIVITY
WILL MOVE EAST OF OUR COUNTIES BY 18Z...ITS GOOD TO KEEP THE WATCH
GOING FOR A FEW MORE HOURS AS FLOODING CAN OFTEN OCCUR HOURS AFTER
THE HEAVIER RAINFALL ENDS.
SHOWER ACTIVITY...THOUGH LESS INTENSE...TO PERSIST INTO SUNDAY NIGHT
AS THE UPPER LOW PASSES JUST TO OUR SOUTH. SOME SUNSHINE WILL RETURN
ON MONDAY ALONG WITH WARMER TEMPS.
IN THE EXT FCST...UPPER LOW WILL BE FAR ENOUGH EAST AND UPPER
RIDGING WILL COMMENCE BY MID WEEK. THIS WILL EQUATE TO WARMER AND
DRIER CONDITIONS. IN FACT...MAY GO POP FREE TUES NT INTO WED.
UPPER RIDGE WILL BEGIN TO FLATTEN BY THE END OF THE WEEK.
INSTABILITY PARAMETERS INDICATE INCREASE CAPES AND LOWERING CAP
STRENGTHS BEGINNING ON THU. A SFC FRONT WILL THEN MOVE CLOSER BY
FRIDAY AND SATURDAY AND THIS WILL ADD TO OUR SHOWER AND TSTM
CHANCES. EXT TEMPS WILL BE RUNNING ABOVE NORMAL FOR THE LAST HALF OF
THE EXTENDED...THU-SAT. WONT DEVIATE MUCH FROM MEX ADVICE.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH THROUGH SUNDAY EVENING FOR TNZ009>011-029>034-
063>066-077>080.
&&
$$
01
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
613 PM CDT SAT MAY 4 2013
.MESOSCALE UPDATE...
LATEST RADAR IMAGERY SHOWS MAIN AXIS OF MODERATE TO OCCASIONALLY
HEAVY RAIN NOW OVER THE UPPER CUMBERLAND REGION...GENERALLY EAST
OF A LINE FROM LAFAYETTE TO ALTAMONT. LATEST HRRR MODEL RUNS
INDICATE THIS MAIN RAIN BAND WILL REMAIN IN PLACE FOR ANOTHER 12
TO 18 HOURS AS A SURFACE TROUGH OF LOW PRESSURE ARCING SOUTHEAST
TO NORTHWEST REMAIN IN PLACE AND DEEPENS WITH THE UPPER LOW
APPROACHING FROM THE WEST. OBS FROM THE CROSSVILLE ASOS INDICATE
RAINFALL RATES OF 0.10 TO 0.25 INCHES PER HOUR ARE OCCURRING IN
THE HEAVIEST RAIN AREAS...WITH 1 TO 2 INCHES OF RAINFALL POSSIBLE
JUST THROUGH MIDNIGHT. HEAVIEST RAIN TOTALS ARE EXPECTED TO BE ON
THE SOUTHERN PLATEAU ACROSS VAN BUREN...WHITE...AND CUMBERLAND
COUNTIES WHERE OROGRAPHIC ENHANCEMENT FROM THE HIGHER TERRAIN
SQUEEZES OUT ADDITIONAL MOISTURE. FLOODING WILL BECOME AN
INCREASING CONCERN IN THIS AREA AS WE CONTINUE THROUGH THE NIGHT
AND ESPECIALLY ON SUNDAY.
SHAMBURGER
&&
.PREV DISCUSSION... /ISSUED 340 PM CDT SAT MAY 4 2013/
DISCUSSION...
PRECIP CLEARING LINE HAS BEEN MAKING A SLOW EASTWARD MOVEMENT TODAY.
AT 2PM THE CLEARING LINE WAS ROUGHLY ORIENTED PARALLEL TO I-65. THIS
EASTWARD PROGRESSION MAY CONTINUE FOR A FEW MORE HOURS BUT WILL
LIKELY STALL BY EVENING.
CURRENTLY UPPER LEVEL LOW IS LOCATED OVER NRN AR WITH A SLOW ESE
MOVEMENT. 2 SFC TROUGH ARE AT WORK WITH ONE LOCATED ALONG THE MS
RIVER AND ANOTHER INVERTED VERSION OF A SFC TROUGH EXTENDING
NORTHWARD THROUGH GA INTO EASTERN TN. AS THE UPPER LOW CONTINUES
MOVING EASTWARD...INTENSIFICATION ALONG THE STATIONARY INVERTED
TROUGH IS EXPECTED. THERE MAY EVEN BE A BIT OF RETROGRADE MOVEMENT
WITH THE INVERTED TROUGH AS IT STRENGTHENS. SO FAR OMEGA RETURNS
HAVE BEEN MARGINALLY IMPRESSIVE OVER EASTERN PORTIONS OF THE MID
STATE WHERE THE RAIN IS ONGOING. TONIGHT HOWEVER...THE STRENGTHENING
INVERTED TROUGH WILL TRANSLATE INTO GREATER FORCING AND THE RAINFALL
INTENSITY LEVELS WILL PICK UP. THUS...THOUGH I WILL LIKELY BE
CUTTING A FEW MORE CENTRAL COUNTIES FROM THE FLOOD WATCH...THE
EASTERN THIRD OF OUR CWA(PLATEAU AND ADJACENT COUNTIES) ARE STILL
VERY MUCH UNDER THE GUN. MODELS ARE ALL CONVERGING ON THE HEAVY
RAINFALL POTENTIAL EXTENDING NORTHWARD INTO OUR SOUTHERN PLATEAU IN
PARTICULAR. ADDITIVE RAINFALL ENHANCEMENT IS CLEARLY INDICATED WITH
HRRR DATA ALONG WITH A GENERAL MODEL QPF CONSENSUS.
AROUND 2 TO 3 INCHES OF ADDITIONAL RAINFALL WITH LOCALIZED AMOUNTS
OF 4 INCHES ARE STILL POSSIBLE ACROSS OUR SOUTHERN PLATEAU.
ELSEWHERE ACROSS THE WATCH AREA...WILL LEAN TOWARD AROUND 2 INCHES
OF ADDITIONAL RAINFALL BEING POSSIBLE BUT WILL REFRAIN FROM THE
EXTRA LOCALIZED WORDING.
CURRENT THINKING FOR THE WATCH AREA IS TO INCLUDE AREAS ALONG AND
EAST OF A LINE FROM MACON COUNTY TO COFFEE COUNTY. WILL KEEP THE
WATCH GOING UNTIL 7 PM SUNDAY NIGHT. ALTHOUGH THE HEAVIEST ACTIVITY
WILL MOVE EAST OF OUR COUNTIES BY 18Z...ITS GOOD TO KEEP THE WATCH
GOING FOR A FEW MORE HOURS AS FLOODING CAN OFTEN OCCUR HOURS AFTER
THE HEAVIER RAINFALL ENDS.
SHOWER ACTIVITY...THOUGH LESS INTENSE...TO PERSIST INTO SUNDAY NIGHT
AS THE UPPER LOW PASSES JUST TO OUR SOUTH. SOME SUNSHINE WILL RETURN
ON MONDAY ALONG WITH WARMER TEMPS.
IN THE EXT FCST...UPPER LOW WILL BE FAR ENOUGH EAST AND UPPER
RIDGING WILL COMMENCE BY MID WEEK. THIS WILL EQUATE TO WARMER AND
DRIER CONDITIONS. IN FACT...MAY GO POP FREE TUES NT INTO WED.
UPPER RIDGE WILL BEGIN TO FLATTEN BY THE END OF THE WEEK.
INSTABILITY PARAMETERS INDICATE INCREASE CAPES AND LOWERING CAP
STRENGTHS BEGINNING ON THU. A SFC FRONT WILL THEN MOVE CLOSER BY
FRIDAY AND SATURDAY AND THIS WILL ADD TO OUR SHOWER AND TSTM
CHANCES. EXT TEMPS WILL BE RUNNING ABOVE NORMAL FOR THE LAST HALF OF
THE EXTENDED...THU-SAT. WONT DEVIATE MUCH FROM MEX ADVICE.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH THROUGH SUNDAY EVENING FOR TNZ009>011-029>034-
063>066-077>080.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS MORRISTOWN TN
938 AM EDT FRI MAY 3 2013
.DISCUSSION...
NO CHANGES ARE NEEDED TO THE FORECAST THIS MORNING. A SE FLOW OF
MOISTURE OFF THE ATLANTIC IS BRINGING BROKEN CLOUDS TO SOUTHERN
AREAS...WHILE DOWNSLOPE EFFECTS ARE PROVIDING MOSTLY SUNNY SKIES IN
THE CENTRAL AND SOUTHERN TN VALLEY. THE RUC AND SREF SHOW LIGHT QPF
COMING INTO SOUTHERN SECTIONS LATE IN THE AFTERNOON...AND THE
CURRENT FORECAST OF LOW CHANCE POPS IN THAT AREA LOOKS GOOD. TEMPS
AND DEWPOINTS APPEAR TO BE IN LINE WITH OBS.
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
DGS
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
930 PM CDT SAT MAY 4 2013
NEW INFORMATION ADDED TO UPDATE SECTION
.UPDATE...
ISSUED AT 926 PM CDT SAT MAY 4 2013
NOT PLANNING ANY SIG CHGS TO THE FCST THIS EVENING. CENTRAL WI
MIXED OUT THE LOW-LEVEL MOISTURE THIS AFTN...SO VERY LARGE SFC
DWPT DEPRESSIONS IN THAT AREA. THAT ALSO EXTENDS INTO N-C WI...S
OF REMNANTS OF BOUNDARY ACRS THAT RGN. THE AREA OF GREATEST
CONCERN IS THE FAR NW PART OF THE FCST AREA. THAT AREA STILL HAS
SOME SNOW/ICE ON THE GROUND...AND THE LOWEST DWPT DEPRESSIONS. BUT
SFC PRESSURE GRADIENT IS A LITTLE STRONGER IN THAT AREA. AT THIS
POINT...JUST HAVING MENTION OF SOME FG IN THE GRIDS/ZONES SEEMS
SUFFICIENT.
&&
.SHORT TERM...TONIGHT AND SUNDAY
ISSUED AT 236 PM CDT SAT MAY 4 2013
AN UPPER LEVEL DISTURBANCE ROTATING AROUND THE UPPER LOW CAUSED
SOME SHOWERS TO DEVELOP LATE THIS MORNING/EARLY THIS AFTERNOON.
MOST OF THESE SHOWERS WERE NOW WEST OF WOOD AND MARATHON COUNTY.
COULD NOT RULE OUT A STRAY SHOWER UNTIL 21Z...BUT WILL NOT
HIGHLIGHT IN A PRE-FIRST PERIOD TO THE ZONE FORECAST TO ACCOUNT
FOR THIS REMOTE POSSIBILITY.
ATTENTION THEN TURNS TO THE FOG. NUMERICAL GUIDANCE NOT INDICATIVE
OF DENSE FOG LATE TONIGHT OUTSIDE THE FAR NORTH. HOWEVER...DEW POINTS
MAINLY IN THE 40S TO AROUND 50 THIS AFTERNOON...PARTLY CLOUDY SKIES
AND LIGHT WINDS TONIGHT...AND A COLDER THAN NORMAL SOIL TEMPERATURES
LEAD ME TO THINK THERE WILL BE MORE FOG/DENSE FOG AROUND TONIGHT THAN
THE NUMERICAL GUIDANCE SUGGEST. WILL MENTION AREAS OF DENSE FOG ACROSS
THE FAR NORTH AND AREAS OF FOG WITH LOCALLY DENSE FOG POSSIBLE ELSEWHERE.
ANY FOG SHOULD BURN OFF BY MID MORNING ON SUNDAY. ANOTHER MILD DAY
IS EXPECTED WITH HIGHS WELL INTO THE 60S TO LOWER 70S. A WEAK BOUNDARY
IS EXPECTED TO DROP SOUTH IN NORTHERN WISCONSIN SUNDAY AFTERNOON. THIS
BOUNDARY COULD TRIGGER SOME ISOLATED/SCATTERED SHOWERS GENERALLY NORTH
OF A WAUSAU TO WAUSAUKEE LINE.
.LONG TERM...SUNDAY NIGHT THROUGH SATURDAY
ISSUED AT 236 PM CDT SAT MAY 4 2013
THE REMNANTS OF THE SYSTEM WHICH CAUSED HAVOC OVER THE MID SECTION
OF THE COUNTRY THE LATER HALF OF THE PREVIOUS WORK WEEK CONTINUES
TO CHURN OVER THE SOUTHEAST STATES AND SLOWLY WEAKEN THROUGH
TUESDAY. ANOTHER UPPER LOW SYSTEM IS PROGGED TO DROP INTO SOUTHWEST
STATES EARLY IN THE NEW WORK WEEK AS WELL.
LOCALLY A RIDGE OF HIGH PRESSURE WILL EXTEND OVER THE GREAT LAKES
REGION TROUGH AT LEAST MID WEEK. ABOVE NORMAL AND MAINLY DRY
CONDITIONS CAN BE EXPECTED THROUGH MID WEEK. WEAK MID LEVEL
CONVERGENCE OVER THE NORTHERN PLAINS AND NORTHWEST WESTERN MAY BE
CLOSE ENOUGH TO PARTS OF NORTH CENTRAL AND CENTRAL WISCONSIN TO
GENERATE AN ISOLATED SHOWER IN THE AFTERNOON EACH MONDAY AND
TUESDAY SINCE MARGINAL INSTABILITY REMAINS IN THIS AREA. SLIGHTLY
COOLER TEMPS ALOFT WERE PRODUCING TOTAL TOTALS IN THE MID TO UPPER
40S. HOWEVER SUBSIDENCE FROM THE EAST WINDS WITH THE UPPER RIDGE
MAY LOWER HUMIDITY TO KEEP THE SHOWERS IN CHECK. AS A RESULT WILL
KEEP THE FORECAST DRY THROUGH MID WEEK.
PROGS BEGIN TO INTRODUCE A PATTERN CHANGE WITH LIFTING THE
SOUTHWEST U.S. LOW INTO THE MID SECTION OF THE COUNTRY BEFORE
DEVELOPING A DEEPER SHORT WAVE TROUGH THE LATER HALF OF THE WEEK.
PCPN CHANCES WILL BE ON THE INCREASE OVER AT LEAST THE SOUTH HALF
OF THE STATE AS THE TROUGH DRAGS A LOW PRESSURE SYSTEM OVER IOWA
AND ILLINOIS WHILE HIGH PRESSURE DROPS INTO THE GREAT LAKES FROM
THE NORTH. A COLDER SURGE OF AIR WITH A FROPA MAY DROP INTO THE
REGION LATE SATURDAY INTO SATURDAY NIGHT. A FEW RAIN/SNOW? SHOWERS
WILL BE POSSIBLE ACROSS NORTH NEXT WEEKEND.
THE RIDGE OF HIGH PRESSURE WITH LIGHT WINDS AND CLEAR SKIES MAY
PROVIDE A FEW NIGHTS WITH FOG.
&&
.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 557 PM CDT SAT MAY 4 2013
MAIN ISSUE IS THE POTENTIAL FOR FG FORMATION TNGT. RAP VSBY FCST
FOCUSES ON THE FAR N...WHERE THERE IS STILL SOME LINGERING
SNOW/ICE COVER...AND HAS MVFR CONDITIONS ELSEWHERE. THAT/S SIMILAR
TO WHAT/S IN THE GOING FCST...SO WL STAY THE COURSE WITH THAT FOR
NOW AND SEE HOW DPWTS REACT THIS EVENING. /PARTS OF CENTRAL WI
MIXED INTO DRIER AIR ALOFT THIS AFTN./.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE.........SKOWRONSKI
SHORT TERM.....ECKBERG
LONG TERM......TDH
AVIATION.......SKOWRONSKI
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
625 PM CDT SAT MAY 4 2013
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 306 PM CDT SAT MAY 4 2013
MAIN FORECAST CONCERN IS ON FOG AND DENSE FOG POTENTIAL TONIGHT
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED UPPER LOWS OVER NORTHERN CALIFORNIA AND IN ARKANSAS...WHILE
AN UPPER HIGH WAS PRESENT ACROSS MUCH OF THE GREAT LAKES. FLOWING
BETWEEN THE ARKANSAS UPPER LOW AND THE GREAT LAKES UPPER HIGH WAS A
SHORTWAVE OVER CENTRAL WISCONSIN. DPVA AHEAD OF THIS SHORTWAVE
COMBINED WITH DAYTIME HEATING AND SOME EVAPOTRANSPIRATION HAS AIDED
IN SHOWERS NORTH OF I-94. FARTHER SOUTH...SCATTERED SHOWERS ARE ALSO
PRESENT ACROSS PORTIONS OF NORTHEAST IOWA AND FAR SOUTHWEST
WISCONSIN...AIDED BY INSTABILITY PRODUCED BY DEWPOINTS CLIMBING INTO
THE LOW 50S AND SOME COOLER TEMPS ALOFT. REGARDING TEMPERATURES...
THEY VARY GREATLY ACROSS THE FORECAST AREA...FROM THE 40S IN
ROCHESTER TO 60S ACROSS MUCH OF SOUTHWEST INTO CENTRAL WISCONSIN.
THE WARMER TEMPERATURES ARE A RESULT OF MORE SUN AND AN EASTERLY
FLOW OF WARMER AIR COMING OUT OF THE UPPER HIGH. 12Z GRB SOUNDING
SHOWED 900MB TEMPS OF +14C...COMPARED TO +5C AT MPX. BOTH SOUNDINGS
HAD AN INVERSION...BUT MPX WAS MUCH DEEPER AND THUS COMBINED WITH
THE CLOUDS WAS HELPING TO KEEP TEMPERATURES COOLER IN SOUTHEAST MN.
THE DEEPER INVERSION ALSO HAS HELPED TRAPPED PLENTY OF LOW LEVEL
MOISTURE...INCLUDING THAT FROM THE MELTING SNOWPACK...WHICH RESULTED
IN LOW VISIBILITIES OVER NORTHEAST IOWA...SOUTHEAST MINNESOTA AND
EVEN NORTH CENTRAL WISCONSIN THIS MORNING.
VERY LITTLE CHANGE IS FORECAST IN THE UPPER LEVEL PATTERN THROUGH
SUNDAY...EXCEPT FOR SOME UPPER RIDGING TRYING TO BUILD WESTWARD
THROUGH THE FORECAST AREA FROM THE UPPER HIGH. THIS UPPER RIDGING
SHOULD HELP TO KEEP THE FORECAST AREA DRY THROUGH SUNDAY AFTER ANY
SHOWERS FROM THIS AFTERNOON DISSIPATE WITH LOSS OF HEATING. THE
BIG ISSUE TONIGHT IS FOG. CONTINUING SNOW MELT OVER WESTERN AND
FAR NORTHERN PORTIONS OF THE AREA WILL HELP TO KEEP THE LOW LEVELS
OF THE ATMOSPHERE MOIST. MEANWHILE...MODELS MAINTAIN AN INVERSION
OVER THE SNOW PACK AREAS...WHICH MAKES SENSE WITH THE EASTERLY
FLOW OF WARMER AIR ALOFT ABOVE A NORTH-NORTHEAST FLOW OF COOL AIR
AT THE SURFACE. GIVEN THAT 1/4SM FOG FORMED THIS MORNING AND WINDS
ARE GOING TO BE EVEN LIGHTER...SITUATION SEEMS VERY FAVORABLE FOR
FOG AND EVEN DENSE FOG. ADDITIONALLY...SOME CLEARING COULD TRY TO
WORK IN BASED ON VISIBLE SATELLITE TRENDS...MAKING FOG EVEN MORE
FAVORABLE. SREF PROBABILITIES FOR VISIBILITY LESS THAN 1 MILE ARE
MUCH MORE EXPANSIVE AND HIGHER TONIGHT COMPARED TO THIS
MORNING...AND THE 04.00Z/06Z/12Z HIRES ARW/NMM ALL SHOW MORE FOG
TOO THAN THIS MORNING. LATEST HRRR/RAP ALSO DEVELOP FOG OVER THE
SNOW PACK. GIVEN THESE SIGNALS...HAVE INCREASED FOG COVERAGE AND
ISSUED A DENSE FOG ADVISORY...CONFINED TO THE AREAS WITH MELTING
SNOW PACK. COMBINATION OF HIGHER DEWPOINTS TONIGHT AND COME CLOUDS
WILL RESULT IN A WARMER NIGHT TONIGHT. WARMER TEMPERATURES ARE
ALSO ON TAP TOMORROW WITH MORE SUN LIKELY AS DRIER AIR COMING OUT
OF THE UPPER HIGH ADVECTS WESTWARD.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 306 PM CDT SAT MAY 4 2013
SUNDAY NIGHT THROUGH TUESDAY...NOT MUCH TO TALK ABOUT WITH REGARDS
TO THE UPPER LEVEL PATTERN. THE UPPER HIGH THAT IS OVER THE GREAT
LAKES SLOWLY BREAKS DOWN IN RESPONSE TO A SHORTWAVE TROUGH TRACKING
ACROSS NORTHERN ONTARIO COME MONDAY. STILL...THE FORECAST AREA JUST
SITS IN A LACK OF ANY UPPER LEVEL FLOW...SPLIT BETWEEN A SOUTHERN
STREAM TRACKING ACROSS THE SOUTHERN U.S. AND THE NORTHERN STREAM
WELL UP IN CANADA. MEANWHILE AT THE SURFACE...HIGH PRESSURE
CURRENTLY PRESENT OVER NORTHERN ONTARIO IS PROGGED TO BUILD SOUTH
INTO THE AREA DURING THIS PERIOD. DRYING AIR WITH THIS HIGH PRESSURE
AREA COMBINED WITH LACK OF ANY FLOW ALOFT WILL HELP TO KEEP THE
FORECAST AREA DRY. MAIN CONCERN AGAIN IS FOG. SREF PROBABILITIES FOR
VISIBILITY LESS THAN 1 MILE SHOOT BACK UP AGAIN SUNDAY NIGHT...
CONFINED TO THE SNOW PACK AREA. ONE QUESTION WOULD BE IS HOW MUCH
SNOW IS LEFT AFTER MELTING FROM THIS WEEKEND. HOWEVER...SOILS ARE
LIKELY GOING TO BE MOIST...AND WITH LIGHT WINDS AND CLEARING FROM
THE HIGH PRESSURE AREA BUILDING IN...RECIPE LOOKS GOOD AGAIN FOR FOG
AND EVEN DENSE FOG. MAY EVEN SEE FOG AGAIN MONDAY NIGHT...DEPENDING
IF THE SOIL IS STILL MOIST.
REGARDING TEMPERATURES THROUGH TUESDAY...850MB TEMPS ARE PROGGED TO
HOLD AROUND 8C FOR MONDAY AND THEN CLIMB TO NEAR 10C BY THE END OF
THE DAY TUESDAY. THESE READINGS ARE 0.5 TO 1 STANDARD DEVIATION
ABOVE NORMAL. BOTH DAYS SHOULD SEE QUITE A BIT OF SUN BEING IN
PROXIMITY TO THE SURFACE HIGH...THUS THINKING MIXING TO 850MB WILL
NOT BE A PROBLEM. THIS RESULTS IN HIGHS MAINLY IN THE LOW 70S ON
MONDAY AND LOW TO MID 70S ON TUESDAY. DID KEEP THE ROCHESTER AREA A
LITTLE COOLER ON MONDAY DUE TO WETTER SOIL. LIGHT WINDS AND DRY AIR
LIKELY TO RESULT IN DECENT COOLING AT NIGHT. FOLLOWED A BLEND OF MOS
GUIDANCE FOR LOWS.
TUESDAY NIGHT THROUGH SATURDAY...04.12Z ECMWF/GFS/CANADIAN AND ECMWF
ENSEMBLES SHOW THAT THE MORE ZONAL LOOKING NORTHERN STREAM WILL
BUCKLE DURING THE EXTENDED PORTION OF THE FORECAST. FOR FRIDAY AND
SATURDAY...GOOD AGREEMENT EXISTS IN FAIRLY DEEP TROUGHING OVER
CENTRAL CANADA...BEGINNING TO DROP DOWN TOWARDS THE FORECAST AREA.
IF THE 04.00Z/04.12Z ECMWF ARE CORRECT...WE COULD BE LOOKING AT A
SIGNIFICANT COOL DOWN HEADING INTO EARLY NEXT WEEK AS 850MB TEMPS
PLUMMET TO -8 TO -10C. BEFORE THAT TROUGH ARRIVES...THOUGH...A
SERIES OF WEAK COLD FRONTS / SYSTEMS ARE PROGGED TO COME THROUGH THE
AREA. THE FIRST MOVES THROUGH LATE WEDNESDAY. INSTABILITY BUILDING
AHEAD OF THIS FRONT...AIDED BY TEMPERATURES CLIMBING AT LEAST INTO
THE LOW IF NOT MID 70S...REQUIRES A CHANCE OF SHOWERS AND
THUNDERSTORMS. FOR THURSDAY INTO FRIDAY...THE 04.00Z/12Z ECMWF
INDICATES A SHORTWAVE TROUGH MOVING WEST TO EAST THROUGH THE
AREA...WHEREAS THE GFS AND CANADIAN KEEP THIS SHORTWAVE MUCH FARTHER
TO THE SOUTH. FOR NOW HAVE INCLUDED A CHANCE OF SHOWERS AND
THUNDERSTORMS UNTIL MODEL CONSISTENCY BECOMES BETTER. THEN FOR
SATURDAY WOULD BE THE STRONGER COLD FRONT ACCOMPANYING THE UPPER
TROUGH...THUS ANOTHER CHANCE OF PRECIPITATION. TEMPERATURES LOOK TO
STAY NEAR OR ABOVE NORMAL...UNTIL SATURDAY. SATURDAY COULD BE TRICKY
WITH HIGHS AS IT DEPENDS ON WHEN THE FRONT COMES THROUGH. 04.12Z
ECMWF IS SLOWER...WHICH WOULD SUGGEST THE BLEND OF ALL AVAILABLE
GUIDANCE MIGHT BE TOO COOL. WE WILL HAVE TO WAIT AND SEE.
&&
.AVIATION...TONIGHT AND SUNDAY
625 PM CDT SAT MAY 4 2013
CLOSED CIRCULATION WELL SOUTH OF THE AREA...CENTERED OVER NORTHERN
ARKANSAS. CIRCULATION AROUND IT STILL ROTATING SOME CLOUD COVER
INTO THE AREA...BUT MAINLY MID AND HIGH LEVEL. BIGGEST CONCERN TO
AVIATION TONIGHT WILL BE FOG...ESPECIALLY OVER THE SNOW PACK
AREAS OF SOUTHEAST MN /KRST/. HIGH DEWPOINT AIR MOVING WEST ACROSS
THE SNOW COVER...AND THIS HAS MAINTAINED CLOUD COVER THROUGH THE
DAY. ONCE DAYLIGHT IS LOST...ANTICIPATE FOG TO FORM. DENSE FOG IS
LIKELY AND AN ADVISORY IS IN EFFECT FOR KRST. CONDITIONS SHOULD
IMPROVE SUNDAY DURING THE MID TO LATE MORNING HOURS. FOR
KLSE...WILL LIKELY STILL BE SOME AREAS OF FOG...BUT PERHAPS NOT AS
THICK. TAFS HAVE FOLLOWED THE GENERAL TREND OF THE ONES ISSUED
EARLIER TODAY. WILL MONITOR CHANGING CONDITIONS AS THE SUN SETS
FOR ANY NECESSARY ADJUSTMENTS.
&&
.HYDROLOGY...
ISSUED AT 306 PM CDT SAT MAY 4 2013
AFTER SOME ISOLATED/SCATTERED RAIN SHOWERS THROUGH THIS
EVENING...A FEW DAYS OF DRY WEATHER ARE EXPECTED. THESE DRY DAYS
WILL BE BENEFICIAL...ALLOWING RUNOFF FROM THE RECENT RAIN AND
SNOWMELT TO WORK ITS WAY THROUGH THE TRIBUTARIES INTO THE MAIN
STEM OF THE MISSISSIPPI RIVER. MOST OF THE TRIBUTARIES ARE
REMAINING BELOW FLOOD STAGE. MEANWHILE...ALL THE WATER EVENTUALLY
LOOKS TO PUSH SOME SITES ALONG THE MISSISSIPPI RIVER RIGHT TO
FLOOD STAGE. SEE THE LATEST FLOOD AND RIVER STATEMENTS FOR MORE
INFORMATION.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...DENSE FOG ADVISORY FROM 1 AM TO 10 AM CDT SUNDAY FOR WIZ032-033.
MN...DENSE FOG ADVISORY FROM 1 AM TO 10 AM CDT SUNDAY FOR MNZ079-
086>088-094-095.
IA...DENSE FOG ADVISORY FROM 1 AM TO 10 AM CDT SUNDAY FOR IAZ008-009-
018-019.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...MW
HYDROLOGY...AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
255 PM CDT FRI MAY 3 2013
.SHORT TERM...(TONIGHT THROUGH SATURDAY NIGHT)
ISSUED AT 255 PM CDT FRI MAY 3 2013
MAIN FORECAST CONCERNS ARE PRECIPITATION CHANCES AND POSSIBLE
THUNDERSTORMS THROUGH PERIOD.
LATEST WATER VAPOR SATELLITE IMAGERY SHOWS UPPER LEVEL LOW CUTTING
OFF OVER THE CENTRAL PLAINS AND INDICATING GOOD FETCH OF MOISTURE
LIFTING NORTHWARD INTO THE UPPER MIDWEST AND GREAT LAKES REGION.
LATEST MOSAIC RADAR SHOWS RAIN ACROSS PORTIONS OF SOUTHEAST
MINNESOTA AND WESTERN WISCONSIN INTO EASTERN IOWA AND NORTHERN
ILLINOIS. THIS IS IN RESPONSE TO DECENT MOISTURE TRANSPORT AND
CONVERGENCE IN THE 925-850MB LAYER PER 03.15Z RAP.
THE 03.12Z GFS/NAM ARE IN GOOD AGREEMENT IN MOVING UPPER LEVEL CUTOFF
LOW OVER THE SOUTHERN PLAINS AND SOUTHEAST UNITED STATES THROUGH
SATURDAY NIGHT. THE DETERMINISTIC MODELS CONTINUE TO SHOW A SERIES OF
SHORTWAVE TROUGHS WRAPPING AROUND UPPER LEVEL LOW INTO THE UPPER
MIDWEST. THE 03.12Z GFS/NAM AND 03.15Z RAP INDICATE THE AREA IS ON
THE NOSE OF DECENT MOISTURE TRANSPORT AND CONVERGENCE AT 925-850MB
LAYER TONIGHT INTO SATURDAY MORNING. THIS WILL CONTINUE TO SPREAD
RAIN/RAIN SHOWERS INTO THE FORECAST AREA THROUGH SATURDAY. ALONG
WITH THE SURGE OF MOISTURE...THE 03.12Z GFS/NAM ADVECT WARMER AIR
ALOFT INTO THE FORECAST AREA THIS EVENING AND INTO TONIGHT...WITH
925MB TEMPERATURES RISING TO PLUS 5 TO PLUS 13 DEGREES CELSIUS BY
12Z SATURDAY. ALL PRECIPITATION SHOULD REMAIN AS RAIN ACROSS THE
FORECAST AREA.
THE 03.12Z GFS/NAM INCREASE 0-6KM MOST UNSTABLE CAPE OF 300-500 J/KG
ACROSS SOUTHERN HALF OF FORECAST AREA AFTER 15Z SATURDAY. CANNOT
RULE OUT AN ISOLATED THUNDERSTORM ACROSS THIS AREA FROM 15Z
SATURDAY TO 00Z SUNDAY.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 255 PM CDT FRI MAY 3 2013
SUNDAY...EASTERLY TO NORTHEASTERLY FLOW ALOFT DEVELOPS OVER REGION
AFTER 06Z SUNDAY AND WILL ADVECT DRIER AIR INTO THE REGION. WITH
925MB TEMPERATURES AROUND PLUS 13 DEGREES CELSIUS AND PARTIAL
SUNSHINE OVER FORECAST AREA...EXPECT HIGH TEMPERATURES TO WARM INTO
THE 60S.
MONDAY NIGHT THROUGH FRIDAY...MAIN FORECAST CONCERNS ARE
PRECIPITATION CHANCES WEDNESDAY INTO FRIDAY. THE 03.00Z
GFS/ECMWF/GEM ARE IN AGREEMENT IN DEVELOPING SPLIT UPPER LEVEL FLOW
OVER THE CONTINENTAL UNITED STATES THROUGH PERIOD. THE MAIN
DIFFERENCE IS THE 03.00Z ECMWF PUSHES A WEAK UPPER LEVEL LOW INTO
THE UPPER MIDWEST WEDNESDAY INTO THURSDAY AND THE GEM/GFS CONTINUE
TO SHOW RIDGING OVER THE REGION. THE 03.00Z ECMWF INDICATE WEAK
MOISTURE CONVERGENCE AND LIFT IN ASSOCIATED WITH WEAK UPPER LEVEL
LOW AND PRODUCES PRECIPITATION OVER THE AREA. THE 03.00Z GEFS
INDICATE UPPER LEVEL RIDGING OVER THE UPPER MIDWEST AND GREAT LAKES
REGION AND NO HINT OF A WEAK UPPER LEVEL LOW OVER THE AREA.
CONFIDENCE IN PRECIPITATION CHANCES WEDNESDAY AND THURSDAY IS
DECREASING AT THIS TIME. THE 03.00Z GEM/ECMWF/GFS ARE SUGGESTING
850MB TEMPERATURES PLUS 6 TO PLUS 10 DEGREES CELSIUS MONDAY NIGHT
THROUGH FRIDAY ACROSS THE AREA. EXPECT HIGH TEMPERATURES TO
CLIMBING TO AROUND 70 ACROSS FORECAST AREA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 108 PM CDT FRI MAY 3 2013
WINTRY MIX FINALLY GIVING WAY TO ALL RAIN AT THE KRST/KLSE TAF
SITES AS WARMER AIR ROTATES IN FROM THE EAST/SOUTHEAST. LOOK FOR
AREAS OF RAIN/RAIN SHOWERS TO CONTINUE OVERNIGHT INTO SATURDAY
MORNING AS MOISTURE ROTATES AROUND LOW PRESSURE MEANDERING AROUND
SOUTHERN IL/MO. MVFR/IFR CIGS EXPECTED THROUGH THE PERIOD.
&&
.HYDROLOGY...
ISSUED AT 255 PM CDT FRI MAY 3 2013
THE RECENT HEAVY SNOW AND EXPECTED RAINFALL AMOUNTS OF THREE
QUARTERS OF AN INCH TO AROUND AN INCH OVER THE REGION TONIGHT INTO
SATURDAY NIGHT...WILL PRODUCE RISES ALONG THE MISSISSIPPI RIVER AND
AREA TRIBUTARIES THROUGH THE WEEKEND. A FEW SITES ALONG THE
MISSISSIPPI RIVER ARE EXPECTED TO RISE TO ABOVE AND TO NEAR FLOOD
STAGE. SOME TRIBUTARIES ARE FORECAST TO HAVE WITHIN BANK RISES.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
255 PM CDT FRI MAY 3 2013
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DTJ
LONG TERM....DTJ
AVIATION.....DAS
HYDROLOGY....DTJ
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
327 AM EDT SUN MAY 5 2013
.DISCUSSION...
