Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 05/07/13
AREA FORECAST DISCUSSION
NWS PUEBLO CO
924 PM MDT MON MAY 6 2013
.UPDATE...
ISSUED AT 901 PM MDT MON MAY 6 2013
UPDATED THE FORECAST TO REMOVE POPS OVER THE PLAINS AND LOWER POPS
OVER THE EASTERN MOUNTAINS. BEST CHANCE FOR PRECIP THE NEXT FEW
HOURS WILL BE OVER THE CENTRAL MOUNTAINS...WHERE OBS/SPOTTERS
SUGGEST LIGHT TO MODERATE RAIN/SNOW IS OCCURRING...WITH THE SNOW
LEVEL AROUND 9000 FEET.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 308 PM MDT MON MAY 6 2013
UPPER DISTURBANCE LIES JUST TO THE SOUTH OF CO WITH BANDS OF
CONVECTION ACROSS NORTHERN NEW MEXICO LIFTING NORTHWARD AHEAD OF
THIS FEATURE. WE`VE HAD PERSISTENT -SHRASN ACROSS THE MOUNTAIN
AREAS TODAY...PARTICULARLY ALONG THE CONTDVD WHERE KMYP AND KCPW WEB
CAMS CONTINUE TO SHOW WET SNOW FALLING. KALS HAS ALSO PICKED UP A
BRIEF RAIN SHOWER...AND EVEN KTAD REPORTED SOME LIGHT RAIN WITH A
BAND THAT MOVED OFF THE MOUNTAINS EARLIER THIS AFTERNOON.
MEANWHILE...SFC DEW POINTS ACROSS THE PLAINS HAVE BEEN SLOW TO COME
UP WITH READINGS STILL IN THE LOWER TO MID 20S FOR MOST AREAS.
AS THE SHORTWAVE CONTINUES TO TRACK TO THE NORTH ACROSS THE AREA
THIS EVENING...WILL CONTINUE HIGH POPS ACROSS THE MOUNTAINS WITH
AXIS OF HIGHEST POPS SHIFTING INTO THE NORTH CENTRAL MOUNTAINS
THROUGH THE EVENING. ACROSS THE PLAINS WILL KEEP GENERALLY ISOLATED POPS
IN THE FCST AS HRRR LOOKS OVERDONE WITH QPF FIELDS GIVEN THE SLOW
REBOUND IN SFC DEW POINTS. THE TWO DIVIDES...PALMER AND
RATON...HAVE THE BEST CHANCE AT SEEING SOME MEASURABLE
PRECIPITATION...SO WILL HOLD ON TO SOME SCT POPS FOR THESE AREAS.
WILL BE CONTINUING TO WATCH THE WALDO CANYON BURN SCAR FOR
RAINFALL. MOST LIKELY SCENARIO IS FOR QPF AMOUNTS TO RANGE UP TO
.10...WHICH IS BELOW FLOOD ADVISORY THRESHOLDS. HOWEVER IF A
STRONGER CELL DEVELOPS...THERE COULD BE SOME LOCAL AMOUNTS APPROACH
.20.
AS THE DISTURBANCE LIFTS NORTHWARD...SHOULD SEE IMPROVING CONDITIONS
SPREAD FROM SOUTH TO NORTH OVERNIGHT WITH SOME CLEARING TAKING PLACE
TOWARDS MORNING. HAVE POPS DROPPING INTO THE ISOLATED CATEGORY
OVERNIGHT ACROSS THE CENTRAL AND SOUTHWEST MOUNTAINS AS FORCING IS
WEAK AND WE LOOSE CONVECTIVE INGREDIENT.
STILL LOOKS LIKE THE WARMEST DAY IS ON TAP FOR TUESDAY. ALTHOUGH
SFC DEW POINTS WILL LIKELY RISE INTO THE 30S OVERNIGHT...THEY FALL
AGAIN ACROSS THE SOUTHEAST PLAINS INTO THE 20S...WITH LCLS IN MODEL
SOUNDINGS AROUND H6. FOR THAT REASON...THINK THAT SUB CLOUD DRY
LAYER WILL KEEP ANY RAINFALL ON THE WALDO BURN SCAR FROM REACHING
FLOOD ADVISORY CRITERIA ONCE AGAIN...WITH AMOUNTS LIKELY TO REMAIN
UNDER .10. BUT WITH MORE SUNSHINE ON TUESDAY RESULTING IN BETTER
POTENTIAL INSTABILITY...AND NAM12 HINTING AT A BOUNDARY STALLING
ALONG THE PALMER DIVIDE IN THE AFTERNOON...WALDO WILL NEED TO BE
MONITORED AS CELLS COULD POTENTIALLY BE STRONGER. OVER THE MOUNTAIN
AREAS...KEPT POPS IN THE SCATTERED RANGE AS WE APPEAR TO LACK ANY
STRONG FORCING ALOFT FOR MORE WIDESPREAD PCPN. OTHERWISE...HIGH
TEMPERATURES SHOULD TOP OUT IN THE 70S ACROSS THE PLAINS...WITH 60S
FOR THE VALLEYS...AND GENERALLY 40S AND 50S FOR THE MOUNTAINS. -KT
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 308 PM MDT MON MAY 6 2013
INCREASING CONCERNS FOR HEAVIER RAIN POTENTIAL(LOWER ELEVATION
SHOWERS AND THUNDERSTORMS)...INCLUDING OVER THE WALDO CANYON
BURN SCAR(ESPECIALLY FROM WEDNESDAY INTO THURSDAY) AS WELL AS
INCREASING STRONG TO SEVERE WEATHER THREAT OVER PORTIONS OF THE
SOUTHEASTERN COLORADO PLAINS FROM WEDNESDAY INTO WEDNESDAY NIGHT
AND HIGHER ELEVATION SNOWS ARE PRIMARY LONGER TERM METEOROLOGICAL
ISSUES.
RECENT LONGER TERM COMPUTER SIMULATIONS SUGGEST THAT CLOSED UPPER
LOW CENTERED OVER FAR SOUTHERN NEVADA AT 00Z WEDNESDAY MOVES INTO
THE FOUR CORNERS REGION BY 00Z THURSDAY WITH LATEST ECMWF SOLUTION
SLOWLY MOVING THE CLOSED UPPER LOW ACROSS SOUTHERN COLORADO INTO
WESTERN KANSAS BY 06Z FRIDAY WHILE LATEST GFS SUGGESTS THAT CLOSED
UPPER LOW WILL REMAIN IN THE VICINITY OF THE FOUR CORNERS REGION
THROUGH THURSDAY BEFORE DROPPING UPPER LOW SOUTH INTO FAR
SOUTHEASTERN ARIZONA BY 00Z SATURDAY. IN ADDITION...NORTHERLY
SURGES(CAPABLE OF ENHANCING PRECIPITATION POTENTIAL) ARE PROJECTED
TO MOVE ACROSS PRIMARILY EASTERN SECTIONS OF THE CWFA TUESDAY
NIGHT...WEDNESDAY AND THEN AGAIN ON SATURDAY.
BOTH ECMWF AND GFS SOLUTIONS GENERATE HEALTHY AMOUNTS OF
PRECIPITATION OVER THE FORECAST DISTRICT THROUGH THURSDAY
NIGHT...WITH OF COURSE THE GFS MODEL MUCH MORE AGGRESSIVE WITH
RESPECT TO POTENTIAL TOTAL PRECIPITATION AMOUNTS.
PRECIPITATION...HEAVY AT TIMES...WILL BE POSSIBLE OVER MANY
PORTIONS OF THE FORECAST DISTRICT FROM TUESDAY NIGHT INTO AT
LEAST THURSDAY NIGHT AND FLOOD WATCHES MAY BECOME NECESSARY FOR
AREAS SUCH AS THE WALDO CANYON BURN SCAR(ESPECIALLY FROM WEDNESDAY
INTO THURSDAY) IF METEOROLOGICAL TRENDS CONTINUE. WFO PUEBLO WILL
CONTINUE TO MONITOR CLOSELY AND ISSUE HIGHLIGHTS/ADVISORIES
AND/OR HYDRO WARNINGS IF/AS NEEDED.
ANOTHER LONGER TERM CONCERN WILL BE THE POTENTIAL FOR STRONG TO
SEVERE CONVECTION OVER PORTIONS OF THE SOUTHEASTERN COLORADO
PLAINS...ESPECIALLY FROM WEDNESDAY INTO WEDNESDAY NIGHT AS DEEPER
ATMOSPHERIC MOISTURE...LOCALIZED 0 TO 6 KM SHEARS AROUND 30
KNOTS...LOCALIZED CAPES AROUND 2100 J/KG AND LOCALIZED LIS AROUND
-8C RESPECTIVELY ARE ANTICIPATED OVER PORTIONS(ESPECIALLY FAR
EASTERN SECTIONS) OF THE SOUTHEASTERN COLORADO PLAINS. AS
ALWAYS...WFO PUEBLO WILL CONTINUE TO MONITOR CLOSELY AND ISSUE
SEVERE WEATHER PRODUCTS AS NEEDED.
ACCUMULATING SNOW IS ALSO EXPECTED AT TIMES OVER HIGHER TERRAIN
AREAS FROM TUESDAY NIGHT INTO LATER THIS WEEK. WINTER WEATHER
HIGHLIGHTS MAY BECOME NECESSARY OVER HIGHER TERRAIN AREAS DURING
THIS TIME-FRAME(ESPECIALLY OVER PUBLIC ZONES 58/60/66/68/73/75/81
AND 82).
IMPROVING METEOROLOGICAL CONDITIONS IN THE FORM OF WARMING
TEMPERATURES AND DECREASING POPS ARE THEN ANTICIPATED FROM LATER
THIS WEEKEND INTO EARLY NEXT WEEK. COOLEST TEMPERATURES DURING THE
LONGER TERM ARE EXPECTED TUESDAY AND WEDNESDAY WHILE WARMEST LONGER
TERM TEMPERATURES ARE PROJECTED SUNDAY AND NEXT MONDAY. FINALLY...
STILL ANTICIPATE THAT LOW-GRADE GRADIENT WINDS SHOULD CONTINUE
OVER THE FORECAST DISTRICT DURING THE LONGER TERM.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 308 PM MDT MON MAY 6 2013
UPPER DISTURBANCE WILL SPREAD ISOLATED TO NUMEROUS
SHOWERS ACROSS SOUTH CENTRAL AND SOUTHEAST CO THROUGH THE
EVENING...WITH HIGHEST COVERAGE ACROSS THE MOUNTAIN AREAS. MOUNTAIN
AREAS ALONG THE CONTDVD WILL CONTINUE TO SEE IFR CONDITIONS WITH
LOCAL LIFR AND MTN OBSCURATIONS ACROSS THE HIGHER PEAKS IN -SHSN.
THE SOUTHEAST MTS COULD SEE SOME IFR CONDITIONS AT TIMES THIS
EVENING WITH -SHRASN AND EVEN SOME ISOLATED -TS. AS FOR THE TAF
SITES...KALS WILL CONTINUE TO SEE THE POTENTIAL FOR -SHRA THROUGH
THE EARLY EVENING WITH VFR TO MVFR CIGS AT TIMES. KCOS AND KPUB COULD
SEE A PASSING SHOWER AFTER 21Z...HOWEVER PROBABILITY IS NOT AS GREAT
AS LOW LEVEL MOISTURE HAS BEEN SLOW TO RETURN. CIGS SHOULD STAY IN
THE VFR CATEGORY...THOUGH HIGHER TERRAIN NORTH AND WEST OF KCOS
COULD SEE SOME MVFR CIGS IN -SHRA. CLEARING CONDITIONS CAN BE
EXPECTED OVERNIGHT WITH A SUNNIER START TO THE DAY ON TUESDAY.