...ROUGH SURF/HIGH RIP CURRENT RISK TODAY...
CURRENTLY-TODAY...WEAK FRONTAL BOUNDARY OVER WEST CENTRAL FLORIDA
IS POISED TO SLIDE ACROSS THE AREA. THERE WILL BE CONSIDERABLE
LOW CLOUDS AHEAD OF AND JUST BEHIND THE BOUNDARY. BY LATE MORNING
HEATING/MIXING WILL DISSIPATE MOST OF THIS CLOUDINESS.
WEST/NORTHWEST FLOW WILL BE OCCASIONALLY GUSTY DURING THE DAY. MAX
TEMPS WILL CONTINUE A LITTLE BELOW NORMAL IN THE UPPER 70S TO
LOWER 80S.
TONIGHT...WEAK RIDGING BEHIND THE FRONT WILL KEEP SKIES MOSTLY
CLEAR EARLY. ANOTHER WEAK FRONTAL TROUGH WILL PUSH INTO THE
PENINSULA AFTER MIDNIGHT. THE AIR MASS WILL BE QUITE DRY SO EXPECT
JUST A NARROW BAND OF CLOUDINESS WITH THIS BOUNDARY. OVERNIGHT
LOWS WILL BE A LITTLE BELOW NORMAL IN THE UPPER 50S TO LOWER 60S.
MON-MON NIGHT...LARGE EXPANSIVE UPPER LOW OVER THE TENNESSEE VALLEY
IS FORECAST TO SLOWLY MOVE EAST INTO THE CAROLINAS THROUGH THE END
OF THIS PERIOD. ONLY WEAK ENERGY ALOFT ASSOCIATED WITH THIS FEATURE
WILL TRAVERSE EAST CENTRAL FLORIDA. A WEAK FRONTAL TROUGH WILL MOVE
ACROSS THE COVERAGE WARNING AREA AND PROVIDE A SMALL THREAT FOR
SHOWERS...MAINLY SOUTH OF THE I-4 CORRIDOR. YET ANOTHER FEATURE IS
FORECAST TO DROP INTO NORTH-CENTRAL FLORIDA OVERNIGHT. WILL KEEP
POPS AT 20 PERCENT OR LESS. WESTERLY WINDS INCREASING TO 10-15 MPH
IN THE AFTERNOON. HIGHS IN THE UPPER 70S TO AROUND 80 DEGREES NORTH
OF THE I-4 CORRIDOR WITH LOWER 80S FURTHER SOUTHWARD. LOWS MAINLY IN
THE UPPER 50S...EXCEPT AROUND 60 DEGREES TO LOWER 60S ACROSS THE
SPACE/TREASURE COASTS AND ORLANDO METRO.
TUE-TUE NIGHT...THE PREVIOUSLY MENTIONED UPPER LOW WILL GRADUALLY
WEAKEN AS IT BEGINS TO MOVE UP THE MID ATLANTIC COAST. CLOSER TO
HOME THE NEXT WEAK FRONTAL TROUGH WILL MOVE FROM NORTH-CENTRAL
FLORIDA THROUGH EAST CENTRAL FLORIDA DURING THE DAY. AGAIN ISOLATED
SHOWERS WILL BE POSSIBLE THROUGH THE DAY BUT EXPECT PRECIPITATION TO
BE LIGHT AS MOISTURE VALUES ARE POOR. MAINLY WESTERLY WINDS AGAIN
INCREASING TO 10-15 MPH IN THE AFTERNOON. HIGHS NEAR 80 DEGREES TO
LOWER 80S MOST LOCATIONS...EXCEPT A FEW MIDDLE 80S POSSIBLE ACROSS
OKEECHOBEE COUNTY AND SOUTHERN OSCEOLA COUNTY. OVERNIGHT LOWS ONCE
AGAIN IN THE MIDDLE TO UPPER 50S WITH A FEW LOWER 60S POSSIBLE ALONG
THE TREASURE COAST AND ORLANDO METRO.
WED-SAT...THE UPPER LOW CONTINUES TO WEAKEN AS IT SLOWLY MOVES UP
THE ATLANTIC SEABOARD...FINALLY OPENING UP INTO A TROUGH AND MOVING
INTO THE NORTH ATLANTIC DURING THE DAY ON FRI. MAINLY ZONAL WINDS
ALOFT OVER THE AREA WITH ONLY A FEW SUBTLE IMPULSES EMBEDDED WITHIN.
SLIGHT SHORTWAVE RIDGING BEGINS TO INCREASE OVER THE REGION ON SAT.
THE LOCAL SURFACE PRESSURE GRADIENT REMAINS RATHER WEAK AS HIGH
PRESSURE OVER THE AREA INITIALLY MOVES INTO THE WESTERN ATLANTIC ON
THU WITH RIDGING EXTENDING ACROSS THE CENTRAL PENINSULA INTO THE
WEEKEND. LIGHT WESTERLY SURFACE FLOW ON WED WILL GIVE WAY TO
AFTERNOON SEA BREEZES EACH DAY THU-SAT. ENOUGH MOISTURE MAY CREEP
BACK INTO THE AREA ON SAT FOR A FEW LATE DAY STORMS ACROSS THE
INTERIOR. BELOW NORMAL MAX/MIN TEMPERATURES WILL CONTINUE INTO WED
BEFORE A GRADUAL WARMING TREND COMMENCES THU LASTING INTO THE
WEEKEND.
&&
.AVIATION...
MVFR STRATUS HAS BEEN ADVANCING SLOWLY EAST ACROSS THE PENINSULA
AHEAD OF AND JUST BEHIND WEAK FRONTAL BOUNDARY. SOME IFR CEILINGS
MAY OCCUR KISM-KMCO-KDAB NORTHWARD IN THE PRE DAWN HOURS. THE MVFR
STRATUS SHOULD ARRIVE A LITTLE LATER KMLB-KVRB-KFPR-KSUA...JUST
BEFORE SUNRISE...AND SHOULD GRADUALLY BREAK UP BY LATE MORNING.
VFR EXPECTED BY LATE MORNING/EARLY AFTERNOON...BUT WEST/NORTHWEST
WINDS WILL GUST TO NEAR 20 KNOTS AT MOST TERMINALS.
&&
.MARINE...
CURRENTLY-TONIGHT...THE NORTHERN OFFSHORE LEG STILL HAS SOUTHEAST
WINDS AROUND 20 KNOTS BUT THE GFS AND LATEST RAP SHOW SURFACE LOW
OVER NORTHEAST FLORIDA MOVING FARTHER AWAY AND WINDS WEAKENING BY
FORECAST ISSUANCE TIME. WEST/NORTHWEST WINDS 10 TO 15 KNOTS
EXPECTED MOST OF THE DAY AND INTO TONIGHT.
SEAS ARE STILL ELEVATED ESPECIALLY IN THE NORTH DUE TO EAST/NORTHEAST
SWELLS. THIS WILL LIKELY MAKE INLETS HAZARDOUS DURING THE OUTGOING
TIDE THIS MORNING. THEREFORE...WILL CARRY A SMALL CRAFT ADVISORY
FOR HAZARDOUS SEAS THIS MORNING OVER ALL THE WATERS.
MON-MON NIGHT...WEAK HIGH PRESSURE WILL BUILD INTO THE AREA BEHIND
THE MOST RECENT WEAK FRONTAL TROUGH. WESTERLY WINDS THROUGH THIS
TIME WITH SPEEDS NEAR 10 KTS NEAR SHORE AND OCCASIONALLY 10-15 KTS
OFFSHORE. INCREASING LARGE EASTERLY SWELL WILL KEEP SEAS 3-5 FT NEAR
SHORE AND 5-6 FT OFFSHORE. CAUTIONARY STATEMENTS WILL BE NECESSARY
FOR OFFSHORE LEGS DUE TO THE SWELL.
TUE-THU...ANOTHER WEAK TROUGH PASSES THROUGH THE AREA ON TUE BEFORE
HIGH PRESSURE BUILDS BACK INTO THE REGION EMERGING INTO THE WESTERN
ATLANTIC ON THU. MAINLY A WESTERLY COMPONENT OF WIND BUT MAY SEE
WINDS BACK TO THE E/ESE ALONG THE COAST BY WED/THU WITH EAST COAST
SEA BREEZE FORMATION. WIND SPEEDS 10-12 KTS NEAR SHORE WITH PERIODS
AROUND 15 KTS OFFSHORE. SEAS TO SUBSIDE DURING THIS TIME WITH
INITIAL 3-5 FT SEAS FALLING BACK 3 FT OR LESS BY EARLY THU.
&&
.FIRE WEATHER...
TODAY...A FEW HOURS OF RH 30 TO 35 PERCENT SHOULD OCCUR OVER THE
INTERIOR NORTH THIS AFTERNOON. WEST WINDS NEAR 15 MPH WILL BE
GUSTY TO AROUND 20 MPH AT TIMES. HOWEVER...THE ERC VALUES ARE TOO
LOW AFTER RECENT RAINS FOR RED FLAG CRITERIA TO OCCUR.
MON-THU...GUIDANCE CONTINUES TO SHOW MIN RH VALUES DROPPING INTO THE
M-U30S OVER THE INTERIOR EACH AFTERNOON. WINDS SHOULD NOT BE A HUGE
CONCERN...AND FORTUNATELY...ERC VALUES HAVE DROPPED SIGNIFICANTLY
FROM LAST WEEK`S RAINFALL.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 78 60 76 58 / 20 10 10 10
MCO 81 60 81 58 / 10 10 20 10
MLB 79 62 80 60 / 10 10 20 10
VRB 80 61 82 59 / 10 10 20 10
LEE 80 59 79 58 / 10 10 10 10
SFB 80 60 80 59 / 10 10 20 10
ORL 80 62 81 61 / 10 10 20 10
FPR 79 58 81 60 / 10 10 20 10
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 12 NOON TODAY
FOR ALL OF THE COASTAL WATERS.
&&
$$
SHORT TERM...LASCODY
LONG TERM....SEDLOCK
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
404 AM EDT SUN MAY 5 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 402 AM EDT SUN MAY 5 2013
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR RDG STRETCHING
FM SE CANADA INTO THE UPR GRT LKS TO THE N OF CLOSED LO OVER THE SRN
MS RIVER VALLEY THAT WAS RESPONSIBLE FOR THE WINTER WX THE PAST
COUPLE OF DAYS. THE 00Z GRB RAOB AND ESPECIALLY THE APX RAOB SHOW A
VERY DRY AIRMASS UNDER THIS RDG...WITH THE 00Z H85 DEWPT DEPRESSION
AS HI AS 24C/PWAT JUST 0.24 INCH OR 49 PCT OF NORMAL AT APX. BUT
THERE IS STILL A RIBBON OF DEEPER MSTR SOME -SHRA EXTENDING NNWWD
FM THE CLOSED LO TO THE S INTO MN/ADJOINING ONTARIO. THE 00Z INL
RAOB SHOWS A NEARLY SATURATED PROFILE AND 00Z PWAT OF 0.83
INCH...188 PCT OF NORMAL. ALTHOUGH THERE ARE SOME HI CLDS OVER THE
E...THAT AREA IS DOMINATED BY THE DRY AIRMASS SHOWN ON THE APX RAOB.
WITH H85 TEMPS UP TO 10C...MAX TEMPS YDAY REACHED THE 70S OVER THE
SCENTRAL AND ERN CWA WHERE THE DRY AIR ALLOWED FOR QUITE A BIT OF
SUNSHINE AND LAKE COOLING WAS ABSENT IN THE NLY FLOW S OF HI PRES
CENTERED OVER NW ONTARIO. ALTHOUGH THE DRY AIR ALF HAS PUSHED INTO
THE WRN CWA PER THE LATEST RUC ANALYSIS SDNGS...ENUF LLVL MSTR
LINGERS THERE UNDER SHARP INVRN AT H9 TO SUPPORT LO CLDS/FOG OVER
THE WRN CWA FM THE KEWEENAW THRU GOGEBIC COUNTY. SINCE THE 00Z YPL
RAOB SHOWS SOME MSTR BTWN H9-825 EVEN CLOSE TO THE ONTARIO HI
CENTER...THERE IS QUITE A BIT OF LO CLD EXTENDING WELL N OF LK SUP
TO THE HI PRES RDG AXIS.
MAIN FCST CONCERNS IN THE SHORT TERM INVOLVE LO CLD TRENDS/IMPACT ON
TEMPS. POTENTIAL FOR LOW RH OVER THE E/IMPACT ON FIRE WX CONCERNS
THIS AFTN IS THE FOCUS THERE.
TODAY...UPR RDG AXIS/MID LVL DRY AIR WL REMAIN DOMINANT. ALTHOUGH
SFC HI PRES OVER NW ONTARIO IS PROGGED TO DRIFT SLOWLY S TOWARD LK
SUP...THE NNW FLOW IN ADVANCE OF THIS HI...ALBEIT LGT...WL LIKELY
ACT TO HOLD LO CLDS IN PLACE OVER MUCH OF THE NW HALF OF THE CWA
DESPITE THE ONSET OF DIURNAL HEATING THAT WOULD NORMALLY MIX OUT
THIS LLVL MSTR. IN FACT...COOL ADVECTION OFF THE CHILLY WATERS OF LK
SUP WL TEND TO OFFSET THE DIURNAL HEATING AND MAINTAIN A LLVL
INVRN/POTENTIAL FOR MORE PERSISTENT LO CLDS IN THIS AREA AS HI TEMPS
HOLD IN THE 40S NEAR THE SHORE. OVER THE E HALF OF THE CWA...A LGT S
FLOW WL PREVAIL ARND SFC HI PRES OVER SE ONTARIO. ALTHOUGH THERE MAY
BE MODERATION NEAR THE BAY OF GREEN BAY/ LK MI WITH A LK
BREEZE...H85 TEMPS NEAR 10C/MIXING TO H8-85 ON NAM/ GFS FCST SDNGS
WITH A GOOD DEAL OF SUNSHINE SUPPORT HI TEMPS TOPPING OUT IN THE 70S
AWAY FM THE LK COOLING. WITH SFC DEWPTS MIXING OUT TOWARD 35 OVER
THE INTERIOR...MIN RH WL LIKELY FALL AS LO AS ABOUT 25 PCT.
FORTUNATELY...THE WINDS WL BE LGT...SO NO FIRE WX HEADLINES ARE
NECESSARY.
TONIGHT...WITH HI PRES FCST TO SHIFT OVHD AND LGT WINDS...EXPECT
TEMPS TO DIP INTO THE 30S...FALLING MOST SHARPLY OVER THE E AND
SCENTRAL...WHERE MUCH DRIER AIR /PWAT NEAR 0.5 INCH/ WL LINGER.
SINCE MORE LLVL MSTR WL BE LINGERNING OVER THE W/NCENTRAL...
RETAINED A MENTION OF FOG IN THIS AREA OVERNGT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 402 AM EDT SUN MAY 5 2013
WITH THE CUTOFF LOW SITUATED OVER THE SOUTHEAST CONUS AND THE
NORTHERN JET STREAM WELL TO THE NORTH OF THE AREA IN CANADA...A
QUIET START TO THE WORK WEEK IS EXPECTED WITH ABOVE NORMAL
TEMPERATURES OVER MUCH OF THE AREA.
MONDAY AND TUESDAY WILL BE DOMINATED BY HIGH PRESSURE AT THE
SURFACE. EXPECT MOSTLY CLEAR SKIES FOR MUCH OF THIS PERIOD...BUT
THERE COULD BE SOME HIGH BASED DIURNAL CU DEVELOPING OVER THE
INTERIOR WEST DUE TO A POCKET OF 800-750MB MOISTURE. A FEW MODELS
HINT AT SOME SHOWER DEVELOPMENT...BUT WITH THE HIGH BASES AND
LIMITED MOISTURE KEEPING MLCAPE VALUES BELOW 150 J/KG...THINK IT
WILL JUST BE CU. THE SUNSHINE WILL ALLOW FOR AMPLE MIXING...TO
800-775MB...AND LEAD TO HIGHS IN THE LOWER 70S AWAY FROM THE GREAT
LAKES. LAKE BREEZES ON BOTH DAYS WILL KEEP TEMPERATURES COOLER NEAR
THE GREAT LAKES. DID TRY TO MIX OUT DEWPOINTS A LITTLE MORE THAN
THE MODELS HAVE INDICATED BASED OFF WHAT OCCURRED YESTERDAY.
FORTUNATELY...WITH LIGHT WINDS UNDER THE HIGH...IT WILL LIMIT FIRE
WX CONCERNS OVER THE SOUTH CENTRAL AND EAST EVEN THOUGH FFMC VALUES
ARE ON THE INCREASE AND ARE OR BECOMING HIGH.
PATCHY GROUND FOG IS POSSIBLE OVER THE KEWEENAW AND INTERIOR WEST
MONDAY NIGHT WITH THE CLEAR SKIES AND LOW LEVEL COOLING BY LINGERING
SNOW COVER. FARTHER EAST...DRIER AIR IN PLACE WILL LIMIT THE FOG
POTENTIAL. OVER THE GREAT LAKES...MODELS ARE HINTING AT FOG
DEVELOPMENT WITH THE LIGHT WINDS ON MONDAY. BUT DEWPOINTS AREN/T
EXTREMELY HIGH AND WITH DRY AIR ALOFT IT WON/T GET MUCH HELP FROM
THE LAND. WITH THAT BEING SAID...IF IT DOES DEVELOP...THE LIGHT
WINDS WOULD LEAD TO SLOW MOVEMENT AND IT LINGERING INTO WEDNESDAY.
COULD SEE SOME PATCHY GROUND FOG OVER THE FAR WEST LATE TUESDAY
NIGHT...BUT CONFIDENCE IS TOO LOW TO ADD AT THIS POINT.
THE HIGH PRESSURE WILL BEGIN TO GIVE WAY ON WEDNESDAY...AS AN UPPER
TROUGH OVER THE WEST COAST SLIDES INTO THE PLAINS AND A SHORTWAVE
SLIDES THROUGH THE NORTHERN STREAM AND PRODUCES A SURFACE LOW THAT
MOVES INTO NORTHWEST QUEBEC ON WEDNESDAY. A COLD FRONT ASSOCIATED
WITH THIS LOW WILL TRY TO DROP THROUGH THE AREA ON WEDNESDAY
AFTERNOON AND NIGHT. WITH THE UPPER TROUGH MOVING INTO THE
PLAINS...IT MAY PROVIDE ENOUGH MOISTURE TO PRODUCE SOME SHOWERS.
BUT THE MODELS DIFFER ON THE NORTHEASTWARD EXTENT OF THE MOISTURE
FROM THE UPPER TROUGH. THE 12Z ECMWF/GEM KEEP THE MOISTURE FARTHER
TO THE WEST...WHILE THE 18Z GFS PULLS IT INTO THE UPPER GREAT LAKES.
LATEST 00Z GFS/GEM RUNS HAVE TRENDED TOWARDS THE ECMWF IDEA. BASED
ON THE EXISTING DRY AIR MASS AND LIMITED MOISTURE RETURN...WOULD
TEND TO SIDE WITH THE DRIER IDEA AND WILL ONLY HAVE SLIGHTS OR LOW
CHANCE POPS FOR THE PASSAGE OF THE FRONT. BEHIND THE FRONT...ANOTHER
NORTHERN STREAM SHORTWAVE MAY AFFECT THE AREA ON FRIDAY NIGHT INTO
SATURDAY AND BRING ANOTHER POTENTIAL FOR RAIN. BUT AGAIN...MOISTURE
LOOKS TO BE THE CONCERN FOR THAT PERIOD UNLESS THE LOW MOVING
THROUGH THE LOWER GREAT LAKES MOVES FARTHER TO THE NORTH.
TEMPERATURES WED INTO SATURDAY LOOK TO BE COOLER THAN THE FIRST
PART OF THE WORK WEEK...BUT STILL NORMAL OR VERY SLIGHTLY BELOW
NORMAL FOR THIS TIME OF YEAR.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 123 AM EDT SUN MAY 5 2013
EXPECT LOW CLOUDS AND FOG AT ALL TAF SITES THROUGH AROUND DAYBREAK
TODAY WITH LIFR/IFR FLIGHT CATEGORY. LIGHT WINDS WILL BE THE RULE
AS A LARGE AREA OF HIGH PRESSURE SINKS IN FROM CENTRAL ONTARIO...AND
RESIDES OVER THE AREA BY MID AFTERNOON. SKIES SHOULD SCATTER OUT AT
ALL THE TAF SITES BY THE AFTN. LIGHT WIND REGIME WILL LEAD TO LAKE
BREEZES AT ALL SITES. LIGHT WINDS AND CONTINUAL LOW-LEVEL MOISTURE
ALLOWS POTENTIAL FOR LGT FOG AGAIN LATER TONIGHT INTO EARLY MONDAY
MORNING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 402 AM EDT SUN MAY 5 2013
A QUIET PERIOD OF WEATHER IS EXPECTED THROUGH THE PERIOD...WITH THE
WINDS LIKELY STAYING BELOW 25KTS. HIGH PRESSURE THAT HAS SETUP OVER
THE AREA WILL REMAIN THROUGH THE FIRST PART OF THE WORK WEEK AND
LEAD TO LIGHT WINDS. THEN...A COLD FRONT DROPPING SOUTHEAST ACROSS
THE UPPER GREAT LAKES ON WEDNESDAY INTO WEDNESDAY NIGHT WILL BRING
A WIND SHIFT BUT ONLY 10-20KT WINDS. WEAK HIGH PRESSURE WILL MOVE
OVER NORTHERN LAKE SUPERIOR FOR THURSDAY INTO THURSDAY NIGHT AND
DIMINISH THE WINDS.
&&
.HYDROLOGY...
ISSUED AT 402 AM EDT SUN MAY 5 2013
HYDROLOGY CONCERNS WILL REMAIN OVER THE COMING DAYS...UNTIL THE
REMAINING SNOW PACK MELTS OVER THE NORTHWESTERN THIRD OF UPPER
MICHIGAN. VISIBLE SATELLITE AND MODIS IMAGERY TODAY STILL SHOWS SNOW
REMAINING IN THE HIGHER TERRAIN LOCATIONS OF THE HURON MOUNTAINS AND
THE KEWEENAW PENINSULA. FARTHER WEST...THE 10 PLUS INCHES OF WET
SNOW WILL ALSO HELP KEEP THE POTENTIAL OF RISING RIVER LEVELS IN
PLACE. DID SEE RISES AT SOME OF THE SITES OVER THE WEST /RKLM4 AND
ESPECIALLY TRRM4/ WITH THE WARMER TEMPERATURES YESTERDAY AND WOULD
EXPECT THAT TO CONTINUE TODAY INTO THE FIRST PART OF THE WORK WEEK.
THE STURGEON RIVER AT ALSTON AND CHASSELL...THE MICHIGAMME RIVER
AROUND WITCH LAKE...AND THE PAINT RIVER NEAR CRYSTAL FALLS WILL
REMAIN CONCERNS INTO AT LEAST EARLY NEXT WEEK...AND IN THE CASE OF
THE MICHIGAMME RIVER PERHAPS WELL INTO THE COMING WEEK. BUT
OTHERWISE RIVER LEVELS CONTINUE TO COME DOWN DESPITE SOME RECENT
HEAVY PRECIP THAT IMPACTED MAINLY THE W HALF OF UPR MI.
FOR COMPLETE DETAILS...SEE THE LATEST RIVER FLOOD WARNINGS AND
ADVISORIES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...SRF
AVIATION...JLA
MARINE...SRF
HYDROLOGY...SRF
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1158 PM CDT SAT MAY 4 2013
.UPDATE...
ISSUED AT 1150 PM CDT SAT MAY 4 2013
UPDATED TO INCLUDE 06Z AVIATION DISCUSSION BELOW.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 341 PM CDT SAT MAY 4 2013
WARMER WEATHER WILL GRADUALLY MOVE IN ACROSS THE REGION OVER THE
NEXT FEW DAYS AND CONDITIONS BEGIN TO DRY OUT. BY THE MIDDLE OF THE
WEEK A SERIES OF UPPER LEVEL DISTURBANCES WILL BRING RETURNED
CHANCES FOR SHOWERS AND THUNDERSTORMS...ALONG WITH COOLER
TEMPERATURES.
EARLY AFTERNOON NORTH AMERICAN WATER VAPOR IMAGERY TOGETHER WITH
500MB HEIGHTS AND WINDS SHOWED THE CUTOFF LOW SPINNING OVER THE
OZARK MOUNTAINS...WITH A RIDGE LOCATED ALONG EACH COAST. AT THE
SURFACE A LOOSE PRESSURE GRADIENT WAS DRAPED ACROSS THE UPPER
MIDWEST BETWEEN A 1028 HIGH IN NORTH DAKOTA...AND A 1013 LOW IN
SOUTHERN MISSOURI WITH NORTHERLY WINDS OVER MINNESOTA AND
WISCONSIN. THE EXPANSIVE CLOUD SHIELD FROM THE AFOREMENTIONED
UPPER LEVEL LOW WAS BEGINNING TO SHOW SOME HOLES IN
WISCONSIN...AND THIS ALLOWED TEMPERATURES TO CLIMB INTO THE MID
70S WHERE THERE WAS NO SNOWPACK. HOWEVER...FARTHER WEST
TEMPERATURES WERE ONLY IN THE 40S WHERE THE DEEP SNOWPACK LINGERED
FROM THE PREVIOUS WINTER STORM. FARTHER WEST STILL IN NEAR THE
SD/MN BORDER TEMPERATURES WERE ONLY IN THE UPPER 30S ALONG WITH
THICKER CLOUDS AND LIGHT DRIZZLE ASSOCIATED WITH THE DEFORMATION
ZONE FROM THE DECAYING CYCLONE TO THE SOUTH. TONIGHT FORECAST
MODELS SHOW THE PRESSURE GRADIENT RELAXING...RESULTING IN
DECREASING WINDS. AS THE CLEARING TREND PROGRESSES WESTWARD
OVERNIGHT AREAS OF FOG ARE EXPECTED TO DEVELOP ALONG THE MN/WI
BORDER...WITH THE HIGHEST POTENTIAL FOR DENSE FOG ALONG AND EAST
OF A LINE FROM ALBERT LEA UP THROUGH RED WING AND RICE LAKE WI.
FORECAST SOUNDINGS SHOW A DEEP INVERSION WITH LOW LEVEL
MOISTURE...BUT FEEL THE WINDS ARE OVERDONE...SO THE FOG POTENTIAL
IS HIGHER THAN INDICATED. MEMBER 2 OF THE HOPWRF HAS A BETTER
HANDLE OF THE CLEARING TREND...AND SHOWS FOG DEVELOPMENT IN THIS
REGION AROUND 08Z. THE 16Z RUN OF THE HRRR SHOWS A SIMILAR TREND.
THEREFORE HAVE ISSUED A DENSE FOG ADVISORY OVERNIGHT. HIGH
TEMPERATURES ON SUNDAY WILL DEPEND ON HOW QUICKLY WE CAN MIX OUT
THE FOG. THIS WILL BE DIFFICULT TO DO WITH LIGHT WINDS AND WEAK
MECHANICAL MIXING...SO WILL HAVE TO DEPEND ON THE EARLY MAY SUN.
TEMPERATURES ACROSS THE WEST WILL BE 15 TO 20 DEGREES COOLER THAN
SNOW FREE AREAS OF WISCONSIN DUE TO CLOUD COVER.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 341 PM CDT SAT MAY 4 2013
SUNDAY NIGHT WILL HAVE ANOTHER FAVORABLE SETUP FOR FOG
DEVELOPMENT. ON MONDAY SURFACE TEMPERATURES WILL REBOUND TO NEAR
70 DEGREES...WITH WARMER TEMPS ON TUESDAY AS SOUTHERLY FLOW
INCREASES AHEAD OF THE NEXT WEAK UPPER LEVEL WAVE. USED A MIX DOWN
TOOL TO FORECAST HIGH TEMPERATURES...AND INCREASED THEM A FEW
DEGREES ABOVE THE PREVIOUS FORECAST...ESPECIALLY IN FAR WESTERN
MINNESOTA. THIS WAVE IS FORECAST TO BRING A CHANCE FOR SHOWERS AND
THUNDERSTORMS WEDNESDAY. THE SEVERE WEATHER THREAT IS VERY
LOW...WITH SMALL DEEP LAYER SHEAR AND ONLY 500J/KG OF MLCAPE.
UNSETTLED WEATHER WILL CONTINUE THROUGH THE END OF THE WEEK. LOW
POPS AND SLIGHTLY COOLER TEMPERATURES WILL BE FOCUSED ALONG A WARM
FRONT THAT IS FORECAST TO STALL OUT ACROSS THE REGION...AS
PERIODIC SHORTWAVES MOVING ACROSS THE UPPER MIDWEST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1150 PM CDT SAT MAY 4 2013
VERY LITTLE ADVECTIVE FLOW WILL OCCUR ACROSS THE AREA THROUGH THE
PERIOD... WITH JUST SOME SLIGHT INCREASE IN HEIGHTS AND DRYING OF
THE BOUNDARY LAYER INDICATED. WE SHOULD SEE A BIT MORE BREAKS IN
CLOUD COVER TODAY AS THE AIRMASS CONTINUES TO MODERATE... BUT
STILL PLENTY OF MVFR AND SOME IFR CEILINGS WILL BE FOUND FOR AT
LEAST PART OF THE DAY. VISIBILITIES ARE A TOUGH CALL OVERNIGHT
INTO EARLY SUNDAY MORNING... WITH A GOOD POTENTIAL FOR RADIATION
FOG IF ANY HOLES IN THE CLOUD COVER DEVELOP... WHICH LOOKS LIKE A
POSSIBILITY OVER EASTERN SITES. ON THE FLIP SIDE... WESTERN SITES
WILL SEE FOG DEVELOP MORE FROM THE TOP DOWN AS THE STRATUS DECK
LOWERS. WHATEVER LOWS VISIBILITIES DO OCCUR SHOULD MANAGE TO MIX
OUT DURING THE 12-14Z TIME FRAME.
KMSP...
VERY LOW CONFIDENCE IN THE FORECAST SPECIFICS... PARTICULARLY WITH
REGARD TO VISIBILITIES OVERNIGHT AND HOW QUICKLY CEILINGS WILL
IMPROVE ON SUNDAY. COULD EASILY SEE SOME IMPROVEMENT IN CEILINGS
DURING THE FIRST FEW HOURS OF THE FORECAST WITH MINIMAL LOW CLOUDS
JUST OFF TO THE SOUTHEAST OF THE AREA... BUT REMAINED PESSIMISTIC
AT THIS POINT. IF THE LOW CLOUDS DO CLEAR FOR A TIME OVERNIGHT
THEN VISIBILITIES COULD GET A BIT WORSE THAN INDICATED.
OTHERWISE... A GENERAL IMPROVEMENT SHOULD OCCUR SUNDAY WITH THE
BOUNDARY LAYER DRYING OUT A BIT MORE AND THE AREA PROBABLY BREAKING
INTO SOME A DECENT AMOUNT OF SUNSHINE BY EARLY AFTERNOON.
/OUTLOOK FOR KMSP/
MONDAY...MVFR CEILINGS POSSIBLE EARLY. LIGHT AND VARIABLE WINDS.
MONDAY NIGHT AND TUESDAY...VFR CONDITIONS EXPECTED. LIGHT AND
VARIABLE WINDS.
TUESDAY NIGHT...MVFR CEILINGS AND VISIBILITIES POSSIBLE LATE WITH
A CHANCE OF SHRA/TSRA. SOUTH WINDS 5 TO 10 KT.
WEDNESDAY...MVFR CEILINGS AND VISIBILITIES POSSIBLE WITH A CHANCE
OF SHRA/TSRA. SOUTHEAST WINDS 5 TO 15 KT BECOMING EAST.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...DENSE FOG ADVISORY UNTIL 10 AM CDT SUNDAY FOR MNZ077-078-082>085-
091>093.
WI...DENSE FOG ADVISORY UNTIL 10 AM CDT SUNDAY FOR WIZ015-016-023>028.
&&
$$
UPDATE...
SHORT TERM...
LONG TERM...JRB
AVIATION...
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1150 PM CDT SAT MAY 4 2013
.AVIATION...
06Z TAFS FOR KOMA...KLNK...AND KOFK.
NOT MUCH CHANGE FROM PREVIOUS THINKING ON TAFS. CEILINGS ARE ON
THE EDGE OF IFR/MVFR BUT EXPECTED TO SWING TO IFR AND STAY THERE.
KOMA IS AT SOME RISK FOR A SCATTERED SHOWER OR PATCHY
DRIZZLE...BUT DID NOT INCLUDE MENTION FOR NOW AS COVERAGE IS NOT
GREAT AS SHOWERS MOVE ACROSS IOWA TOWARD THE MISSOURI RIVER. SOME
CHANCE FOR PATCHY DRIZZLE TO PASS OVER KOFK/KLNK...BUT RISK SEEMS
TOO LOW TO INCLUDE MENTION AT THIS TIME. DID INCLUDE VISIBILITY
RESTRICTION TO MVFR FOR SOME TIME TONIGHT AT ALL SITES AS WINDS
DECREASE BELOW 10KT AND TEMPERATURE/DEWPOINT SPREADS DECREASE.
CEILINGS SHOULD IMPROVE GRADUALLY ON SUNDAY AFTERNOON...WITH VFR
CONDITIONS EXPECTED FROM LATE AFTERNOON THROUGH THE EVENING.
MAYES
&&
.PREV DISCUSSION... /ISSUED 633 PM CDT SAT MAY 4 2013/
DISCUSSION...
HAVE MADE SEVERAL CHANGES TO THE OVERNIGHT FORECAST TO REFLECT
ONGOING TRENDS. TEMPERATURES ARE ALREADY IN THE LOW 40S...AND
THINK WE WILL SHED AT LEAST A COUPLE OF DEGREES YET TONIGHT. HAVE
REDUCED MIN TEMPS IN MOST LOCATIONS OVERNIGHT...ESPECIALLY IN THE
WEST/NORTHWEST CWA WHERE TEMPS ARE COOLEST. INCREASED SKY COVERAGE
TO 100 PERCENT EVERYWHERE THROUGH THE NIGHT...AS WE WILL BE LOCKED
IN STRATUS THROUGH THE REMAINDER OF THE NIGHT AS LOWER CEILINGS
INVADE FROM THE EAST. AS FAR AS PRECIPITATION...THOUGHT THE 18Z
NAM/12Z 4KM WRF/LATEST FEW RUNS OF RAP HAD A VERY GOOD HANDLE ON
THE CURRENT PRECIP DISTRIBUTION...WITH A NARROW BAND OF RAIN IN
NORTHEAST NEB AND A MORE ROBUST AREA OF SHOWERS IN EAST CENTRAL
IA. THOSE MODELS ERODE THE PRECIPITATION COVERAGE IN IA AS IT
SLIDES WESTWARD THROUGH THE NIGHT...LEAVING JUST A FEW SHOWERS BY
THE TIME IT REACHES WESTERN IA LATER TONIGHT. HAVE KEPT MOST OF
THE CWA FREE OF POPS OVERNIGHT...WITH A PATCHY DRIZZLE MENTION
UNDER WEAK LIFT AND ABUNDANT LOW-LEVEL MOISTURE. DID HOLD ONTO A
CHANCE POP IN THE NORTHWEST CWA EARLY THIS EVENING...AS THE BAND
OF SCATTERED COVERAGE MOVES ACROSS...AS WELL AS A CHANCE IN THE
EAST TONIGHT AS THE DISSIPATING AREAS OF SHOWERS REACH WESTERN IA.
MAYES
PREV DISCUSSION... /ISSUED 249 PM CDT SAT MAY 4 2013/
DISCUSSION...
LARGE CLOSED UPPER LOW CONTINUES TO SLOWLY SPIN ACROSS NORTHWESTERN
ARKANSAS...WITH MOISTURE CONTINUING TO MOVE FROM EAST TO WEST
THROUGH THE FORECAST AREA. FIRST WAVE MOVED IN LATE LAST NIGHT
THROUGH THIS MORNING...WHICH BROUGHT WIDESPREAD PRECIPITATION TO
THE FORECAST AREA...WHICH CONTINUES THIS AFTERNOON ALONG AND NORTH
OF I80...WHICH HAS MOSTLY BEEN RAIN ALTHOUGH A FEW SNOW FLAKES
WERE NOTED FROM TIME TO TIME. THIS FIRST BATCH OF VERY LIGHT
PRECIP WILL CONTINUE TO PUSH WEST NORTHWEST THROUGH THE NORTHERN
CWA EARLY THIS EVENING.
MEANWHILE...THE NEXT BATCH OF SIMILAR PRECIPITATION IS CURRENTLY
MOVING THROUGH THE MID MISSISSIPPI RIVER VALLEY AND SHOULD BEGIN
TO MOVE INTO OUR AREA BY VERY LATE THIS EVENING AND AFTER
MIDNIGHT. THERE WILL BE A DRY PERIOD IN BETWEEN THE FIRST AND
SECOND WAVES...AND ITS ENTIRELY POSSIBLE THAT PARTS OF SOUTHEAST
NEBRASKA COULD REMAIN DRY OVERNIGHT...BUT CLOUDY.
AS THE UPPER LOW CONTINUES TO DRIFT SLOWLY EAST SOUTHEAST THROUGH
THE DAY SUNDAY...OUR REGION IS LEFT IN A COL AREA WITH LINGERING
TRAPPED MOISTURE...WITH SCATTERED SHOWERS IN THE MORNING...WITH
DIMINISHING COVERAGE IN THE AFTERNOON...AND SHOULD BE OVER BY
SUNDAY EVENING AS WEAK RIDGING BUILDS IN ALOFT. MONDAY MORNING
WILL PROBABLY BE DRY...BUT LEFT IN A SLIGHT CHANCE OF SHOWERS
MONDAY AFTERNOON AS LAPSE RATES STEEPEN ALTHOUGH CYCLONIC FORCING
BY THAT TIME IS ALMOST NON EXIST.
FOR THE EXTENDED FORECAST...THE UPPER CLOSED LOW THAT EXISTS
ACROSS THE WEST COAST WILL CONTINUE TO DEEPEN AND MAY EVEN
RETROGRADE THROUGH MONDAY. MEANWHILE...THE FIRST PIECE OF THIS
SYSTEM MOVING INTO THE CALIFORNIA BAJA REGION TODAY APPEARS TO BE
MOVING THROUGH THE PLAINS BY TUESDAY/WEDNESDAY WHICH WILL BRING
MORE SHOWERS AND PROBABLY THUNDERSTORMS AS INSTABILITY INCREASES...
ALTHOUGH SIGNIFICANT LOW LEVEL MOISTURE IS NOT EXPECTED.
MEANWHILE...THE UPPER CLOSED LOW MOVES INTO THE CENTRAL ROCKIES
AND BEGINS EJECTING SMALL WAVES INTO ONTO THE PLAINS THROUGH THE
REMAINDER OF THE WEEK WHICH WILL BRING DAILY CHANCES FOR RAIN.
AGAIN...NOT THAT IT WILL BE A CONTINUOUSLY RAINY PERIOD...BUT IT
SHOULD DEFINITELY BE A MORE ACTIVE PERIOD. ALSO DURING THIS
TIME...A SUBTLE COOL FRONT APPEARS TO BE SETTLING SOUTHWARD
THROUGH THE AREA...TRANSITIONING WINDS FROM SOUTH EARLY IN THE
PERIOD TO EAST NORTHEAST BY FRIDAY AND SATURDAY.
DEWALD
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
99/99
AREA FORECAST DISCUSSION
NWS RALEIGH NC
315 AM EDT SUN MAY 5 2013
.SYNOPSIS...
COOL HIGH PRESSURE WILL EXTEND ALONG THE NORTHEAST AND MID ATLANTIC
COAST THROUGH MONDAY. A STRONG UPPER LOW WILL TRACK SLOWLY EASTWARD
ACROSS THE DEEP SOUTH AND CAROLINAS THROUGH TUESDAY.
&&
.NEAR TERM /THROUGH MONDAY NIGHT/...
AS OF 300 AM SUNDAY...
FOR TODAY: RAIN CHANCES WILL SLOWLY INCREASE FROM SW TO NE LATER
TODAY... HOWEVER IT LOOKS LIKE THE HEAVIER RAIN IS LIKELY TO HOLD
OFF UNTIL LATE. THE UPPER LOW IS CURRENTLY SPINNING NEAR MEMPHIS...
WHILE NC REMAINS BENEATH A MID LEVEL COL AREA BORDERED BY THE
PERSISTENT BLOCKING HIGH OVER THE ERN GREAT LAKES... BROAD WEAK LOW
PRESSURE OUT OVER THE ATLANTIC... AND THE POTENT VORTEX OVER THE
LOWER MISS VALLEY. STRONG MOISTURE TRANSPORT CONTINUES TO DRIVE UP
OVER GA/SC INTO THE SRN APPALACHIANS WITH A 45 KT SOUTHEASTERLY LOW
LEVEL JET ORTHOGONAL TO THE SLOPES OVER SW NC... LEADING TO MAXIMUM
POTENTIAL TERRAIN UPGLIDE HERE AND A HIGH THREAT OF HEAVY RAIN AND
FLOODING ISSUES TO OUR WEST TODAY. ADDING TO THIS LOW-LEVEL-ROOTED
MECHANICAL LIFT IS STRONG UPPER DIVERGENCE WHICH WILL PEAK OVER WRN
NC TODAY... ALTHOUGH THE SLOW MOVEMENT AND THE START OF GRADUAL
WEAKENING OF THIS VORTEX WILL MINIMIZE MID LEVEL DPVA AND HEIGHT
FALLS. SO WHILE SOME OF THIS SHIELD OF HEAVIER RAIN MAY WORK INTO
THE FAR SWRN CWA THIS AFTERNOON... GIVEN THE FOCUS OF STRONGER LIFT
AND MOISTURE FLUX LARGELY OVER WRN NC... EXPECT MORE IN THE WAY OF
VERY PATCHY LIGHT RAIN AND DRIZZLE OVER MUCH OF CENTRAL NC THROUGH
TODAY. THIS IS FURTHER SUPPORTED BY MODEL TRENDS SHOWING A SLOWING
OF THE NE PROGRESS OF THE HEAVY RAIN SHIELD TODAY... AS WELL AS THE
LATEST RAP AND CONVECTION-ALLOWING WRF RUNS. WILL LOWER POPS AND QPF
AND DELAY THE ARRIVAL OF HIGHER CHANCES UNTIL LATE TODAY.
THICKNESSES ABOUT 20-25 METER BELOW NORMAL COMBINED WITH THE BRISK
ENE WINDS AND CONSIDERABLE CLOUD COVER SUPPORT COOL HIGHS OF 58-68.
FOR TONIGHT: WE SHOULD FINALLY SEE THE MORE WIDESPREAD RAIN WORK
INTO CENTRAL NC FROM THE SW. THE VORTEX TO OUR SW WILL BEGIN TO
SLOWLY FILL AS IT WOBBLES ACROSS NRN AL TO NEAR CHATTANOOGA TONIGHT.
AS IT APPROACHES... THE OCCLUDED SURFACE FRONT WILL PIVOT NE INTO SW
NC ACROSS SC... WHILE THE INTENSE PLUME OF ATLANTIC MOISTURE (WITH
PRECIP WATER OVER 150 PERCENT OF NORMAL) STREAMING OVER SC INTO WRN
NC GRADUALLY TRANSLATES TO THE NNE. EXPECT A SLOW BUT STEADY
INCREASE IN POPS FROM VERY LATE AFTERNOON THROUGH TONIGHT IN CENTRAL
NC FROM SW TO NE... TRENDING UP TO CATEGORICAL ACROSS THE SOUTH AND
WEST WITH LIKELY POPS IN THE NE. TOUGH CALL ON AMOUNTS THROUGH
TONIGHT... CONSIDERING THAT THE MID LEVEL VORTEX WILL BE WEAKENING
AND THUS THE DYNAMIC FORCING WILL BE ON THE DECREASE... PLUS THE
NORTHWARD SHIFT OF THE SOUTHEASTERLY LOW LEVEL JET INTO NW NC AND SW
VA WILL ACCORDINGLY PLACE THE BEST LOW LEVEL CONVERGENCE AND
MOISTURE TRANSPORT JUST WEST OF THE FORECAST AREA. WILL FORECAST
AMOUNTS UP TO A HALF INCH OVER THE FAR SRN AND FAR WRN CWA INCLUDING
LAURINBURG INTO SOUTHERN PINES AND THE TRIAD TO THE SW... WHILE
AREAS TO THE NORTH AND EAST SHOULD SEE MUCH LOWER AMOUNTS...
GENERALLY A TENTH INCH OR LESS THROUGH TONIGHT AS WE SIMPLY WON`T
SEE QUITE THE FORCING FOR ASCENT NOR HIGHER PW FLUX IN THE NE CWA
OVERNIGHT. THE CLOUDS AND WINDS SHOULD LIMIT COOLING AND LOWER THE
DIURNAL TEMP SPREAD... THUS HAVE NUDGED UP LOWS SLIGHTLY TO 54-60.
FOR MONDAY/MONDAY NIGHT: THE MID LEVEL VORTEX IS EXPECTED TO REMAIN
POTENT BUT STEADILY WEAKEN AS IT MEANDERS AROUND NE AL MONDAY THEN
EASES INTO EAST CENTRAL GA MONDAY NIGHT AS LOBES OF VORTICITY ROTATE
AROUND IT AND DRIVE ITS MOVEMENT. MODELS DIFFER ON THE EVOLUTION OF
SURFACE FEATURES BUT IT APPEARS MOST LIKELY THAT THE PRIMARY LOW
WILL WEAK OVER TN WHILE A SECONDARY TRIPLE-POINT LOW FORMS OVER THE
CENTRAL NC/SC BORDER AREA... NEAR THE CROOK OF A MID LEVEL DRY SLOT
PUNCHING INTO SC. IF THIS LOW WANDERS UP TOWARD CLT AS MOST
OPERATIONAL MODELS SUGGEST... THE MID LEVEL DRY SLOT SHOULD SHIFT
INTO FAR SRN NC WHILE THE BEST LOW LEVEL MOISTURE FEED AND UPPER
DIVERGENCE (AND HENCE THE GREATEST ASCENT AND LOW LEVEL MOISTURE
TRANSPORT) SHIFT INTO EAST-CENTRAL/NE/NORTH-CENTRAL NC MONDAY... AND
EVENTUALLY UP INTO VA MONDAY NIGHT. THIS SUPPORTS THE GENERAL TREND
OF EARLIER FORECAST OF SHIFTING THE CATEGORICAL POPS NORTHWARD
THROUGH NC DURING THIS PERIOD. INSTABILITY REMAINS MARGINAL BUT DOES
INCREASE ACROSS THE SOUTH MONDAY/MONDAY NIGHT WITH THE ARRIVAL OF
THE DRY SLOT AND RISING MID LEVEL LAPSE RATES TO OVER 6.75 C/KM...
AND THE NAM/GFS TAKE MLCAPE NEAR 1000 J/KG MONDAY AFTERNOON. WILL
NEED TO RETAIN A MENTION OF AT LEAST ISOLATED STORMS... MAINLY SOUTH
OF HIGHWAY 64 AND MAINLY IN THE AFTERNOON/EVENING. THE WIND PROFILE
IS NOT TEXTBOOK BUT 0-6KM SHEAR DOES REACH 30-40 KTS WITH A CURVED
0-3 KM HODOGRAPH AND 0-1 KM SHEAR OF 20-25 KTS... SO WE COULD SEE A
STRONG STORM OR TWO. ADDITIONAL RAINFALL AMOUNTS COULD APPROACH AN
INCH ESPECIALLY IN THE NORTHERN HALF ACCOMPANYING THE AXIS OF MORE
STEADY RAIN. THE DIURNAL SPREAD SHOULD AGAIN BE MUCH LOWER THAN
USUAL... ALTHOUGH A FEW ANTICIPATED BREAKS IN THE CLOUDS IN THE
SOUTH MONDAY AFTERNOON SHOULD CAUSE A SPIKE IN TEMPS. HIGHS FROM 61
NW TO 72 SE. LOWS 53 SW TO 59 NE. -GIH
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 315 AM SUNDAY...
TUESDAY...
THE UPPER LOW OVER THE SAVANNAH RIVER BASIN WILL LIFT VERY SLOWLY
NORTHEAST ACROSS THE CAROLINAS TUESDAY. HEAVIER RAIN ASSOCIATED
WITH THE WARM CONVEYOR BELT AND DEEP MOIST AXIS WILL SHIFT NORTH
ACROSS VA WITH THE OCCLUDED FRONT...AS A DRY SLOT WORKS ITS WAY
AROUND THE EAST SIDE OF THE UPPER LOW. COOLING ALOFT AND STEEPENING
MID LEVEL LAPSE RATES (TO AROUND 7 C/KM) SHOULD STILL SUPPORT AT
LEAST SCATTERED SHOWERS AND STORMS...PARTICULARLY OVER THE COASTAL
PLAIN WHERE HEIGHT FALLS ALOFT AND LOW LEVEL CONVERGENCE WILL BE
MAXIMIZED AHEAD OF THE UPPER LOW AND ASSOCIATED BAGGY SURFACE LOW.
WHILE FAIRLY WIDESPREAD CLOUD COVER MAY INHIBIT HEATING...STRONG
DEEP LAYER SHEAR AROUND 40KT ON THE EASTERN PERIPHERY OF THE UPPER
LOW COULD STILL SUPPORT SOME STORM ORGANIZATION AND ENHANCE THE
THREAT OF HAIL IF INSTABILITY CAN DEVELOP...MAINLY OVER THE NORTHERN
COASTAL PLAIN. THE THREAT SEVERE WEATHER APPEARS TO BE
LOW...HOWEVER.
SOME BREAKS IN CLOUD COVER APPEAR MORE LIKELY OVER THE EAST
TUESDAY...THOUGH GUIDANCE STILL ONLY INDICATES HIGHS AROUND 70 OVER
THE COASTAL PLAIN. OVER THE WEST...DEEPER MOISTURE WRAPPED AROUND
THE NORTHWEST SIDE OF THE UPPER LOW WILL MAINTAIN MOSTLY CLOUDY
SKIES AND MAY KEEP TEMPS FROM RISING OUT OF THE LOWER 60S.
TUESDAY NIGHT AND WEDNESDAY...
THE UPPER LOW WILL MOVE OVERHEAD TUESDAY NIGHT AND OFF THE VA
TIDEWATER REGION DURING THE DAY WEDNESDAY. FORCING FOR ASCENT WILL
BECOME LESS FAVORABLE BEHIND THE UPPER LOW AS THE DEEP LAYER FLOW
EXHIBITS MORE BACKING AND SUBSIDENCE BEGINS TO SET IN. SOME SHOWERS
ARE POSSIBLE IN THE WRAP AROUND MOISTURE LIKELY TO ENCOMPASS VA
WEDNESDAY...SOME OF WHICH MAY LINGER OF DRIFT SOUTH INTO THE
NORTHERN PORTION OF THE CWA. THERMODYNAMIC PROFILES SUGGEST SOME
WEAK INSTABILITY AND A FEW STORMS WILL BE POSSIBLE...THOUGH AGAIN
THE THREAT OF SEVERE IS LOW. LOWS IN THE MID 50S WEDNESDAY MORNING
SHOULD REBOUND INTO THE LOW TO MID 70S AREAWIDE BY WEDNESDAY
AFTERNOON.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
AS OF 315 AM SUNDAY...
HEIGHTS WILL CONTINUE TO SLOWLY RISE THURSDAY THROUGH FRIDAY IN THE
WAKE OF THE DEPARTING UPPER LOW AND AHEAD OF SOUTHERN STREAM ENERGY
MOVING OUT OF THE SOUTHWESTERN US. WITH SHORTWAVE RIDGING ALOFT
OVERHEAD...DRY CONDITIONS AREA EXPECTED WITH TEMPS MODERATING INTO
THE UPPER 70S AND LOWER 80S. MEDIUM RANGE MODELS THEN SHOW THE
POTENTIAL FOR THE SPLIT FLOW PATTERN TO AMPLIFY NEXT WEEKEND...WITH
A CUT OFF LOW OVER THE SOUTHWESTERN US AND TROUGHING FROM THE NORTH
CENTRAL US TO THE EAST COAST. A COLD FRONT OVER THE MIDWEST STATES
FRIDAY SHOULD EVENTUALLY PUSH EAST ACROSS THE MOUNTAINS BY
SUNDAY...THOUGH THERE IS QUITE A BIT OF DISAGREEMENT BETWEEN THE
ECMWF AND GFS ON THE EVOLUTION OF ENERGY OVER THE CENTRAL US AND THE
PROGRESSION OF THE FRONT. PREFER TO MAINTAIN THE CHANCE POPS
CURRENTLY IN THE FORECAST FOR SATURDAY AND FAVOR A SOLUTION IN
BETWEEN THE FASTER ECMWF AND SLOWER GFS.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AS OF 1240 AM SUNDAY...
BRISK AND GUSTY SURFACE WINDS FROM THE ENE (FROM 060-080 DEGREES)
WILL PERSIST THROUGH TODAY/TONIGHT... AND THIS FLOW OF MOIST
ATLANTIC AIR INTO NC WILL MAKE SUB-VFR CONDITIONS DOMINANT OVER
CENTRAL NC TAF SITES. CLOUDS BASED AT ONE TO THREE THOUSAND FT AGL
HAVE VARIED FROM SCATTERED TO BROKEN OVER THE LAST SEVERAL HOURS
(TOPPED BY BROKEN VFR CLOUDS BASED FOUR THOUSAND TO TWELVE THOUSAND
FT AGL)... MAKING IT DIFFICULT TO PINPOINT EXACTLY WHEN AND WHERE
PERIODIC MVFR CIGS WILL PREVAIL. WITH LOWER-THAN-USUAL CONFIDENCE...
EXPECT MAINLY VFR CIGS THROUGH 09Z-10Z THIS MORNING... FOLLOWED BY
MVFR TO IFR CIGS AFTER 10Z. A FEW LIGHT SPRINKLES OR DRIZZLE ARE
POSSIBLE THIS MORNING THROUGH MID AFTERNOON... BUT VSBYS SHOULD
REMAIN MOSTLY VFR AND THE HEAVIEST RAINFALL WILL HOLD WEST OF A LINE
FROM MT AIRY TO SALISBURY TO CLT. THE MVFR/IFR CIGS SHOULD RISE TO
VFR AFTER 16Z-18Z THIS MORNING. MORE SUBSTANTIAL RAIN AND SUB-VFR
VSBYS/CIGS WILL MOVE IN SLOWLY FROM THE SW TOWARD THE NE THIS
AFTERNOON/ EVENING... REACHING INT/GSO/FAY AFTER 21Z... BUT NOT
EXPECTED TO REACH RDU/RWI UNTIL NEAR OR AFTER 06Z TONIGHT. SUSTAINED
WINDS OF 10-16 KTS GUSTING TO AROUND 20 KTS WILL CONTINUE THROUGH
THE FORECAST PERIOD.
LOOKING BEYOND 06Z TONIGHT: GOOD CHANCE OF CONTINUED DOMINATION OF
SUB-VFR CONDITIONS WITH PERIODS OF RAIN THROUGH AT LEAST TUESDAY AS
AN UPPER LEVEL LOW SLOWLY CROSSES THE REGION. BRISK ENE SURFACE
WINDS WILL PERSIST THROUGH MONDAY BEFORE WEAKENING MONDAY NIGHT.
SHALLOW IFR FOG IS POSSIBLE TUESDAY NIGHT/WEDNESDAY MORNING... AND
AGAIN THURSDAY MORNING.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...SMITH
LONG TERM...SMITH
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
300 AM EDT SUN MAY 5 2013
.SYNOPSIS...
COOL HIGH PRESSURE WILL EXTEND ALONG THE NORTHEAST AND MID ATLANTIC
COAST THROUGH MONDAY. A STRONG UPPER LOW WILL TRACK SLOWLY EASTWARD
ACROSS THE DEEP SOUTH AND CAROLINAS THROUGH TUESDAY.
&&
.NEAR TERM /THROUGH MONDAY NIGHT/...
AS OF 300 AM SUNDAY...
FOR TODAY: RAIN CHANCES WILL SLOWLY INCREASE FROM SW TO NE LATER
TODAY... HOWEVER IT LOOKS LIKE THE HEAVIER RAIN IS LIKELY TO HOLD
OFF UNTIL LATE. THE UPPER LOW IS CURRENTLY SPINNING NEAR MEMPHIS...
WHILE NC REMAINS BENEATH A MID LEVEL COL AREA BORDERED BY THE
PERSISTENT BLOCKING HIGH OVER THE ERN GREAT LAKES... BROAD WEAK LOW
PRESSURE OUT OVER THE ATLANTIC... AND THE POTENT VORTEX OVER THE
LOWER MISS VALLEY. STRONG MOISTURE TRANSPORT CONTINUES TO DRIVE UP
OVER GA/SC INTO THE SRN APPALACHIANS WITH A 45 KT SOUTHEASTERLY LOW
LEVEL JET ORTHOGONAL TO THE SLOPES OVER SW NC... LEADING TO MAXIMUM
POTENTIAL TERRAIN UPGLIDE HERE AND A HIGH THREAT OF HEAVY RAIN AND
FLOODING ISSUES TO OUR WEST TODAY. ADDING TO THIS LOW-LEVEL-ROOTED
MECHANICAL LIFT IS STRONG UPPER DIVERGENCE WHICH WILL PEAK OVER WRN
NC TODAY... ALTHOUGH THE SLOW MOVEMENT AND THE START OF GRADUAL
WEAKENING OF THIS VORTEX WILL MINIMIZE MID LEVEL DPVA AND HEIGHT
FALLS. SO WHILE SOME OF THIS SHIELD OF HEAVIER RAIN MAY WORK INTO
THE FAR SWRN CWA THIS AFTERNOON... GIVEN THE FOCUS OF STRONGER LIFT
AND MOISTURE FLUX LARGELY OVER WRN NC... EXPECT MORE IN THE WAY OF
VERY PATCHY LIGHT RAIN AND DRIZZLE OVER MUCH OF CENTRAL NC THROUGH
TODAY. THIS IS FURTHER SUPPORTED BY MODEL TRENDS SHOWING A SLOWING
OF THE NE PROGRESS OF THE HEAVY RAIN SHIELD TODAY... AS WELL AS THE
LATEST RAP AND CONVECTION-ALLOWING WRF RUNS. WILL LOWER POPS AND QPF
AND DELAY THE ARRIVAL OF HIGHER CHANCES UNTIL LATE TODAY.
THICKNESSES ABOUT 20-25 METER BELOW NORMAL COMBINED WITH THE BRISK
ENE WINDS AND CONSIDERABLE CLOUD COVER SUPPORT COOL HIGHS OF 58-68.
FOR TONIGHT: WE SHOULD FINALLY SEE THE MORE WIDESPREAD RAIN WORK
INTO CENTRAL NC FROM THE SW. THE VORTEX TO OUR SW WILL BEGIN TO
SLOWLY FILL AS IT WOBBLES ACROSS NRN AL TO NEAR CHATTANOOGA TONIGHT.
AS IT APPROACHES... THE OCCLUDED SURFACE FRONT WILL PIVOT NE INTO SW
NC ACROSS SC... WHILE THE INTENSE PLUME OF ATLANTIC MOISTURE (WITH
PRECIP WATER OVER 150 PERCENT OF NORMAL) STREAMING OVER SC INTO WRN
NC GRADUALLY TRANSLATES TO THE NNE. EXPECT A SLOW BUT STEADY
INCREASE IN POPS FROM VERY LATE AFTERNOON THROUGH TONIGHT IN CENTRAL
NC FROM SW TO NE... TRENDING UP TO CATEGORICAL ACROSS THE SOUTH AND
WEST WITH LIKELY POPS IN THE NE. TOUGH CALL ON AMOUNTS THROUGH
TONIGHT... CONSIDERING THAT THE MID LEVEL VORTEX WILL BE WEAKENING
AND THUS THE DYNAMIC FORCING WILL BE ON THE DECREASE... PLUS THE
NORTHWARD SHIFT OF THE SOUTHEASTERLY LOW LEVEL JET INTO NW NC AND SW
VA WILL ACCORDINGLY PLACE THE BEST LOW LEVEL CONVERGENCE AND
MOISTURE TRANSPORT JUST WEST OF THE FORECAST AREA. WILL FORECAST
AMOUNTS UP TO A HALF INCH OVER THE FAR SRN AND FAR WRN CWA INCLUDING
LAURINBURG INTO SOUTHERN PINES AND THE TRIAD TO THE SW... WHILE
AREAS TO THE NORTH AND EAST SHOULD SEE MUCH LOWER AMOUNTS...
GENERALLY A TENTH INCH OR LESS THROUGH TONIGHT AS WE SIMPLY WON`T
SEE QUITE THE FORCING FOR ASCENT NOR HIGHER PW FLUX IN THE NE CWA
OVERNIGHT. THE CLOUDS AND WINDS SHOULD LIMIT COOLING AND LOWER THE
DIURNAL TEMP SPREAD... THUS HAVE NUDGED UP LOWS SLIGHTLY TO 54-60.
FOR MONDAY/MONDAY NIGHT: THE MID LEVEL VORTEX IS EXPECTED TO REMAIN
POTENT BUT STEADILY WEAKEN AS IT MEANDERS AROUND NE AL MONDAY THEN
EASES INTO EAST CENTRAL GA MONDAY NIGHT AS LOBES OF VORTICITY ROTATE
AROUND IT AND DRIVE ITS MOVEMENT. MODELS DIFFER ON THE EVOLUTION OF
SURFACE FEATURES BUT IT APPEARS MOST LIKELY THAT THE PRIMARY LOW
WILL WEAK OVER TN WHILE A SECONDARY TRIPLE-POINT LOW FORMS OVER THE
CENTRAL NC/SC BORDER AREA... NEAR THE CROOK OF A MID LEVEL DRY SLOT
PUNCHING INTO SC. IF THIS LOW WANDERS UP TOWARD CLT AS MOST
OPERATIONAL MODELS SUGGEST... THE MID LEVEL DRY SLOT SHOULD SHIFT
INTO FAR SRN NC WHILE THE BEST LOW LEVEL MOISTURE FEED AND UPPER
DIVERGENCE (AND HENCE THE GREATEST ASCENT AND LOW LEVEL MOISTURE
TRANSPORT) SHIFT INTO EAST-CENTRAL/NE/NORTH-CENTRAL NC MONDAY... AND
EVENTUALLY UP INTO VA MONDAY NIGHT. THIS SUPPORTS THE GENERAL TREND
OF EARLIER FORECAST OF SHIFTING THE CATEGORICAL POPS NORTHWARD
THROUGH NC DURING THIS PERIOD. INSTABILITY REMAINS MARGINAL BUT DOES
INCREASE ACROSS THE SOUTH MONDAY/MONDAY NIGHT WITH THE ARRIVAL OF
THE DRY SLOT AND RISING MID LEVEL LAPSE RATES TO OVER 6.75 C/KM...
AND THE NAM/GFS TAKE MLCAPE NEAR 1000 J/KG MONDAY AFTERNOON. WILL
NEED TO RETAIN A MENTION OF AT LEAST ISOLATED STORMS... MAINLY SOUTH
OF HIGHWAY 64 AND MAINLY IN THE AFTERNOON/EVENING. THE WIND PROFILE
IS NOT TEXTBOOK BUT 0-6KM SHEAR DOES REACH 30-40 KTS WITH A CURVED
0-3 KM HODOGRAPH AND 0-1 KM SHEAR OF 20-25 KTS... SO WE COULD SEE A
STRONG STORM OR TWO. ADDITIONAL RAINFALL AMOUNTS COULD APPROACH AN
INCH ESPECIALLY IN THE NORTHERN HALF ACCOMPANYING THE AXIS OF MORE
STEADY RAIN. THE DIURNAL SPREAD SHOULD AGAIN BE MUCH LOWER THAN
USUAL... ALTHOUGH A FEW ANTICIPATED BREAKS IN THE CLOUDS IN THE
SOUTH MONDAY AFTERNOON SHOULD CAUSE A SPIKE IN TEMPS. HIGHS FROM 61
NW TO 72 SE. LOWS 53 SW TO 59 NE. -GIH
&&
.SHORT TERM / /...
AS OF 245 PM SATURDAY...
TO BE UPDATED.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 245 PM SATURDAY...
TUESDAY...THE UPPER LOW MOVING ACROSS SOUTH CAROLINA SHOULD
START TO LIFT NORTHEAST TUESDAY NIGHT BASED ON THE LATEST GUIDANCE.
THE NAM IS FARTHER WEST WITH THE TRACK OF THE UPPER LOW...AND WITH
THE GFS TRENDING TOWARD THE ECMWF...WILL LEAN TOWARD THE GFS FOR
THIS FORECAST. WILL NOTE THAT THE NAM AND THE CANADIAN ARE FAIRLY
SIMILAR...SO CONFIDENCE IS ONLY MODEST. AS THE LEFT EXIT REGION OF A
60-KNOT 500MB JET MOVES NORTHEAST ALONG THE COAST TUESDAY...THIS
SHOULD SUPPORT INCREASED DIVERGENCE ALOFT RELATIVE TO THE REST OF
CENTRAL NORTH CAROLINA OVER THE NORTHEAST PIEDMONT AND THE NORTHERN
COASTAL PLAIN...WHERE A LOW-LEVEL CONVERGENT ZONE MAY EXIST AND
WHERE STRONG 850MB LIFT IS FORECAST BY THE GFS...ALONG WITH BETTER
700-500MB FRONTOGENESIS COMPARED TO THE REST OF CENTRAL NORTH
CAROLINA. MOISTURE IS DEEPEST TO THE NORTHEAST AS WELL...AND AS SUCH
WILL CONTINUE THE FORECAST OF THE HIGHEST CHANCES FOR SHOWERS...
LOW-END CATEGORICAL...MAINLY ALONG AND NORTH OF A LINE FROM ABOUT
PERSON COUNTY TO WILSON WHERE THE GFS FORECASTS AN 850MB THETA-E
RIDGE. ANTICIPATE THE HEAVIEST RAIN DURING THE DAY TO OCCUR THERE.
ELSEWHERE...WITH THE STEEP LAPSE RATES UNDER COLD TEMPERATURES
ALOFT...AND LAPSE RATES ARE FORECAST BY THE GFS TO APPROACH 7C/KM IN
PARTS OF CENTRAL NORTH CAROLINA TUESDAY AFTERNOON...ANTICIPATE
SCATTERED-TO-NUMEROUS SHOWERS AND ISOLATED-TO-SCATTERED
THUNDERSTORMS. SURFACE-BASED CAPE IS FORECAST BY THE GFS TO BE
BETWEEN 500 AND 750J/KG TUESDAY AFTERNOON...BUT DOWNDRAFT CAPE IS
WEAK...SO THE POTENTIAL FOR SEVERE WEATHER SHOULD BE LIMITED. -10C
TO -30C CAPE IS MAXIMIZED BY THE GFS IN A CORRIDOR FROM ABOUT KRWI
TO KRDU TO KAFP TUESDAY AFTERNOON...SO IF THERE ARE ENOUGH BREAKS
FOR A STRONG STORM OR TWO WITH SMALL HAIL...PERFECT PROGGING THE GFS
IT WOULD BE IN THAT LOCATION. IN A NORTHEAST FLOW WITH SOME GUSTS
AND LOWER CLOUDS THE TRIAD MAY STRUGGLE TO GET TO 60 TUESDAY...WITH
HIGHS OF 65 TO 70 FOR MUCH OF THE REST OF THE AREA.
TUESDAY NIGHT...NUMEROUS SHOWERS MAY CONTINUE IN THE EVENING
ESPECIALLY TOWARD THE VIRGINIA BORDER...WITH SCATTERED SHOWERS
ELSEWHERE BEFORE BUFR SOUNDINGS FROM THE GFS SHOW THE LAYER FROM
850MB TO 700MB STARTING TO WARM AFTER 03Z. SUFFICIENT LOW-LEVEL
MOISTURE AND LIFT MAY EXIST FOR SCATTERED SHOWERS TO PERSIST
OVERNIGHT ESPECIALLY ALONG AND NORTH OF ABOUT U.S. 64. MAINTAINED A
SLIGHT CHANCE OF A SHOWER OVERNIGHT IN THE SOUTHWEST PIEDMONT...
THROUGH THE SANDHILLS AND THE SOUTHERN COASTAL PLAIN...BUT A LARGE
PART OF THE OVERNIGHT MAY END UP DRY THERE AS THE UPPER LOW MOVES
NORTH AND SOME SUBSIDENCE STARTS TO CREEP IN. LEANED TOWARD THE GFS
GRIDDED OVERNIGHT LOWS IN THE LOWER TO MID 50S...WITH THE WARMEST
TEMPERATURES OVERNIGHT QUITE POSSIBLY NEAR THE VIRGINIA BORDER UNDER
THICKER CLOUDS AND DEEPER MOISTURE.
FOR THE PERIOD WEDNESDAY THROUGH SATURDAY...UPPER-LEVEL LOW PRESSURE
WILL ONLY SLOWLY LIFT AWAY FROM CENTRAL NORTH CAROLINA. THE ECMWF
HAS GENERALLY BEEN FASTER LIFTING THE LOW TO THE NORTHEAST...BUT
GIVEN THE CLOSED NATURE OF THE UPPER LOW...IT MAY BE A LITTLE SLOWER
WITH COLD TEMPERATURES ALOFT LINGERING INTO THURSDAY. COARSE MODEL
SOUNDINGS FROM BOTH THE GFS AND THE ECMWF ARE SLIGHTLY MORE CAPPED
TOWARD THE SANDHILLS WEDNESDAY AS COMPARED TO FARTHER NORTH...AND
EVEN THE SLOWER AND MORE UNSTABLE GFS HAS DECENT LOW-LEVEL CIN BELOW
STEEP LAPSE RATES ALOFT...WITH THE STEEPEST LAPSE RATES CLOSER TO
THE CENTER OF THE LOW OVER THE NORTHERN COASTAL PLAIN. THE HIGHEST
CHANCES FOR SHOWERS WEDNESDAY SHOULD BE NORTH OF A LINE FROM WILSON
TO ROXBORO...GRADUALLY DIMINISHING SOUTH FARTHER FROM THE LOW AND
DEEPER MOISTURE. BY THURSDAY...THINKING THE LOW WILL MAKE SLOW
PROGRESS NORTH AND NORTHEAST...ANTICIPATE LINGERING ISOLATED CHANCES
FOR SHOWERS NORTH AND NORTHEAST OF THE TRIANGLE. HEIGHTS ALOFT THEN
START TO RISE AND...WITH INCREASING SUBSIDENCE...THE END OF THE NEXT
WORK WEEK SHOULD BE DRY AND SEASONABLY MILD.