ISOLATED TO SCATTERED AFTERNOON -TSRA HIGHER MTN -SHSN WILL DEVELOP
OVER THE MOUNTAINS AGAIN WITH MVFR TO IFR CIGS. TAF SITES ARE MORE
LIKELY TO REMAIN DRY WITH VFR CONDITIONS. KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...PETERSEN
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
841 PM MDT MON MAY 6 2013
.UPDATE...SHORT WAVE MOVING SOUTHWEST TO NORTHEAST ACROSS COLORADO
THIS EVENING BUT IT IS EXPECTED TO SHEAR APART WITH A PORTION OVER
WESTERN COLORADO AND ANOTHER SECTIONS MOVING TO THE SOUTH AND EAST
OF THE CWFA. LATEST RUC AND NAM12 SHOW MOST OF THE QPF OVER THE
MOUNTAINS THIS EVENING AND OVERNIGHT...WITH LESS ENERGY OVER THE
NORTHEAST PLAINS. FOR THIS REASON...HAVE DROPPED THE MENTION OF
TSTMS OVER THE URBAN CORRIDOR AND PLAINS THIS EVENING...AND
BROAD BRUSHED SLIGHT CHANCE OF RAIN SHOWERS THERE. WL LEAVE
TSTMS IN THE HIGHER COUNTRY AS WELL AS THE HIGHER POPS SO NO
CHANGES THERE.
&&
.AVIATION...SHOULD KEEP MID LEVEL BKN CIGS OF 070-090 MSL OVER
THE AIRPORTS THIS EVENING WITH HIGHER CIGS DEVELOPING OVERNIGHT.
STLT SHOWING CLOUD TOPS WARMING OVER THE URBAN CORRIDOR AND
NORTHEAST PLAINS SO DO NOT ANTICIPATE MUCH RAINFALL
OVERNIGHT...VCSH AT BEST. WNWLY WINDS THROUGH THIS EVENING THEN IT
SHOULD TRANSITION CLOSER TO WEAK DRAINAGE WINDS AFTER 06Z.
&&
.PREV DISCUSSION... /ISSUED 308 PM MDT MON MAY 6 2013/
SHORT TERM...A FEW SHOWERS ARE DEVELOPING OVER THE HIGHER TERRAIN
WHERE IT HAS BECOME SOMEWHAT UNSTABLE. CAPES ARE RUNNING 100-300
J/KG. AIRMASS DRIER ON THE PLAINS THAN ADVERTISED BY THE MODELS WITH
DEW POINTS IN THE 20S TO LOWER 30S. THINKING THUNDERSTORMS WILL JUST
BE ISOLATED AT BEST BECAUSE OF THE WEAK INSTABILITY. EXPECT MOST OF
THE ACTIVITY TO BE SHOWERS/RAIN WITH SNOW UP HIGH. WATER VAPOR
IMAGERY CLEARLY SHOWING A SHORT WAVE TROUGH SPINNING OVER NEW
MEXICO. THIS WAVE WILL SHIFT NORTHEAST TONIGHT. CURRENT CLOUDS AND
PRECIPITATION CORRESPONDS TO THE LIFT AHEAD OF THIS SHORT WAVE OVER
SOUTHERN COLORADO. BEST CHANCE FOR PRECIPITATION WILL BE
TONIGHT...EARLY SOUTH AND LATER NORTH. WILL TREND POPS THIS WAY.
FOR TUESDAY MORNING...MAY SEE A FEW SHOWERS LINGER NORTH...OTHERWISE
EXPECT DRY CONDITIONS. EXPECT TO SEE A SOME BREAKS IN THE CLOUDS.
THIS WILL ALLOW TEMPERATURES TO CLIMB A LITTLE HIGHER WITH HIGHS IN
THE UPPER 60S ACROSS NORTHEAST COLORADO. THE WARMER TEMPERATURES
WILL ALSO LEAD TO A SLIGHT INCREASE IN INSTABILITY. CAPES WILL BE UP
TO 500 J/KG TUESDAY AFTERNOON. EXPECT TO SEE MORE THUNDERSTORMS
TUESDAY THAN TODAY. HOWEVER NOT SEEING A WELL DEFINED WAVE LIKE
TODAY SO WILL KEEP POPS IN THE SCATTERED CATEGORY.
LONG TERM...EVERYTHING STILL ON TRACK FOR A SIGNIFICANT
PRECIPITATION EVENT ACROSS THE FORECAST AREA ON WEDNESDAY AND
THURSDAY. MODELS STILL INDICATE THAT THE UPPER LOW OFF THE
CALIFORNIA COAST THIS AFTERNOON WILL BE MOVING OVER SOUTHERN
COLORADO WEDNESDAY NIGHT AND THURSDAY. AS THE UPPER LOW APPROACHES
FROM THE WEST TUESDAY NIGHT AND WEDNESDAY...THE DOWNSTREAM
DEFORMATION WILL MOVE OVERHEAD WITH INCREASING CLOUDS AND THE
ONSET OF WARM ADVECTION PRECIPITATION. AFTER THE PRECIPITATION
STARTS TUESDAY NIGHT IT SHOULD CONTINUE THROUGH THURSDAY NIGHT OR
FRIDAY AS THE WEAK DYNAMIC LIFT ASSOCIATED WITH THE UPPER LOW
PROVIDES LIFT TO THE MOIST AIRMASS. THE QPF FIELDS FROM THE GFS
SEEM TO BE OVERDOING PRECIPITATION AMOUNTS...BUT THE ECMWF
INDICATES SOMEWHERE BETWEEN ONE AND TWO INCHES OF RAINFALL DURING
THE 36 TO 48 HOUR PERIOD FROM WEDNESDAY NIGHT TO FRIDAY MORNING.
SNOW LEVELS IN THE MOUNTAINS COULD DROP TO 7500-8000 FEET AS THE
UPPER LOW PASSES OVER...WHICH WILL ALLOW ACCUMULATING SNOW ABOVE
THOSE LEVELS. IMPACT ON HIGHWAYS IN THE MOUNTAINS SHOULD BE
LIMITED TO THE HIGHEST PASSES...SO NO HIGHLIGHTS ARE EXPECTED AT
THIS TIME. THE AMOUNT OF RAIN ALSO SEEMS LOW ENOUGH THAT ONLY
MODEST RESPONSES IN CREEKS AND RIVERS IS EXPECTED...SO NO
HYDROLOGY HIGHLIGHTS ARE ANTICIPATED EITHER.
THE PRECIPITATION EVENT WILL BECOME A BIT MORE SHOWERY ON FRIDAY
AS WE GET UNDER THE NORTHWEST QUADRANT OF THE SLOWLY DEPARTING
UPPER LOW. SCATTERED SHOWER ACTIVITY COULD CONTINUE INTO SATURDAY.
SUNDAY AND MONDAY LOOK DRIER AND WARMER AS UPPER LEVEL RIDGING
FINALLY BUILDS OVER THE STATE AND THE AIRMASS BEGINS TO DRY OUT.
UNTIL THEN WET AND COOL WILL BE THE MAIN WEATHER STORY OF THE
WEEK.
AVIATION...MID AND HIGH CLOUDS WILL CONTINUE TO STREAM NORTHEAST
ACROSS THE STATE TONIGHT AHEAD OF A DISTURBANCE OVER NEW MEXICO.
VERY LOW CHANCE AT A THUNDERSTORM. IF ANY DEVELOP THEY WILL BE
WEAK. CEILING MAY FALL AS LOW 5000 FEET UNDER SHOWERS AND
THUNDERSTORMS. OUTSIDE OF ANY CONVECTION...WINDS WILL REMAIN ON
THE LIGHT SIDE THROUGH TUESDAY.
HYDROLOGY...THE HEAVIER SHOWERS AND ISOLATED THUNDERSTORMS
THROUGH TONIGHT AND ON TUESDAY WILL HAVE THE POTENTIAL TO PRODUCE
UP TO A QUARTER INCH OF RAIN IN 45 MINUTES. AT THIS TIME...THE
THREAT OF HEAVY RUNOFF DUE TO THIS RAINFALL APPEARS LOW.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...COOPER
LONG TERM....MEIER
AVIATION...COOPER
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 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 GRAND RAPIDS MI
723 PM EDT MON MAY 6 2013
.SYNOPSIS...
ISSUED AT 330 PM EDT MON MAY 6 2013
ABOVE NORMAL TEMPERATURES WILL PERSIST THROUGH THE WORK WEEK. THE
BEST CHANCE FOR SHOWERS AND THUNDERSTORMS WILL BE THURSDAY INTO
THURSDAY NIGHT. THE WEEKEND WILL BE COOLER WITH LOW TEMPERATURES
DIPPING INTO THE 30S BY MONDAY MORNING.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 330 PM EDT MON MAY 6 2013
MAIN CONCERN HAS BEEN TEMPERATURE AND DEW POINT TRENDS. HAVE GONE
NEAR OR SLIGHTLY ABOVE PERSISTENCE FOR TEMPERATURES AND DEW POINTS
TUESDAY AND WEDNESDAY AS A DEEP RESIDUAL MIXED LAYER FROM PREVIOUS
DAYS HAS BEEN A DOMINANT FACTOR AND IS NOT HANDLED BY THE MODELS. IT
WAS INTERESTING TO SEE 88D VAD WIND PROFILE RETURNS JUMP FROM 1000
FT TO 5000 FT AGL JUST PRIOR TO 11 AM AS THE RESIDUAL BOUNDARY LAYER
FROM THE LAST COUPLE DAYS WAS TAPPED.
INCLUDED A SLIGHT CHANCE FOR SHOWERS WEDNESDAY AFTERNOON AS LAKE
BREEZE CONVERGENCE SHOULD BE STRONGER. HOWEVER...THIS REMAINS A LOW
CONFIDENCE SCENARIO GIVEN QUESTIONABLE MOISTURE.
.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 330 PM EDT MON MAY 6 2013
THE UPPER AIR PATTERN AT THE BEGINNING OF THE LONG TERM WILL FEATURE
A SPLIT IN THE UPPER AIR PATTERN. THE PESKY UPPER LOW THAT HAS BEEN
PLAGUING THE AREA AROUND MI WILL FINALLY LIFT OUT TO THE NE. ANOTHER
TROUGH WILL BE ESTABLISHED ACROSS THE DESERT SW.
WE WILL SEE A SHORT WAVE MOVING IN FROM THE W/NW THAT WILL BRING THE
CHC OF SOME PCPN TO THE AREA. WITH IT COMING IN DURING THE DAYLIGHT
HOURS...SOME INSTABILITY IS FCST TO BUILD SUPPORTING A CHC OF A
STORM. THERE IS SOME UNCERTAINTY WITH REGARDS TO THE SPEED OF WHICH
IT MOVES OUT. WE PREFER THE QUICKER EURO SOLUTION AS THE WAVE SHOULD
WEAKEN AS IT APPROACHES THE AREA. THE GFS CLOSES IT OFF AND RESULTS
IN IT BEING SLOWER. THIS IT LIKELY DUE TO SOME CONVECTIVE FEEDBACK
IT IS EXPERIENCING. WE HAVE KEPT A LOW CHC OF RAIN IN FOR THU NIGHT
AND FRI...BUT WE HAVE LOWERED THE POPS AND RESTRICTED THE CHC ON FRI
TO SOUTHERN AREAS.