HEIGHTS ALOFT WILL LIKELY START TO FALL AGAIN FOR THE WEEKEND IN
RESPONSE TO UPPER-LEVEL TROUGHINESS MOVING FROM CANADA INTO THE
GREAT LAKES. THE ECMWF HAS GENERALLY BEEN FASTER THAN THE GFS WITH A
POSITIVELY-TILTED FRONT MOVING TOWARD CENTRAL NORTH CAROLINA OVER
THE WEEKEND. SOMETIMES POSITIVELY-TILTED FRONTS END UP BEING SLOWER
THAN EXPECTED WITH THE ONSET OF SHOWERS IF SURFACE HIGH PRESSURE
AHEAD OF A FRONT IS AT LEAST MODERATELY STRONG. IN THIS CASE...
THOUGH...IN THE WAKE OF THE UPPER-LEVEL LOW...HIGH PRESSURE RIDGING
THAT IS FORECAST INTO THE SOUTHEAST AND GULF OF MEXICO SEEMS
RELATIVELY WEAKER...AND AS SUCH THERE MAY BE THE POTENTIAL FOR
BETTER MOISTURE TRANSPORT AND CHANCES FOR SHOWERS MORE LIKELY IN THE
WESTERN PIEDMONT BY SATURDAY AFTERNOON...AND ACROSS ALL OF CENTRAL
NORTH CAROLINA SATURDAY NIGHT. HIGH TEMPERATURES WILL BE FORECAST
BELOW NORMAL WEDNESDAY...AND AROUND NORMAL BY THE START OF NEXT
WEEKEND. OVERNIGHT LOWS SHOULD BE NEAR OR ABOVE NORMAL. JUST TO
NOTE...THE LAST 80-DEGREE DAY AT KGSO WAS APRIL 17...AND APRIL 19 AT
BOTH KRDU AND KFAY. ASSUMING WE MAKE IT TO 80 BY THE END OF THE
WEEK...IT WILL HAVE BEEN AROUND THREE WEEKS SINCE THE LAST TOUCH OF
80. FOR WHAT IT IS WORTH...LAST MAY...CENTRAL NORTH CAROLINA HAD
ALREADY EXPERIENCED AROUND 90 TO THE LOWER 90S EARLY IN THE MONTH.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AS OF 1240 AM SUNDAY...
BRISK AND GUSTY SURFACE WINDS FROM THE ENE (FROM 060-080 DEGREES)
WILL PERSIST THROUGH TODAY/TONIGHT... AND THIS FLOW OF MOIST
ATLANTIC AIR INTO NC WILL MAKE SUB-VFR CONDITIONS DOMINANT OVER
CENTRAL NC TAF SITES. CLOUDS BASED AT ONE TO THREE THOUSAND FT AGL
HAVE VARIED FROM SCATTERED TO BROKEN OVER THE LAST SEVERAL HOURS
(TOPPED BY BROKEN VFR CLOUDS BASED FOUR THOUSAND TO TWELVE THOUSAND
FT AGL)... MAKING IT DIFFICULT TO PINPOINT EXACTLY WHEN AND WHERE
PERIODIC MVFR CIGS WILL PREVAIL. WITH LOWER-THAN-USUAL CONFIDENCE...
EXPECT MAINLY VFR CIGS THROUGH 09Z-10Z THIS MORNING... FOLLOWED BY
MVFR TO IFR CIGS AFTER 10Z. A FEW LIGHT SPRINKLES OR DRIZZLE ARE
POSSIBLE THIS MORNING THROUGH MID AFTERNOON... BUT VSBYS SHOULD
REMAIN MOSTLY VFR AND THE HEAVIEST RAINFALL WILL HOLD WEST OF A LINE
FROM MT AIRY TO SALISBURY TO CLT. THE MVFR/IFR CIGS SHOULD RISE TO
VFR AFTER 16Z-18Z THIS MORNING. MORE SUBSTANTIAL RAIN AND SUB-VFR
VSBYS/CIGS WILL MOVE IN SLOWLY FROM THE SW TOWARD THE NE THIS
AFTERNOON/ EVENING... REACHING INT/GSO/FAY AFTER 21Z... BUT NOT
EXPECTED TO REACH RDU/RWI UNTIL NEAR OR AFTER 06Z TONIGHT. SUSTAINED
WINDS OF 10-16 KTS GUSTING TO AROUND 20 KTS WILL CONTINUE THROUGH
THE FORECAST PERIOD.
LOOKING BEYOND 06Z TONIGHT: GOOD CHANCE OF CONTINUED DOMINATION OF
SUB-VFR CONDITIONS WITH PERIODS OF RAIN THROUGH AT LEAST TUESDAY AS
AN UPPER LEVEL LOW SLOWLY CROSSES THE REGION. BRISK ENE SURFACE
WINDS WILL PERSIST THROUGH MONDAY BEFORE WEAKENING MONDAY NIGHT.
SHALLOW IFR FOG IS POSSIBLE TUESDAY NIGHT/WEDNESDAY MORNING... AND
AGAIN THURSDAY MORNING.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...
LONG TERM...DJF
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
313 AM CDT SUN MAY 5 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 313 AM CDT SUN MAY 5 2013
THE LATEST WATER VAPOR IMAGERY SHOWS AN H5-H3 CIRCULATION OVER
CENTRAL SOUTH DAKOTA. LATEST RADAR SHOWS A NARROW AND PERSISTENT
BAND OF LIGHT RAIN BING STEERED NORTHBOUND BY THE AFOREMENTIONED
UPPER LOW FROM EASTERN SOUTH DAKOTA...INTO LAMOURE AND DICKEY
COUNTIES OF NORTH DAKOTA. THE LATEST RAP AND GFS CONTINUE WITH THE
IDEA OF LIGHT RAIN THROUGH MID AFTERNOON...AND HAVE TRENDED POPS
APPROPRIATELY...BEGINNING WITH CATEGORICAL AND TRENDING LOWER
THIS AFTERNOON. WITH WESTERN AND CENTRAL NORTH DAKOTA ESSENTIALLY
IN A COL AREA...THE UPPER LOW REMAINS NEARLY STATIONARY AND
MEANDERS LITTLE THROUGH THE SHORT TERM PERIOD. H85 TEMPERATURES
RISE A FEW DEGREES IN THE NEXT TWO DAYS...CONSEQUENTLY WILL SEE
WARMING TEMPERATURES REFLECTED AT THE SURFACE. HIGHS TODAY WILL
REACH INTO 60S WITH LIGHT WINDS.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 313 AM CDT SUN MAY 5 2013
HIGHLIGHTS OF THE EXTENDED FORECAST IS A WARM UP TO SLIGHTLY ABOVE
NORMAL TEMPERATURES IN THE 70S ON MONDAY INTO TUESDAY..WITH
SCATTERED RAIN SHOWERS AND THUNDERSTORMS POSSIBLE WEDNESDAY INTO
FRIDAY...WITH TEMPERATURES COOLING LATE IN THE WEEK.
A SPLIT FLOW UPPER LEVEL PATTERN IS EXPECTED TO BE IN PLACE ACROSS
THE CONUS THROUGH AT LEAST TUESDAY WITH A CUTOFF LOW ACROSS THE
SOUTHEASTERN CONUS...AND A SECOND ACROSS THE DESERT SOUTHWEST.
THIS PATTERN SUPPORTS DRY CONDITIONS FOR THE NORTHERN PLAINS WITH
NEAR TO SLIGHTLY ABOVE NORMAL TEMPERATURES. THE NEXT CHANCE FOR
PRECIPITATION...POSSIBLY THUNDERSTORMS...IS WEDNESDAY INTO FRIDAY
AS POTENTIAL NORTHERN STREAM ENERGY SINKS SOUTH ACROSS THE
NORTHERN PLAINS. THIS SLIGHT SHIFT OF THE POLAR JET FURTHER SOUTH
WITH NORTHWEST FLOW ALOFT SUPPORTS A POSSIBLE COOL DOWN BACK INTO
THE 60S THURSDAY AND FRIDAY...AND THE 50S BY SATURDAY.
OVERALL...UTILIZED A BLEND OF THE 00 UTC GUIDANCE SUITE FOR MOST
FIELDS...FAVORING THE WARMER EDGE OF TEMPERATURE GUIDANCE WHICH
HAS SHOWN GREATER VERIFICATION SCORES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 313 AM CDT SUN MAY 5 2013
VFR CIGS/VSBYS NEXT 24HRS WITH MOSTLY CLEAR SKIES AND LIGHT WINDS.
KJMS WILL BE THE ONLY AERODROME WITH BKN CIGS AT AROUND 10KFT.
&&
.HYDROLOGY...
ISSUED AT 313 AM CDT SUN MAY 5 2013
THE SOURIS RIVER CONTINUES TO BE A COMPLEX MIXTURE OF LOCATIONS
RISING WHILE OTHER FORECAST POINTS ARE IN RECESSION. LOWER RELEASES
FROM BOUNDARY DAM AND REDUCED SNOWMELT RUNOFF BELOW ALAMEDA AND
RAFFERTY DAMS HAS RESULTED IN THE ENTIRE UPPER SOURIS RIVER BASIN
FROM SHERWOOD TO MINOT TO VELVA FALLING AND REMAINING BELOW FLOOD
STAGE. FARTHER DOWNSTREAM AT TOWNER...BANTRY AND WESTHOPE...THE
SOURIS RIVER REMAINS STEADY TO RISING AS FLOOD WATERS SLOWLY MAKE
THEIR WAY THROUGH THE AREA.
WILLOW CREEK NEAR WILLOW CITY IS EXPECTED TO EXPERIENCE ANOTHER RISE
TO JUST ABOVE MINOR FLOOD STAGE THROUGH MONDAY. MUCH OF THE MELT WATER
GENERATED IN THIS AREA APPEARS TO BE GOING INTO THE SOIL AND TEMPERING
EARLIER EXPECTATIONS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...KS
LONG TERM...AYD
AVIATION...KS
HYDROLOGY...AYD
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1257 AM CDT SUN MAY 5 2013
.UPDATE...
ISSUED AT 1253 AM CDT SUN MAY 5 2013
UDPATED TO EXTEND CATGEORICAL POPS FOR LIGHT RAIN INTO MIDDAY
SUNDAY FOR SOUTHEAST ND INTO NW MN FROM FORMAN-WAHPETON THROUGH
FARGO TO BEMIDJI-WASKISH AS BAND OF MID LEVEL CONVERGENCE REMAINS
IN THAT AREA UNTIL IT FINALLY FALLS APART LATER SUNDAY.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 342 PM CDT SAT MAY 4 2013
MAIN CHALLENGE FOR THIS FORECAST PACKAGE WILL BE PCPN. LATEST
ANALYSIS SHOWS UPPER LOW OVER NRN ARKANSAS. EXPECT SLOWER CHANGES TO
THE LOCAL WEATHER OVER THE NEXT FEW DAYS AS THE OVERALL PATTERN
SHOWS A REX BLOCK OVER WRN CONUS AND ANOTHER BLOCK OVER THE EAST
COAST.
MODELS INITIALIZED WELL AND AND OPTED FOR A BLENDED SOLN. FOR TODAY
AND TONIGHT...MAIN QUESTION IS WHERE AREA OF PCPN WILL SETTLE.
REGIONAL RADAR SHOWS BAND OF PCPN MOVING NORTH INTO WEST CENTRAL AND
NW MINNESOTA. HRRR AND RAP MODELS IN GENERAL AGREEMENT ON PLACEMENT
OF PCPN AND EXPECT MOST PCPN AMOUNTS WILL BE UNDER A QUARTER INCH
OVER THE NEXT 24 HOURS. THE 300K ISENTROPIC ANALYSIS SHOWS SOME
DECENT LIFT AND EXPECTING AN 850MB BAROCLINIC ZONE TO SET UP.
HOWEVER...CONDENSATION PRESSURE DEFICITS WEAK SO FOR NOW WILL ONLY
KEEP LIKELY POPS IN THAT AREA. FOR SUNDAY...LOOKING FOR THE
BAROCLINIC ZONE TO SLOWLY SLIDE SOUTHEAST AND WILL SEE THE END OF
PCPN. OTHERWISE...LOOKING FOR DRIER WEATHER GOING INTO MONDAY.
EXTENSIVE CLOUD COVER WILL KEEP TEMPERATURES A BIT LOWER TODAY
INTO SUNDAY WHEN THE UPPER RIDGE BEGINS SLIDE OVER THE AREA AND A
WARMING TREND BEGINS.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 342 PM CDT SAT MAY 4 2013
12 UTC GFS/ECMWF SHOW THE FORECAST AREA IN POORLY DEFINED SPLIT FLOW
MID-WEEK...TRANSITIONING TO NORTHWEST FLOW ALOFT FRIDAY NIGHT INTO
SATURDAY WITH A STRONG CANADIAN COLD FRONT. PRECIPITATION CHANCES
THROUGH FRIDAY WILL DEPEND ON EVOLUTION OF A WEAK CUT-OFF LOW ACROSS
THE SOUTHERN ROCKIES. MOST MODELS PAINT MOST QPF ACROSS THE CENTRAL
PLAINS...BUT SOME DOES MAKE IT FARTHER NORTH. WITH THESE CUT-OFF
LOWS NOT A LOT OF CONFIDENCE...SO WILL KEEP ALL BLEND 20-40 POPS FOR
MOST OF THE WEEK. HOWEVER...THERE SHOULD BE MORE DRY PERIODS THAN
WET. WILL ALSO LIMIT THUNDER MENTION AS INSTABILITY APPEARS TO BE
MINIMAL AT THIS TIME. TEMPERATURES WILL BE ON THE WARM-SIDE OF THE
MOST RECENT THERMAL REGIME WITH HIGHS IN THE 60S AND LOWS MAINLY IN
THE 40S. IT DOES APPEAR CONDITIONS WILL COOL ON SATURDAY WITH
PASSAGE OF THE FRONT FRIDAY NIGHT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1253 AM CDT SUN MAY 5 2013
BEMIDJI-PARK RAPIDS REGION SHOULD STAY IN IFR-LOW END MVFR CIGS
THROUGH 16Z SUNDAY AS MOISTURE REMAINS IN THE AREA WITH LIGHT
NORTHEAST WINDS. IN PRECIP BAND FROM FARGO INTO NW MN VFR CLDS
THOUGH AS MOISTURE ISNT AS DEEP. VFR CLOUDS IN GRAND FORKS TO MORE
CIRRUS IN DVL. SLOW DECREASE IN CLOUDS FROM THE NORTHWEST SUN
AFTN-EVE WITH LIGHT NORTH-NORTHEAST WINDS TURNING VARIABLE SUN
LATE AFTN-EVE.
&&
.HYDROLOGY...
ISSUED AT 1258 PM CDT SAT MAY 4 2013
THE BROAD CREST WAVE OF SNOWMELT RUNOFF IS APPROACHING THE
DRAYTON AREA THIS WEEKEND WITH A CREST EXPECTED NEAR 40 FEET.
THE CREST WAVE WILL MOVE INTO THE PEMBINA REGION TOWARD THE END OF
NEXT WEEK WITH A FORECAST NEAR 48.5 FEET...JUST UNDER MAJOR FLOOD
STAGE. A SECOND ROUND OF RUNOFF IS EXPECTED ALONG THE PEMBINA RIVER
WITH ADDITIONAL RISES FORECAST AT WALHALLA AND NECHE THIS NEXT WEEK.
ELSEWHERE RIVERS CONTINUE TO RECEDE AS NO NEW RUNOFF IS OCCURRING
WITH THE DRY WEATHER OVER THE PAST WEEK.
AREAL FLOODING...WILL KEEP THE NORTH DAKOTA WARNINGS GOING AS
OVERLAND FLOODING CONTINUES TO CAUSE ISSUES AND ROAD CLOSURES. AS
FOR THE BELTRAMI AND CLEARWATER COUNTIES WILL CANCEL AFTER
CONFIRMING WITH COUNTY OFFICIALS THAT OVERLAND WATER HAS
DIMINISHED DRAMATICALLY.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...RIDDLE
SHORT TERM...HOPKINS
LONG TERM...ROGERS
AVIATION...RIDDLE
HYDROLOGY...JK
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1215 AM CDT SUN MAY 5 2013
.UPDATE...
ISSUED AT 1215 AM CDT SUN MAY 5 2013
LATEST WATER VAPOR IMAGERY SHOWS A H5-H3 CIRCULATION TAKING SHAPE OVER
SOUTH CENTRAL SOUTH DAKOTA. LONG FETCH OF LIGHT RAIN EXTENDING IN
EASTERN SOUTH DAKOTA WILL CONTINUE TO BE PULLED NORTH INTO OUR SOUTHEAST
COUNTIES OF LAMOURE AND DICKEY OVERNIGHT. THE RAP AND GFS MAINTAIN
LIGHT PRECIPITATION THROUGH 20Z SUNDAY...AND SEE NO REASON TO
DEVIATE MUCH FROM THIS. THUS...HAVE INCREASED POPS TO CATEGORICAL
THROUGH 12Z SUNDAY...AND GRADUALLY SUBSIDING TO LIKELY POPS
THROUGH 18Z SUNDAY. THE GFS/RAP DO SHOW SOME WANING OF THE
PRECIPITATION BETWEEN 12Z AND 18Z SUNDAY...BEFORE ENDING BY MID
AFTERNOON. THE REST OF THE FORECAST REMAINS IN GOOD STANDING AND
MADE LITTLE OR NO CHANGES TO THE OTHER ELEMENTS.
UPDATE ISSUED AT 1001 PM CDT SAT MAY 4 2013
STABLE WEATHER PATTERN CONTINUES WITH SURFACE HIGH ACROSS THE
DAKOTAS INTO SOUTHERN CANADA. UPPER LEVEL LOW CONTINUES TO SPREAD
SOME MIDDLE AND HIGH CLOUDS ACROSS EASTERN NORTH DAKOTA. SKIES
WERE MOSTLY CLEAR WEST. RADARS CONTINUE TO SHOW SOME LIGHT RAIN
ACROSS EASTERN DICKEY AND LAMOURE COUNTIES...WITH OAKES REPORTING
SOME LIGHT RAIN IN THE PAST HOUR. RAISED THE CHANCE OF RAIN ACROSS
DICKEY AND LAMOURE COUNTIES THROUGH EARLY MORNING OTHERWISE
CURRENT TREND LOOKS GOOD.
FOR HYDROLOGY...LOWER RELEASES FROM THE CANADIAN DAMS AND
DECREASED EXPECTATIONS FROM SNOW MELT RUNOFF HAS RESULTED IN THE
UPPER SOURIS FALLING BELOW FLOOD STAGE FROM SHERWOOD...THROUGH MINOT
TO VELVA. THE LOWER SOURIS FROM TOWNER TO BANTRY TO WESTHOPE AS
WELL AS THE WILLOW CREEK NEAR WILLOW CITY WILL CONTINUE TO SEE
STEADY TO SLOW RISES IN RIVER LEVELS AS THE WATER MAKES ITS WAY
THROUGH THE LOWER SOURIS RIVER VALLEY THROUGH NEXT WEEK.
UPDATE ISSUED AT 609 PM CDT SAT MAY 4 2013
UPPER LEVEL LOW SWIRLING LIGHT RAIN ACROSS SOUTHEAST NORTH DAKOTA.
ABERDEEN REPORTED LIGHT RAIN WITH THE LAST HOUR. CUTOFF FOR THE
RAIN WILL BE ACROSS CENTRAL DICKEY AND EASTERN LAMOURE COUNTIES
THIS EVENING. CURRENT FORECAST GOOD...JUST RAISED THE CHANCE OF
RAIN EASTERN DICKEY AND LAMOURE COUNTIES THIS EVENING.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 332 PM CDT SAT MAY 4 2013
A FAIRLY STAGNANT WEATHER PATTERN WILL CONTINUE OVER WESTERN AND
CENTRAL NORTH DAKOTA THROUGH THE PERIOD. NORTHEASTERLY WINDS THIS
AFTERNOON WILL BECOME LIGHT AND VARIABLE OVERNIGHT AND SUNDAY AS
HIGH PRESSURE RE-ESTABLISHES ITSELF ACROSS THE REGION.
AS FAR AS PRECIP CHANCES ARE CONCERNED...WRAP AROUND MOISTURE
ASSOCIATED WITH A STRONG UPPER LOW OVER THE LOWER MISSISSIPPI
RIVER VALLEY WILL GENERATE A SLIGHT CHANCE OF LIGHT RAIN OVER THE
EASTERN PORTIONS OF LAMOURE AND DICKEY COUNTIES TONIGHT.
OTHERWISE...DEEP LAYER ANTICYCLONIC FLOW WILL MAINTAIN DRY
CONDITIONS ACROSS WESTERN AND CENTRAL NORTH DAKOTA THROUGH SUNDAY.
DUE TO DECREASING WINDS AND MOSTLY CLEAR SKIES...TEMPERATURES
SHOULD RADIATE TO WELL BELOW NORMAL READINGS TONIGHT WITH READINGS
GENERALLY IN THE 20S WEST OF THE MISSOURI RIVER AND IN THE 30S
EAST OF THE MISSOURI RIVER. HIGHS SUNDAY SHOULD BE NEAR NORMAL
WITH READINGS MAINLY IN THE 60S.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 332 PM CDT SAT MAY 4 2013
MAIN HIGHLIGHTS OF THE EXTENDED FORECAST INCLUDES A CONTINUED WARM
UP TO SLIGHTLY ABOVE NORMAL TEMPERATURES IN THE 70S ON MONDAY
POSSIBLY INTO WEDNESDAY...WITH SCATTERED RAIN SHOWERS AND POSSIBLE
THUNDERSTORMS TUESDAY AFTERNOON INTO FRIDAY.
A SPLIT FLOW UPPER LEVEL PATTERN IS EXPECTED TO BE IN PLACE ACROSS
THE CONUS THROUGH AT LEAST TUESDAY MORNING WITH A CUTOFF LOW ACROSS
THE SOUTHEASTERN CONUS...AND A SECOND SLOWLY PROPAGATING ONSHORE
ACROSS CALIFORNIA. THIS PATTERN SUPPORTS DRY CONDITIONS FOR THE
NORTHERN PLAINS WITH NEAR TO SLIGHTLY ABOVE NORMAL TEMPERATURES WITH
THE LACK OF LARGE SCALE GREEN UP THUS FAR. THE NEXT CHANCE FOR
PRECIPITATION...POSSIBLY THUNDERSTORMS...IS TUESDAY AFTERNOON AS
SOME IMPULSE ENERGY FROM THE WESTERN CUTOFF LOW MOVES INTO THE
CENTRAL/NORTHERN PLAINS TUESDAY AFTERNOON THROUGH FRIDAY...AND AT
THE SAME TIME POTENTIAL NORTHERN STREAM ENERGY SINKS SOUTH ACROSS
THE NORTHERN PLAINS. THIS SLIGHT SHIFT OF THE POLAR JET FURTHER
SOUTH MAY LEAD TO A SLIGHT COOL DOWN BACK INTO THE 60S THURSDAY AND
FRIDAY...AND INTO THE 50S FOR NEXT SATURDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1215 AM CDT SUN MAY 5 2013
VFR CIGS/VSBYS NEXT 24HRS WITH MOSTLY CLEAR SKIES AND LIGHT WINDS.
KJMS WILL BE THE ONLY AERORDROME WITH BKN CIGS AT AROUND 10KFT.
&&
.HYDROLOGY...
ISSUED AT 332 PM CDT SAT MAY 4 2013
AFTER COORDINATION WITH EMERGENCY MANAGEMENT AFFECTED BY OVERLAND
FLOODING...DECIDED TO CANCEL THE AREAL FLOOD WARNING FOR OVERLAND
FLOODING FOR WELLS...PIERCE...AND FOSTER COUNTIES. EVEN THOUGH
OVERLAND FLOODING CONTINUES TO DIMINISH...ISOLATED INSTANCES OF
WATER OVER THE ROADWAY CONTINUE TO BE REPORTED. AS A RESULT...WILL
CONTINUE TO HIGHLIGHT THIS THREAT IN THE HWO.
THE RIVER FLOOD WATCH FOR THE JAMES RIVER AT GRACE CITY HAS BEEN
CANCELLED AND REPLACED WITH A HYDROLOGIC STATEMENT. THE RIVER LEVEL
HAS FALLEN BELOW MINOR FLOOD STAGE AND WILL CONTINUE A SLOW FALL FOR
THE NEXT SEVERAL DAYS. HOWEVER...THE FLOOD WARNING FOR THE PIPESTEM
CREEK NEAR PINGREE SHOULD REMAIN ABOVE MODERATE STAGE FOR THE NEXT
FEW DAYS.
MINOR TO MODERATE FLOODING IS STILL FORECAST FOR THE SOURIS RIVER
BASIN NEAR SHERWOOD...TOWNER...BANTRY...WILLOW CITY...AND WESTHOPE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KS
SHORT TERM...TM
LONG TERM...JV
AVIATION...KS
HYDROLOGY...TM
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1137 PM CDT SAT MAY 4 2013
.UPDATE...FOR 06Z AVIATION FORECAST
.AVIATION...
POOR FLYING CONDITIONS WILL CONTINUE FOR THE NEXT 24 HOURS. COLD UPPER
LOW CENTERED OVER EASTERN ARKANSAS AT 04Z WITH MOISTURE PLUME OFF
THE ATLANTIC THROUGH GEORGIA AND ACROSS EASTERN HALF OF TENNESSEE
INTO KENTUCKY. WIDESPREAD RAIN WILL CONTINUE ACROSS EASTERN HALF
OF MID STATE AND PLATEAU WITH THE HEAVIEST RAINS FORECAST TO FALL
IN EASTERN MIDDLE TENNESSEE AND PLATEAU OVERNIGHT TONIGHT. AS UPPER LOW
MOVES EAST LIFT AND INSTABILITY WILL INCREASE WITH ACTIVITY BECOMING
MORE SHOWERY BY SUNDAY AFTERNOON WITH THUNDERSTORM POTENTIAL INCREASING
SUNDAY AFTERNOON AND EVENING ESPECIALLY SOUTH HALF OF THE MID STATE
CLOSER TO THE CENTER OF COLD CORE ALOFT.
BOYD
&&
.PREV DISCUSSION... /ISSUED 832 PM CDT SAT MAY 4 2013/
UPDATE...
LATEST RADAR IMAGERY SHOWS LIGHT TO MODERATE RAIN SHIELD REMAINS
ACROSS EASTERN ZONES...GENERALLY ALONG AND EAST OF A LINE FROM
GALLATIN TO MANCHESTER. WEST OF THAT LINE...SCATTERED TO NUMEROUS
LIGHT TO OCCASIONALLY MODERATE SHOWERS HAVE DEVELOPED WESTWARD TO
NEAR A CLARKSVILLE TO PULASKI LINE. LOCATIONS REMAIN DRY TO THE
WEST OF THERE...BUT LIGHT SHOWERS HAVE BEGUN SPREADING ACROSS THE
TENNESSEE RIVER IN THE PAST HOUR IN ASSOCIATION WITH THE
APPROACHING UPPER LOW. TEMPERATURES REMAIN UNUSUALLY COLD AND
WIDELY VARIABLE AT THIS HOUR...WITH LOW 50S ON THE PLATEAU...MID
TO UPPER 40S IN THE CENTRAL CWA...AND LOW 50S IN THE SOUTHWEST.
HAVE MADE SEVERAL ADJUSTMENTS TO GRIDS/ZONES BASED ON LATEST OBS
AND RADAR TRENDS. RAISED POPS ACROSS THE WEST WHERE LIGHT RAIN IS
SPREADING EASTWARD WITH UPPER LOW...AND EXTENDED LIKELY POPS
FURTHER TO THE WEST TO NEAR A CLARKSVILLE/PULASKI LINE. LATEST
HRRR RUNS INDICATE CURRENT SHOWER ACTIVITY ALONG THE I-65 CORRIDOR
WILL CONTINUE THIS EVENING THEN DISSIPATE OVERNIGHT AS DRIER AIR
AROUND CIRCULATION OF UPPER LOW SHIFTS EASTWARD. AS THIS
OCCURS...HRRR INDICATES PRECIPITATION INTENSITIES WITHIN RAIN
SHIELD WILL STRENGTHEN OVERNIGHT AS SURFACE TROUGH DEEPENS AND
UPPER LOW APPROACHES...LEADING TO AN INCREASE IN RAINFALL RATES
IN THE FLOOD WATCH AREA. AS MENTIONED PREVIOUSLY...OF PARTICULAR
CONCERN WILL BE THE SOUTHERN PLATEAU COUNTIES OF VAN
BUREN...WHITE...CUMBERLAND...AND PUTNAM WHERE HIGHEST MOISTURE
TRANSPORT WILL BE FOCUSED AND OROGRAPHIC LIFT IN THE 2000-3000 FT
TERRAIN ENHANCES PRECIPITATION. THE CROSSVILLE ASOS HAS RECEIVED
1.31 INCHES OF RAIN AS OF 7 PM...AND ANOTHER 1 TO 1.5 INCHES IS
POSSIBLE THROUGH MIDNIGHT IN THE FLOOD WATCH AREA. STORM TOTAL
AMOUNTS THROUGH SUNDAY FROM 2 TO POTENTIALLY 4 INCHES STILL APPEAR
REASONABLE IN EASTERN ZONES AND NO CHANGES ARE PLANNED TO THE
FLOOD WATCH.
SHAMBURGER
PREV DISCUSSION... /ISSUED 646 PM CDT SAT MAY 4 2013/
UPDATE...FOR 00Z AVIATION FORECAST
AVIATION...
POOR FLYING CONDITIONS TO CONTINUE ACROSS THE MID STATE NEXT 24
HOURS AS UPPER LOW CURRENTLY SPINNING OVER CENTRAL ARKANSAS KEEPS
A MOISTURE PLUME STREAMING INTO TENNESSEE. SHORT RANGE MODELS HAVE
GOOD HANDLE ON RAINFALL WITH THE HEAVIEST TO FALL ALONG THE
CENTRAL AND SOUTHERN PLATEAU COUNTIES WHERE RAINFALL WILL BECOME
HEAVY OVERNIGHT. RAIN WILL CONTINUE ON SUNDAY. HAVE FORECASTED
LOW IFR CEILINGS AT CROSSVILLE IN THE OVERNIGHT ALONG WITH HEAVY
RAINFALL. ALSO EXPECT LOW IFR CEILINGS AT NASHVILLE BUT WITH LIGHT
RANIFALL.
BOYD
PREV DISCUSSION... /ISSUED 613 PM CDT SAT MAY 4 2013/
MESOSCALE UPDATE...
LATEST RADAR IMAGERY SHOWS MAIN AXIS OF MODERATE TO OCCASIONALLY
HEAVY RAIN NOW OVER THE UPPER CUMBERLAND REGION...GENERALLY EAST
OF A LINE FROM LAFAYETTE TO ALTAMONT. LATEST HRRR MODEL RUNS
INDICATE THIS MAIN RAIN BAND WILL REMAIN IN PLACE FOR ANOTHER 12
TO 18 HOURS AS A SURFACE TROUGH OF LOW PRESSURE ARCING SOUTHEAST
TO NORTHWEST REMAIN IN PLACE AND DEEPENS WITH THE UPPER LOW
APPROACHING FROM THE WEST. OBS FROM THE CROSSVILLE ASOS INDICATE
RAINFALL RATES OF 0.10 TO 0.25 INCHES PER HOUR ARE OCCURRING IN
THE HEAVIEST RAIN AREAS...WITH 1 TO 2 INCHES OF RAINFALL POSSIBLE
JUST THROUGH MIDNIGHT. HEAVIEST RAIN TOTALS ARE EXPECTED TO BE ON
THE SOUTHERN PLATEAU ACROSS VAN BUREN...WHITE...AND CUMBERLAND
COUNTIES WHERE OROGRAPHIC ENHANCEMENT FROM THE HIGHER TERRAIN
SQUEEZES OUT ADDITIONAL MOISTURE. FLOODING WILL BECOME AN
INCREASING CONCERN IN THIS AREA AS WE CONTINUE THROUGH THE NIGHT
AND ESPECIALLY ON SUNDAY.
SHAMBURGER
PREV DISCUSSION... /ISSUED 340 PM CDT SAT MAY 4 2013/
DISCUSSION...
PRECIP CLEARING LINE HAS BEEN MAKING A SLOW EASTWARD MOVEMENT TODAY.
AT 2PM THE CLEARING LINE WAS ROUGHLY ORIENTED PARALLEL TO I-65. THIS
EASTWARD PROGRESSION MAY CONTINUE FOR A FEW MORE HOURS BUT WILL
LIKELY STALL BY EVENING.
CURRENTLY UPPER LEVEL LOW IS LOCATED OVER NRN AR WITH A SLOW ESE
MOVEMENT. 2 SFC TROUGH ARE AT WORK WITH ONE LOCATED ALONG THE MS
RIVER AND ANOTHER INVERTED VERSION OF A SFC TROUGH EXTENDING
NORTHWARD THROUGH GA INTO EASTERN TN. AS THE UPPER LOW CONTINUES
MOVING EASTWARD...INTENSIFICATION ALONG THE STATIONARY INVERTED
TROUGH IS EXPECTED. THERE MAY EVEN BE A BIT OF RETROGRADE MOVEMENT
WITH THE INVERTED TROUGH AS IT STRENGTHENS. SO FAR OMEGA RETURNS
HAVE BEEN MARGINALLY IMPRESSIVE OVER EASTERN PORTIONS OF THE MID
STATE WHERE THE RAIN IS ONGOING. TONIGHT HOWEVER...THE STRENGTHENING
INVERTED TROUGH WILL TRANSLATE INTO GREATER FORCING AND THE RAINFALL
INTENSITY LEVELS WILL PICK UP. THUS...THOUGH I WILL LIKELY BE
CUTTING A FEW MORE CENTRAL COUNTIES FROM THE FLOOD WATCH...THE
EASTERN THIRD OF OUR CWA(PLATEAU AND ADJACENT COUNTIES) ARE STILL
VERY MUCH UNDER THE GUN. MODELS ARE ALL CONVERGING ON THE HEAVY
RAINFALL POTENTIAL EXTENDING NORTHWARD INTO OUR SOUTHERN PLATEAU IN
PARTICULAR. ADDITIVE RAINFALL ENHANCEMENT IS CLEARLY INDICATED WITH
HRRR DATA ALONG WITH A GENERAL MODEL QPF CONSENSUS.
AROUND 2 TO 3 INCHES OF ADDITIONAL RAINFALL WITH LOCALIZED AMOUNTS
OF 4 INCHES ARE STILL POSSIBLE ACROSS OUR SOUTHERN PLATEAU.
ELSEWHERE ACROSS THE WATCH AREA...WILL LEAN TOWARD AROUND 2 INCHES
OF ADDITIONAL RAINFALL BEING POSSIBLE BUT WILL REFRAIN FROM THE
EXTRA LOCALIZED WORDING.
CURRENT THINKING FOR THE WATCH AREA IS TO INCLUDE AREAS ALONG AND
EAST OF A LINE FROM MACON COUNTY TO COFFEE COUNTY. WILL KEEP THE
WATCH GOING UNTIL 7 PM SUNDAY NIGHT. ALTHOUGH THE HEAVIEST ACTIVITY
WILL MOVE EAST OF OUR COUNTIES BY 18Z...ITS GOOD TO KEEP THE WATCH
GOING FOR A FEW MORE HOURS AS FLOODING CAN OFTEN OCCUR HOURS AFTER
THE HEAVIER RAINFALL ENDS.
SHOWER ACTIVITY...THOUGH LESS INTENSE...TO PERSIST INTO SUNDAY NIGHT
AS THE UPPER LOW PASSES JUST TO OUR SOUTH. SOME SUNSHINE WILL RETURN
ON MONDAY ALONG WITH WARMER TEMPS.
IN THE EXT FCST...UPPER LOW WILL BE FAR ENOUGH EAST AND UPPER
RIDGING WILL COMMENCE BY MID WEEK. THIS WILL EQUATE TO WARMER AND
DRIER CONDITIONS. IN FACT...MAY GO POP FREE TUES NT INTO WED.
UPPER RIDGE WILL BEGIN TO FLATTEN BY THE END OF THE WEEK.
INSTABILITY PARAMETERS INDICATE INCREASE CAPES AND LOWERING CAP
STRENGTHS BEGINNING ON THU. A SFC FRONT WILL THEN MOVE CLOSER BY
FRIDAY AND SATURDAY AND THIS WILL ADD TO OUR SHOWER AND TSTM
CHANCES. EXT TEMPS WILL BE RUNNING ABOVE NORMAL FOR THE LAST HALF OF
THE EXTENDED...THU-SAT. WONT DEVIATE MUCH FROM MEX ADVICE.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH THROUGH SUNDAY EVENING FOR TNZ009>011-029>034-
063>066-077>080.
&&
$$
01
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1206 AM CDT SUN MAY 5 2013
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 306 PM CDT SAT MAY 4 2013
MAIN FORECAST CONCERN IS ON FOG AND DENSE FOG POTENTIAL TONIGHT
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED UPPER LOWS OVER NORTHERN CALIFORNIA AND IN ARKANSAS...WHILE
AN UPPER HIGH WAS PRESENT ACROSS MUCH OF THE GREAT LAKES. FLOWING
BETWEEN THE ARKANSAS UPPER LOW AND THE GREAT LAKES UPPER HIGH WAS A
SHORTWAVE OVER CENTRAL WISCONSIN. DPVA AHEAD OF THIS SHORTWAVE
COMBINED WITH DAYTIME HEATING AND SOME EVAPOTRANSPIRATION HAS AIDED
IN SHOWERS NORTH OF I-94. FARTHER SOUTH...SCATTERED SHOWERS ARE ALSO
PRESENT ACROSS PORTIONS OF NORTHEAST IOWA AND FAR SOUTHWEST
WISCONSIN...AIDED BY INSTABILITY PRODUCED BY DEWPOINTS CLIMBING INTO
THE LOW 50S AND SOME COOLER TEMPS ALOFT. REGARDING TEMPERATURES...
THEY VARY GREATLY ACROSS THE FORECAST AREA...FROM THE 40S IN
ROCHESTER TO 60S ACROSS MUCH OF SOUTHWEST INTO CENTRAL WISCONSIN.
THE WARMER TEMPERATURES ARE A RESULT OF MORE SUN AND AN EASTERLY
FLOW OF WARMER AIR COMING OUT OF THE UPPER HIGH. 12Z GRB SOUNDING
SHOWED 900MB TEMPS OF +14C...COMPARED TO +5C AT MPX. BOTH SOUNDINGS
HAD AN INVERSION...BUT MPX WAS MUCH DEEPER AND THUS COMBINED WITH
THE CLOUDS WAS HELPING TO KEEP TEMPERATURES COOLER IN SOUTHEAST MN.
THE DEEPER INVERSION ALSO HAS HELPED TRAPPED PLENTY OF LOW LEVEL
MOISTURE...INCLUDING THAT FROM THE MELTING SNOWPACK...WHICH RESULTED
IN LOW VISIBILITIES OVER NORTHEAST IOWA...SOUTHEAST MINNESOTA AND
EVEN NORTH CENTRAL WISCONSIN THIS MORNING.
VERY LITTLE CHANGE IS FORECAST IN THE UPPER LEVEL PATTERN THROUGH
SUNDAY...EXCEPT FOR SOME UPPER RIDGING TRYING TO BUILD WESTWARD
THROUGH THE FORECAST AREA FROM THE UPPER HIGH. THIS UPPER RIDGING
SHOULD HELP TO KEEP THE FORECAST AREA DRY THROUGH SUNDAY AFTER ANY
SHOWERS FROM THIS AFTERNOON DISSIPATE WITH LOSS OF HEATING. THE
BIG ISSUE TONIGHT IS FOG. CONTINUING SNOW MELT OVER WESTERN AND
FAR NORTHERN PORTIONS OF THE AREA WILL HELP TO KEEP THE LOW LEVELS
OF THE ATMOSPHERE MOIST. MEANWHILE...MODELS MAINTAIN AN INVERSION
OVER THE SNOW PACK AREAS...WHICH MAKES SENSE WITH THE EASTERLY
FLOW OF WARMER AIR ALOFT ABOVE A NORTH-NORTHEAST FLOW OF COOL AIR
AT THE SURFACE. GIVEN THAT 1/4SM FOG FORMED THIS MORNING AND WINDS
ARE GOING TO BE EVEN LIGHTER...SITUATION SEEMS VERY FAVORABLE FOR
FOG AND EVEN DENSE FOG. ADDITIONALLY...SOME CLEARING COULD TRY TO
WORK IN BASED ON VISIBLE SATELLITE TRENDS...MAKING FOG EVEN MORE
FAVORABLE. SREF PROBABILITIES FOR VISIBILITY LESS THAN 1 MILE ARE
MUCH MORE EXPANSIVE AND HIGHER TONIGHT COMPARED TO THIS
MORNING...AND THE 04.00Z/06Z/12Z HIRES ARW/NMM ALL SHOW MORE FOG
TOO THAN THIS MORNING. LATEST HRRR/RAP ALSO DEVELOP FOG OVER THE
SNOW PACK. GIVEN THESE SIGNALS...HAVE INCREASED FOG COVERAGE AND
ISSUED A DENSE FOG ADVISORY...CONFINED TO THE AREAS WITH MELTING
SNOW PACK. COMBINATION OF HIGHER DEWPOINTS TONIGHT AND COME CLOUDS
WILL RESULT IN A WARMER NIGHT TONIGHT. WARMER TEMPERATURES ARE
ALSO ON TAP TOMORROW WITH MORE SUN LIKELY AS DRIER AIR COMING OUT
OF THE UPPER HIGH ADVECTS WESTWARD.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 306 PM CDT SAT MAY 4 2013
SUNDAY NIGHT THROUGH TUESDAY...NOT MUCH TO TALK ABOUT WITH REGARDS
TO THE UPPER LEVEL PATTERN. THE UPPER HIGH THAT IS OVER THE GREAT
LAKES SLOWLY BREAKS DOWN IN RESPONSE TO A SHORTWAVE TROUGH TRACKING
ACROSS NORTHERN ONTARIO COME MONDAY. STILL...THE FORECAST AREA JUST
SITS IN A LACK OF ANY UPPER LEVEL FLOW...SPLIT BETWEEN A SOUTHERN
STREAM TRACKING ACROSS THE SOUTHERN U.S. AND THE NORTHERN STREAM
WELL UP IN CANADA. MEANWHILE AT THE SURFACE...HIGH PRESSURE
CURRENTLY PRESENT OVER NORTHERN ONTARIO IS PROGGED TO BUILD SOUTH
INTO THE AREA DURING THIS PERIOD. DRYING AIR WITH THIS HIGH PRESSURE
AREA COMBINED WITH LACK OF ANY FLOW ALOFT WILL HELP TO KEEP THE
FORECAST AREA DRY. MAIN CONCERN AGAIN IS FOG. SREF PROBABILITIES FOR
VISIBILITY LESS THAN 1 MILE SHOOT BACK UP AGAIN SUNDAY NIGHT...
CONFINED TO THE SNOW PACK AREA. ONE QUESTION WOULD BE IS HOW MUCH
SNOW IS LEFT AFTER MELTING FROM THIS WEEKEND. HOWEVER...SOILS ARE
LIKELY GOING TO BE MOIST...AND WITH LIGHT WINDS AND CLEARING FROM
THE HIGH PRESSURE AREA BUILDING IN...RECIPE LOOKS GOOD AGAIN FOR FOG
AND EVEN DENSE FOG. MAY EVEN SEE FOG AGAIN MONDAY NIGHT...DEPENDING
IF THE SOIL IS STILL MOIST.
REGARDING TEMPERATURES THROUGH TUESDAY...850MB TEMPS ARE PROGGED TO
HOLD AROUND 8C FOR MONDAY AND THEN CLIMB TO NEAR 10C BY THE END OF
THE DAY TUESDAY. THESE READINGS ARE 0.5 TO 1 STANDARD DEVIATION
ABOVE NORMAL. BOTH DAYS SHOULD SEE QUITE A BIT OF SUN BEING IN
PROXIMITY TO THE SURFACE HIGH...THUS THINKING MIXING TO 850MB WILL
NOT BE A PROBLEM. THIS RESULTS IN HIGHS MAINLY IN THE LOW 70S ON
MONDAY AND LOW TO MID 70S ON TUESDAY. DID KEEP THE ROCHESTER AREA A
LITTLE COOLER ON MONDAY DUE TO WETTER SOIL. LIGHT WINDS AND DRY AIR
LIKELY TO RESULT IN DECENT COOLING AT NIGHT. FOLLOWED A BLEND OF MOS
GUIDANCE FOR LOWS.
TUESDAY NIGHT THROUGH SATURDAY...04.12Z ECMWF/GFS/CANADIAN AND ECMWF
ENSEMBLES SHOW THAT THE MORE ZONAL LOOKING NORTHERN STREAM WILL
BUCKLE DURING THE EXTENDED PORTION OF THE FORECAST. FOR FRIDAY AND
SATURDAY...GOOD AGREEMENT EXISTS IN FAIRLY DEEP TROUGHING OVER
CENTRAL CANADA...BEGINNING TO DROP DOWN TOWARDS THE FORECAST AREA.
IF THE 04.00Z/04.12Z ECMWF ARE CORRECT...WE COULD BE LOOKING AT A
SIGNIFICANT COOL DOWN HEADING INTO EARLY NEXT WEEK AS 850MB TEMPS
PLUMMET TO -8 TO -10C. BEFORE THAT TROUGH ARRIVES...THOUGH...A
SERIES OF WEAK COLD FRONTS / SYSTEMS ARE PROGGED TO COME THROUGH THE
AREA. THE FIRST MOVES THROUGH LATE WEDNESDAY. INSTABILITY BUILDING
AHEAD OF THIS FRONT...AIDED BY TEMPERATURES CLIMBING AT LEAST INTO
THE LOW IF NOT MID 70S...REQUIRES A CHANCE OF SHOWERS AND
THUNDERSTORMS. FOR THURSDAY INTO FRIDAY...THE 04.00Z/12Z ECMWF
INDICATES A SHORTWAVE TROUGH MOVING WEST TO EAST THROUGH THE
AREA...WHEREAS THE GFS AND CANADIAN KEEP THIS SHORTWAVE MUCH FARTHER
TO THE SOUTH. FOR NOW HAVE INCLUDED A CHANCE OF SHOWERS AND
THUNDERSTORMS UNTIL MODEL CONSISTENCY BECOMES BETTER. THEN FOR
SATURDAY WOULD BE THE STRONGER COLD FRONT ACCOMPANYING THE UPPER
TROUGH...THUS ANOTHER CHANCE OF PRECIPITATION. TEMPERATURES LOOK TO
STAY NEAR OR ABOVE NORMAL...UNTIL SATURDAY. SATURDAY COULD BE TRICKY
WITH HIGHS AS IT DEPENDS ON WHEN THE FRONT COMES THROUGH. 04.12Z
ECMWF IS SLOWER...WHICH WOULD SUGGEST THE BLEND OF ALL AVAILABLE
GUIDANCE MIGHT BE TOO COOL. WE WILL HAVE TO WAIT AND SEE.
&&
.AVIATION...THROUGH 06Z MONDAY
1205 AM CDT SUN MAY 5 2013
BIGGEST CONCERN FOR AVIATION INTERESTS OVERNIGHT IS THE POTENTIAL
FOR FOG. PREVIOUS FORECAST CYCLES WERE SUGGESTING THAT THE HIGH
BOUNDRY LAYER MOISTURE OVER THE SNOW FIELD WOULD RESULT IN A BOUT
OF DENSE FOG. HOWEVER...WINDS THUS FAR HAVE STAYED UP AND
MAINTAINED ENOUGH MIXING TO PRECLUDE WIDESPREAD REDUCTIONS IN
VISIBILITY SO FAR. THE NEWER 00Z MODEL RUNS HAVE NOW PULLED BACK
ON THE FOG THREAT. HOWEVER...IF THE WINDS DO SLACKEN...WE COULD
SEE THE TEMPERATURE/DEWPOINT SPREAD TIGHTEN UP. FOR NOW...WILL
MAINTAIN THE DENSE FOG POTENTIAL AT THE KRST AIRPORT OVERNIGHT...
BUT DID REDUCE THE NUMBER OF HOURS. AT KLSE OPTED TO IMPROVE THE
VISIBILITY FROM WHAT PREVIOUS FORECASTS HAD. BEYOND TONIGHT...ONCE
THE FOG THREAT ENDS BY MID-MORNING...VFR CONDITIONS WILL PREVAIL.
&&
.HYDROLOGY...
ISSUED AT 306 PM CDT SAT MAY 4 2013
AFTER SOME ISOLATED/SCATTERED RAIN SHOWERS THROUGH THIS
EVENING...A FEW DAYS OF DRY WEATHER ARE EXPECTED. THESE DRY DAYS
WILL BE BENEFICIAL...ALLOWING RUNOFF FROM THE RECENT RAIN AND
SNOWMELT TO WORK ITS WAY THROUGH THE TRIBUTARIES INTO THE MAIN
STEM OF THE MISSISSIPPI RIVER. MOST OF THE TRIBUTARIES ARE
REMAINING BELOW FLOOD STAGE. MEANWHILE...ALL THE WATER EVENTUALLY
LOOKS TO PUSH SOME SITES ALONG THE MISSISSIPPI RIVER RIGHT TO
FLOOD STAGE. SEE THE LATEST FLOOD AND RIVER STATEMENTS FOR MORE
INFORMATION.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...DENSE FOG ADVISORY FROM 1 AM TO 10 AM CDT SUNDAY FOR WIZ032-033.
MN...DENSE FOG ADVISORY FROM 1 AM TO 10 AM CDT SUNDAY FOR MNZ079-
086>088-094-095.
IA...DENSE FOG ADVISORY FROM 1 AM TO 10 AM CDT SUNDAY FOR IAZ008-009-
018-019.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...MW
HYDROLOGY...AJ
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
1011 AM EDT Sun May 5 2013
.NEAR TERM [Through Tonight]...
The 12z regional RAP analysis depicted an anomalous upper level
low centered over northern Mississippi, spanning much of the
eastern third of the country. This morning`s subjective surface
analysis places two low pressure systems and attending fronts
across the Southeast. The first low/front, which were responsible
for yesterday`s weather, have moved to the eastern U.S. coastline,
with the low centered over southeast Georgia. The second low is
positioned over northern Alabama, with a cold front extending
south through western Alabama, then riding west along the
northern Gulf of Mexico coastline. The second system will impact
the Tri-State area later today.
Expect the cool and sunny start to transition to a warm and
eventually cloudy/rainy afternoon. Highs will reach the middle to
upper 70s for most locations as we reside in a dry slot between
fronts to start the day, with the cold center of the upper low
remaining well to our northwest. Expect breezy conditions this
afternoon as we will be able to tap into the strong winds aloft
associated with the aforementioned low. As the surface front
passes through the region later this afternoon, expect scattered
light showers to accompany it. These showers will be less
expansive than yesterday, and rather quick moving. They have
already begun developing along the western Panhandle coastline and
will spread east and expand inland through the afternoon. Expect
the bulk of the rain between the 2 PM EDT and 9 PM EDT time range.
Tonight, clouds and showers will clear our area to the east, and
we will have another unseasonably cool night. Expect the middle
40s to be common area wide.
&&
.SHORT TERM [Monday Through Tuesday]...
A 550-dm upper low will be be positioned near the border of
Northeast AL and Northwest GA at 12Z Monday and then drift south for
a few hours before pulling east Monday night. By Tuesday evening,
the low will be centered over the Carolinas and have filled to 560
dm. The associated surface low will be occluded through this time
and remain north and then northeast of the area. In the wake of
another cold front, drier air will move into the lowest levels.
However, there will still be enough moisture to tap into the steep
mid level lapse rates associated with the upper low to allow
scattered showers to develop Monday afternoon. An isolated
thunderstorm cannot be ruled out during peak heating across our GA
zones north of U.S 84. The showers will be more isolated further
south over the coastal counties of the FL Big Bend and Panhandle. As
the upper low lifts away, PoPs will drop over our western zones
Monday evening, but remain in the chance category further east
across the Big Bend and our GA zones. By Tuesday, a slight chance
for morning showers was maintained only for our far eastern zones in
South Central GA and the eastern FL Big Bend. Temps will be well
below normal, by some 10-12 degrees for afternoon highs Monday. Most
areas will top out in the lower 70s, more typical for early March.
Lows Monday night will not be as chilly as tonight`s, but will still
be 6-8 degrees below normal, generally within a degree or two of 50.
Tuesday will see more sunshine which will allow temps to warm into
the mid to upper 70s which is still 8-10 degrees below normal.
&&
.LONG TERM [Tuesday Night through Saturday]...
In the wake of the upper low, we will dry out an warm up quite a
bit. No major weather systems are forecast to impact the local
area, and temperatures will warm to seasonal averages by mid week.
&&
.AVIATION [Beginning 14Z Sunday]...
VFR conditions are anticipated for the duration of the TAF. Gusty
winds will be the main forecast concern today. Expect gusts to 30
knots near our northwestern terminals, and up to 15 knots further
southeast. Light rain will fall from mid-level cloudiness this
afternoon and should not result in any category restrictions.
&&
.MARINE...
The lull in advisory level winds will be short lived this morning
as another cold front approaches from the west. Expect another
surge in westerly winds later today before falling to below
advisory criteria tomorrow morning. Cautionary conditions are
forecast through Monday, remaining light to moderate out of the
west or northwest from Monday night through mid week.
&&
.FIRE WEATHER...
Drier air is still expected to move into the area for today and
Monday, but conditions will not be dry enough for Red Flag concerns.
However, dispersions are expected to be quite high across much of
North Florida today and Monday.
&&
.HYDROLOGY...
With only light rainfall amounts anticipated through mid week, we
do not expect any meaningful river or creek rises.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 78 47 72 51 77 / 20 10 30 30 10
Panama City 74 52 73 55 76 / 20 10 20 20 10
Dothan 72 45 71 50 74 / 30 10 40 20 10
Albany 75 47 72 50 76 / 30 10 40 40 10
Valdosta 76 47 72 51 75 / 20 10 30 40 20
Cross City 78 49 75 50 77 / 10 20 20 30 20
Apalachicola 71 50 72 55 73 / 20 10 20 20 10
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AL...None.
GM...Small Craft Advisory until 5 AM EDT Monday for Gulf of
Mexico waters from Apalachicola to Destin and out to 60 NM.
Small Craft Advisory from 5 PM this afternoon to 5 AM EDT
Monday for Gulf of Mexico waters from Apalachicola to the
Suwannee River and out to 60 NM.
&&
$$
NEAR TERM...Harrigan
SHORT TERM...Wool
LONG TERM...Harrigan
AVIATION...Harrigan
MARINE...Harrigan/Wool
FIRE WEATHER...Gould
HYDROLOGY...Wool
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
930 AM EDT SUN MAY 5 2013
.DISCUSSION...
...ROUGH SURF/HIGH RIP CURRENT RISK TODAY...
CURRENTLY-THIS AFTERNOON...REMOVED RAIN CHANCES FROM THE FORECAST AS
RADAR TRENDS WERE INDICATING THAT THE STORMS IN THE ATLANTIC WERE
EAST OF OUR COASTAL WATERS AND WILL CONTINUE TO MOVE AWAY THIS
AFTERNOON. VISIBLE SATELLITE IMAGERY LOOP SHOWS PARTLY CLOUDY SKIES
FROM SOUTH BREVARD OSCEOLA COUNTIES NORTH. TO THE SOUTH...CUMULUS
AND STRATOCUMULUS MOVING OFF TO THE SOUTHEAST. MORE CUMULUS AND
STRATOCUMULUS TO FORM AS DAYTIME HEATING WARMS UP THE LOWEST LAYERS.
MORNING SOUNDINGS FROM THE FLORIDA UPPER AIR SITES SHOW A DRY LAYER
STARTING AROUND 900MB/APPROX 3500 FEET AND ABOVE. SURFACE ANALYSIS
SHOWING WEAK HIGH PRESSURE WORKING ITS WAY ACROSS THE EASTERN GULF
OF MEXICO AND CENTRAL FLORIDA. THE NORTHWEST TO WEST WIND WILL KEEP
TEMPERATURES AND HUMIDITY LEVELS COMFORTABLE THIS AFTERNOON.
PREVIOUS ZONE DISCUSSION
TONIGHT...WEAK RIDGING BEHIND THE FRONT WILL KEEP SKIES MOSTLY
CLEAR EARLY. ANOTHER WEAK FRONTAL TROUGH WILL PUSH INTO THE
PENINSULA AFTER MIDNIGHT. THE AIR MASS WILL BE QUITE DRY SO EXPECT
JUST A NARROW BAND OF CLOUDINESS WITH THIS BOUNDARY. OVERNIGHT
LOWS WILL BE A LITTLE BELOW NORMAL IN THE UPPER 50S TO LOWER 60S.
MON-MON NIGHT...LARGE EXPANSIVE UPPER LOW OVER THE TENNESSEE VALLEY
IS FORECAST TO SLOWLY MOVE EAST INTO THE CAROLINAS THROUGH THE END
OF THIS PERIOD. ONLY WEAK ENERGY ALOFT ASSOCIATED WITH THIS FEATURE
WILL TRAVERSE EAST CENTRAL FLORIDA. A WEAK FRONTAL TROUGH WILL MOVE
ACROSS THE COVERAGE WARNING AREA AND PROVIDE A SMALL THREAT FOR
SHOWERS...MAINLY SOUTH OF THE I-4 CORRIDOR. YET ANOTHER FEATURE IS
FORECAST TO DROP INTO NORTH-CENTRAL FLORIDA OVERNIGHT. WILL KEEP
POPS AT 20 PERCENT OR LESS. WESTERLY WINDS INCREASING TO 10-15 MPH
IN THE AFTERNOON. HIGHS IN THE UPPER 70S TO AROUND 80 DEGREES NORTH
OF THE I-4 CORRIDOR WITH LOWER 80S FURTHER SOUTHWARD. LOWS MAINLY IN
THE UPPER 50S...EXCEPT AROUND 60 DEGREES TO LOWER 60S ACROSS THE
SPACE/TREASURE COASTS AND ORLANDO METRO.
TUE-TUE NIGHT...THE PREVIOUSLY MENTIONED UPPER LOW WILL GRADUALLY
WEAKEN AS IT BEGINS TO MOVE UP THE MID ATLANTIC COAST. CLOSER TO
HOME THE NEXT WEAK FRONTAL TROUGH WILL MOVE FROM NORTH-CENTRAL
FLORIDA THROUGH EAST CENTRAL FLORIDA DURING THE DAY. AGAIN ISOLATED
SHOWERS WILL BE POSSIBLE THROUGH THE DAY BUT EXPECT PRECIPITATION TO
BE LIGHT AS MOISTURE VALUES ARE POOR. MAINLY WESTERLY WINDS AGAIN
INCREASING TO 10-15 MPH IN THE AFTERNOON. HIGHS NEAR 80 DEGREES TO
LOWER 80S MOST LOCATIONS...EXCEPT A FEW MIDDLE 80S POSSIBLE ACROSS
OKEECHOBEE COUNTY AND SOUTHERN OSCEOLA COUNTY. OVERNIGHT LOWS ONCE
AGAIN IN THE MIDDLE TO UPPER 50S WITH A FEW LOWER 60S POSSIBLE ALONG
THE TREASURE COAST AND ORLANDO METRO.
WED-SAT...THE UPPER LOW CONTINUES TO WEAKEN AS IT SLOWLY MOVES UP
THE ATLANTIC SEABOARD...FINALLY OPENING UP INTO A TROUGH AND MOVING
INTO THE NORTH ATLANTIC DURING THE DAY ON FRI. MAINLY ZONAL WINDS
ALOFT OVER THE AREA WITH ONLY A FEW SUBTLE IMPULSES EMBEDDED WITHIN.
SLIGHT SHORTWAVE RIDGING BEGINS TO INCREASE OVER THE REGION ON SAT.
THE LOCAL SURFACE PRESSURE GRADIENT REMAINS RATHER WEAK AS HIGH
PRESSURE OVER THE AREA INITIALLY MOVES INTO THE WESTERN ATLANTIC ON
THU WITH RIDGING EXTENDING ACROSS THE CENTRAL PENINSULA INTO THE
WEEKEND. LIGHT WESTERLY SURFACE FLOW ON WED WILL GIVE WAY TO
AFTERNOON SEA BREEZES EACH DAY THU-SAT. ENOUGH MOISTURE MAY CREEP
BACK INTO THE AREA ON SAT FOR A FEW LATE DAY STORMS ACROSS THE
INTERIOR. BELOW NORMAL MAX/MIN TEMPERATURES WILL CONTINUE INTO WED
BEFORE A GRADUAL WARMING TREND COMMENCES THU LASTING INTO THE
WEEKEND.
&&
.AVIATION...
VFR. BROKEN-SCATTERED VFR FROM KVRB SOUTH THE REST OF THE MORNING AS
&&
.MARINE...
CURRENTLY-THIS AFTERNOON...BUOY 009 RECORDING NORTHWEST WINDS AROUND
20 KNOTS AND 7 FOOT SEAS WITH LARGE LONG PERIOD EASTERLY SWELLS
BEING THE PRIMARY COMPONENT TO SIGNIFICANT WAVE HEIGHTS. THE TWO
NEARSHORE SCRIPPS BUOYS WERE RECORDING 4 TO 5 FOOT SEAS WITH A 2
FOOT LONG PERIOD EASTERLY SWELL.
WILL HAVE TO FOLLOW BUOY WAVE HEIGHT TRENDS AND MAKE A LAST MINUTE
CALL ON WHETHER TO EXTEND OR DROP THE SMALL CRAFT ADVISORY AT MIDDAY.
PREVIOUS MARINE DISCUSSION
CURRENTLY-TONIGHT...THE NORTHERN OFFSHORE LEG STILL HAS SOUTHEAST
WINDS AROUND 20 KNOTS BUT THE GFS AND LATEST RAP SHOW SURFACE LOW
OVER NORTHEAST FLORIDA MOVING FARTHER AWAY AND WINDS WEAKENING BY
FORECAST ISSUANCE TIME. WEST/NORTHWEST WINDS 10 TO 15 KNOTS
EXPECTED MOST OF THE DAY AND INTO TONIGHT.
SEAS ARE STILL ELEVATED ESPECIALLY IN THE NORTH DUE TO EAST/NORTHEAST
SWELLS. THIS WILL LIKELY MAKE INLETS HAZARDOUS DURING THE OUTGOING
TIDE THIS MORNING. THEREFORE...WILL CARRY A SMALL CRAFT ADVISORY
FOR HAZARDOUS SEAS THIS MORNING OVER ALL THE WATERS.
MON-MON NIGHT...WEAK HIGH PRESSURE WILL BUILD INTO THE AREA BEHIND
THE MOST RECENT WEAK FRONTAL TROUGH. WESTERLY WINDS THROUGH THIS
TIME WITH SPEEDS NEAR 10 KTS NEAR SHORE AND OCCASIONALLY 10-15 KTS
OFFSHORE. INCREASING LARGE EASTERLY SWELL WILL KEEP SEAS 3-5 FT NEAR
SHORE AND 5-6 FT OFFSHORE. CAUTIONARY STATEMENTS WILL BE NECESSARY
FOR OFFSHORE LEGS DUE TO THE SWELL.
TUE-THU...ANOTHER WEAK TROUGH PASSES THROUGH THE AREA ON TUE BEFORE
HIGH PRESSURE BUILDS BACK INTO THE REGION EMERGING INTO THE WESTERN
ATLANTIC ON THU. MAINLY A WESTERLY COMPONENT OF WIND BUT MAY SEE
WINDS BACK TO THE E/ESE ALONG THE COAST BY WED/THU WITH EAST COAST
SEA BREEZE FORMATION. WIND SPEEDS 10-12 KTS NEAR SHORE WITH PERIODS
AROUND 15 KTS OFFSHORE. SEAS TO SUBSIDE DURING THIS TIME WITH
INITIAL 3-5 FT SEAS FALLING BACK 3 FT OR LESS BY EARLY THU.
&&
.FIRE WEATHER...
TODAY...A FEW HOURS OF RH 30 TO 35 PERCENT SHOULD OCCUR OVER THE
INTERIOR NORTH THIS AFTERNOON. WEST WINDS NEAR 15 MPH WILL BE
GUSTY TO AROUND 20 MPH AT TIMES. HOWEVER...THE ERC VALUES ARE TOO
LOW AFTER RECENT RAINS FOR RED FLAG CRITERIA TO OCCUR.
MON-THU...GUIDANCE CONTINUES TO SHOW MIN RH VALUES DROPPING INTO THE
M-U30S OVER THE INTERIOR EACH AFTERNOON. WINDS SHOULD NOT BE A HUGE
CONCERN...AND FORTUNATELY...ERC VALUES HAVE DROPPED SIGNIFICANTLY
FROM LAST WEEK`S RAINFALL.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 12 NOON TODAY
FOR ALL OF THE COASTAL WATERS.
&&
$$
UPDATES/AVIATION...WIMMER
RADAR/IMPACT WX....CRISTALDI
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
734 AM EDT SUN MAY 5 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 402 AM EDT SUN MAY 5 2013
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR RDG STRETCHING
FM SE CANADA INTO THE UPR GRT LKS TO THE N OF CLOSED LO OVER THE SRN
MS RIVER VALLEY THAT WAS RESPONSIBLE FOR THE WINTER WX THE PAST
COUPLE OF DAYS. THE 00Z GRB RAOB AND ESPECIALLY THE APX RAOB SHOW A
VERY DRY AIRMASS UNDER THIS RDG...WITH THE 00Z H85 DEWPT DEPRESSION
AS HI AS 24C/PWAT JUST 0.24 INCH OR 49 PCT OF NORMAL AT APX. BUT
THERE IS STILL A RIBBON OF DEEPER MSTR SOME -SHRA EXTENDING NNWWD
FM THE CLOSED LO TO THE S INTO MN/ADJOINING ONTARIO. THE 00Z INL
RAOB SHOWS A NEARLY SATURATED PROFILE AND 00Z PWAT OF 0.83
INCH...188 PCT OF NORMAL. ALTHOUGH THERE ARE SOME HI CLDS OVER THE
E...THAT AREA IS DOMINATED BY THE DRY AIRMASS SHOWN ON THE APX RAOB.
WITH H85 TEMPS UP TO 10C...MAX TEMPS YDAY REACHED THE 70S OVER THE
SCENTRAL AND ERN CWA WHERE THE DRY AIR ALLOWED FOR QUITE A BIT OF
SUNSHINE AND LAKE COOLING WAS ABSENT IN THE NLY FLOW S OF HI PRES
CENTERED OVER NW ONTARIO. ALTHOUGH THE DRY AIR ALF HAS PUSHED INTO
THE WRN CWA PER THE LATEST RUC ANALYSIS SDNGS...ENUF LLVL MSTR
LINGERS THERE UNDER SHARP INVRN AT H9 TO SUPPORT LO CLDS/FOG OVER
THE WRN CWA FM THE KEWEENAW THRU GOGEBIC COUNTY. SINCE THE 00Z YPL
RAOB SHOWS SOME MSTR BTWN H9-825 EVEN CLOSE TO THE ONTARIO HI
CENTER...THERE IS QUITE A BIT OF LO CLD EXTENDING WELL N OF LK SUP
TO THE HI PRES RDG AXIS.
MAIN FCST CONCERNS IN THE SHORT TERM INVOLVE LO CLD TRENDS/IMPACT ON
TEMPS. POTENTIAL FOR LOW RH OVER THE E/IMPACT ON FIRE WX CONCERNS
THIS AFTN IS THE FOCUS THERE.
TODAY...UPR RDG AXIS/MID LVL DRY AIR WL REMAIN DOMINANT. ALTHOUGH
SFC HI PRES OVER NW ONTARIO IS PROGGED TO DRIFT SLOWLY S TOWARD LK
SUP...THE NNW FLOW IN ADVANCE OF THIS HI...ALBEIT LGT...WL LIKELY
ACT TO HOLD LO CLDS IN PLACE OVER MUCH OF THE NW HALF OF THE CWA
DESPITE THE ONSET OF DIURNAL HEATING THAT WOULD NORMALLY MIX OUT
THIS LLVL MSTR. IN FACT...COOL ADVECTION OFF THE CHILLY WATERS OF LK
SUP WL TEND TO OFFSET THE DIURNAL HEATING AND MAINTAIN A LLVL
INVRN/POTENTIAL FOR MORE PERSISTENT LO CLDS IN THIS AREA AS HI TEMPS
HOLD IN THE 40S NEAR THE SHORE. OVER THE E HALF OF THE CWA...A LGT S
FLOW WL PREVAIL ARND SFC HI PRES OVER SE ONTARIO. ALTHOUGH THERE MAY
BE MODERATION NEAR THE BAY OF GREEN BAY/ LK MI WITH A LK
BREEZE...H85 TEMPS NEAR 10C/MIXING TO H8-85 ON NAM/ GFS FCST SDNGS
WITH A GOOD DEAL OF SUNSHINE SUPPORT HI TEMPS TOPPING OUT IN THE 70S
AWAY FM THE LK COOLING. WITH SFC DEWPTS MIXING OUT TOWARD 35 OVER
THE INTERIOR...MIN RH WL LIKELY FALL AS LO AS ABOUT 25 PCT.
FORTUNATELY...THE WINDS WL BE LGT...SO NO FIRE WX HEADLINES ARE
NECESSARY.