WE WILL SEE A BREAK IN THE UNSETTLED WEATHER FOR FRI ALONG WITH
CONTINUED MILD CONDITIONS. THEN A STRONG SHORT WAVE WHICH LOOKS TO
HAVE A ORIGIN FROM THE ARCTIC NW OF ALASKA WILL DIVE SE INTO THE
AREA ON SAT. THIS WILL BRING A SHOT OF COLDER AIR FOR LATE SAT AND
SUN. SOME RAIN SHOWERS LOOK TO ACCOMPANY THE ARRIVAL OF THIS COLDER
AIR. THE UPPER TROUGH WILL BE OVER THE AREA SAT AND SAT NIGHT WHICH
WILL BE WHEN THE CHC OF RAIN WILL BE. TEMPS ON SAT MAY SNEAK INTO
THE 60S BEFORE THE COLDER AIR ARRIVES. TEMPS WILL LIKELY BE IN THE
50S ON SUN.
THE TROUGH WILL MOVE OUT ON SUN AND RETURN FLOW WILL HELP TO ADVECT
WARMER AIR BACK IN. THE AIR MASS SHOULD REMAIN DRY ENOUGH TO KEEP
PCPN FROM OCCURRING ON MON.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 722 PM EDT MON MAY 6 2013
VERY LITTLE CHANGE IN THINKING FROM THE PREVIOUS SHIFT. VFR
CONDITIONS WILL PREVAIL THROUGH TUESDAY. CIRRUS CLOUDS WILL
CONTINUE TO PROVIDE A SCATTERED TO BROKEN CLOUD DECK ABOVE 20,000 FT
AGL. WINDS WILL STAY UNDER 10 KNOTS THROUGH TUESDAY (WINDS A JXN
WILL COME DOWN BELOW 10 KNOTS BY 01Z). I SEE LITTLE IN THE WAY OF
A THREAT FOR FOG EITHER.
AS FOR THE THREAT OF CONVECTION TUESDAY AFTERNOON... AS SHOWN BY THE
NAM...GFS AND ECMWF... I BELIEVE THIS TO BE A MODEL SURFACE DEW
POINT ISSUE. CURRENT DEW POINTS ARE FROM THE MID 20S TO MID
30S OVER MOST OF CWA. EVEN THE THE ECMWF 12Z RUN SHOWS DEW POINTS
IN THE LOWER TO MID 40S THIS AFTERNOON. HOWEVER... THE RAP MODEL
HAS MUCH MORE REALISTIC DEW POINTS AND ONLY SHOWS DEW POINTS IN
THE 30S TUESDAY. LOOKING AT SOUNDINGS FROM THE NAM AND RAP MODELS
IT IS CLEAR IF THE RAP IS CORRECT THE AIR WILL BE TO DRY FOR
CONVECTION. BASED ON HOW THIS HAS PLAYED OUT THE PAST FEW DAYS I
AM GOING WITH THE DRY AIR-NO CONVECTION OUTCOME.
&&
.MARINE...
ISSUED AT 330 PM EDT MON MAY 6 2013
NO CONCERNS AS WINDS SHOULD STAY BELOW 15 KNOTS AND BE NORTHERLY OR
OFFSHORE IN DIRECTION.
&&
.FIRE WEATHER...
ISSUED AT 330 PM EDT MON MAY 6 2013
AS NOTED IN THE SHORT TERM SECTION...EXPECT TEMPERATURES AND
HUMIDITIES TUESDAY TO BE VERY SIMILAR TO TODAY. THE LIMITING FACTOR
FOR RED FLAG WARNING CRITERIA WILL BE WINDS...WHICH SHOULD BE LIGHT
EASTERLY...BUT MORE VARIABLE IN DIRECTION NEAR THE LAKESHORE.
&&
.HYDROLOGY...
ISSUED AT 330 PM EDT MON MAY 6 2013
NO CONCERNS AS MEAN AREAL QPF WITH PRECIPITATION THURSDAY IS
EXPECTED TO REMAIN WELL BELOW A QUARTER OF AN INCH.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
SYNOPSIS...TJT
SHORT TERM...TJT
LONG TERM...NJJ
AVIATION...WDM
FIRE WEATHER...TJT
HYDROLOGY...TJT
MARINE...TJT
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
710 PM EDT MON MAY 6 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 405 PM EDT MON MAY 6 2013
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW BLOCKY FLOW ACROSS THE
CONUS TO THE S OF NEARLY ZONAL FLOW ACROSS CNTRL CANADA. A NARROW
RIDGE EXTENDS FROM SRN BRITISH COLUMBIA E ACROSS THE UPPER GREAT
LAKES TO NEW ENGLAND. FARTHER S...CLOSED MID LEVEL LOWS WERE LOCATED
JUST OFF THE CA COAST...OVER SD AND OVER THE SE CONUS. WITH THE
UPPER GREAT LAKES UNDER THE RIDGE...IT`S BEEN A PLEASANT EARLY MAY
DAY ACROSS UPPER MI AS DEEP DRY COLUMN IS ALLOWING FOR ABUNDANT
SUNSHINE. LAKE BREEZES HAVE DEVELOPED ACROSS THE BOARD. WHILE IT`S
CHILLY ALONG LAKE SUPERIOR WITH TEMPS IN THE 40S...SIGNIFICANT
COOLING HAS YET TO OCCUR ALONG MOST OF THE LAKE MI SHORELINE.
INLAND...TEMPS HAVE SOARED THRU THE 60S TO AS HIGH AS THE LOW/MID
70S. LAST BIT OF LINGERING FOG OVER WRN LAKE SUPERIOR BTWN THE
APOSTLE ISLANDS AND UPPER MI HAS JUST ABOUT DISSIPATED AS OF 1930Z.
WITH LITTLE CHANGE IN THE AIR MASS THRU TUE...FCST FOR TONIGHT/TUE
WILL BE SIMILAR TO LAST NIGHT/TODAY. LIGHT/CALM WIND AND CLEAR SKIES
WILL LEAD TO GOOD RADIATIONAL COOLING CONDITIONS TONIGHT. HOWEVER...
PRECIPITABLE WATER DOES RISE SOME COMPARED TO LAST NIGHT OVER THE W
HALF OR SO (UP TOWARD NORMAL FROM 60PCT OF NORMAL LAST NIGHT). ALONG
WITH AIR MASS MODERATION TODAY...MINS TONIGHT SHOULD BE SEVERAL
DEGREES HIGHER THAN LAST NIGHT. COLUMN REMAINS DRIER OVER THE E...SO
MINS THERE WILL PROBABLY BE WITHIN A COUPLE OF DEGREES OF LAST
NIGHTS MINS. OVERALL...EXPECT MIN TEMPS TONIGHT IN THE 30S. MIGHT
SEE SOME PATCHY GROUND FOG OVER THE INTERIOR W LATE TONIGHT. 850MB
TEMPS TUE ARE NEARLY THE SAME AS TODAY. WITH ABUNDANT SUNSHINE AGAIN
(SHOULD BE SOME CU OVER THE W)...MAX TEMPS WILL BE SIMILAR TO WHAT
IS BEING OBSERVED THIS AFTN. SFC HIGH PRES RIDGED ACROSS THE UPPER
LAKES WILL LEAD TO ANOTHER DAY OF LAKE BREEZES. HOWEVER...WITH HIGH
CENTER SETTING UP A LITTLE FARTHER E...LIGHT SOUTHERLY GRADIENT FLOW
SHOULD LEAD TO A LESS AGGRESSIVE INLAND PUSH OF THE LAKE SUPERIOR
LAKE BREEZE...AND COOLING SHOULD BE A LITTLE STRONGER ALONG LAKE MI
SAT AFTN COMPARED TO TODAY. TAKING INTO ACCOUNT MIXING DEPTH...
DWPTS SHOULD TANK IN SOME INLAND AREAS WITH RH BOTTOMING OUT AS LOW
AS AROUND 20PCT. IN GENERAL...RH SHOULD BE IN 20S INLAND.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 436 PM EDT MON MAY 6 2013
THE 500MB RIDGE THAT HAS BEEN SET UP ACROSS UPPER MICHIGAN WILL BE
EXITING EASTWARD TUESDAY NIGHT...WITH AN OPEN WAVE/TROUGH EXTENDING
FROM NORTHERN CANADA THROUGH THE DAKOTAS SHIFTING TOWARD MINNESOTA
AND ONTARIO.
WEAK SSW WINDS FLOW WILL SLOWLY BRING BACK INCREASED MOISTURE
THROUGH THE DAY WEDNESDAY...WITH PW VALUES JUMPING AT OR ABOVE 1IN
BY MID AFTERNOON OVER THE WESTERN THIRD OF THE CWA /175 PERCENT OR
NORMAL OR MORE/. THE MAIN RESULT WILL BE INCREASED CLOUD COVER. A
WEAKENING SFC TROUGH WILL SINK FROM NW LAKE SUPERIOR AT DAYBREAK
WEDNESDAY. FCST MODELS ARE VERY CONSISTENT WITH THE TRACK/TIMING OF
THE TROUGH AS OF THE 12Z RUNS. EXPECT THE TROUGH TO PUSH ACROSS
CENTRAL LAKE SUPERIOR BY 18Z...AND THEN SINK ACROSS UPPER MI
WEDNESDAY AFTERNOON...TO JUST S OF THE CWA BY 06Z THURSDAY. A FEW
SHOWERS WILL BE POSSIBLE WEDNESDAY NIGHT THROUGH THURSDAY...WITH
TOTAL QPF AROUND A TENTH OF AN INCH OR LESS.
STRONG HIGH PRESSURE ACROSS MOST OF CENTRAL CANADA WILL SLOWLY SINK
IN BEHIND THE TROUGH...BRINGING WITH IT A RETURN OF DRIER AND COLDER
AIR. 850MB TEMPS ARE ANTICIPATED TO FALL FROM AROUND 9C WEDNESDAY
AFTERNOON TO AROUND 4C BY FRIDAY AFTERNOON.
LOOKING MORE AT THE FIRE FRONT...THE CENTRAL AND EASTERN UPPER
MICHIGAN WILL CONTINUE TO BE THE DRIEST THROUGH AT LEAST FRIDAY
NIGHT.
WINDS MAY BECOME A CONCERN ON SATURDAY...PICKING UP OUT OF A NW
DIRECTION THROUGHOUT THE DAY...BEHIND A STRONGER COLD FRONT WITH A
REINFORCING SHORTWAVE. A 30-35KT LLJ CORE AROUND 800BM THROUGH
MUCH OF THE DAY SATURDAY OVER THE WEST...RESULTING IN 20-25KT GUSTS
SATURDAY THROUGH MUCH OF SUNDAY.
ON A POSITIVE NOTE...A TENTH TO QUARTER OF AN INCH IS OF RAIN IS
FORECAST...AND MUCH COLDER AIR WILL BE SINKING IN. 850MB TEMPS WILL
COOL SIGNIFICANTLY...WITH THE 12Z ECMWF COMING IN WITH -8 TO -10C
READINGS FROM 06-18Z SUNDAY. WITH A DEEPER AND SLOWER SYSTEM
OVERALL...A FEW FLURRIES WILL BE POSSIBLE FROM SATURDAY THROUGH
SUNDAY. THE GOOD NEWS FOR THOSE WHO WOULD RATHER NOT SEE ANOTHER
SNOWFLAKE UNTIL THE FALL...MOST OF THE MOISTURE WILL BE OUT OF THE
AREA BEFORE THE COLD AIR ARRIVES. DO NOT EXPECT ANY TRAVEL CONCERNS
OR PLOWING NEEDED...GIVEN THE STRENGTH OF THE SUN THIS TIME OF
YEAR...AND THE WARM ROADWAYS. GRASSY SURFACES WILL REALLY SEE THE
ONLY CHANCE OF ANY DUSTING OF SNOW.
AFTER A COOL WEEKEND WITH HIGHS IN THE 40S TO AROUND 50...TEMPS WILL
WARM UP AGAIN TO NEAR NORMAL READINGS BY MONDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 706 PM EDT MON MAY 6 2013
EXPECT VFR CONDITIONS/LIGHT WINDS AT KIWD/KCMX/KSAW THIS TAF PERIOD
WITH DRY HIGH PRES DOMINATING. HOWEVER...THERE MAY BE ONE EXCEPTION.
SOME FOG (MVFR VIS) MAY DEVELOP AT KIWD LATE TONIGHT. NOT OUT OF THE
QUESTION THAT BRIEF IFR OR EVEN LIFR COULD OCCUR AS WELL.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 405 PM EDT MON MAY 6 2013
QUIET WEATHER WILL CONTINUE OVER THE UPPER GREAT LAKES FOR THE NEXT
COUPLE OF DAYS. WITH HIGH PRES RIDGE REMAINING OVER THE AREA...WINDS
WILL LIKELY REMAIN UNDER 15KT THRU WED AFTN. THEN...A COLD FRONT
DROPPING SOUTHEAST ACROSS THE UPPER GREAT LAKES WEDNESDAY NIGHT WILL
BRING A WIND SHIFT AND STRONGER WINDS INTO THE 15-25KT RANGE FOR A
TIME LATER WED NIGHT INTO THU. WINDS WILL DIMINISH HEADING INTO FRI
AS A HIGH PRES SYSTEM MOVES ACROSS NRN ONTARIO. A STRONG COLD FRONT
PASSING FRI NIGHT/SAT MORNING WILL BRING ANOTHER ROUND OF 15-25KT
WINDS FOR SAT.
&&
.HYDROLOGY...
ISSUED AT 436 PM EDT MON MAY 6 2013
HYDROLOGY CONCERNS CONTINUE...BUT ARE SLOWLY DIMINISHING AT ALL
SITES EXCEPT FOR LAKE LINDEN ON THE TRAP ROCK RIVER WHICH HAS BEEN
SHOWING ITS USUAL DIURNAL INCREASE AS A RESULT OF THE SIGNIFICANT
SNOW PACK STILL MELTING ACROSS THE KEWEENAW PENINSULA. THE LATEST
SNOW DEPTH OBSERVATIONS /FROM EARLIER THIS MORNING AROUND 8AM/ STILL
HAVE AROUND 3IN AT IRONWOOD...AND 7IN AT ATLANTIC MINE. A FEW
POCKETS OF HIGHER AMOUNTS ARE LIKELY ACROSS THE KEWEENAW.
THE ONGOING FLOODING ON THE STURGEON RIVER AT ALSTON AND
CHASSELL...THE MICHIGAMME RIVER AROUND WITCH LAKE...AND THE PAINT
RIVER NEAR CRYSTAL FALLS WILL REMAIN A CONCERN FOR THE NEXT COUPLE
OF DAYS. 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...ROLFSON
LONG TERM...KF
AVIATION...VOSS
MARINE...ROLFSON
HYDROLOGY...KF
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 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 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 GREAT FALLS MT
911 PM MDT Mon May 6 2013
.UPDATE...
Tonight...The region will remain underneath weak high pressure
tonight. Update to nudge a few temps lower, mainly across the
central zones and east. A shortwave will move through the flow
aloft across Alberta and this should cause some increased winds
after midnight across the Rockies and adjacent plains. These winds
should help keep local overnight lows quite moderate in this area.
Moisture has moved into extreme Southwest Montana from a low
pressure system to the south. This moisture should also keep this
area slightly warmer overnight. Other than temps, no changes to the
forecast. Zelzer
&&
.AVIATION...
UPDATED 2345Z.
VFR conditions expected across the region through 18Z Tuesday. High
pressure will keep skies mostly clear and winds relatively light
through tonight. Isolated showers over far Southwest Montana will
diminish after sunset but weak instability will result in isolated
showers and a few thunderstorms again Tuesday afternoon. Any
development will likely remain south of a KBZN-KBTM line. Expect a
front to move into the region from the northwest after 15z Tuesday.
Winds will turn to the north behind the front with gusts to around
20 knots. Scattered low clouds will develop behind the front.
&&
.PREV DISCUSSION...
/ISSUED 545 PM MDT Mon May 6 2013/
Tonight through Wednesday...Fairly benign weather pattern will
continue overnight. An upper ridge remains in place across central
and northern Montana with associated subsidence providing cloud-
free skies and mild temperatures. Circulation from an upper low
offshore of the California coast is spreading moisture and
instability across the inter-mountain region and into extreme
southern and southwest Montana. Models indicate some CAPE is
available over the area but HRRR analysis indicates moisture is
lacking and very few thunderstorms are depicted through the early
evening hours. The upper low begins moving east on Tuesday with
showers and/or thunderstorms becoming a bit more numerous across
the south and southwest during the afternoon. By Wednesday, the
upper ridge gets suppressed to the south and northwest flow aloft
sets up over the area. Enough moisture and instability will be
present for isolated thunderstorms across the area. Temperatures
will remain above seasonal averages. Emanuel
Wednesday Night through Monday...Medium range models continue to
indicate that unsettled weather will remain across the area through
Saturday. An upper level ridge of high pressure from along the
California coast into the Pacific Northwest and an upper level
trough of low pressure over central/eastern Canada will combine to
keep Montana under a moist and cyclonic northwesterly flow aloft.
Weak disturbances in the flow will generally keep a chance of mainly
afternoon and evening showers and thunderstorms over the area.
Moisture being drawn north by an upper level low pressure area
moving across the central Rockies Wednesday night through Thursday
night will enhance this chance of measurable precipitation. However,
the models seem to agree with this forecast cycle that a strong
Canadian cold front will move south through the area on Friday. Have
therefore increased the overall chance for showers/thunderstorms
during this time and introduced breezy northerly winds in the wake
of the front. For Saturday night into Sunday night, models are in
better agreement with moving the upper level ridge will move east
into Montana. Have mostly gone with dry conditions during this time,
with only a slight chance of showers/thunderstorms in the mountains.
As the ridge axis moves east of the area, models are indicating that
a moist southwesterly flow aloft will combine with the passage of a
Pacific cold front to bring a slightly better chance for
showers/thunderstorms into Monday. Temperatures will generally be 5
to 10 degrees warmer than seasonal averages through Saturday, with a
brief cooling back to near normal associated with the cold frontal
passage on Friday. As the ridge builds into the area, temperatures
will reach 10 to 15 degrees above normal for the latter portion of
the weekend, but they will then cool about 5 to 10 degrees again on
Monday with the passage of the second cold front. Coulston
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 44 70 44 72 / 0 10 10 20
CTB 44 63 40 70 / 0 10 10 30
HLN 42 72 45 75 / 0 10 20 20
BZN 36 74 41 74 / 10 20 30 20
WEY 30 64 35 65 / 20 40 40 40
DLN 39 71 42 72 / 10 20 30 30
HVR 41 76 42 72 / 0 0 10 20
LWT 41 72 42 68 / 0 10 10 20
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
weather.gov/greatfalls
AREA FORECAST DISCUSSION
NWS GREAT FALLS MT
545 PM MDT Mon May 6 2013
UPDATED AVIATION SECTION
.DISCUSSION...
Tonight through Wednesday...Fairly benign weather pattern will
continue overnight. An upper ridge remains in place across central
and northern Montana with associated subsidence providing cloud-
free skies and mild temperatures. Circulation from an upper low
offshore of the California coast is spreading moisture and
instability across the inter-mountain region and into extreme
southern and southwest Montana. Models indicate some CAPE is
available over the area but HRRR analysis indicates moisture is
lacking and very few thunderstorms are depicted through the early
evening hours. The upper low begins moving east on Tuesday with
showers and/or thunderstorms becoming a bit more numerous across
the south and southwest during the afternoon. By Wednesday, the
upper ridge gets suppressed to the south and northwest flow aloft
sets up over the area. Enough moisture and instability will be
present for isolated thunderstorms across the area. Temperatures
will remain above seasonal averages. Emanuel
Wednesday Night through Monday...Medium range models continue to
indicate that unsettled weather will remain across the area through
Saturday. An upper level ridge of high pressure from along the
California coast into the Pacific Northwest and an upper level
trough of low pressure over central/eastern Canada will combine to
keep Montana under a moist and cyclonic northwesterly flow aloft.
Weak disturbances in the flow will generally keep a chance of mainly
afternoon and evening showers and thunderstorms over the area.
Moisture being drawn north by an upper level low pressure area
moving across the central Rockies Wednesday night through Thursday
night will enhance this chance of measurable precipitation. However,
the models seem to agree with this forecast cycle that a strong
Canadian cold front will move south through the area on Friday. Have
therefore increased the overall chance for showers/thunderstorms
during this time and introduced breezy northerly winds in the wake
of the front. For Saturday night into Sunday night, models are in
better agreement with moving the upper level ridge will move east
into Montana. Have mostly gone with dry conditions during this time,
with only a slight chance of showers/thunderstorms in the mountains.
As the ridge axis moves east of the area, models are indicating that
a moist southwesterly flow aloft will combine with the passage of a
Pacific cold front to bring a slightly better chance for
showers/thunderstorms into Monday. Temperatures will generally be 5
to 10 degrees warmer than seasonal averages through Saturday, with a
brief cooling back to near normal associated with the cold frontal
passage on Friday. As the ridge builds into the area, temperatures
will reach 10 to 15 degrees above normal for the latter portion of
the weekend, but they will then cool about 5 to 10 degrees again on
Monday with the passage of the second cold front. Coulston
&&
.AVIATION...
UPDATED 2345Z.
VFR conditions expected across the region through 18Z Tuesday. High
pressure will keep skies mostly clear and winds relatively light
through tonight. Isolated showers over far Southwest Montana will
diminish after sunset but weak instability will result in isolated
showers and a few thunderstorms again Tuesday afternoon. Any
development will likely remain south of a KBZN-KBTM line. Expect a
front to move into the region from the northwest after 15z Tuesday.
Winds will turn to the north behind the front with gusts to around
20 knots. Scattered low clouds will develop behind the front.