TONIGHT...WITH HI PRES FCST TO SHIFT OVHD AND LGT WINDS...EXPECT
TEMPS TO DIP INTO THE 30S...FALLING MOST SHARPLY OVER THE E AND
SCENTRAL...WHERE MUCH DRIER AIR /PWAT NEAR 0.5 INCH/ WL LINGER.
SINCE MORE LLVL MSTR WL BE LINGERNING OVER THE W/NCENTRAL...
RETAINED A MENTION OF FOG IN THIS AREA OVERNGT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 402 AM EDT SUN MAY 5 2013
WITH THE CUTOFF LOW SITUATED OVER THE SOUTHEAST CONUS AND THE
NORTHERN JET STREAM WELL TO THE NORTH OF THE AREA IN CANADA...A
QUIET START TO THE WORK WEEK IS EXPECTED WITH ABOVE NORMAL
TEMPERATURES OVER MUCH OF THE AREA.
MONDAY AND TUESDAY WILL BE DOMINATED BY HIGH PRESSURE AT THE
SURFACE. EXPECT MOSTLY CLEAR SKIES FOR MUCH OF THIS PERIOD...BUT
THERE COULD BE SOME HIGH BASED DIURNAL CU DEVELOPING OVER THE
INTERIOR WEST DUE TO A POCKET OF 800-750MB MOISTURE. A FEW MODELS
HINT AT SOME SHOWER DEVELOPMENT...BUT WITH THE HIGH BASES AND
LIMITED MOISTURE KEEPING MLCAPE VALUES BELOW 150 J/KG...THINK IT
WILL JUST BE CU. THE SUNSHINE WILL ALLOW FOR AMPLE MIXING...TO
800-775MB...AND LEAD TO HIGHS IN THE LOWER 70S AWAY FROM THE GREAT
LAKES. LAKE BREEZES ON BOTH DAYS WILL KEEP TEMPERATURES COOLER NEAR
THE GREAT LAKES. DID TRY TO MIX OUT DEWPOINTS A LITTLE MORE THAN
THE MODELS HAVE INDICATED BASED OFF WHAT OCCURRED YESTERDAY.
FORTUNATELY...WITH LIGHT WINDS UNDER THE HIGH...IT WILL LIMIT FIRE
WX CONCERNS OVER THE SOUTH CENTRAL AND EAST EVEN THOUGH FFMC VALUES
ARE ON THE INCREASE AND ARE OR BECOMING HIGH.
PATCHY GROUND FOG IS POSSIBLE OVER THE KEWEENAW AND INTERIOR WEST
MONDAY NIGHT WITH THE CLEAR SKIES AND LOW LEVEL COOLING BY LINGERING
SNOW COVER. FARTHER EAST...DRIER AIR IN PLACE WILL LIMIT THE FOG
POTENTIAL. OVER THE GREAT LAKES...MODELS ARE HINTING AT FOG
DEVELOPMENT WITH THE LIGHT WINDS ON MONDAY. BUT DEWPOINTS AREN/T
EXTREMELY HIGH AND WITH DRY AIR ALOFT IT WON/T GET MUCH HELP FROM
THE LAND. WITH THAT BEING SAID...IF IT DOES DEVELOP...THE LIGHT
WINDS WOULD LEAD TO SLOW MOVEMENT AND IT LINGERING INTO WEDNESDAY.
COULD SEE SOME PATCHY GROUND FOG OVER THE FAR WEST LATE TUESDAY
NIGHT...BUT CONFIDENCE IS TOO LOW TO ADD AT THIS POINT.
THE HIGH PRESSURE WILL BEGIN TO GIVE WAY ON WEDNESDAY...AS AN UPPER
TROUGH OVER THE WEST COAST SLIDES INTO THE PLAINS AND A SHORTWAVE
SLIDES THROUGH THE NORTHERN STREAM AND PRODUCES A SURFACE LOW THAT
MOVES INTO NORTHWEST QUEBEC ON WEDNESDAY. A COLD FRONT ASSOCIATED
WITH THIS LOW WILL TRY TO DROP THROUGH THE AREA ON WEDNESDAY
AFTERNOON AND NIGHT. WITH THE UPPER TROUGH MOVING INTO THE
PLAINS...IT MAY PROVIDE ENOUGH MOISTURE TO PRODUCE SOME SHOWERS.
BUT THE MODELS DIFFER ON THE NORTHEASTWARD EXTENT OF THE MOISTURE
FROM THE UPPER TROUGH. THE 12Z ECMWF/GEM KEEP THE MOISTURE FARTHER
TO THE WEST...WHILE THE 18Z GFS PULLS IT INTO THE UPPER GREAT LAKES.
LATEST 00Z GFS/GEM RUNS HAVE TRENDED TOWARDS THE ECMWF IDEA. BASED
ON THE EXISTING DRY AIR MASS AND LIMITED MOISTURE RETURN...WOULD
TEND TO SIDE WITH THE DRIER IDEA AND WILL ONLY HAVE SLIGHTS OR LOW
CHANCE POPS FOR THE PASSAGE OF THE FRONT. BEHIND THE FRONT...ANOTHER
NORTHERN STREAM SHORTWAVE MAY AFFECT THE AREA ON FRIDAY NIGHT INTO
SATURDAY AND BRING ANOTHER POTENTIAL FOR RAIN. BUT AGAIN...MOISTURE
LOOKS TO BE THE CONCERN FOR THAT PERIOD UNLESS THE LOW MOVING
THROUGH THE LOWER GREAT LAKES MOVES FARTHER TO THE NORTH.
TEMPERATURES WED INTO SATURDAY LOOK TO BE COOLER THAN THE FIRST
PART OF THE WORK WEEK...BUT STILL NORMAL OR VERY SLIGHTLY BELOW
NORMAL FOR THIS TIME OF YEAR.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 733 AM EDT SUN MAY 5 2013
EXPECT LO CLDS/FOG AT MAINLY THE WRN SITES OF CMX AND ESPECIALLY IWD
TO LINGER THRU THIS MRNG BEFORE DIURNAL HEATING MIXES OUT THE LLVL
MSTR DURING THE AFTN. WHERE THE LLVL NNE FLOW PRESENTS THE GREATEST
UPSLOPE COMPONENT AT IWD...CONDITIONS WL BE AS LO AS LIFR TO
VLIFR...AND THE LO CLDS WL LINGER LONGER THRU MUCH OF THE DAY.
ALTHOUGH SOME LO CLDS COULD IMPACT SAW EARLY IN THE TAF PERIOD...
THIS SITE APPEARS TO BE TOO DEEP INTO THE DRY AIR SHOWN ON THE 00Z
GRB/APX RAOBS TO SEE PERSISTENT LO CLD/IFR WX. EXPECT FOG/IFR
CONDITIONS TO REDVLP TNGT AS HI PRES/LGT WINDS DOMINATE THE AREA
WITH LINGERING LLVL MSTR. THE LOWEST CONDITIONS SHOULD AGAIN PREVAIL
AT IWD AND CMX...WHERE MORE LLVL MSTR WL LINGER.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 402 AM EDT SUN MAY 5 2013
A QUIET PERIOD OF WEATHER IS EXPECTED THROUGH THE PERIOD...WITH THE
WINDS LIKELY STAYING BELOW 25KTS. HIGH PRESSURE THAT HAS SETUP OVER
THE AREA WILL REMAIN THROUGH THE FIRST PART OF THE WORK WEEK AND
LEAD TO LIGHT WINDS. THEN...A COLD FRONT DROPPING SOUTHEAST ACROSS
THE UPPER GREAT LAKES ON WEDNESDAY INTO WEDNESDAY NIGHT WILL BRING
A WIND SHIFT BUT ONLY 10-20KT WINDS. WEAK HIGH PRESSURE WILL MOVE
OVER NORTHERN LAKE SUPERIOR FOR THURSDAY INTO THURSDAY NIGHT AND
DIMINISH THE WINDS.
&&
.HYDROLOGY...
ISSUED AT 402 AM EDT SUN MAY 5 2013
HYDROLOGY CONCERNS WILL REMAIN OVER THE COMING DAYS...UNTIL THE
REMAINING SNOW PACK MELTS OVER THE NORTHWESTERN THIRD OF UPPER
MICHIGAN. VISIBLE SATELLITE AND MODIS IMAGERY TODAY STILL SHOWS SNOW
REMAINING IN THE HIGHER TERRAIN LOCATIONS OF THE HURON MOUNTAINS AND
THE KEWEENAW PENINSULA. FARTHER WEST...THE 10 PLUS INCHES OF WET
SNOW WILL ALSO HELP KEEP THE POTENTIAL OF RISING RIVER LEVELS IN
PLACE. DID SEE RISES AT SOME OF THE SITES OVER THE WEST /RKLM4 AND
ESPECIALLY TRRM4/ WITH THE WARMER TEMPERATURES YESTERDAY AND WOULD
EXPECT THAT TO CONTINUE TODAY INTO THE FIRST PART OF THE WORK WEEK.
THE STURGEON RIVER AT ALSTON AND CHASSELL...THE MICHIGAMME RIVER
AROUND WITCH LAKE...AND THE PAINT RIVER NEAR CRYSTAL FALLS WILL
REMAIN CONCERNS INTO AT LEAST EARLY NEXT WEEK...AND IN THE CASE OF
THE MICHIGAMME RIVER PERHAPS WELL INTO THE COMING WEEK. BUT
OTHERWISE RIVER LEVELS CONTINUE TO COME DOWN DESPITE SOME RECENT
HEAVY PRECIP THAT IMPACTED MAINLY THE W HALF OF UPR MI.
FOR COMPLETE DETAILS...SEE THE LATEST RIVER FLOOD WARNINGS AND
ADVISORIES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...SRF
AVIATION...KC
MARINE...SRF
HYDROLOGY...SRF
AREA FORECAST DISCUSSION
NWS RALEIGH NC
705 AM EDT SUN MAY 5 2013
.SYNOPSIS...
COOL HIGH PRESSURE WILL EXTEND ALONG THE NORTHEAST AND MID ATLANTIC
COAST THROUGH MONDAY. A STRONG UPPER LOW WILL TRACK SLOWLY EASTWARD
ACROSS THE DEEP SOUTH AND CAROLINAS THROUGH TUESDAY.
&&
.NEAR TERM /THROUGH MONDAY NIGHT/...
AS OF 300 AM SUNDAY...
FOR TODAY: RAIN CHANCES WILL SLOWLY INCREASE FROM SW TO NE LATER
TODAY... HOWEVER IT LOOKS LIKE THE HEAVIER RAIN IS LIKELY TO HOLD
OFF UNTIL LATE. THE UPPER LOW IS CURRENTLY SPINNING NEAR MEMPHIS...
WHILE NC REMAINS BENEATH A MID LEVEL COL AREA BORDERED BY THE
PERSISTENT BLOCKING HIGH OVER THE ERN GREAT LAKES... BROAD WEAK LOW
PRESSURE OUT OVER THE ATLANTIC... AND THE POTENT VORTEX OVER THE
LOWER MISS VALLEY. STRONG MOISTURE TRANSPORT CONTINUES TO DRIVE UP
OVER GA/SC INTO THE SRN APPALACHIANS WITH A 45 KT SOUTHEASTERLY LOW
LEVEL JET ORTHOGONAL TO THE SLOPES OVER SW NC... LEADING TO MAXIMUM
POTENTIAL TERRAIN UPGLIDE HERE AND A HIGH THREAT OF HEAVY RAIN AND
FLOODING ISSUES TO OUR WEST TODAY. ADDING TO THIS LOW-LEVEL-ROOTED
MECHANICAL LIFT IS STRONG UPPER DIVERGENCE WHICH WILL PEAK OVER WRN
NC TODAY... ALTHOUGH THE SLOW MOVEMENT AND THE START OF GRADUAL
WEAKENING OF THIS VORTEX WILL MINIMIZE MID LEVEL DPVA AND HEIGHT
FALLS. SO WHILE SOME OF THIS SHIELD OF HEAVIER RAIN MAY WORK INTO
THE FAR SWRN CWA THIS AFTERNOON... GIVEN THE FOCUS OF STRONGER LIFT
AND MOISTURE FLUX LARGELY OVER WRN NC... EXPECT MORE IN THE WAY OF
VERY PATCHY LIGHT RAIN AND DRIZZLE OVER MUCH OF CENTRAL NC THROUGH
TODAY. THIS IS FURTHER SUPPORTED BY MODEL TRENDS SHOWING A SLOWING
OF THE NE PROGRESS OF THE HEAVY RAIN SHIELD TODAY... AS WELL AS THE
LATEST RAP AND CONVECTION-ALLOWING WRF RUNS. WILL LOWER POPS AND QPF
AND DELAY THE ARRIVAL OF HIGHER CHANCES UNTIL LATE TODAY.
THICKNESSES ABOUT 20-25 METER BELOW NORMAL COMBINED WITH THE BRISK
ENE WINDS AND CONSIDERABLE CLOUD COVER SUPPORT COOL HIGHS OF 58-68.
FOR TONIGHT: WE SHOULD FINALLY SEE THE MORE WIDESPREAD RAIN WORK
INTO CENTRAL NC FROM THE SW. THE VORTEX TO OUR SW WILL BEGIN TO
SLOWLY FILL AS IT WOBBLES ACROSS NRN AL TO NEAR CHATTANOOGA TONIGHT.
AS IT APPROACHES... THE OCCLUDED SURFACE FRONT WILL PIVOT NE INTO SW
NC ACROSS SC... WHILE THE INTENSE PLUME OF ATLANTIC MOISTURE (WITH
PRECIP WATER OVER 150 PERCENT OF NORMAL) STREAMING OVER SC INTO WRN
NC GRADUALLY TRANSLATES TO THE NNE. EXPECT A SLOW BUT STEADY
INCREASE IN POPS FROM VERY LATE AFTERNOON THROUGH TONIGHT IN CENTRAL
NC FROM SW TO NE... TRENDING UP TO CATEGORICAL ACROSS THE SOUTH AND
WEST WITH LIKELY POPS IN THE NE. TOUGH CALL ON AMOUNTS THROUGH
TONIGHT... CONSIDERING THAT THE MID LEVEL VORTEX WILL BE WEAKENING
AND THUS THE DYNAMIC FORCING WILL BE ON THE DECREASE... PLUS THE
NORTHWARD SHIFT OF THE SOUTHEASTERLY LOW LEVEL JET INTO NW NC AND SW
VA WILL ACCORDINGLY PLACE THE BEST LOW LEVEL CONVERGENCE AND
MOISTURE TRANSPORT JUST WEST OF THE FORECAST AREA. WILL FORECAST
AMOUNTS UP TO A HALF INCH OVER THE FAR SRN AND FAR WRN CWA INCLUDING
LAURINBURG INTO SOUTHERN PINES AND THE TRIAD TO THE SW... WHILE
AREAS TO THE NORTH AND EAST SHOULD SEE MUCH LOWER AMOUNTS...
GENERALLY A TENTH INCH OR LESS THROUGH TONIGHT AS WE SIMPLY WON`T
SEE QUITE THE FORCING FOR ASCENT NOR HIGHER PW FLUX IN THE NE CWA
OVERNIGHT. THE CLOUDS AND WINDS SHOULD LIMIT COOLING AND LOWER THE
DIURNAL TEMP SPREAD... THUS HAVE NUDGED UP LOWS SLIGHTLY TO 54-60.
FOR MONDAY/MONDAY NIGHT: THE MID LEVEL VORTEX IS EXPECTED TO REMAIN
POTENT BUT STEADILY WEAKEN AS IT MEANDERS AROUND NE AL MONDAY THEN
EASES INTO EAST CENTRAL GA MONDAY NIGHT AS LOBES OF VORTICITY ROTATE
AROUND IT AND DRIVE ITS MOVEMENT. MODELS DIFFER ON THE EVOLUTION OF
SURFACE FEATURES BUT IT APPEARS MOST LIKELY THAT THE PRIMARY LOW
WILL WEAK OVER TN WHILE A SECONDARY TRIPLE-POINT LOW FORMS OVER THE
CENTRAL NC/SC BORDER AREA... NEAR THE CROOK OF A MID LEVEL DRY SLOT
PUNCHING INTO SC. IF THIS LOW WANDERS UP TOWARD CLT AS MOST
OPERATIONAL MODELS SUGGEST... THE MID LEVEL DRY SLOT SHOULD SHIFT
INTO FAR SRN NC WHILE THE BEST LOW LEVEL MOISTURE FEED AND UPPER
DIVERGENCE (AND HENCE THE GREATEST ASCENT AND LOW LEVEL MOISTURE
TRANSPORT) SHIFT INTO EAST-CENTRAL/NE/NORTH-CENTRAL NC MONDAY... AND
EVENTUALLY UP INTO VA MONDAY NIGHT. THIS SUPPORTS THE GENERAL TREND
OF EARLIER FORECAST OF SHIFTING THE CATEGORICAL POPS NORTHWARD
THROUGH NC DURING THIS PERIOD. INSTABILITY REMAINS MARGINAL BUT DOES
INCREASE ACROSS THE SOUTH MONDAY/MONDAY NIGHT WITH THE ARRIVAL OF
THE DRY SLOT AND RISING MID LEVEL LAPSE RATES TO OVER 6.75 C/KM...
AND THE NAM/GFS TAKE MLCAPE NEAR 1000 J/KG MONDAY AFTERNOON. WILL
NEED TO RETAIN A MENTION OF AT LEAST ISOLATED STORMS... MAINLY SOUTH
OF HIGHWAY 64 AND MAINLY IN THE AFTERNOON/EVENING. THE WIND PROFILE
IS NOT TEXTBOOK BUT 0-6KM SHEAR DOES REACH 30-40 KTS WITH A CURVED
0-3 KM HODOGRAPH AND 0-1 KM SHEAR OF 20-25 KTS... SO WE COULD SEE A
STRONG STORM OR TWO. ADDITIONAL RAINFALL AMOUNTS COULD APPROACH AN
INCH ESPECIALLY IN THE NORTHERN HALF ACCOMPANYING THE AXIS OF MORE
STEADY RAIN. THE DIURNAL SPREAD SHOULD AGAIN BE MUCH LOWER THAN
USUAL... ALTHOUGH A FEW ANTICIPATED BREAKS IN THE CLOUDS IN THE
SOUTH MONDAY AFTERNOON SHOULD CAUSE A SPIKE IN TEMPS. HIGHS FROM 61
NW TO 72 SE. LOWS 53 SW TO 59 NE. -GIH
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 315 AM SUNDAY...
TUESDAY...
THE UPPER LOW OVER THE SAVANNAH RIVER BASIN WILL LIFT VERY SLOWLY
NORTHEAST ACROSS THE CAROLINAS TUESDAY. HEAVIER RAIN ASSOCIATED
WITH THE WARM CONVEYOR BELT AND DEEP MOIST AXIS WILL SHIFT NORTH
ACROSS VA WITH THE OCCLUDED FRONT...AS A DRY SLOT WORKS ITS WAY
AROUND THE EAST SIDE OF THE UPPER LOW. COOLING ALOFT AND STEEPENING
MID LEVEL LAPSE RATES (TO AROUND 7 C/KM) SHOULD STILL SUPPORT AT
LEAST SCATTERED SHOWERS AND STORMS...PARTICULARLY OVER THE COASTAL
PLAIN WHERE HEIGHT FALLS ALOFT AND LOW LEVEL CONVERGENCE WILL BE
MAXIMIZED AHEAD OF THE UPPER LOW AND ASSOCIATED BAGGY SURFACE LOW.
WHILE FAIRLY WIDESPREAD CLOUD COVER MAY INHIBIT HEATING...STRONG
DEEP LAYER SHEAR AROUND 40KT ON THE EASTERN PERIPHERY OF THE UPPER
LOW COULD STILL SUPPORT SOME STORM ORGANIZATION AND ENHANCE THE
THREAT OF HAIL IF INSTABILITY CAN DEVELOP...MAINLY OVER THE NORTHERN
COASTAL PLAIN. THE THREAT SEVERE WEATHER APPEARS TO BE
LOW...HOWEVER.
SOME BREAKS IN CLOUD COVER APPEAR MORE LIKELY OVER THE EAST
TUESDAY...THOUGH GUIDANCE STILL ONLY INDICATES HIGHS AROUND 70 OVER
THE COASTAL PLAIN. OVER THE WEST...DEEPER MOISTURE WRAPPED AROUND
THE NORTHWEST SIDE OF THE UPPER LOW WILL MAINTAIN MOSTLY CLOUDY
SKIES AND MAY KEEP TEMPS FROM RISING OUT OF THE LOWER 60S.
TUESDAY NIGHT AND WEDNESDAY...
THE UPPER LOW WILL MOVE OVERHEAD TUESDAY NIGHT AND OFF THE VA
TIDEWATER REGION DURING THE DAY WEDNESDAY. FORCING FOR ASCENT WILL
BECOME LESS FAVORABLE BEHIND THE UPPER LOW AS THE DEEP LAYER FLOW
EXHIBITS MORE BACKING AND SUBSIDENCE BEGINS TO SET IN. SOME SHOWERS
ARE POSSIBLE IN THE WRAP AROUND MOISTURE LIKELY TO ENCOMPASS VA
WEDNESDAY...SOME OF WHICH MAY LINGER OF DRIFT SOUTH INTO THE
NORTHERN PORTION OF THE CWA. THERMODYNAMIC PROFILES SUGGEST SOME
WEAK INSTABILITY AND A FEW STORMS WILL BE POSSIBLE...THOUGH AGAIN
THE THREAT OF SEVERE IS LOW. LOWS IN THE MID 50S WEDNESDAY MORNING
SHOULD REBOUND INTO THE LOW TO MID 70S AREAWIDE BY WEDNESDAY
AFTERNOON.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
AS OF 315 AM SUNDAY...
HEIGHTS WILL CONTINUE TO SLOWLY RISE THURSDAY THROUGH FRIDAY IN THE
WAKE OF THE DEPARTING UPPER LOW AND AHEAD OF SOUTHERN STREAM ENERGY
MOVING OUT OF THE SOUTHWESTERN US. WITH SHORTWAVE RIDGING ALOFT
OVERHEAD...DRY CONDITIONS AREA EXPECTED WITH TEMPS MODERATING INTO
THE UPPER 70S AND LOWER 80S. MEDIUM RANGE MODELS THEN SHOW THE
POTENTIAL FOR THE SPLIT FLOW PATTERN TO AMPLIFY NEXT WEEKEND...WITH
A CUT OFF LOW OVER THE SOUTHWESTERN US AND TROUGHING FROM THE NORTH
CENTRAL US TO THE EAST COAST. A COLD FRONT OVER THE MIDWEST STATES
FRIDAY SHOULD EVENTUALLY PUSH EAST ACROSS THE MOUNTAINS BY
SUNDAY...THOUGH THERE IS QUITE A BIT OF DISAGREEMENT BETWEEN THE
ECMWF AND GFS ON THE EVOLUTION OF ENERGY OVER THE CENTRAL US AND THE
PROGRESSION OF THE FRONT. PREFER TO MAINTAIN THE CHANCE POPS
CURRENTLY IN THE FORECAST FOR SATURDAY AND FAVOR A SOLUTION IN
BETWEEN THE FASTER ECMWF AND SLOWER GFS.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
AS OF 705 AM SUNDAY...
BRISK AND GUSTY SURFACE WINDS FROM THE ENE (FROM 060-080 DEGREES)
WILL PERSIST THROUGH TODAY/TONIGHT... AND THIS FLOW OF MOIST
ATLANTIC AIR INTO NC WILL MAKE SUB-VFR CONDITIONS DOMINANT OVER
CENTRAL NC TAF SITES FOR THE NEXT 24 HOURS. IFR TO MVFR CLOUDS
(BASED AT 700 TO 1500 FT AGL) HAVE BECOME MOSTLY BROKEN OVER THE
LAST SEVERAL HOURS (TOPPED BY BROKEN VFR CLOUDS BASED 4 THOUSAND TO
12 THOUSAND FT AGL). EXPECT MVFR-IFR CIGS TO PERSIST THROUGH THE
DAY... ALONG WITH A FEW LIGHT SPRINKLES OR DRIZZLE... BUT VSBYS
SHOULD REMAIN MOSTLY VFR TODAY... AND THE HEAVIEST RAINFALL WILL
HOLD WEST OF A LINE FROM MT AIRY TO SALISBURY TO CLT TODAY. A PERIOD
OF VFR CIGS IS POSSIBLE AFTER 16Z-18Z THIS AFTERNOON... BUT CIGS
SHOULD DROP BACK TO MVFR THEN IFR THIS EVENING. WIDESPREAD RAIN WITH
SUB-VFR VSBYS WILL MOVE IN SLOWLY FROM THE SW TOWARD THE NE
TONIGHT... REACHING INT/GSO/FAY AFTER 01Z AND RDU/RWI AFTER 04Z.
SUSTAINED WINDS OF 10-16 KTS GUSTING TO AROUND 20 KTS WILL CONTINUE
THROUGH THE FORECAST PERIOD.
LOOKING BEYOND 12Z MONDAY MORNING: GOOD CHANCE OF CONTINUED
DOMINATION OF SUB-VFR CONDITIONS WITH PERIODS OF RAIN THROUGH AT
LEAST TUESDAY AS AN UPPER LEVEL LOW SLOWLY CROSSES THE REGION. BRISK
ENE SURFACE WINDS WILL PERSIST THROUGH MONDAY BEFORE WEAKENING
MONDAY NIGHT. SHALLOW IFR FOG IS POSSIBLE TUESDAY NIGHT/WEDNESDAY
MORNING... AND AGAIN THURSDAY MORNING.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...SMITH
LONG TERM...SMITH
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1000 AM CDT SUN MAY 5 2013
.UPDATE...
ISSUED AT 1000 AM CDT SUN MAY 5 2013
MORNING RADAR TRENDS SHOW DECREASING PRECIPITATION ACROSS
SOUTHEASTERN NORTH DAKOTA. SHORT RANGE MODEL GUIDANCE CONTINUES
THIS DECREASING TREND THROUGH THE AFTERNOON. AS A RESULT...UPDATED
THE HOURLY POPS TO CHANCE IN THE MORNING DECREASING TO SLIGHT
CHANCE OVER LAMOURE AND DICKEY COUNTIES THIS AFTERNOON. THE
REMAINING WEATHER ELEMENTS WERE BLENDED TO CURRENT OBS/TRENDS. THE
UPDATED GRIDDED AND TEXT PRODUCTS HAVE BEEN SENT.
UPDATE ISSUED AT 644 AM CDT SUN MAY 5 2013
NO SIGNIFICANT CHANGES WERE REQUIRED WITH THIS FORECAST UPDATE
OTHER THAN TO BLEND TO THE LATEST OBSERVED TRENDS THROUGH 1130
UTC. PATCHY DENSE FOG IS BEGINNING TO FORM JUST OUTSIDE OF THE CWA
ACROSS TOWNER AND CAVALIER COUNTIES. LEFT IT OUT OF THE FORECAST
FOR ROLETTE AND TOWNER COUNTIES FOR NOW AS THE SUN IS ON THE RISE.
THAT SAID...WILL CONTINUE TO MONITOR FOR THE NEXT HOUR OR SO
SHOULD THE FOG DEVELOP FURTHER SOUTH AND WEST.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 313 AM CDT SUN MAY 5 2013
THE LATEST WATER VAPOR IMAGERY SHOWS AN H5-H3 CIRCULATION OVER
CENTRAL SOUTH DAKOTA. LATEST RADAR SHOWS A NARROW AND PERSISTENT
BAND OF LIGHT RAIN BING STEERED NORTHBOUND BY THE AFOREMENTIONED
UPPER LOW FROM EASTERN SOUTH DAKOTA...INTO LAMOURE AND DICKEY
COUNTIES OF NORTH DAKOTA. THE LATEST RAP AND GFS CONTINUE WITH THE
IDEA OF LIGHT RAIN THROUGH MID AFTERNOON...AND HAVE TRENDED POPS
APPROPRIATELY...BEGINNING WITH CATEGORICAL AND TRENDING LOWER
THIS AFTERNOON. WITH WESTERN AND CENTRAL NORTH DAKOTA ESSENTIALLY
IN A COL AREA...THE UPPER LOW REMAINS NEARLY STATIONARY AND
MEANDERS LITTLE THROUGH THE SHORT TERM PERIOD. H85 TEMPERATURES
RISE A FEW DEGREES IN THE NEXT TWO DAYS...CONSEQUENTLY WILL SEE
WARMING TEMPERATURES REFLECTED AT THE SURFACE. HIGHS TODAY WILL
REACH INTO 60S WITH LIGHT WINDS.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 313 AM CDT SUN MAY 5 2013
HIGHLIGHTS OF THE EXTENDED FORECAST IS A WARM UP TO SLIGHTLY ABOVE
NORMAL TEMPERATURES IN THE 70S ON MONDAY INTO TUESDAY..WITH
SCATTERED RAIN SHOWERS AND THUNDERSTORMS POSSIBLE WEDNESDAY INTO
FRIDAY...WITH TEMPERATURES COOLING LATE IN THE WEEK.
A SPLIT FLOW UPPER LEVEL PATTERN IS EXPECTED TO BE IN PLACE ACROSS
THE CONUS THROUGH AT LEAST TUESDAY WITH A CUTOFF LOW ACROSS THE
SOUTHEASTERN CONUS...AND A SECOND ACROSS THE DESERT SOUTHWEST.
THIS PATTERN SUPPORTS DRY CONDITIONS FOR THE NORTHERN PLAINS WITH
NEAR TO SLIGHTLY ABOVE NORMAL TEMPERATURES. THE NEXT CHANCE FOR
PRECIPITATION...POSSIBLY THUNDERSTORMS...IS WEDNESDAY INTO FRIDAY
AS POTENTIAL NORTHERN STREAM ENERGY SINKS SOUTH ACROSS THE
NORTHERN PLAINS. THIS SLIGHT SHIFT OF THE POLAR JET FURTHER SOUTH
WITH NORTHWEST FLOW ALOFT SUPPORTS A POSSIBLE COOL DOWN BACK INTO
THE 60S THURSDAY AND FRIDAY...AND THE 50S BY SATURDAY.
OVERALL...UTILIZED A BLEND OF THE 00 UTC GUIDANCE SUITE FOR MOST
FIELDS...FAVORING THE WARMER EDGE OF TEMPERATURE GUIDANCE WHICH
HAS SHOWN GREATER VERIFICATION SCORES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY)
ISSUED AT 644 AM CDT SUN MAY 5 2013
VFR/MOSTLY CLEAR SKIES WILL DOMINATE THE AERODROMES NEXT 24HR. THE
EXCEPTION WILL BE AT KJMS...WHERE BKN CIGS AT AROUND 10KFT CAN BE
EXPECTED. WINDS WILL BE LIGHT...LESS THAN 10KT THROUGH THE PERIOD.
&&
.HYDROLOGY...
ISSUED AT 313 AM CDT SUN MAY 5 2013
THE SOURIS RIVER CONTINUES TO BE A COMPLEX MIXTURE OF LOCATIONS
RISING WHILE OTHER FORECAST POINTS ARE IN RECESSION. LOWER RELEASES
FROM BOUNDARY DAM AND REDUCED SNOWMELT RUNOFF BELOW ALAMEDA AND
RAFFERTY DAMS HAS RESULTED IN THE ENTIRE UPPER SOURIS RIVER BASIN
FROM SHERWOOD TO MINOT TO VELVA FALLING AND REMAINING BELOW FLOOD
STAGE. FARTHER DOWNSTREAM AT TOWNER...BANTRY AND WESTHOPE...THE
SOURIS RIVER REMAINS STEADY TO RISING AS FLOOD WATERS SLOWLY MAKE
THEIR WAY THROUGH THE AREA.
WILLOW CREEK NEAR WILLOW CITY IS EXPECTED TO EXPERIENCE ANOTHER RISE
TO JUST ABOVE MINOR FLOOD STAGE THROUGH MONDAY. MUCH OF THE MELT WATER
GENERATED IN THIS AREA APPEARS TO BE GOING INTO THE SOIL AND TEMPERING
EARLIER EXPECTATIONS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TM
SHORT TERM...KS
LONG TERM...AYD
AVIATION...KS
HYDROLOGY...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
644 AM CDT SUN MAY 5 2013
.UPDATE...
ISSUED AT 644 AM CDT SUN MAY 5 2013
NO SIGNIFICANT CHANGES WERE REQUIRED WITH THIS FORECAST UPDATE
OTHER THAN TO BLEND TO THE LATEST OBSERVED TRENDS THROUGH 1130
UTC. PATCHY DENSE FOG IS BEGINNING TO FORM JUST OUTSIDE OF THE CWA
ACROSS TOWNER AND CAVALIER COUNTIES. LEFT IT OUT OF THE FORECAST
FOR ROLETTE AND TOWNER COUNTIES FOR NOW AS THE SUN IS ON THE RISE.
THAT SAID...WILL CONTINUE TO MONITOR FOR THE NEXT HOUR OR SO
SHOULD THE FOG DEVELOP FURTHER SOUTH AND WEST.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 313 AM CDT SUN MAY 5 2013
THE LATEST WATER VAPOR IMAGERY SHOWS AN H5-H3 CIRCULATION OVER
CENTRAL SOUTH DAKOTA. LATEST RADAR SHOWS A NARROW AND PERSISTENT
BAND OF LIGHT RAIN BING STEERED NORTHBOUND BY THE AFOREMENTIONED
UPPER LOW FROM EASTERN SOUTH DAKOTA...INTO LAMOURE AND DICKEY
COUNTIES OF NORTH DAKOTA. THE LATEST RAP AND GFS CONTINUE WITH THE
IDEA OF LIGHT RAIN THROUGH MID AFTERNOON...AND HAVE TRENDED POPS
APPROPRIATELY...BEGINNING WITH CATEGORICAL AND TRENDING LOWER
THIS AFTERNOON. WITH WESTERN AND CENTRAL NORTH DAKOTA ESSENTIALLY
IN A COL AREA...THE UPPER LOW REMAINS NEARLY STATIONARY AND
MEANDERS LITTLE THROUGH THE SHORT TERM PERIOD. H85 TEMPERATURES
RISE A FEW DEGREES IN THE NEXT TWO DAYS...CONSEQUENTLY WILL SEE
WARMING TEMPERATURES REFLECTED AT THE SURFACE. HIGHS TODAY WILL
REACH INTO 60S WITH LIGHT WINDS.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 313 AM CDT SUN MAY 5 2013
HIGHLIGHTS OF THE EXTENDED FORECAST IS A WARM UP TO SLIGHTLY ABOVE
NORMAL TEMPERATURES IN THE 70S ON MONDAY INTO TUESDAY..WITH
SCATTERED RAIN SHOWERS AND THUNDERSTORMS POSSIBLE WEDNESDAY INTO
FRIDAY...WITH TEMPERATURES COOLING LATE IN THE WEEK.
A SPLIT FLOW UPPER LEVEL PATTERN IS EXPECTED TO BE IN PLACE ACROSS
THE CONUS THROUGH AT LEAST TUESDAY WITH A CUTOFF LOW ACROSS THE
SOUTHEASTERN CONUS...AND A SECOND ACROSS THE DESERT SOUTHWEST.
THIS PATTERN SUPPORTS DRY CONDITIONS FOR THE NORTHERN PLAINS WITH
NEAR TO SLIGHTLY ABOVE NORMAL TEMPERATURES. THE NEXT CHANCE FOR
PRECIPITATION...POSSIBLY THUNDERSTORMS...IS WEDNESDAY INTO FRIDAY
AS POTENTIAL NORTHERN STREAM ENERGY SINKS SOUTH ACROSS THE
NORTHERN PLAINS. THIS SLIGHT SHIFT OF THE POLAR JET FURTHER SOUTH
WITH NORTHWEST FLOW ALOFT SUPPORTS A POSSIBLE COOL DOWN BACK INTO
THE 60S THURSDAY AND FRIDAY...AND THE 50S BY SATURDAY.
OVERALL...UTILIZED A BLEND OF THE 00 UTC GUIDANCE SUITE FOR MOST
FIELDS...FAVORING THE WARMER EDGE OF TEMPERATURE GUIDANCE WHICH
HAS SHOWN GREATER VERIFICATION SCORES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY)
ISSUED AT 644 AM CDT SUN MAY 5 2013
VFR/MOSTLY CLEAR SKIES WILL DOMINATE THE AERODROMES NEXT 24HR. THE
EXCEPTION WILL BE AT KJMS...WHERE BKN CIGS AT AROUND 10KFT CAN BE
EXPECTED. WINDS WILL BE LIGHT...LESS THAN 10KT THROUGH THE PERIOD.
&&
.HYDROLOGY...
ISSUED AT 313 AM CDT SUN MAY 5 2013
THE SOURIS RIVER CONTINUES TO BE A COMPLEX MIXTURE OF LOCATIONS
RISING WHILE OTHER FORECAST POINTS ARE IN RECESSION. LOWER RELEASES
FROM BOUNDARY DAM AND REDUCED SNOWMELT RUNOFF BELOW ALAMEDA AND
RAFFERTY DAMS HAS RESULTED IN THE ENTIRE UPPER SOURIS RIVER BASIN
FROM SHERWOOD TO MINOT TO VELVA FALLING AND REMAINING BELOW FLOOD
STAGE. FARTHER DOWNSTREAM AT TOWNER...BANTRY AND WESTHOPE...THE
SOURIS RIVER REMAINS STEADY TO RISING AS FLOOD WATERS SLOWLY MAKE
THEIR WAY THROUGH THE AREA.
WILLOW CREEK NEAR WILLOW CITY IS EXPECTED TO EXPERIENCE ANOTHER RISE
TO JUST ABOVE MINOR FLOOD STAGE THROUGH MONDAY. MUCH OF THE MELT WATER
GENERATED IN THIS AREA APPEARS TO BE GOING INTO THE SOIL AND TEMPERING
EARLIER EXPECTATIONS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...KS
LONG TERM...AYD
AVIATION...KS
HYDROLOGY...AYD
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
937 AM CDT SUN MAY 5 2013
.UPDATE...
UPPER LOW MOVING SLOWLY ACROSS NORTHERN MS THIS MORNING. SFC
TROUGH STILL EXPECTED TO RETROGRADE SLIGHTLY THROUGH 18Z AND THEN
START TO MOVE SLOWLY EASTWARD. THESE 2 DISTINCT FEATURES ARE
SHOWING UP NICELY ON RADAR THIS MORNING AS SHOWERS CONTINUE.
LATEST 24 HR RADAR ESTIMATES SHOW THE HIGHEST QPF TOTALS ACROSS
OUR SOUTHERN PLATEAU. NOW THOUGH THE RAIN AREA IN THE EAST HAS
SHIFTED A LITTLE FURTHER EAST...SOME BACK BUILDING AND OR
REDEVELOPMENT IS LIKELY FOR THE AFTERNOON. HRRR IS SHOWING THE
REDEVELOPMENT AND THIS MAY BE INDUCED BY SOME PARTIAL CLEARING
WHICH WILL LEAD TO WARMER SFC TEMPS AND SOME ADDED DESTABILIZATION.
FOR THE FORECAST...NO CHANGES AT THIS TIME. WILL ALLOW THE FLOOD
WATCH TO CONTINUE AS IS.
&&
.PREV DISCUSSION... /ISSUED 625 AM CDT SUN MAY 5 2013/
AVIATION UPDATE...FOR 12Z TAF PACKAGE...
CURRENT RADAR TRENDS INDICATE THE RAIN SHIELD HAS CLEARED KBNA AND
KCKV. KCSV CONTINUES TO BE IMPACTED BY RA AND WILL LIKELY CONTINUE
THIS TREND THROUGHOUT THE NEXT 6 TO 12 HOURS. SHOULD STAY MOSTLY
MVFR FOR KCSV BUT BRIEF LIFR CONDITIONS COULD DEVELOP DURING
HEAVIEST RAINS. KBNA INDICATED SOME LIGHT BR AT TAF ISSUANCE BUT
EXPECT THAT TO DISSIPATE QUICKLY AS TEMPERATURES WARM THIS
MORNING. MODELS INDICATE REDEVELOPMENT OF SHOWERS BY AROUND 18Z
DUE TO WARMING AND CENTRAL LOW PRESSURE BEING OVER TOP MIDDLE
TENNESSEE. MIGHT BE AN ISOLATED TSRA DURING THIS PERIOD BUT
CONFIDENCE NOT HIGH SO LEFT SHRA IN TAFS FOR NOW.
PREV DISCUSSION... /ISSUED 356 AM CDT SUN MAY 5 2013/
SHORT TERM...RAIN CONTINUES TO FALL OVER MOST OF THE NORTHEASTERN
HALF OF THE MID STATE THIS MORNING, WITH ANOTHER AREA SHOWERS,
WRAPPED AROUND UPPER LOW, APPROACHING OUR SOUTHWESTERN COUNTIES.
SEVERAL INCHES OF RAIN HAVE FALLEN OVER MUCH, IF NOT MOST, OF THE
FLOOD WATCH AREA AND GROUNDS ARE FULLY SATURATED. ANY HEAVY
DOWNPOURS THAT DEVELOP OVER THAT AREA TODAY WILL LEAD TO THE
LIKELIHOOD OF PONDING OF WATER AND THE POSSIBILITY OF FLASH
FLOODING. A FLOOD ADVISORY IS IN EFFECT FOR PARTS OF EASTERN
MIDDLE TENNESSEE, BETWEEN MONTEREY, CROSSVILLE AND ALTAMONT UNTIL
515 AM CDT.
NOT MUCH CHANGE IN THE EXPECTED WEATHER PATTERN OVER THE NEXT
SEVERAL DAYS, AS CLOSED UPPER LOW WANDERS ACROSS NORTHERN PARTS OF
MISSISSIPPI AND ALABAMA. WITH FREEZING LEVEL AND WET-BULB ZERO
VALUES SO LOW, WOULDN`T BE SURPRISED IF A FEW THUNDERSTORMS DEVELOP
OVER THE SOUTH TODAY AND ARE ACCOMPANIED BY SOME SMALL HAIL.
FURTHER NORTH, EXPECT A CONTINUATION OF JUST PLAIN RAIN.
LIKELIHOOD FOR SHOWERS AND THUNDERSTORMS CONTINUES ON MONDAY,
ESPECIALLY IN DEEPEST MOISTURE OVER THE NORTHEAST AND EXTREME
SOUTHERN COUNTIES.
EVEN THOUGH UPPER LOW PULLS TO THE ATLANTIC COAST BY TUESDAY,
ENOUGH ATMOSPHERIC MOISTURE REMAINS OVER THE MID STATE TO KEEP AT
LEAST A CHANCE FOR SHOWERS AND THUNDERSTORMS IN OUR NECK OF THE
WOODS.
CLEARING SKIES, WET GROUND, AND DEW POINTS IN THE 50S WILL CREATE
GOOD CONDITIONS FOR THE FORMATION OF AREAS OF FOG LATE TUESDAY
NIGHT AND WEDNESDAY NIGHT.
PRECIPITATION BY WEDNESDAY AND THURSDAY SHOULD BECOME RESTRICTED TO
THE AFTERNOON HOURS, AND IN THE FORM OF ISOLATED POP-UP SHOWERS
AND THUNDERSTORMS.
LONG TERM...BELIEVE IT OR NOT, THE EXTENDED FORECAST CONTINUES TO
PAINT AN INCREASED CHANCE OF RAIN BY NEXT SATURDAY, WHICH WOULD
MAKE IT THE THIRD STRAIGHT SATURDAY WITH RAIN (UGH!). EXTENDED
MODELS ARE ALSO YIELDING A RATHER CHILLY PATTERN FOR NEXT WEEKEND,
WITH UPPER RIDGE BUILDING OVER THE ROCKIES AND A TROUGH DEEPENING
OVER THE OHIO RIVER AND TENNESSEE VALLEYS.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH UNTIL 7 PM CDT THIS EVENING FOR TNZ009>011-029>034-
063>066-077>080.
&&
$$
21
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
149 PM EDT SUN MAY 5 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 402 AM EDT SUN MAY 5 2013
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR RDG STRETCHING
FM SE CANADA INTO THE UPR GRT LKS TO THE N OF CLOSED LO OVER THE SRN
MS RIVER VALLEY THAT WAS RESPONSIBLE FOR THE WINTER WX THE PAST
COUPLE OF DAYS. THE 00Z GRB RAOB AND ESPECIALLY THE APX RAOB SHOW A
VERY DRY AIRMASS UNDER THIS RDG...WITH THE 00Z H85 DEWPT DEPRESSION
AS HI AS 24C/PWAT JUST 0.24 INCH OR 49 PCT OF NORMAL AT APX. BUT
THERE IS STILL A RIBBON OF DEEPER MSTR SOME -SHRA EXTENDING NNWWD
FM THE CLOSED LO TO THE S INTO MN/ADJOINING ONTARIO. THE 00Z INL
RAOB SHOWS A NEARLY SATURATED PROFILE AND 00Z PWAT OF 0.83
INCH...188 PCT OF NORMAL. ALTHOUGH THERE ARE SOME HI CLDS OVER THE
E...THAT AREA IS DOMINATED BY THE DRY AIRMASS SHOWN ON THE APX RAOB.
WITH H85 TEMPS UP TO 10C...MAX TEMPS YDAY REACHED THE 70S OVER THE
SCENTRAL AND ERN CWA WHERE THE DRY AIR ALLOWED FOR QUITE A BIT OF
SUNSHINE AND LAKE COOLING WAS ABSENT IN THE NLY FLOW S OF HI PRES
CENTERED OVER NW ONTARIO. ALTHOUGH THE DRY AIR ALF HAS PUSHED INTO
THE WRN CWA PER THE LATEST RUC ANALYSIS SDNGS...ENUF LLVL MSTR
LINGERS THERE UNDER SHARP INVRN AT H9 TO SUPPORT LO CLDS/FOG OVER
THE WRN CWA FM THE KEWEENAW THRU GOGEBIC COUNTY. SINCE THE 00Z YPL
RAOB SHOWS SOME MSTR BTWN H9-825 EVEN CLOSE TO THE ONTARIO HI
CENTER...THERE IS QUITE A BIT OF LO CLD EXTENDING WELL N OF LK SUP
TO THE HI PRES RDG AXIS.
MAIN FCST CONCERNS IN THE SHORT TERM INVOLVE LO CLD TRENDS/IMPACT ON
TEMPS. POTENTIAL FOR LOW RH OVER THE E/IMPACT ON FIRE WX CONCERNS
THIS AFTN IS THE FOCUS THERE.
TODAY...UPR RDG AXIS/MID LVL DRY AIR WL REMAIN DOMINANT. ALTHOUGH
SFC HI PRES OVER NW ONTARIO IS PROGGED TO DRIFT SLOWLY S TOWARD LK
SUP...THE NNW FLOW IN ADVANCE OF THIS HI...ALBEIT LGT...WL LIKELY
ACT TO HOLD LO CLDS IN PLACE OVER MUCH OF THE NW HALF OF THE CWA
DESPITE THE ONSET OF DIURNAL HEATING THAT WOULD NORMALLY MIX OUT
THIS LLVL MSTR. IN FACT...COOL ADVECTION OFF THE CHILLY WATERS OF LK
SUP WL TEND TO OFFSET THE DIURNAL HEATING AND MAINTAIN A LLVL
INVRN/POTENTIAL FOR MORE PERSISTENT LO CLDS IN THIS AREA AS HI TEMPS
HOLD IN THE 40S NEAR THE SHORE. OVER THE E HALF OF THE CWA...A LGT S
FLOW WL PREVAIL ARND SFC HI PRES OVER SE ONTARIO. ALTHOUGH THERE MAY
BE MODERATION NEAR THE BAY OF GREEN BAY/ LK MI WITH A LK
BREEZE...H85 TEMPS NEAR 10C/MIXING TO H8-85 ON NAM/ GFS FCST SDNGS
WITH A GOOD DEAL OF SUNSHINE SUPPORT HI TEMPS TOPPING OUT IN THE 70S
AWAY FM THE LK COOLING. WITH SFC DEWPTS MIXING OUT TOWARD 35 OVER
THE INTERIOR...MIN RH WL LIKELY FALL AS LO AS ABOUT 25 PCT.
FORTUNATELY...THE WINDS WL BE LGT...SO NO FIRE WX HEADLINES ARE
NECESSARY.
TONIGHT...WITH HI PRES FCST TO SHIFT OVHD AND LGT WINDS...EXPECT
TEMPS TO DIP INTO THE 30S...FALLING MOST SHARPLY OVER THE E AND
SCENTRAL...WHERE MUCH DRIER AIR /PWAT NEAR 0.5 INCH/ WL LINGER.
SINCE MORE LLVL MSTR WL BE LINGERNING OVER THE W/NCENTRAL...
RETAINED A MENTION OF FOG IN THIS AREA OVERNGT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 402 AM EDT SUN MAY 5 2013
WITH THE CUTOFF LOW SITUATED OVER THE SOUTHEAST CONUS AND THE
NORTHERN JET STREAM WELL TO THE NORTH OF THE AREA IN CANADA...A
QUIET START TO THE WORK WEEK IS EXPECTED WITH ABOVE NORMAL
TEMPERATURES OVER MUCH OF THE AREA.
MONDAY AND TUESDAY WILL BE DOMINATED BY HIGH PRESSURE AT THE
SURFACE. EXPECT MOSTLY CLEAR SKIES FOR MUCH OF THIS PERIOD...BUT
THERE COULD BE SOME HIGH BASED DIURNAL CU DEVELOPING OVER THE
INTERIOR WEST DUE TO A POCKET OF 800-750MB MOISTURE. A FEW MODELS
HINT AT SOME SHOWER DEVELOPMENT...BUT WITH THE HIGH BASES AND
LIMITED MOISTURE KEEPING MLCAPE VALUES BELOW 150 J/KG...THINK IT
WILL JUST BE CU. THE SUNSHINE WILL ALLOW FOR AMPLE MIXING...TO
800-775MB...AND LEAD TO HIGHS IN THE LOWER 70S AWAY FROM THE GREAT
LAKES. LAKE BREEZES ON BOTH DAYS WILL KEEP TEMPERATURES COOLER NEAR
THE GREAT LAKES. DID TRY TO MIX OUT DEWPOINTS A LITTLE MORE THAN
THE MODELS HAVE INDICATED BASED OFF WHAT OCCURRED YESTERDAY.
FORTUNATELY...WITH LIGHT WINDS UNDER THE HIGH...IT WILL LIMIT FIRE
WX CONCERNS OVER THE SOUTH CENTRAL AND EAST EVEN THOUGH FFMC VALUES
ARE ON THE INCREASE AND ARE OR BECOMING HIGH.
PATCHY GROUND FOG IS POSSIBLE OVER THE KEWEENAW AND INTERIOR WEST
MONDAY NIGHT WITH THE CLEAR SKIES AND LOW LEVEL COOLING BY LINGERING
SNOW COVER. FARTHER EAST...DRIER AIR IN PLACE WILL LIMIT THE FOG
POTENTIAL. OVER THE GREAT LAKES...MODELS ARE HINTING AT FOG
DEVELOPMENT WITH THE LIGHT WINDS ON MONDAY. BUT DEWPOINTS AREN/T
EXTREMELY HIGH AND WITH DRY AIR ALOFT IT WON/T GET MUCH HELP FROM
THE LAND. WITH THAT BEING SAID...IF IT DOES DEVELOP...THE LIGHT
WINDS WOULD LEAD TO SLOW MOVEMENT AND IT LINGERING INTO WEDNESDAY.
COULD SEE SOME PATCHY GROUND FOG OVER THE FAR WEST LATE TUESDAY
NIGHT...BUT CONFIDENCE IS TOO LOW TO ADD AT THIS POINT.
THE HIGH PRESSURE WILL BEGIN TO GIVE WAY ON WEDNESDAY...AS AN UPPER
TROUGH OVER THE WEST COAST SLIDES INTO THE PLAINS AND A SHORTWAVE
SLIDES THROUGH THE NORTHERN STREAM AND PRODUCES A SURFACE LOW THAT
MOVES INTO NORTHWEST QUEBEC ON WEDNESDAY. A COLD FRONT ASSOCIATED
WITH THIS LOW WILL TRY TO DROP THROUGH THE AREA ON WEDNESDAY
AFTERNOON AND NIGHT. WITH THE UPPER TROUGH MOVING INTO THE
PLAINS...IT MAY PROVIDE ENOUGH MOISTURE TO PRODUCE SOME SHOWERS.
BUT THE MODELS DIFFER ON THE NORTHEASTWARD EXTENT OF THE MOISTURE
FROM THE UPPER TROUGH. THE 12Z ECMWF/GEM KEEP THE MOISTURE FARTHER
TO THE WEST...WHILE THE 18Z GFS PULLS IT INTO THE UPPER GREAT LAKES.
LATEST 00Z GFS/GEM RUNS HAVE TRENDED TOWARDS THE ECMWF IDEA. BASED
ON THE EXISTING DRY AIR MASS AND LIMITED MOISTURE RETURN...WOULD
TEND TO SIDE WITH THE DRIER IDEA AND WILL ONLY HAVE SLIGHTS OR LOW
CHANCE POPS FOR THE PASSAGE OF THE FRONT. BEHIND THE FRONT...ANOTHER
NORTHERN STREAM SHORTWAVE MAY AFFECT THE AREA ON FRIDAY NIGHT INTO
SATURDAY AND BRING ANOTHER POTENTIAL FOR RAIN. BUT AGAIN...MOISTURE
LOOKS TO BE THE CONCERN FOR THAT PERIOD UNLESS THE LOW MOVING
THROUGH THE LOWER GREAT LAKES MOVES FARTHER TO THE NORTH.
TEMPERATURES WED INTO SATURDAY LOOK TO BE COOLER THAN THE FIRST
PART OF THE WORK WEEK...BUT STILL NORMAL OR VERY SLIGHTLY BELOW
NORMAL FOR THIS TIME OF YEAR.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 149 PM EDT SUN MAY 5 2013
VFR CEILINGS AND VIS ARE QUICKLY TAKING HOLD THIS AFTERNOON AS DRY
AIR PUSHES IN FROM THE EAST...ERODING THE LOW CLOUDS THAT HAVE BEEN
STUCK OVER THE WEST END OF UPPER MICHIGAN THROUGH MUCH OF THE DAY
/IWD AND CMX/. YET ANOTHER ROUND OF FOG IS ANTICIPATED TONIGHT...BUT
GIVEN SUCH DRY AIR...THE FOG IS NOT EXPECTED TO BE QUITE AS DENSE OR
LAST NEARLY AS LONG INTO THE DAY MONDAY. VFR CEILINGS AND VIS SHOULD
BE THE RULE AGAIN AT ALL SITES BY APPROX 15Z MONDAY.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 402 AM EDT SUN MAY 5 2013
A QUIET PERIOD OF WEATHER IS EXPECTED THROUGH THE PERIOD...WITH THE
WINDS LIKELY STAYING BELOW 25KTS. HIGH PRESSURE THAT HAS SETUP OVER
THE AREA WILL REMAIN THROUGH THE FIRST PART OF THE WORK WEEK AND
LEAD TO LIGHT WINDS. THEN...A COLD FRONT DROPPING SOUTHEAST ACROSS
THE UPPER GREAT LAKES ON WEDNESDAY INTO WEDNESDAY NIGHT WILL BRING
A WIND SHIFT BUT ONLY 10-20KT WINDS. WEAK HIGH PRESSURE WILL MOVE
OVER NORTHERN LAKE SUPERIOR FOR THURSDAY INTO THURSDAY NIGHT AND
DIMINISH THE WINDS.
&&
.HYDROLOGY...
ISSUED AT 402 AM EDT SUN MAY 5 2013
HYDROLOGY CONCERNS WILL REMAIN OVER THE COMING DAYS...UNTIL THE
REMAINING SNOW PACK MELTS OVER THE NORTHWESTERN THIRD OF UPPER
MICHIGAN. VISIBLE SATELLITE AND MODIS IMAGERY TODAY STILL SHOWS SNOW
REMAINING IN THE HIGHER TERRAIN LOCATIONS OF THE HURON MOUNTAINS AND
THE KEWEENAW PENINSULA. FARTHER WEST...THE 10 PLUS INCHES OF WET
SNOW WILL ALSO HELP KEEP THE POTENTIAL OF RISING RIVER LEVELS IN
PLACE. DID SEE RISES AT SOME OF THE SITES OVER THE WEST /RKLM4 AND
ESPECIALLY TRRM4/ WITH THE WARMER TEMPERATURES YESTERDAY AND WOULD
EXPECT THAT TO CONTINUE TODAY INTO THE FIRST PART OF THE WORK WEEK.
THE STURGEON RIVER AT ALSTON AND CHASSELL...THE MICHIGAMME RIVER
AROUND WITCH LAKE...AND THE PAINT RIVER NEAR CRYSTAL FALLS WILL
REMAIN CONCERNS INTO AT LEAST EARLY NEXT WEEK...AND IN THE CASE OF
THE MICHIGAMME RIVER PERHAPS WELL INTO THE COMING WEEK. BUT
OTHERWISE RIVER LEVELS CONTINUE TO COME DOWN DESPITE SOME RECENT
HEAVY PRECIP THAT IMPACTED MAINLY THE W HALF OF UPR MI.
FOR COMPLETE DETAILS...SEE THE LATEST RIVER FLOOD WARNINGS AND
ADVISORIES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...SRF
AVIATION...KF
MARINE...SRF
HYDROLOGY...SRF
AREA FORECAST DISCUSSION
NWS HASTINGS NE
346 PM CDT SUN MAY 5 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 345 PM CDT SUN MAY 5 2013
OTHER THAN THE FAIRLY LOW PROBABILITY OF SOME PATCHY FOG
OVERNIGHT...THE NEXT 24 HOURS ARE LOOKING DRY AND RATHER
UNEVENTFUL...AS TEMPERATURES FINALLY MAKE A LEGITIMATE RUN BACK
TOWARD 70 DEGREES ON MONDAY.
19Z OBJECTIVE SURFACE ANALYSIS HIGHLIGHTS A BROAD...ROUGHLY 1022
MILLIBAR NORTH-SOUTH ORIENTED RIDGE AXIS EXTENDING SOUTHWARD
ACROSS THE CENTRAL CONUS...IN THE WAKE OF THE DEPARTED SURFACE LOW
REFLECTION OF THE SLOW-MOVING CUT OFF UPPER LOW. BREEZES THIS
AFTERNOON ACROSS THE CWA ARE GENERALLY OUT OF THE NORTH AT
SUSTAINED SPEEDS 10-15 MPH WITH SOME HIGHER GUSTS. ALOFT...WATER
VAPOR IMAGERY AND SHORT TERM MODEL DATA HIGHLIGHT A SPLIT-FLOW
UPPER AIR PATTERN THAT WILL DEFINE MUCH OF THE WEEK...WITH THE
CENTRAL PLAINS LOCATED NORTH OF THE SOUTHERN STREAM AND SOUTH OF
THE NORTHERN STREAM. DIRECTLY OVERHEAD IN THE MID LEVELS...FAIRLY
WEAK WEST-NORTHWEST FLOW PREVAILS...AS THE CENTRAL PLAINS LIES IN
BETWEEN TWO DOMINANT CLOSED 500 MILLIBAR LOWS..ONE DEPARTING
ACROSS THE SOUTHEAST STATES...AND ANOTHER CENTERED JUST OFF THE
CA COAST. IN BETWEEN...A MID/UPPER RIDGE EXTENDS NORTH TOWARD THE
CENTRAL PLAINS FROM MEXICO...BUT WITH ANOTHER SMALL-SCALE CUT
CLOSED MID LEVEL LOW SPINNING JUST TO THE NORTH OVER SD. AS
OUTLINED IN THE EARLIER DISCUSSION...SKY COVER AND RESULTANT TEMPS
WERE AT THE MERCY OF LOW STRATUS SCATTERING OUT AND/OR CLEARING
FROM WEST-EAST...AND ALL THINGS CONSIDERED...THINGS HAVE ACTUALLY
WORKED OUT FAIRLY WELL WITH ROUGHLY THE WESTERN 2/3 OF THE CWA NOW
PREDOMINANTLY SUNNY-PARTLY CLOUDY AT THIS HOUR...WHILE MOSTLY
CLOUDY SKIES ARE HANGING ON LONGER MAINLY EAST OF HIGHWAY 14.
HIGH TEMPS APPEAR ON TRACK TO RANGE FROM THE UPPER 50S NORTHEAST
TO MID 60S SOUTHWEST. FORTUNATELY FOR FIRE WEATHER CONCERNS...WINDS
ARE GUSTING WELL UNDER 25 MPH...AS DEWPOINTS HAVE CRASHED ENOUGH
TO DROP RELATIVE HUMIDITY VALUES TO NEAR/SLIGHTLY BELOW 20 PERCENT
IN THE EXTREME WESTERN CWA...MAINLY WESTERN DAWSON/GOSPER/FURNAS
COUNTIES.
HEADING INTO THIS EVENING/TONIGHT...WILL RUN WITH THE ASSUMPTION
THAT THE CURRENTLY ERODING STRATUS DECK WILL CONTINUE TO FADE AWAY
EASTWARD WITH TIME INTO THE OAX/TOP AREAS...AND NOT COMPLETELY
STALL OUT IN OUR EASTERN COUNTIES OR EVEN PUSH BACK WEST.
HOWEVER...AM NOT 100 PERCENT CONFIDENT IN THIS...GIVEN THAT
STEERING FLOW AT 900MB DOES TURN MORE EASTERLY TONIGHT...SO WILL
HAVE TO KEEP AN EYE ON THESE LOW LEVEL CLOUD TRENDS. OTHERWISE...A
GRADUAL INCREASE IN MAINLY THIN MID/HIGH CLOUDS WILL OCCUR
TONIGHT...IN RESPONSE TO SUBTLE...LOW AMPLITUDE ENERGY LIFTING
NORTHEAST TOWARD THE CENTRAL PLAINS OUT AHEAD OF THE AFOREMENTIONED
WESTERN CONUS PARENT TROUGH/CLOSED LOW. GIVEN THAT SKIES SHOULD
GENERALLY AVERAGE PARTLY CLOUDY OVERNIGHT...ESPECIALLY WEST...AM
NOT ANTICIPATING IDEAL RADIATIONAL COOLING CONDITIONS DESPITE THE
CONTINUED PRESENCE OF THE LOW LEVEL RIDGE AXIS SITTING DIRECTLY
OVER THE AREA...WHICH WILL RESULT IN SEVERAL HOURS OF GENERALLY
LIGHT/VARIABLE TO EASTERLY BREEZES. FOR LOW TEMPS...SLIGHTLY
UNDERCUT A BLEND OF 12Z MET/MAV GUIDANCE...WHICH RESULTS IN THE
MAJORITY OF THE AREA BOTTOMING OUT BETWEEN 38-43...AND MAYBE DOWN
AROUND 36 IN THE COLDER-PRONE WESTERN DAWSON COUNTY AREA. THAT
BEING SAID...IF SKIES AVERAGE CLEARER THAN ANTICIPATED...COULD SEE
MORE OF THE CWA MAKE A RUN TOWARD THE MID 30S...AND THIS WILL NEED
WATCHED IN CASE A FEW SPOTS FLIRT WITH FROST-WORTHY READINGS. FOR
NOW...HAVE LEFT OUT FROST MENTION ALL AREAS. HOWEVER...HAVE LEFT
IN A MENTION OF PATCHY FOG CWA-WIDE FROM 09Z-13Z AS THE LIGHT WIND
REGIME COULD PROMOTE SOME DEVELOPMENT. THIS WOULD GENERALLY SEEM
MOST FAVORED WITHIN THE EASTERN 1/2 OF THE CWA IN CLOSEST
PROXIMITY TO THE WEST EDGE OF LOWER STRATUS...AND ALSO OVER WHERE
A BIT MORE LIGHT PRECIP FELL DURING THE PAST FEW DAYS. FOR
NOW...AM NOT EXPECTING SIGNIFICANT VISIBILITY ISSUES...BUT ITS
WORTH NOTING THAT THE LATEST HRRR ACTUALLY DOES SUGGEST SOME
DENSER FOG DEVELOPMENT MAINLY EAST OF HIGHWAY 281...SO THIS ALSO
BEARS WATCHING.
TURNING TO THE DAYTIME HOURS MONDAY...THE OVERALL MID/UPPER AIR
PATTERN CHANGES LITTLE...AS THE CENTRAL PLAINS REMAIN UNDER FAIRLY
UNEVENTFUL QUASI-ZONAL FLOW ALOFT...AND STILL DOWNSTREAM FROM A
LEAD SHORTWAVE EJECTING NORTHEAST TOWARD THE REGION FROM THE
DESERT SOUTHWEST...WHICH COULD PROMOTE SOME RAIN CHANCES MONDAY
NIGHT AS DESCRIBED BELOW. IN ADDITION...JUST TO THE NORTH THE
COMPACT LITTLE CLOSED LOW OVER SD SHOULD PRETTY MUCH REMAIN IN
PLACE...WITH LITTLE CONSEQUENCE INTO NEB/KS. AT THE SURFACE...THE
RIDGE AXIS WILL ONLY SLOWLY EDGE EAST DURING THE DAY...PROVIDING A
DAY OF FAIRLY LIGHT BREEZES. EVEN DURING THE AFTERNOON...THE
EASTERN 1/2 OF THE CWA WILL ONLY AVERAGE AROUND 5 MPH...WHILE
WESTERN COUNTIES PICK UP A SLIGHTLY STRONGER EAST-SOUTHEAST BREEZE
OF 10 TO POSSIBLY 15 MPH. ASSUMING THAT SKIES AVERAGE MOSTLY
CLEAR/PARTLY CLOUDY UNDER ONLY PASSING MID-HIGH CLOUDS...SHOULD
SEE A NICE JUMP IN HIGH TEMPS VERSUS TODAY...AND MADE LITTLE
CHANGE TO PREVIOUS FORECAST WITH ALL AREAS RISING TO WITHIN A FEW
DEGREES EITHER SIDE OF 70. THE ONLY CAVEAT FOR THESE WARM TEMPS
WOULD BE IF ANY MORNING FOG TURNS INTO A SLOW-ERODING STRATUS
DECK THAT LINGERS WELL INTO THE DAY WITHIN THE RIDGE AXIS MAINLY
IN THE EASTERN CWA...BUT IT SEEMS UNLIKELY THAT THE SITUATION GETS
THIS PESSIMISTIC.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 345 PM CDT SUN MAY 5 2013
A PROLONGED PERIOD OF UNSETTLED WEATHER IS SHAPING UP
ACROSS THE REGION AS THE UPPER LEVEL LOW OFF THE CALIFORNIA COAST
SLOWLY PROGRESSES EASTWARD WHILE SPINNING OFF SEVERAL WEAK
DISTURBANCES AHEAD OF IT. WHILE A GENERALLY BLOCKY PATTERN WITH
RIDGING WILL EXIST ACROSS THE CENTRAL PLAINS THROUGH MUCH OF THE
PERIOD...THE LOW LEVEL FLOW WILL BEGIN TO SHIFT AND BECOME SOUTHERLY
LATE MONDAY...HELPING MOISTURE ADVECT NORTHWARD. THIS FLOW SHOULD
HELP DEWPOINTS CLIMB BACK INTO THE 50S BY TUESDAY AFTERNOON...WITH
BUILDING INSTABILITY ACROSS THE PLAINS.
WHILE INITIALLY...THERE WILL BE A SMALL CHANCE FOR SOME RAIN SHOWERS
AHEAD OF THE FIRST UPPER LEVEL WAVE SPINNING OFF THE WESTERN
LOW...INSTABILITY WILL BE VERY WEAK...AND LOW LEVEL MOISTURE WILL
STILL BE LACKING...IN ORDER TO SUPPORT MUCH IN THE WAY OF SHOWER OR
THUNDERSTORM ACTIVITY. AS A RESULT...SLOWED DOWN THE INITIAL TIMING
OF THE ONSET OF ANY PRECIPITATION TO THE PRE-DAWN HOURS TUESDAY. AS
MOISTURE CONTINUES TO SURGE NORTH DURING THE DAY TUESDAY
AFTERNOON...INSTABILITY WILL BUILD...AND SEE THE POTENTIAL FOR SOME
THUNDERSTORMS TO DEVELOP DURING THE LATE MORNING/EARLY AFTERNOON
HOURS AS STEEP LOW LEVEL LAPSE RATES WILL REQUIRE LITTLE IN THE WAY
OF FORCING FOR SHOWER AND THUNDERSTORM DEVELOPMENT. AS WE THEN
TRANSITION INTO TUESDAY NIGHT...THE NOSE OF THE LOW LEVEL JET IS
EXPECTED TO BE POINTED TOWARDS THE LOCAL AREA...WHICH SHOULD ALLOW
FOR THE DEVELOPMENT OF ELEVATED CONVECTION ACROSS THE LOCAL AREA
DURING THE LATE EVENING AND OVERNIGHT HOURS...SOME OF WHICH COULD
BECOME STRONG TO MARGINALLY SEVERE. AS A RESULT...PLAN ON
HIGHLIGHTING THE POTENTIAL FOR SOME MARGINALLY SEVERE HAIL FOR THE
TUESDAY NIGHT PERIOD IN THE AFTERNOON HWO.
BEYOND TUESDAY NIGHT...THINGS GET A LITTLE MORE MUDDLED AS MULTIPLE
WEAK DISTURBANCES AHEAD OF THE MAIN UPPER LEVEL LOW TRANSITION
ACROSS THE PLAINS. EVEN SO...THERE IS SOME AGREEMENT AMONGST THE
MODELS FOR ANOTHER DECENT SHOT OF PRECIPITATION ACROSS NORTH
CENTRAL KANSAS AND PORTIONS OF SOUTH CENTRAL NEBRASKA WEDNESDAY
NIGHT AND THURSDAY...AND SAW NO REASON TO REDUCE THE LIKELY POPS
GIVEN BY THE ALLBLEND SOLUTION FOR THIS PERIOD. THEN...DEPENDING ON
WHICH MODEL SOLUTION YOU BELIEVE...THE MAIN UPPER LEVEL LOW SHOULD
BEGIN TO TRACK EASTWARD ON FRIDAY...WITH A COLD FRONT DROPPING DOWN
ACROSS THE NORTHERN PLAINS FRIDAY NIGHT OR SATURDAY. DUE TO THE
DISCREPANCIES IN TIMING...HUNG ONTO CHANCES FOR PRECIPITATION
THROUGH SATURDAY AFTERNOON...WITH PRECIPITATION COMING TO AN END
BEHIND THIS COLD FRONT BY THE LATTER HALF OF NEXT WEEKEND. WHILE
THERE WILL BE A NOTICEABLE DROP IN TEMPERATURES BEHIND THIS
FRONT...ON THE ORDER OF 10-15F BASED ON 850MB TEMPS...DO NOT EXPECT
A RETURN TO THE CHILLY TEMPERATURES OF LATE...AS ABOVE NORMAL
TEMPERATURES ARE EXPECTED ALL WEEK...GENERALLY IN THE LOWER TO
MIDDLE 70S...WITH THIS NEXT FRONT SIMPLY DROPPING TEMPERATURES A FEW
DEGREES BELOW CLIMATOLOGY FOR EARLY/MID MAY.