Langlieb
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 46 70 44 72 / 0 10 10 20
CTB 44 63 40 70 / 0 10 10 30
HLN 44 72 45 75 / 0 10 20 20
BZN 38 74 41 74 / 10 20 30 20
WEY 33 64 35 65 / 20 40 40 40
DLN 40 71 42 72 / 10 20 30 30
HVR 43 76 42 72 / 0 0 10 20
LWT 41 72 42 68 / 0 10 10 20
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
weather.gov/greatfalls
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 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
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 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
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 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 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
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 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 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
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
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 PUEBLO CO
1135 PM MDT MON MAY 6 2013
.UPDATE...
ISSUED AT 901 PM MDT MON MAY 6 2013
UPDATED THE FORECAST TO REMOVE POPS OVER THE PLAINS AND LOWER POPS
OVER THE EASTERN MOUNTAINS. BEST CHANCE FOR PRECIP THE NEXT FEW
HOURS WILL BE OVER THE CENTRAL MOUNTAINS...WHERE OBS/SPOTTERS
SUGGEST LIGHT TO MODERATE RAIN/SNOW IS OCCURRING...WITH THE SNOW
LEVEL AROUND 9000 FEET.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 308 PM MDT MON MAY 6 2013
UPPER DISTURBANCE LIES JUST TO THE SOUTH OF CO WITH BANDS OF
CONVECTION ACROSS NORTHERN NEW MEXICO LIFTING NORTHWARD AHEAD OF
THIS FEATURE. WE`VE HAD PERSISTENT -SHRASN ACROSS THE MOUNTAIN
AREAS TODAY...PARTICULARLY ALONG THE CONTDVD WHERE KMYP AND KCPW WEB
CAMS CONTINUE TO SHOW WET SNOW FALLING. KALS HAS ALSO PICKED UP A
BRIEF RAIN SHOWER...AND EVEN KTAD REPORTED SOME LIGHT RAIN WITH A
BAND THAT MOVED OFF THE MOUNTAINS EARLIER THIS AFTERNOON.
MEANWHILE...SFC DEW POINTS ACROSS THE PLAINS HAVE BEEN SLOW TO COME
UP WITH READINGS STILL IN THE LOWER TO MID 20S FOR MOST AREAS.
AS THE SHORTWAVE CONTINUES TO TRACK TO THE NORTH ACROSS THE AREA
THIS EVENING...WILL CONTINUE HIGH POPS ACROSS THE MOUNTAINS WITH
AXIS OF HIGHEST POPS SHIFTING INTO THE NORTH CENTRAL MOUNTAINS
THROUGH THE EVENING. ACROSS THE PLAINS WILL KEEP GENERALLY ISOLATED POPS
IN THE FCST AS HRRR LOOKS OVERDONE WITH QPF FIELDS GIVEN THE SLOW
REBOUND IN SFC DEW POINTS. THE TWO DIVIDES...PALMER AND
RATON...HAVE THE BEST CHANCE AT SEEING SOME MEASURABLE
PRECIPITATION...SO WILL HOLD ON TO SOME SCT POPS FOR THESE AREAS.
WILL BE CONTINUING TO WATCH THE WALDO CANYON BURN SCAR FOR
RAINFALL. MOST LIKELY SCENARIO IS FOR QPF AMOUNTS TO RANGE UP TO
.10...WHICH IS BELOW FLOOD ADVISORY THRESHOLDS. HOWEVER IF A
STRONGER CELL DEVELOPS...THERE COULD BE SOME LOCAL AMOUNTS APPROACH
.20.
AS THE DISTURBANCE LIFTS NORTHWARD...SHOULD SEE IMPROVING CONDITIONS
SPREAD FROM SOUTH TO NORTH OVERNIGHT WITH SOME CLEARING TAKING PLACE
TOWARDS MORNING. HAVE POPS DROPPING INTO THE ISOLATED CATEGORY
OVERNIGHT ACROSS THE CENTRAL AND SOUTHWEST MOUNTAINS AS FORCING IS
WEAK AND WE LOOSE CONVECTIVE INGREDIENT.
STILL LOOKS LIKE THE WARMEST DAY IS ON TAP FOR TUESDAY. ALTHOUGH
SFC DEW POINTS WILL LIKELY RISE INTO THE 30S OVERNIGHT...THEY FALL
AGAIN ACROSS THE SOUTHEAST PLAINS INTO THE 20S...WITH LCLS IN MODEL
SOUNDINGS AROUND H6. FOR THAT REASON...THINK THAT SUB CLOUD DRY
LAYER WILL KEEP ANY RAINFALL ON THE WALDO BURN SCAR FROM REACHING
FLOOD ADVISORY CRITERIA ONCE AGAIN...WITH AMOUNTS LIKELY TO REMAIN
UNDER .10. BUT WITH MORE SUNSHINE ON TUESDAY RESULTING IN BETTER
POTENTIAL INSTABILITY...AND NAM12 HINTING AT A BOUNDARY STALLING
ALONG THE PALMER DIVIDE IN THE AFTERNOON...WALDO WILL NEED TO BE
MONITORED AS CELLS COULD POTENTIALLY BE STRONGER. OVER THE MOUNTAIN
AREAS...KEPT POPS IN THE SCATTERED RANGE AS WE APPEAR TO LACK ANY
STRONG FORCING ALOFT FOR MORE WIDESPREAD PCPN. OTHERWISE...HIGH
TEMPERATURES SHOULD TOP OUT IN THE 70S ACROSS THE PLAINS...WITH 60S
FOR THE VALLEYS...AND GENERALLY 40S AND 50S FOR THE MOUNTAINS. -KT
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 308 PM MDT MON MAY 6 2013
INCREASING CONCERNS FOR HEAVIER RAIN POTENTIAL(LOWER ELEVATION
SHOWERS AND THUNDERSTORMS)...INCLUDING OVER THE WALDO CANYON
BURN SCAR(ESPECIALLY FROM WEDNESDAY INTO THURSDAY) AS WELL AS
INCREASING STRONG TO SEVERE WEATHER THREAT OVER PORTIONS OF THE
SOUTHEASTERN COLORADO PLAINS FROM WEDNESDAY INTO WEDNESDAY NIGHT
AND HIGHER ELEVATION SNOWS ARE PRIMARY LONGER TERM METEOROLOGICAL
ISSUES.
RECENT LONGER TERM COMPUTER SIMULATIONS SUGGEST THAT CLOSED UPPER
LOW CENTERED OVER FAR SOUTHERN NEVADA AT 00Z WEDNESDAY MOVES INTO
THE FOUR CORNERS REGION BY 00Z THURSDAY WITH LATEST ECMWF SOLUTION
SLOWLY MOVING THE CLOSED UPPER LOW ACROSS SOUTHERN COLORADO INTO
WESTERN KANSAS BY 06Z FRIDAY WHILE LATEST GFS SUGGESTS THAT CLOSED
UPPER LOW WILL REMAIN IN THE VICINITY OF THE FOUR CORNERS REGION
THROUGH THURSDAY BEFORE DROPPING UPPER LOW SOUTH INTO FAR
SOUTHEASTERN ARIZONA BY 00Z SATURDAY. IN ADDITION...NORTHERLY
SURGES(CAPABLE OF ENHANCING PRECIPITATION POTENTIAL) ARE PROJECTED
TO MOVE ACROSS PRIMARILY EASTERN SECTIONS OF THE CWFA TUESDAY
NIGHT...WEDNESDAY AND THEN AGAIN ON SATURDAY.
BOTH ECMWF AND GFS SOLUTIONS GENERATE HEALTHY AMOUNTS OF
PRECIPITATION OVER THE FORECAST DISTRICT THROUGH THURSDAY
NIGHT...WITH OF COURSE THE GFS MODEL MUCH MORE AGGRESSIVE WITH
RESPECT TO POTENTIAL TOTAL PRECIPITATION AMOUNTS.
PRECIPITATION...HEAVY AT TIMES...WILL BE POSSIBLE OVER MANY
PORTIONS OF THE FORECAST DISTRICT FROM TUESDAY NIGHT INTO AT
LEAST THURSDAY NIGHT AND FLOOD WATCHES MAY BECOME NECESSARY FOR
AREAS SUCH AS THE WALDO CANYON BURN SCAR(ESPECIALLY FROM WEDNESDAY
INTO THURSDAY) IF METEOROLOGICAL TRENDS CONTINUE. WFO PUEBLO WILL
CONTINUE TO MONITOR CLOSELY AND ISSUE HIGHLIGHTS/ADVISORIES
AND/OR HYDRO WARNINGS IF/AS NEEDED.
ANOTHER LONGER TERM CONCERN WILL BE THE POTENTIAL FOR STRONG TO
SEVERE CONVECTION OVER PORTIONS OF THE SOUTHEASTERN COLORADO
PLAINS...ESPECIALLY FROM WEDNESDAY INTO WEDNESDAY NIGHT AS DEEPER
ATMOSPHERIC MOISTURE...LOCALIZED 0 TO 6 KM SHEARS AROUND 30
KNOTS...LOCALIZED CAPES AROUND 2100 J/KG AND LOCALIZED LIS AROUND
-8C RESPECTIVELY ARE ANTICIPATED OVER PORTIONS(ESPECIALLY FAR
EASTERN SECTIONS) OF THE SOUTHEASTERN COLORADO PLAINS. AS
ALWAYS...WFO PUEBLO WILL CONTINUE TO MONITOR CLOSELY AND ISSUE
SEVERE WEATHER PRODUCTS AS NEEDED.
ACCUMULATING SNOW IS ALSO EXPECTED AT TIMES OVER HIGHER TERRAIN
AREAS FROM TUESDAY NIGHT INTO LATER THIS WEEK. WINTER WEATHER
HIGHLIGHTS MAY BECOME NECESSARY OVER HIGHER TERRAIN AREAS DURING
THIS TIME-FRAME(ESPECIALLY OVER PUBLIC ZONES 58/60/66/68/73/75/81
AND 82).
IMPROVING METEOROLOGICAL CONDITIONS IN THE FORM OF WARMING
TEMPERATURES AND DECREASING POPS ARE THEN ANTICIPATED FROM LATER
THIS WEEKEND INTO EARLY NEXT WEEK. COOLEST TEMPERATURES DURING THE
LONGER TERM ARE EXPECTED TUESDAY AND WEDNESDAY WHILE WARMEST LONGER
TERM TEMPERATURES ARE PROJECTED SUNDAY AND NEXT MONDAY. FINALLY...
STILL ANTICIPATE THAT LOW-GRADE GRADIENT WINDS SHOULD CONTINUE
OVER THE FORECAST DISTRICT DURING THE LONGER TERM.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1130 PM MDT MON MAY 6 2013
EXPECT VFR CONDITIONS AT ALL TAF SITES TONIGHT THROUGH THE DAY ON
TUESDAY. OVER THE MOUNTAINS...STILL SOME IFR CONDITIONS DUE TO
-SHSN ALONG THE CONTINENTAL DIVIDE THROUGH 10Z...THEN SOME PARTIAL
CLEARING THROUGH MIDDAY TUESDAY AS AREA WILL BE BETWEEN WEATHER
SYSTEMS. SCT -SHRA WILL REDEVELOP OVER THE HIGHER TERRAIN AGAIN
TUE AFTERNOON...LEADING TO BRIEF MVFR/IFR...ESPECIALLY OVER THE
HIGHER PEAKS.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...PETERSEN
AVIATION...PETERSEN
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
539 AM EDT TUE MAY 7 2013
.SYNOPSIS...