&&
.AVIATION...(FOR THE 18Z KGRI TAF THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 100 PM CDT SUN MAY 5 2013
ALTHOUGH VFR CEILING/VISIBILITY AND PRECIP-FREE CONDITIONS ARE
FORECAST THROUGH THE MAJORITY OF THE PERIOD...WILL HAVE TO CONTEND
WITH AT LEAST A FEW HOURS OF LINGERING MVFR CEILING THIS
AFTERNOON...AS A LOW STRATUS DECK ONLY VERY VERY SLOWLY ERODES
AND/OR LIFTS ACROSS CENTRAL NEBRASKA. TOOK A BEST STAB USING LATEST
TRENDS/GUIDANCE BY RAISING CEILING ABOVE 2000 FT BY 19Z...AND
ABOVE 3000 FT BY 22Z...STAYING IN LINE WITH PREVIOUS MORNING TAF
ISSUANCE. WILL DEPICT A SCATTERED LOW CLOUD SITUATION BY 00Z EARLY
THIS EVENING...AND ASSUME THAT A BKN/OVC LOW DECK WILL NOT AGAIN
RETURN. HOWEVER...GIVEN THAT THE LOW LEVEL STEERING FLOW TAKES ON
MORE OF AN EASTERLY COMPONENT OVERNIGHT...ITS NOT COMPLETELY OUT
OF THE QUESTION THAT MVFR CEILING COULD MAKE A RETURN...AND THIS
WILL NEED CLOSELY WATCHED DESPITE LACK OF SUPPORT IN COMPUTER
MODELS/GUIDANCE. AS FOR VISIBILITY...CONFIDENCE IS FAIRLY HIGH IN
VFR THROUGH THE PERIOD...ALTHOUGH ITS ALSO NOT OUT OF THE QUESTION
THAT SOME HAZE/LIGHT FOG COULD DEVELOP WITHIN A SURFACE RIDGE AXIS
LATE TONIGHT. THIS STILL SEEMS UNLIKELY ENOUGH TO OMIT FOR NOW.
SURFACE WIND-WISE...FAIRLY LIGHT SPEEDS SUSTAINED AT NO MORE THAN
5-10KT ARE ANTICIPATED THROUGH THE MAJORITY OF THE PERIOD...AS
NORTHERLY FLOW THIS AFTERNOON BECOMES LIGHT/VARIABLE OVERNIGHT AND
EVENTUALLY EASTERLY MONDAY MORNING.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...PFANNKUCH
LONG TERM...SAR
AVIATION...PFANNKUCH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1258 PM CDT SUN MAY 5 2013
.UPDATE...
ISSUED AT 1258 PM CDT SUN MAY 5 2013
NO MAJOR MODIFICATIONS WERE MADE TO THE ONGOING FORECAST. ONLY
UPDATED THE AFTERNOON MAX TEMP FORECAST ACROSS NORTH CENTRAL NORTH
DAKOTA BASED ON CURRENT OBS/TRENDS. OTHERWISE...THE REMAINING
WEATHER ELEMENTS ARE IN GOOD SHAPE. THE UPDATED GRIDDED/TEXT
PRODUCTS HAVE BEEN SENT.
UPDATE ISSUED AT 1000 AM CDT SUN MAY 5 2013
MORNING RADAR TRENDS SHOW DECREASING PRECIPITATION ACROSS
SOUTHEASTERN NORTH DAKOTA. SHORT RANGE MODEL GUIDANCE CONTINUES
THIS DECREASING TREND THROUGH THE AFTERNOON. AS A RESULT...UPDATED
THE HOURLY POPS TO CHANCE IN THE MORNING DECREASING TO SLIGHT
CHANCE OVER LAMOURE AND DICKEY COUNTIES THIS AFTERNOON. THE
REMAINING WEATHER ELEMENTS WERE BLENDED TO CURRENT OBS/TRENDS. THE
UPDATED GRIDDED AND TEXT PRODUCTS HAVE BEEN SENT.
UPDATE ISSUED AT 644 AM CDT SUN MAY 5 2013
NO SIGNIFICANT CHANGES WERE REQUIRED WITH THIS FORECAST UPDATE
OTHER THAN TO BLEND TO THE LATEST OBSERVED TRENDS THROUGH 1130
UTC. PATCHY DENSE FOG IS BEGINNING TO FORM JUST OUTSIDE OF THE CWA
ACROSS TOWNER AND CAVALIER COUNTIES. LEFT IT OUT OF THE FORECAST
FOR ROLETTE AND TOWNER COUNTIES FOR NOW AS THE SUN IS ON THE RISE.
THAT SAID...WILL CONTINUE TO MONITOR FOR THE NEXT HOUR OR SO
SHOULD THE FOG DEVELOP FURTHER SOUTH AND WEST.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 313 AM CDT SUN MAY 5 2013
THE LATEST WATER VAPOR IMAGERY SHOWS AN H5-H3 CIRCULATION OVER
CENTRAL SOUTH DAKOTA. LATEST RADAR SHOWS A NARROW AND PERSISTENT
BAND OF LIGHT RAIN BING STEERED NORTHBOUND BY THE AFOREMENTIONED
UPPER LOW FROM EASTERN SOUTH DAKOTA...INTO LAMOURE AND DICKEY
COUNTIES OF NORTH DAKOTA. THE LATEST RAP AND GFS CONTINUE WITH THE
IDEA OF LIGHT RAIN THROUGH MID AFTERNOON...AND HAVE TRENDED POPS
APPROPRIATELY...BEGINNING WITH CATEGORICAL AND TRENDING LOWER
THIS AFTERNOON. WITH WESTERN AND CENTRAL NORTH DAKOTA ESSENTIALLY
IN A COL AREA...THE UPPER LOW REMAINS NEARLY STATIONARY AND
MEANDERS LITTLE THROUGH THE SHORT TERM PERIOD. H85 TEMPERATURES
RISE A FEW DEGREES IN THE NEXT TWO DAYS...CONSEQUENTLY WILL SEE
WARMING TEMPERATURES REFLECTED AT THE SURFACE. HIGHS TODAY WILL
REACH INTO 60S WITH LIGHT WINDS.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 313 AM CDT SUN MAY 5 2013
HIGHLIGHTS OF THE EXTENDED FORECAST IS A WARM UP TO SLIGHTLY ABOVE
NORMAL TEMPERATURES IN THE 70S ON MONDAY INTO TUESDAY..WITH
SCATTERED RAIN SHOWERS AND THUNDERSTORMS POSSIBLE WEDNESDAY INTO
FRIDAY...WITH TEMPERATURES COOLING LATE IN THE WEEK.
A SPLIT FLOW UPPER LEVEL PATTERN IS EXPECTED TO BE IN PLACE ACROSS
THE CONUS THROUGH AT LEAST TUESDAY WITH A CUTOFF LOW ACROSS THE
SOUTHEASTERN CONUS...AND A SECOND ACROSS THE DESERT SOUTHWEST.
THIS PATTERN SUPPORTS DRY CONDITIONS FOR THE NORTHERN PLAINS WITH
NEAR TO SLIGHTLY ABOVE NORMAL TEMPERATURES. THE NEXT CHANCE FOR
PRECIPITATION...POSSIBLY THUNDERSTORMS...IS WEDNESDAY INTO FRIDAY
AS POTENTIAL NORTHERN STREAM ENERGY SINKS SOUTH ACROSS THE
NORTHERN PLAINS. THIS SLIGHT SHIFT OF THE POLAR JET FURTHER SOUTH
WITH NORTHWEST FLOW ALOFT SUPPORTS A POSSIBLE COOL DOWN BACK INTO
THE 60S THURSDAY AND FRIDAY...AND THE 50S BY SATURDAY.
OVERALL...UTILIZED A BLEND OF THE 00 UTC GUIDANCE SUITE FOR MOST
FIELDS...FAVORING THE WARMER EDGE OF TEMPERATURE GUIDANCE WHICH
HAS SHOWN GREATER VERIFICATION SCORES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY)
ISSUED AT 1258 PM CDT SUN MAY 5 2013
VFR CONDITIONS WILL PREVAIL OVER WESTERN AND CENTRAL NORTH DAKOTA
THROUGH THE TAF PERIOD. WINDS WILL GENERALLY BE LIGHT AND VARIABLE.
&&
.HYDROLOGY...
ISSUED AT 313 AM CDT SUN MAY 5 2013
THE SOURIS RIVER CONTINUES TO BE A COMPLEX MIXTURE OF LOCATIONS
RISING WHILE OTHER FORECAST POINTS ARE IN RECESSION. LOWER RELEASES
FROM BOUNDARY DAM AND REDUCED SNOWMELT RUNOFF BELOW ALAMEDA AND
RAFFERTY DAMS HAS RESULTED IN THE ENTIRE UPPER SOURIS RIVER BASIN
FROM SHERWOOD TO MINOT TO VELVA FALLING AND REMAINING BELOW FLOOD
STAGE. FARTHER DOWNSTREAM AT TOWNER...BANTRY AND WESTHOPE...THE
SOURIS RIVER REMAINS STEADY TO RISING AS FLOOD WATERS SLOWLY MAKE
THEIR WAY THROUGH THE AREA.
WILLOW CREEK NEAR WILLOW CITY IS EXPECTED TO EXPERIENCE ANOTHER RISE
TO JUST ABOVE MINOR FLOOD STAGE THROUGH MONDAY. MUCH OF THE MELT WATER
GENERATED IN THIS AREA APPEARS TO BE GOING INTO THE SOIL AND TEMPERING
EARLIER EXPECTATIONS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TM
SHORT TERM...KS
LONG TERM...AYD
AVIATION...TM
HYDROLOGY...AYD
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1245 PM CDT SUN MAY 5 2013
.UPDATE...
&&
.AVIATION...
18Z TAFS..LOW PRESSURE HANGING OVER THE AREA WILL CONTINUE TO
PRODUCE SCT SHRA THROUGH THE TAF PERIOD. MODELS SUGGEST THAT THE
DRY SLOT OVER BNA AND CKV WILL FILL IN WITH MOISTURE AND AT LEAST
SCATTERED SHOWERS AFTER 21Z. BNA/CKV WILL THEN VARY FROM MVFR TO
IFR WITH ON AND OFF RAIN OVERNIGHT INTO MONDAY MORNING. CSV WILL
VARY FROM IFR TO LIFR THROUGH THE PERIOD WITH SOME IMPROVEMENT
POSSIBLE AFTER 14Z MONDAY.
13
&&
.PREV DISCUSSION... /ISSUED 1145 AM CDT SUN MAY 5 2013/
UPDATE...
HAVE OPTED TO CANCEL THE FLOOD WATCH. THOUGH ADDITIONAL
REDEVELOPMENT IS EXPECTED ACROSS THE MID STATE...QPF RETURNS ARE
EXPECTED TO REMAIN INSIGNIFICANT. FURTHERMORE...LATEST RFC ISSUED
FFG IS WELL ABOVE ANY EXPECTED QPF RETURNS OVER THE NEXT 24 TO 48
HOURS. MOISTURE IN ASSOCIATION WITH THE UPPER LEVEL LOW WILL
CONTINUE TO MOVE ACROSS SOUTHERN MIDDLE TN TODAY...BUT AGAIN...QPF
RETURNS WILL REMAIN RATHER LOW.
ONLY OTHER CHANGE AT THIS TIME WILL BE TO LOWER MAX TEMPS A DEGREE
OR TWO ACROSS THE BOARD. COULD STILL SEE A BRIEF PEAK OF SUNSHINE
THIS AFTERNOON TO THE WEST OF THE PLATEAU. IT SHOULD REMAIN BRIEF
HOWEVER.
UPDATES INCLUDING THE FLOOD WATCH CANCELLATION WILL BE SENT SHORTLY.
PREV DISCUSSION... /ISSUED 937 AM CDT SUN MAY 5 2013/
UPDATE...
UPPER LOW MOVING SLOWLY ACROSS NORTHERN MS THIS MORNING. SFC
TROUGH STILL EXPECTED TO RETROGRADE SLIGHTLY THROUGH 18Z AND THEN
START TO MOVE SLOWLY EASTWARD. THESE 2 DISTINCT FEATURES ARE
SHOWING UP NICELY ON RADAR THIS MORNING AS SHOWERS CONTINUE.
LATEST 24 HR RADAR ESTIMATES SHOW THE HIGHEST QPF TOTALS ACROSS
OUR SOUTHERN PLATEAU. NOW THOUGH THE RAIN AREA IN THE EAST HAS
SHIFTED A LITTLE FURTHER EAST...SOME BACK BUILDING AND OR
REDEVELOPMENT IS LIKELY FOR THE AFTERNOON. HRRR IS SHOWING THE
REDEVELOPMENT AND THIS MAY BE INDUCED BY SOME PARTIAL CLEARING
WHICH WILL LEAD TO WARMER SFC TEMPS AND SOME ADDED DESTABILIZATION.
FOR THE FORECAST...NO CHANGES AT THIS TIME. WILL ALLOW THE FLOOD
WATCH TO CONTINUE AS IS.
PREV DISCUSSION... /ISSUED 356 AM CDT SUN MAY 5 2013/
SHORT TERM...RAIN CONTINUES TO FALL OVER MOST OF THE NORTHEASTERN
HALF OF THE MID STATE THIS MORNING, WITH ANOTHER AREA SHOWERS,
WRAPPED AROUND UPPER LOW, APPROACHING OUR SOUTHWESTERN COUNTIES.
SEVERAL INCHES OF RAIN HAVE FALLEN OVER MUCH, IF NOT MOST, OF THE
FLOOD WATCH AREA AND GROUNDS ARE FULLY SATURATED. ANY HEAVY
DOWNPOURS THAT DEVELOP OVER THAT AREA TODAY WILL LEAD TO THE
LIKELIHOOD OF PONDING OF WATER AND THE POSSIBILITY OF FLASH
FLOODING. A FLOOD ADVISORY IS IN EFFECT FOR PARTS OF EASTERN
MIDDLE TENNESSEE, BETWEEN MONTEREY, CROSSVILLE AND ALTAMONT UNTIL
515 AM CDT.
NOT MUCH CHANGE IN THE EXPECTED WEATHER PATTERN OVER THE NEXT
SEVERAL DAYS, AS CLOSED UPPER LOW WANDERS ACROSS NORTHERN PARTS OF
MISSISSIPPI AND ALABAMA. WITH FREEZING LEVEL AND WET-BULB ZERO
VALUES SO LOW, WOULDN`T BE SURPRISED IF A FEW THUNDERSTORMS DEVELOP
OVER THE SOUTH TODAY AND ARE ACCOMPANIED BY SOME SMALL HAIL.
FURTHER NORTH, EXPECT A CONTINUATION OF JUST PLAIN RAIN.
LIKELIHOOD FOR SHOWERS AND THUNDERSTORMS CONTINUES ON MONDAY,
ESPECIALLY IN DEEPEST MOISTURE OVER THE NORTHEAST AND EXTREME
SOUTHERN COUNTIES.
EVEN THOUGH UPPER LOW PULLS TO THE ATLANTIC COAST BY TUESDAY,
ENOUGH ATMOSPHERIC MOISTURE REMAINS OVER THE MID STATE TO KEEP AT
LEAST A CHANCE FOR SHOWERS AND THUNDERSTORMS IN OUR NECK OF THE
WOODS.
CLEARING SKIES, WET GROUND, AND DEW POINTS IN THE 50S WILL CREATE
GOOD CONDITIONS FOR THE FORMATION OF AREAS OF FOG LATE TUESDAY
NIGHT AND WEDNESDAY NIGHT.
PRECIPITATION BY WEDNESDAY AND THURSDAY SHOULD BECOME RESTRICTED TO
THE AFTERNOON HOURS, AND IN THE FORM OF ISOLATED POP-UP SHOWERS
AND THUNDERSTORMS.
LONG TERM...BELIEVE IT OR NOT, THE EXTENDED FORECAST CONTINUES TO
PAINT AN INCREASED CHANCE OF RAIN BY NEXT SATURDAY, WHICH WOULD
MAKE IT THE THIRD STRAIGHT SATURDAY WITH RAIN (UGH!). EXTENDED
MODELS ARE ALSO YIELDING A RATHER CHILLY PATTERN FOR NEXT WEEKEND,
WITH UPPER RIDGE BUILDING OVER THE ROCKIES AND A TROUGH DEEPENING
OVER THE OHIO RIVER AND TENNESSEE VALLEYS.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1145 AM CDT SUN MAY 5 2013
.UPDATE...
HAVE OPTED TO CANCEL THE FLOOD WATCH. THOUGH ADDITIONAL
REDEVELOPMENT IS EXPECTED ACROSS THE MID STATE...QPF RETURNS ARE
EXPECTED TO REMAIN INSIGNIFICANT. FURTHERMORE...LATEST RFC ISSUED
FFG IS WELL ABOVE ANY EXPECTED QPF RETURNS OVER THE NEXT 24 TO 48
HOURS. MOISTURE IN ASSOCIATION WITH THE UPPER LEVEL LOW WILL
CONTINUE TO MOVE ACROSS SOUTHERN MIDDLE TN TODAY...BUT AGAIN...QPF
RETURNS WILL REMAIN RATHER LOW.
ONLY OTHER CHANGE AT THIS TIME WILL BE TO LOWER MAX TEMPS A DEGREE
OR TWO ACROSS THE BOARD. COULD STILL SEE A BRIEF PEAK OF SUNSHINE
THIS AFTERNOON TO THE WEST OF THE PLATEAU. IT SHOULD REMAIN BRIEF
HOWEVER.
UPDATES INCLUDING THE FLOOD WATCH CANCELLATION WILL BE SENT SHORTLY.
&&
.PREV DISCUSSION... /ISSUED 937 AM CDT SUN MAY 5 2013/
UPDATE...
UPPER LOW MOVING SLOWLY ACROSS NORTHERN MS THIS MORNING. SFC
TROUGH STILL EXPECTED TO RETROGRADE SLIGHTLY THROUGH 18Z AND THEN
START TO MOVE SLOWLY EASTWARD. THESE 2 DISTINCT FEATURES ARE
SHOWING UP NICELY ON RADAR THIS MORNING AS SHOWERS CONTINUE.
LATEST 24 HR RADAR ESTIMATES SHOW THE HIGHEST QPF TOTALS ACROSS
OUR SOUTHERN PLATEAU. NOW THOUGH THE RAIN AREA IN THE EAST HAS
SHIFTED A LITTLE FURTHER EAST...SOME BACK BUILDING AND OR
REDEVELOPMENT IS LIKELY FOR THE AFTERNOON. HRRR IS SHOWING THE
REDEVELOPMENT AND THIS MAY BE INDUCED BY SOME PARTIAL CLEARING
WHICH WILL LEAD TO WARMER SFC TEMPS AND SOME ADDED DESTABILIZATION.
FOR THE FORECAST...NO CHANGES AT THIS TIME. WILL ALLOW THE FLOOD
WATCH TO CONTINUE AS IS.
PREV DISCUSSION... /ISSUED 625 AM CDT SUN MAY 5 2013/
AVIATION UPDATE...FOR 12Z TAF PACKAGE...
CURRENT RADAR TRENDS INDICATE THE RAIN SHIELD HAS CLEARED KBNA AND
KCKV. KCSV CONTINUES TO BE IMPACTED BY RA AND WILL LIKELY CONTINUE
THIS TREND THROUGHOUT THE NEXT 6 TO 12 HOURS. SHOULD STAY MOSTLY
MVFR FOR KCSV BUT BRIEF LIFR CONDITIONS COULD DEVELOP DURING
HEAVIEST RAINS. KBNA INDICATED SOME LIGHT BR AT TAF ISSUANCE BUT
EXPECT THAT TO DISSIPATE QUICKLY AS TEMPERATURES WARM THIS
MORNING. MODELS INDICATE REDEVELOPMENT OF SHOWERS BY AROUND 18Z
DUE TO WARMING AND CENTRAL LOW PRESSURE BEING OVER TOP MIDDLE
TENNESSEE. MIGHT BE AN ISOLATED TSRA DURING THIS PERIOD BUT
CONFIDENCE NOT HIGH SO LEFT SHRA IN TAFS FOR NOW.
PREV DISCUSSION... /ISSUED 356 AM CDT SUN MAY 5 2013/
SHORT TERM...RAIN CONTINUES TO FALL OVER MOST OF THE NORTHEASTERN
HALF OF THE MID STATE THIS MORNING, WITH ANOTHER AREA SHOWERS,
WRAPPED AROUND UPPER LOW, APPROACHING OUR SOUTHWESTERN COUNTIES.
SEVERAL INCHES OF RAIN HAVE FALLEN OVER MUCH, IF NOT MOST, OF THE
FLOOD WATCH AREA AND GROUNDS ARE FULLY SATURATED. ANY HEAVY
DOWNPOURS THAT DEVELOP OVER THAT AREA TODAY WILL LEAD TO THE
LIKELIHOOD OF PONDING OF WATER AND THE POSSIBILITY OF FLASH
FLOODING. A FLOOD ADVISORY IS IN EFFECT FOR PARTS OF EASTERN
MIDDLE TENNESSEE, BETWEEN MONTEREY, CROSSVILLE AND ALTAMONT UNTIL
515 AM CDT.
NOT MUCH CHANGE IN THE EXPECTED WEATHER PATTERN OVER THE NEXT
SEVERAL DAYS, AS CLOSED UPPER LOW WANDERS ACROSS NORTHERN PARTS OF
MISSISSIPPI AND ALABAMA. WITH FREEZING LEVEL AND WET-BULB ZERO
VALUES SO LOW, WOULDN`T BE SURPRISED IF A FEW THUNDERSTORMS DEVELOP
OVER THE SOUTH TODAY AND ARE ACCOMPANIED BY SOME SMALL HAIL.
FURTHER NORTH, EXPECT A CONTINUATION OF JUST PLAIN RAIN.
LIKELIHOOD FOR SHOWERS AND THUNDERSTORMS CONTINUES ON MONDAY,
ESPECIALLY IN DEEPEST MOISTURE OVER THE NORTHEAST AND EXTREME
SOUTHERN COUNTIES.
EVEN THOUGH UPPER LOW PULLS TO THE ATLANTIC COAST BY TUESDAY,
ENOUGH ATMOSPHERIC MOISTURE REMAINS OVER THE MID STATE TO KEEP AT
LEAST A CHANCE FOR SHOWERS AND THUNDERSTORMS IN OUR NECK OF THE
WOODS.
CLEARING SKIES, WET GROUND, AND DEW POINTS IN THE 50S WILL CREATE
GOOD CONDITIONS FOR THE FORMATION OF AREAS OF FOG LATE TUESDAY
NIGHT AND WEDNESDAY NIGHT.
PRECIPITATION BY WEDNESDAY AND THURSDAY SHOULD BECOME RESTRICTED TO
THE AFTERNOON HOURS, AND IN THE FORM OF ISOLATED POP-UP SHOWERS
AND THUNDERSTORMS.
LONG TERM...BELIEVE IT OR NOT, THE EXTENDED FORECAST CONTINUES TO
PAINT AN INCREASED CHANCE OF RAIN BY NEXT SATURDAY, WHICH WOULD
MAKE IT THE THIRD STRAIGHT SATURDAY WITH RAIN (UGH!). EXTENDED
MODELS ARE ALSO YIELDING A RATHER CHILLY PATTERN FOR NEXT WEEKEND,
WITH UPPER RIDGE BUILDING OVER THE ROCKIES AND A TROUGH DEEPENING
OVER THE OHIO RIVER AND TENNESSEE VALLEYS.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
21
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
240 PM CDT SUN MAY 5 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 230 PM CDT SUN MAY 5 2013
MAIN FORECAST CONCERN IS ON ANY FOG POTENTIAL TONIGHT
CURRENTLY AS OF 19Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED UPPER HIGHS IN SOUTHERN BRITISH COLUMBIA AND OVER THE GREAT
LAKES REGIONS...WHILE UPPER LOWS WERE PRESENT JUST WEST OF SAN
FRANSISCO CA...OVER CENTRAL SOUTH DAKOTA AND OVER ALABAMA. THIS
SETUP RESULTS IN LITTLE FLOW IN THE UPPER LEVELS ACROSS THE NORTHERN
U.S.. THERE REMAINS SCATTERED-BROKEN HIGH CLOUDS OVER THE AREA...ON
THE SOUTHWEST SIDE OF THE UPPER HIGH. OTHERWISE...A DRY AIRMASS HAS
BEEN ADVECTING INTO THE FORECAST AREA FROM THE EAST...WITH THE 12Z
GRB SOUNDING REFLECTIVE OF THE DRY AIR. THE COMBINATION OF THE DRY
AIR...850MB TEMPS AROUND 8C...AND THE SUN HAS ALLOWED TEMPERATURES
TO CLIMB INTO THE 65 TO 75 DEGREE RANGE WHERE SNOW DOES NOT EXIST.
MEANWHILE...DODGE CENTER WHICH STILL HAS A DECENT AMOUNT OF SNOW ON
THE GROUND...TEMPERATURES ARE STUCK IN THE MID 40S. REGARDING THE
SEA LEVEL PRESSURE PATTERN...HIGH PRESSURE STRETCHED ACROSS NORTHERN
MINNESOTA INTO NORTHERN ONTARIO...WHILE AN INVERTED TROUGH WAS
PRESENT OVER WESTERN WISCONSIN...EXTENDING NORTH FROM LOW PRESSURE
IN ALABAMA.
LITTLE CHANGE IS PROGGED TO THE UPPER LEVEL PATTERN ACROSS THE
UPPER MIDWEST INTO THE GREAT LAKES WITH PERHAPS JUST A SLIGHT
BREAKDOWN OF THE UPPER RIDGE OVER THE GREAT LAKES. AS A
RESULT...NOT EXPECTING MUCH CHANGE BETWEEN WHAT HAPPENED TODAY TO
WHAT WILL HAPPEN TOMORROW. IF ANYTHING...WINDS SHOULD BE A BIT
LIGHTER WITH THE HIGH PRESSURE AREA OVER NORTHERN ONTARIO PROGGED
TO DRIFT SOUTH INTO NORTHERN WISCONSIN BY 00Z TUESDAY. PER
200-300MB RH PROGS...LOOKS LIKE THE SCATTERED TO BROKEN HIGH
CLOUDS WILL PERSIST ACROSS THE AREA THROUGH MONDAY. THESE CLOUDS
COMBINED WITH LIGHT NORTHERLY DRY ADVECTION SHOULD PRECLUDE ANY
FOG DEVELOPMENT TONIGHT...DESPITE PERSISTENCE FROM SREF PROGS AND
NMM CORE MODELS WHICH CONTINUE TO SHOW TOO HIGH OF DEWPOINTS. EVEN
WORSE...THE 05.12Z NAM AND NCEP HIRES NMM MODELS BASICALLY HAD FOG
AND TEMPS AROUND 34F AT KRST ALL DAY TODAY. NCEP HIRES ARW
MODELS...WHICH ARE DOING BETTER WITH DEWPOINTS BUT STILL TOO
HIGH...THIS TIME TONIGHT DO NOT SHOW FOG. REGARDING LOW...THE HIGH
CLOUDS TONIGHT WILL KEEP TEMPERATURES UP SOMEWHAT...BUT THE DRY
AIRMASS ALSO SUPPORTS READINGS FALLING...ESPECIALLY IN THE TYPICAL
COLD SPOTS. TRENDED TOWARDS THE COLDER SIDE OF GUIDANCE. ON
MONDAY...850MB TEMPS ARE STILL HOLDING AROUND 8C...SO EXPECTING
HIGHS SIMILAR TO TODAY. ONLY DIFFERENCE WOULD BE OUT WEST WHERE
LESSER SNOW SHOULD ALLOW FOR WARMER TEMPERATURES.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 230 PM CDT SUN MAY 5 2013
MONDAY NIGHT THROUGH WEDNESDAY...ONLY MAIN CONCERN FROM A
PRECIPITATION PERSPECTIVE IS THE UPPER LOW SITUATED OVER CENTRAL
SOUTH DAKOTA. HANDLING OF THIS UPPER LOW HAS BEEN VERY PROBLEMATIC
RUN TO RUN AND BETWEEN MODEL TO MODEL. THERE HAS BEEN A GENERAL SLOW
DOWN IN BRINGING THIS UPPER LOW TOWARDS THE AREA...WHICH MAKES SENSE
AS IT IS CAUGHT IN A LACK OF FLOW BETWEEN THE NORTHERN AND SOUTHERN
STREAMS. THE WAY MODELS EVENTUALLY BRING IT TOWARDS THE AREA IS FROM
A NORTHERN STREAM TROUGH DROPPING INTO SOUTH CENTRAL CANADA...THUS
PICKING UP THE UPPER LOW. THE 05.12Z GFS IS THE FASTEST SOLUTION...
AND QUITE A BIT FASTER COMPARED TO ITS 05.06Z GFS...IMPACTING THE
AREA DURING THE DAY WEDNESDAY. 05.12Z NAM/UKMET/CANADIAN AND
05.00Z/05.12Z ECMWF ARE SLOWER. BELIEVE SLOWER IS THE WAY TO
GO...WHICH WOULD KEEP ANY PRECIPITATION FORCED BY THE UPPER LOW
MOSTLY WEST OF THE AREA. THUS HAVE KEPT ANY PRECIPITATION CHANCES
LOW AND CONFINED TO WESTERN SECTIONS. OTHERWISE...DRY CONDITIONS
WILL PREVAIL UNDER THE INFLUENCE OF HIGH PRESSURE AND LITTLE IN THE
WAY OF FLOW ALOFT. 850MB TEMPS HOLD IN THE 8-10C RANGE FOR BOTH
TUESDAY AND WEDNESDAY...WHICH SHOULD YIELD HIGHS IN THE 70S BOTH
DAYS WITH JUST SOME SCATTERED CLOUDS AROUND. A DRY AIRMASS
ACCOMPANYING THE HIGH...LIGHT WINDS AND THE SCATTERED CLOUDS LIKELY
TO ALLOW FOR DECENT COOLING AT NIGHT. STAYED TOWARDS THE COLD END OF
GUIDANCE...PARTICULARLY FOR THE TYPICAL COLD SPOTS.
WEDNESDAY NIGHT THROUGH SUNDAY...FOCUS AT THE BEGINNING OF THIS
PERIOD REMAINS ON THE UPPER LOW AND A COLD FRONTAL BOUNDARY THAT
LOOKS TO ACCOMPANY THIS UPPER LOW...AS WELL AS THE AFOREMENTIONED
NORTHERN STREAM SHORTWAVE TROUGH. AS MENTIONED THE 05.12Z GFS WAS A
BIT FAST WITH THE UPPER LOW...THUS PREFER THE SLOWER 05.00Z/05.12Z
ECMWF. EITHER SOLUTION REQUIRES AT LEAST SOME CHANCES OF SHOWERS AND
THUNDERSTORMS WITH THE COLD FRONTAL PASSAGE AND EVENTUALLY UPPER
LOW. IT APPEARS THE COLD FRONT WILL SLOWLY DROP SOUTHEAST THROUGH
THE AREA WEDNESDAY NIGHT THROUGH THURSDAY...WITH THE BEST CHANCES OF
PRECIPITATION OVER SOUTHERN PORTIONS OF THE AREA CLOSER TO THE
PROGGED UPPER LOW. CANADIAN HIGH PRESSURE BUILDS IN FOR
FRIDAY...YIELDING DRIER AND SLIGHTLY COOLER CONDITIONS WITH 850MB
TEMPS OF 6-8C.
MODELS CONTINUE TO HINT AT BIG CHANGES FOR THE WEEKEND WITH THE
05.12Z ECMWF/GFS/CANADIAN/GFS ENSEMBLES AND ECMWF ENSEMBLES ALL
SHOWING A POTENT TROUGH DROPPING DOWN INTO THE WESTERN GREAT LAKES
REGION. THIS TROUGH CURRENTLY IS IN THE ARCTIC NORTH OF SIBERIA...
THUS EXPECTING A DECENT COLD SHOT. IN FACT...850MB TEMPS ARE PROGGED
TO PLUMMET TO -4 TO -6C BY 12Z SUNDAY OVER THE FORECAST AREA. A COLD
FRONT LOOKS TO RACE AHEAD OF THIS POTENT TROUGH...WHICH MEANS
BETWEEN THE TWO A LIKELY DEFORMATION BAND OF LIGHT PRECIPITATION.
THUS...CHANCES OF SHOWERS ARE IN THE FORECAST FOR SATURDAY.
TEMPERATURES SATURDAY WILL BE TRICKY...ALL DEPENDING ON WHEN THE
FRONT COMES THROUGH. IF IT IS SLOWER...850MB TEMPS OF 6-8C WOULD
SUPPORT MOST LOCATIONS TOPPING OUT INTO THE 60S AND POSSIBLY EVEN
LOW 70S LIKE THE 05.00Z ECMWF. ON THE OTHER HAND...A FASTER SOLUTION
LIKE THE 05.12Z ECMWF/CANADIAN WOULD BE IN THE 50S...OR COLDER. FOR
NOW WENT WITH THE COMPROMISE AND FOLLOWED A BLEND OF GUIDANCE FOR
TEMPERATURES. DEFINITELY COLDER BUT DRIER FOR SUNDAY AS THE 850MB
THERMAL TROUGH AND CANADIAN AIR MOVE IN. HIGHS LIKELY TO ONLY TOP
OUT IN THE 50S ON SUNDAY...A GOOD 15 DEGREES OR SO BELOW NORMAL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1228 PM CDT SUN MAY 5 2013
MID/UPPER LEVEL RIDGE OF HIGH PRESSURE WILL KEEP THE AREA UNDER
VFR CONDITIONS GOING INTO TONIGHT WITH JUST A FEW CIRRUS NOTED.
GOOD MIXING THROUGH THE BOUNDARY LAYER TODAY AND DRIER/LIGHT
NORTHERLY FLOW THROUGH TONIGHT EXPECTED TO PREVENT ANY WIDESPREAD
FOG ACTIVITY. DID INCLUDE 4SM BR AT KRST/KLSE IN THE 08-14Z TIME
FRAME. OTHERWISE...VFR CONDITIONS/LIGHT WINDS WILL CONTINUE
THROUGH MONDAY AS THE RIDGE OF HIGH PRESSURE HOLDS OVER THE AREA.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...DAS