DRY WEATHER WILL CONTINUE THROUGH AT LEAST THE FIRST HALF OF
WEDNESDAY AS HIGH PRESSURE REMAINS IN CONTROL. HOWEVER...SOME
COASTAL LOW CLOUDS AND FOG IS EXPECTED AGAIN TONIGHT AND TUESDAY
NIGHT. LOW PRESSURE WILL GRADUALLY WORK UP THE COAST ON WEDNESDAY
ALLOWING US OUR FIRST SHOT OF MEASURABLE RAINFALL WEDNESDAY NIGHT
THROUGH FRIDAY...WITH YET ANOTHER SYSTEM POSSIBLE SATURDAY NIGHT
AND SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATE...LITTLE CHANGE TO THE FORECAST. HAVE USED CURRENT OBS TO
TREND FORECAST INTO THE MID MORNING. HAVE HUNG ON TO THE AREAL
COVERAGE OF STRATUS A COUPLE HOURS LONGER ACROSS THE MIDCOAST AS
WELL.
PREVIOUS DISCUSSION...COASTAL STRATUS HAS ABOUT REACHED ITS WWD
EXTENT ATTM...WHILE IT SLOWLY CREEPS NWD THRU SRN FRANKLIN AND
SOMERSET COUNTIES. WITHIN THE STRATUS...AREAS OF FOG WILL CONTINUE
THRU SUNRISE. VSBYS ARE GENERALLY AOA 1/2SM...SO DON/T FEEL THE
NEED FOR A DENSE FOG ADVISORY.
STRATUS WILL SLOWLY ERODE TODAY WITH DIURNAL HEATING...ESPECIALLY
ALONG THE IMMEDIATE COASTLINE. MET GUIDANCE IS AWFULLY BULLISH ON
HIGH TEMPS REACHING THE LOW 70S FOR SRN COASTAL ZONES DESPITE THE
CLOUDY START AND ONSHORE FLOW. FEEL A MORE CONSERVATIVE APPROACH
TO MAX TEMPS ON THE COAST WAS A BETTER BET...WITH THE LOCAL
WRF...BIAS CORRECTED MOS...AND CMC REGIONAL SUGGESTING CLOSER TO
THE MID 60S. ACROSS THE INTERIOR...THE CONTINUED DRY CONDS AND
FULL SUNSHINE TO START WILL RESULT IN QUICK WARMING. TEMPS HERE
WILL LIKELY BE A COUPLE DEGREES ABV GUIDANCE...NEAR 80.
HAVE ALSO UNDERCUT MOS GUIDANCE ON DEW POINTS FOR THE INTERIOR.
EVEN USING RAP VALUES...REPRESENTING THE COOLEST GUIDANCE...RH
VALUES REMAIN AROUND 25% AND WINDS ARE LIGHT ENOUGH THAT NO RED
FLAG CONDS ARE EXPECTED.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
STRATUS WILL LURK JUST OFFSHORE FOR MOST OF THE DAY TODAY...AND
SURGE BACK SWD ALONG THE COAST TONIGHT. EXPECT MAINLY MIDCOAST TO
BE AFFECTED BY LOW CIGS/VSBYS THIS TIME AROUND. INCREASING
MOISTURE WILL KEEP LOW TEMPS FROM BOTTOMING OUT AS COLD AS THE
PAST FEW NIGHTS. WITH LOW STRATUS AND INCREASINGLY MOIST AIR
MASS...HAVE STAYED AWAY FROM BIAS CORRECTED GRIDS GIVEN THE
CHANGING CONDS.
ON WED...UPR LOW WILL MEANDER OUT OF THE MID ATLANTIC. CLOUDS WILL
INCREASE FROM S TO N THRU THE DAY WED. BY LATE IN THE AFTERNOON
EXPECTED SHWRS TO MOVE INTO SRN NH AND ADJACENT ME. PRIOR TO 00Z
THU NOT MUCH IN THE WAY OF QPF SHOULD IMPACT THE AREA.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
THE BEST CHANCE FOR SHOWERS WILL BE WEDNESDAY NIGHT AS A SOUTHERLY
GRADIENT ALIGNS THROUGH A DEEP LAYER. MOISTURE AHEAD OF A
WEAKENING ARE OF LOW PRESSURE WILL ENTER FROM THE GULF OF MAINE.
THIS WILL CONTINUE ON THURSDAY...HOWEVER INFLOW WILL NOT BE AS
PROMINENT AS THE TROUGH WEAKENS OVERHEAD.
A COLD FRONT WILL APPROACH FROM THE WEST ON FRIDAY. HOWEVER...WEAK
WAVES OF LOW PRESSURE WILL LIKELY FORM ALONG THE SLOW MOVING
BOUNDARY. AN UPPER LEVEL TROUGH APPROACHING FROM THE NW WILL ALSO
ALLOW THIS SYSTEM TO STALL JUST SOUTH OF OUR FORECAST AREA. THIS
WILL ALLOW FOR A CHANCE OF (WELL NEEDED) SHOWERS RIGHT THROUGH THE
WEEKEND.
&&
.AVIATION /10Z TUESDAY THROUGH SATURDAY/...
SHORT TERM...LIFR CONDS TO LINGER ON COAST THRU 13 OR
14Z...ERODING FROM S TO N ALONG THE COAST. LOW CLOUDS MAY LINGER
INTO THE MIDDAY INVOF KRKD. VFR CONDS EXPECTED TODAY. IFR/LIFR
CIGS WILL WORK BACK INTO COASTAL AREAS AGAIN TONIGHT...ESPECIALLY
KRKD BUT NOT AS LIKELY AS FAR S AS KPWM. VFR CONDS TO START THE
DAY ON WED...WITH MVFR CIGS/VSBYS IN SHWRS ACROSS SRN NH LATE IN
THE AFTERNOON.
LONG TERM...
EXPECT SHOWERY WEATHER FROM WEDNESDAY NIGHT THROUGH
SATURDAY. CONDITIONS COULD BE MVFR OR IFR DURING THIS PERIOD.
&&
.MARINE...
SHORT TERM...WINDS AND SEAS EXPECTED TO REMAIN BLO SCA THRESHOLDS.
LONG TERM...
SLOW MOVING LOW PRESSURE WILL BRING SHOWERY WEATHER BUT THE
PRESSURE GRADIENT WILL BE TOO LIGHT TO CAUSE GUSTY WINDS THROUGH THIS
WEEKEND. SEAS WILL SLOWLY BUILD DURING THE MIDWEEK PERIOD.
&&
.FIRE WEATHER...
HIGH PRESSURE SLOWLY LOSING ITS GRIP ON THE AREA. NO RAIN IS
EXPECTED TODAY...WITH AFTERNOON RH VALUES DIPPING TO NEAR 25%
AWAY FROM THE COAST. WINDS WILL REMAIN LIGHT ACROSS THE
INTERIOR. THE CHANCE OF WETTING RAINS INCREASES LATER WEDNESDAY
FOR SOUTHERN AREAS...AND BY THURSDAY FOR THE NORTH COUNTRY. RH
VALUES ARE EXPECTED TO CLIMB FURTHER WEDNESDAY...AS AIR MASS
GRADUALLY MOISTENS.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
LEGRO/JC
AREA FORECAST DISCUSSION
NWS GRAY ME
248 AM EDT TUE MAY 7 2013
.SYNOPSIS...
DRY WEATHER WILL CONTINUE THROUGH AT LEAST THE FIRST HALF OF
WEDNESDAY AS HIGH PRESSURE REMAINS IN CONTROL. HOWEVER...SOME
COASTAL LOW CLOUDS AND FOG IS EXPECTED AGAIN TONIGHT AND TUESDAY
NIGHT. LOW PRESSURE WILL GRADUALLY WORK UP THE COAST ON WEDNESDAY
ALLOWING US OUR FIRST SHOT OF MEASURABLE RAINFALL WEDNESDAY NIGHT
THROUGH FRIDAY...WITH YET ANOTHER SYSTEM POSSIBLE SATURDAY NIGHT
AND SUNDAY.
&&
.NEAR TERM /THROUGH TODAY/...
COASTAL STRATUS HAS ABOUT REACHED ITS WWD EXTENT ATTM...WHILE IT
SLOWLY CREEPS NWD THRU SRN FRANKLIN AND SOMERSET COUNTIES. WITHIN
THE STRATUS...AREAS OF FOG WILL CONTINUE THRU SUNRISE. VSBYS ARE
GENERALLY AOA 1/2SM...SO DON/T FEEL THE NEED FOR A DENSE FOG
ADVISORY.
STRATUS WILL SLOWLY ERODE TODAY WITH DIURNAL HEATING...ESPECIALLY
ALONG THE IMMEDIATE COASTLINE. MET GUIDANCE IS AWFULLY BULLISH ON
HIGH TEMPS REACHING THE LOW 70S FOR SRN COASTAL ZONES DESPITE THE
CLOUDY START AND ONSHORE FLOW. FEEL A MORE CONSERVATIVE APPROACH
TO MAX TEMPS ON THE COAST WAS A BETTER BET...WITH THE LOCAL
WRF...BIAS CORRECTED MOS...AND CMC REGIONAL SUGGESTING CLOSER TO
THE MID 60S. ACROSS THE INTERIOR...THE CONTINUED DRY CONDS AND
FULL SUNSHINE TO START WILL RESULT IN QUICK WARMING. TEMPS HERE
WILL LIKELY BE A COUPLE DEGREES ABV GUIDANCE...NEAR 80.
HAVE ALSO UNDERCUT MOS GUIDANCE ON DEW POINTS FOR THE INTERIOR.
EVEN USING RAP VALUES...REPRESENTING THE COOLEST GUIDANCE...RH
VALUES REMAIN AROUND 25% AND WINDS ARE LIGHT ENOUGH THAT NO RED
FLAG CONDS ARE EXPECTED.
&&
.SHORT TERM /TONIGHT THROUGH 6 PM WEDNESDAY/...
STRATUS WILL LURK JUST OFFSHORE FOR MOST OF THE DAY TODAY...AND
SURGE BACK SWD ALONG THE COAST TONIGHT. EXPECT MAINLY MIDCOAST TO
BE AFFECTED BY LOW CIGS/VSBYS THIS TIME AROUND. INCREASING
MOISTURE WILL KEEP LOW TEMPS FROM BOTTOMING OUT AS COLD AS THE
PAST FEW NIGHTS. WITH LOW STRATUS AND INCREASINGLY MOIST AIR
MASS...HAVE STAYED AWAY FROM BIAS CORRECTED GRIDS GIVEN THE
CHANGING CONDS.
ON WED...UPR LOW WILL MEANDER OUT OF THE MID ATLANTIC. CLOUDS WILL
INCREASE FROM S TO N THRU THE DAY WED. BY LATE IN THE AFTERNOON
EXPECTED SHWRS TO MOVE INTO SRN NH AND ADJACENT ME. PRIOR TO 00Z
THU NOT MUCH IN THE WAY OF QPF SHOULD IMPACT THE AREA.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
THE BEST CHANCE FOR SHOWERS WILL BE WEDNESDAY NIGHT AS A SOUTHERLY
GRADIENT ALIGNS THROUGH A DEEP LAYER. MOISTURE AHEAD OF A
WEAKENING ARE OF LOW PRESSURE WILL ENTER FROM THE GULF OF MAINE.
THIS WILL CONTINUE ON THURSDAY...HOWEVER INFLOW WILL NOT BE AS
PROMINENT AS THE TROUGH WEAKENS OVERHEAD.
A COLD FRONT WILL APPROACH FROM THE WEST ON FRIDAY. HOWEVER...WEAK
WAVES OF LOW PRESSURE WILL LIKELY FORM ALONG THE SLOW MOVING
BOUNDARY. AN UPPER LEVEL TROUGH APPROACHING FROM THE NW WILL ALSO
ALLOW THIS SYSTEM TO STALL JUST SOUTH OF OUR FORECAST AREA. THIS
WILL ALLOW FOR A CHANCE OF (WELL NEEDED) SHOWERS RIGHT THROUGH THE
WEEKEND.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
SHORT TERM...LIFR CONDS TO LINGER ON COAST THRU 13 OR
14Z...ERODING FROM S TO N ALONG THE COAST. LOW CLOUDS MAY LINGER
INTO THE MIDDAY INVOF KRKD. VFR CONDS EXPECTED TODAY. IFR/LIFR
CIGS WILL WORK BACK INTO COASTAL AREAS AGAIN TONIGHT...ESPECIALLY
KRKD BUT NOT AS LIKELY AS FAR S AS KPWM. VFR CONDS TO START THE
DAY ON WED...WITH MVFR CIGS/VSBYS IN SHWRS ACROSS SRN NH LATE IN
THE AFTERNOON.
LONG TERM...
EXPECT SHOWERY WEATHER FROM WEDNESDAY NIGHT THROUGH
SATURDAY. CONDITIONS COULD BE MVFR OR IFR DURING THIS PERIOD.
&&
.MARINE...
SHORT TERM...WINDS AND SEAS EXPECTED TO REMAIN BLO SCA THRESHOLDS.
LONG TERM...
SLOW MOVING LOW PRESSURE WILL BRING SHOWERY WEATHER BUT THE
PRESSURE GRADIENT WILL BE TOO LIGHT TO CAUSE GUSTY WINDS THROUGH THIS
WEEKEND. SEAS WILL SLOWLY BUILD DURING THE MIDWEEK PERIOD.
&&
.FIRE WEATHER...
HIGH PRESSURE SLOWLY LOSING ITS GRIP ON THE AREA. NO RAIN IS
EXPECTED TODAY...WITH AFTERNOON RH VALUES DIPPING TO NEAR 25%
AWAY FROM THE COAST. WINDS WILL REMAIN LIGHT ACROSS THE
INTERIOR. THE CHANCE OF WETTING RAINS INCREASES LATER WEDNESDAY
FOR SOUTHERN AREAS...AND BY THURSDAY FOR THE NORTH COUNTRY. RH
VALUES ARE EXPECTED TO CLIMB FURTHER WEDNESDAY...AS AIR MASS
GRADUALLY MOISTENS.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
LEGRO/JC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
419 AM EDT TUE MAY 7 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 418 AM EDT TUE MAY 7 2013
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW W-E ORIENTED UPR
RDG STRETCHING ALONG THE US/CNDN BORDER TO THE N OF CLOSED UPR LOWS
OVER THE SE CONUS AND ANOTHER JUST OFF THE CA COAST. AT THE SFC...
HI PRES IS CENTERED OVER LK SUP...AND WINDS ARE NEAR CALM UNDER
SLACK PRES GRADIENT. WITH VERY DRY AIRMASS SHOWN ON THE 00Z GRB
RAOB...WHERE PWAT WAS ONLY 0.15 INCH OR 27 PCT OF NORMAL...QUIET WX
DOMINATES THE CWA. THERE ARE SOME HI CLDS OVER THE SCENTRAL...BUT
OTRW SKIES ARE CLR.
DRY HI PRES IS FCST TO DOMINATE THE UPR LKS TDAY/TNGT...SO QUIET
WX/MOCLR SKIES SHOULD CONTINUE. MAIN FCST CONCERNS ARE TEMPS/HOW LO
MIN RH WL FALL THIS AFTN. ANY SHALLOW GROUND FOG THAT FORMS OVER THE
INTERIOR W EARLY THIS MRNG WL BURN OFF QUICKLY AFT SUNRISE. WITH H85
TEMPS THIS AFTN IN THE 10-11C RANGE...ABOUT THE SAME OR 1C HIER THAN
YDAY...MAX TEMPS SHOULD BE SIMILAR TO WHAT OCCURRED ON MON. DEEP
MIXING TO H75 ON FCST SDNGS YIELDS HI TEMPS RISING WELL INTO THE 70S
AWAY FM LK MODERATION. ONE DIFFERENCE IS THE H925 FLOW IS FCST TO BE
A BIT STRONGER OUT OF THE S-SE THAN YDAY AND UP TO 10 KTS WITH HI
CENTER SHIFTING SLOWLY TO THE E. AS A RESULT...LK MODERATION OFF LK
SUP SHOULD NOT PENETRATE AS FAR INLAND AS ON MON. ON THE OTHER
HAND...MODERATION OFF LK MI WL BE A BIT MORE AGGRESSIVE. AWAY FM LK
COOLING/ MOISTENING...THE DEEP MIXING WL ALLOW SFC DEWPTS TO FALL TO
ARND 30 THIS AFTN...RESULTING IN MIN RH ARND 20 PCT. SINCE WINDS
SHOULD BE NO HIER THAN ABOUT 10 MPH...NO FIRE WX HEADLINES ARE
NECESSARY.
CONTINUED AIRMASS MODERATION...A SOMEWHAT STRONGER S WIND...AND THE
ARRIVAL OF MOISTER AIR ESPECIALLY OVER THE W...WHERE THE PWAT IS
FCST TO RISE TO NEAR 0.75 INCH BY 12Z WED...WL CONSPIRE TO KEEP MIN
TEMPS TNGT HIER THAN THIS MRNG. THE DIFFERENCE SHOULD BE MOST
PRONOUNCED OVER THE W CLOSER TO THE INCOMING MOISTER AIR.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 418 AM EDT TUE MAY 7 2013
LIMITED CHANGES TO THE GOING FORECAST FROM 24HRS AGO. THE HIGH
PRESSURE RIDGE THAT THE AREA IS CURRENTLY UNDER WILL BEGIN TO
LOOSEN IT/S GRIP ON THE AREA ON WEDNESDAY...BUT NOT BEFORE
PROVIDING ANOTHER ABOVE NORMAL TEMPERATURE DAY FOR MUCH OF UPPER
MICHIGAN. MOST AREAS WILL SEE TEMPERATURES IN THE 70S...BUT LAKE
BREEZES WILL LEAD TO SLIGHTLY COOLER VALUES NEAR THE GREAT LAKES.
MOST MODELS HAVE BACKED OFF ON PRECIPITATION FROM THE DIURNAL CU
OVER THE WESTERN CWA IN THE AFTERNOON...AND THAT SEEMS REASONABLE
BASED OFF THE MOISTURE BEING FOCUSED ABOVE 6-7KFT. WITH THE HIGH
BASED CLOUDS AND THE LINGERING LOW LEVEL DRY AIR...IT MAY BE TOUGH
TO GET PRECIPITATION TO REACH THE SURFACE. IN ADDITION...LOOKING AT
MODEL SOUNDINGS...THE VERY LOW LEVELS ARE TRYING TO OVER MOISTEN
THE SURFACE...WHICH INCREASES THE SFC BASED CAPE TOWARDS 500-750
J/KG. LOOKING AT MLCAPE...THAT DRY AIR CUTS BACK CAPE VALUES TO
50-250 J/KG AND WITH THE OTHER NEGATIVE VALUES...WILL CUT BACK
POPS TO SLIGHTS OVER THE FAR WEST. ALSO FOR WEDNESDAY...LOWERED
DEWPOINTS BASED OFF DRIER AIR HOLDING OVER THE AREA. THIS WILL LEAD
TO ANOTHER DAY OF RH VALUES IN THE 20S OVER THE INTERIOR CENTRAL AND
EAST. FORTUNATELY...THE WINDS WILL AGAIN REMAIN LIGHT AND BE THE
STRONGEST ALONG THE LEADING EDGE OF THE LAKE BREEZES.
FOR WEDNESDAY NIGHT INTO THURSDAY...FOCUS TURNS TO THE WEAK COLD
FRONT DROPPING SOUTHEAST ACROSS THE AREA IN THE EARLY EVENING AND
WEAK SHORTWAVE ENERGY AND ASSOCIATED MOISTURE PUSHING EAST FROM
SOUTHERN MINNESOTA AND INTO THE LOWER GREAT LAKES. WITH THE MOISTURE
FAIRLY LIMITED WITH THE COLD FRONT...THE PRECIPITATION CHANCES WILL
BE LARGELY DEPENDENT ON THE TRACK OF THE SHORTWAVE. WITH THE BEST
MOISTURE AND CLOSEST PROXIMITY TO THE ENERGY TO THE SOUTHWEST OF THE
AREA...WILL HAVE THE HIGHEST POPS OVER THE WEST...WITH LOW END
LIKELY AND HIGH END CHANCE VALUES FOR OVERNIGHT WEDNESDAY NIGHT AND
THURSDAY MORNING BEFORE DIMINISHING DURING THE AFTERNOON. QPF
AMOUNTS SHOULD BE ON THE LIGHT SIDE /LESS THAN A QUARTER OF AN
INCH/ UNLESS THE SHORTWAVE IS FARTHER TO THE NORTH...WHICH ALLOW
FOR GREATER INTERACTION BETWEEN THE WAVE AND THE FRONT.
BEHIND THE COLD FRONT...CANADIAN HIGH PRESSURE WILL BUILD OVER THE
AREA FROM THE NORTHWEST ON THURSDAY NIGHT AND REMAIN INTO FRIDAY
EVENING. THIS SHOULD LEAD TO DRY WEATHER...BUT WITH COOLER
TEMPERATURES ALOFT /850MB TEMPS AROUND 2-4C/ WOULD EXPECT HIGHS TO
BE IN THE 50S INLAND AND IN THE UPPER 40S TO AROUND 50 NEAR LAKE
SUPERIOR WITH THE NORTHEAST WINDS.
STRONG NORTHERN STREAM UPPER TROUGH WILL DIVE SOUTHEAST ACROSS THE
AREA LATE FRIDAY NIGHT AND SATURDAY. WITH THE STRENGTH OF THE
FRONT...WOULD EXPECT A NICE LINE OF SHOWERS MOVING ACROSS THE
AREA LATE FRIDAY NIGHT AND SATURDAY. THE SPEED OF THE FRONT WILL
LIMIT ACCUMULATIONS...BUT MOST AREAS SHOULD SEE A TENTH OF AN INCH
OF RAIN. THERE IS THE POTENTIAL THE BACK SIDE OF THIS PRECIPITATION
COULD TURN OVER TO SNOW AND WILL CONTINUE THAT MENTION. WITH THE
VERY COLD AIR ALOFT BEHIND THE FRONT ON SATURDAY AFTERNOON...WOULD
EXPECT DIURNAL SHOWERS TO DEVELOP ON THE BACK SIDE OF THE LOW...DUE
TO THE SFC-700MB LAPSE RATES AROUND 8-8.5 C/KM. THIS PRECIPITATION
WILL START AS SNOW ALOFT AND P-TYPE AT THE SURFACE DEPENDS ON LOW
LEVEL TEMPERATURES. MODELS ARE HINTING AT SURFACE TEMPERATURES BEING
WARMER...BUT WITH THE DRY LOW LEVEL AIR AND INVERTED V LOOK TO THE
SOUNDING...OPTED TO UTILIZE THE WETBULB ZERO HEIGHT FOR RAIN/SNOW
LINE. THIS PLACES A RAIN/SNOW MIX OVER THE NORTH AND RAIN OVER THE
SOUTH. WITH THE LATEST MODEL TRENDS...IT MAY END UP BEING SNOW
ACROSS MUCH OF THE AREA. ALSO ADJUSTED HIGHS DOWN TOWARDS RAW MODEL
DATA...SINCE MOS TREND TOWARDS NORMAL IS BIASING THE COLD TEMPS.
THIS PRODUCES HIGHS IN THE LOW-MID 40S OVER THE NORTHWEST HALF OF
THE CWA AND UPPER 40S OVER THE SOUTHEAST HALF. THE COOLER
TEMPERATURES AND THE GUSTY NORTHWEST WINDS...25-30KTS...IT WILL NOT
FEEL LIKE A MID MAY DAY ACROSS UPPER MICHIGAN. COULD EVEN BE A FEW
LAKE EFFECT SNOW SHOWERS ON SATURDAY NIGHT OVER THE EAST. DECENT
SFC-775MB DELTA-T VALUES...BUT MOISTURE APPEARS LIMITED AT THIS
POINT WITH AN INVERTED V LOOK BELOW THE CLOUD BASE AND WILL ONLY
MENTION SLIGHT CHANCES.
UPPER TROUGH WILL BEGIN TO SHIFT EAST ON SUNDAY AND PULL THE
MOISTURE WITH IT. THUS...EXPECT A DIMINISHING TREND TO THE
PRECIPITATION ON SATURDAY NIGHT AND A DRY SUNDAY. TEMPERATURES WILL
REMAIN ON THE COLD SIDE ON SUNDAY...WITH HIGHS IN THE LOW 40S OVER
THE EAST AND MID 40S OVER THE WEST DUE TO WARMING TEMPERATURES
ALOFT. UPPER RIDGE WILL THEN BUILD OVER THE UPPER GREAT LAKES FOR
MONDAY INTO TUESDAY. MEANWHILE...A LOW PRESSURE SYSTEM MOVING
THROUGH NORTHERN ONTARIO WILL SWEEP A WARM FRONT ACROSS SOUTHERN
ONTARIO ON MONDAY NIGHT...WHICH COULD BRUSH THE CWA. THIS FRONT
WILL ALSO BRING TEMPERATURES BACK TO NORMAL ACROSS THE AREA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 125 AM EDT TUE MAY 7 2013
EXPECT LIGHT WINDS AT KIWD/KCMX/KSAW THIS TAF PERIOD WITH DRY HIGH
PRES DOMINATING. SOME FOG WITH MVFR VSBYS MAY DEVELOP AT KIWD AND
KCMX EARLY THIS MORNING. NOT OUT OF THE QUESTION THAT BRIEF IFR COULD
OCCUR AS WELL. OTHERWISE...VFR CONDITIONS WILL DOMINATE THROUGH THE
DAY ON TUE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 418 AM EDT TUE MAY 7 2013
HIGH PRESSURE WILL CONTINUE TO PRODUCE LIGHT WINDS TODAY AND
WEDNESDAY...BUT A COLD FRONT MOVING THROUGH ON WEDNESDAY AFTERNOON
AND EARLY EVENING WILL LEAD TO INCREASING NORTH-NORTHEAST WINDS
PEAKING IN THE 15-25KT RANGE ON WEDNESDAY NIGHT INTO THURSDAY
MORNING. HIGH PRESSURE WILL BUILD BACK OVER THE AREA FOR FRIDAY AND
DIMINISH THE WINDS. BUT A STRONGER COLD FRONT WILL SLIDE THROUGH
FRIDAY NIGHT AND SHIFT WINDS TO THE NORTHWEST AT 20-30KTS ON
SATURDAY. THESE WINDS WILL CONTINUE INTO SATURDAY NIGHT BEFORE
GRADUALLY DIMINISHING ON SUNDAY.
&&
.HYDROLOGY...
ISSUED AT 418 AM EDT TUE MAY 7 2013
HYDROLOGY CONCERNS REMAIN FOR TODAY AND WEDNESDAY...BUT THEY
ARE STARTING TO DIMINISH WITH THE DWINDLING SNOW PACK OVER
WESTERN UPPER MICHIGAN. VISIBLE SATELLITE AND MODIS IMAGERY
YESTERDAY STILL SHOWS SNOW REMAINING IN THE HIGHER TERRAIN LOCATIONS
OF THE HURON MOUNTAINS AND THE KEWEENAW PENINSULA. THE LATEST SNOW
DEPTH OBSERVATIONS /FROM EARLIER THIS MORNING AROUND 8AM/ STILL HAVE
AROUND 3IN AT IRONWOOD...AND 7IN AT ATLANTIC MINE. A FEW POCKETS OF
HIGHER AMOUNTS ARE LIKELY ACROSS THE KEWEENAW. DID SEE RISES AT SOME
OF THE SITES OVER THE WEST /ESPECIALLY TRRM4 AND BESM4/ WITH THE
WARMER TEMPERATURES YESTERDAY. BUT THE TRAP ROCK RIVER LEVELED OFF
MUCH FASTER OVERNIGHT AND THAT MAY BE A SIGN OF THE LACK OF SNOW
WATER EQUIVALENT LEFT IN THE BASIN. WITH THE SOLID RISE YESTERDAY OF
BESM4 AND DECENT SNOW COVER...WOULD THINK IT WOULD MAKE ANOTHER PUSH
TODAY. AT THIS TIME...AN EDUCATED GUESS WOULD PUT IT BETWEEN 8 AND 9
FEET THIS AFTERNOON/EVENING...WHICH WOULD LIKELY BE THE LAST MAJOR
PUSH.
THE ONGOING FLOODING ON THE MICHIGAMME RIVER AROUND WITCH LAKE WILL
REMAIN A CONCERN FOR THE NEXT COUPLE OF DAYS UNTIL THE SNOW WATER
MAKES IT OUT OF THE HIGHER TERRAIN OF NORTHWEST MARQUETTE COUNTY.
THE STURGEON RIVER AT ALSTON AND CHASSELL CONTINUES TO HOVER BETWEEN
ADVISORY AND WARNING LEVELS AND WOULD EXPECT THAT TO CONTINUE BASED
ON THE STEADY FLOW THROUGH THE STURGEON RIVER AT SIDNAW UPSTREAM.
OTHERWISE...THE REST RIVER LEVELS ARE ON THE DOWNWARD TREND AND
WILL LIKELY CONTINUE THIS WEEK.
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 MARQUETTE MI
127 AM EDT TUE MAY 7 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 405 PM EDT MON MAY 6 2013
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW BLOCKY FLOW ACROSS THE
CONUS TO THE S OF NEARLY ZONAL FLOW ACROSS CNTRL CANADA. A NARROW
RIDGE EXTENDS FROM SRN BRITISH COLUMBIA E ACROSS THE UPPER GREAT
LAKES TO NEW ENGLAND. FARTHER S...CLOSED MID LEVEL LOWS WERE LOCATED
JUST OFF THE CA COAST...OVER SD AND OVER THE SE CONUS. WITH THE
UPPER GREAT LAKES UNDER THE RIDGE...IT`S BEEN A PLEASANT EARLY MAY
DAY ACROSS UPPER MI AS DEEP DRY COLUMN IS ALLOWING FOR ABUNDANT
SUNSHINE. LAKE BREEZES HAVE DEVELOPED ACROSS THE BOARD. WHILE IT`S
CHILLY ALONG LAKE SUPERIOR WITH TEMPS IN THE 40S...SIGNIFICANT
COOLING HAS YET TO OCCUR ALONG MOST OF THE LAKE MI SHORELINE.
INLAND...TEMPS HAVE SOARED THRU THE 60S TO AS HIGH AS THE LOW/MID
70S. LAST BIT OF LINGERING FOG OVER WRN LAKE SUPERIOR BTWN THE
APOSTLE ISLANDS AND UPPER MI HAS JUST ABOUT DISSIPATED AS OF 1930Z.
WITH LITTLE CHANGE IN THE AIR MASS THRU TUE...FCST FOR TONIGHT/TUE
WILL BE SIMILAR TO LAST NIGHT/TODAY. LIGHT/CALM WIND AND CLEAR SKIES
WILL LEAD TO GOOD RADIATIONAL COOLING CONDITIONS TONIGHT. HOWEVER...
PRECIPITABLE WATER DOES RISE SOME COMPARED TO LAST NIGHT OVER THE W
HALF OR SO (UP TOWARD NORMAL FROM 60PCT OF NORMAL LAST NIGHT). ALONG
WITH AIR MASS MODERATION TODAY...MINS TONIGHT SHOULD BE SEVERAL
DEGREES HIGHER THAN LAST NIGHT. COLUMN REMAINS DRIER OVER THE E...SO
MINS THERE WILL PROBABLY BE WITHIN A COUPLE OF DEGREES OF LAST
NIGHTS MINS. OVERALL...EXPECT MIN TEMPS TONIGHT IN THE 30S. MIGHT
SEE SOME PATCHY GROUND FOG OVER THE INTERIOR W LATE TONIGHT. 850MB
TEMPS TUE ARE NEARLY THE SAME AS TODAY. WITH ABUNDANT SUNSHINE AGAIN
(SHOULD BE SOME CU OVER THE W)...MAX TEMPS WILL BE SIMILAR TO WHAT
IS BEING OBSERVED THIS AFTN. SFC HIGH PRES RIDGED ACROSS THE UPPER
LAKES WILL LEAD TO ANOTHER DAY OF LAKE BREEZES. HOWEVER...WITH HIGH
CENTER SETTING UP A LITTLE FARTHER E...LIGHT SOUTHERLY GRADIENT FLOW
SHOULD LEAD TO A LESS AGGRESSIVE INLAND PUSH OF THE LAKE SUPERIOR
LAKE BREEZE...AND COOLING SHOULD BE A LITTLE STRONGER ALONG LAKE MI
SAT AFTN COMPARED TO TODAY. TAKING INTO ACCOUNT MIXING DEPTH...
DWPTS SHOULD TANK IN SOME INLAND AREAS WITH RH BOTTOMING OUT AS LOW
AS AROUND 20PCT. IN GENERAL...RH SHOULD BE IN 20S INLAND.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 436 PM EDT MON MAY 6 2013
THE 500MB RIDGE THAT HAS BEEN SET UP ACROSS UPPER MICHIGAN WILL BE
EXITING EASTWARD TUESDAY NIGHT...WITH AN OPEN WAVE/TROUGH EXTENDING
FROM NORTHERN CANADA THROUGH THE DAKOTAS SHIFTING TOWARD MINNESOTA
AND ONTARIO.
WEAK SSW WINDS FLOW WILL SLOWLY BRING BACK INCREASED MOISTURE
THROUGH THE DAY WEDNESDAY...WITH PW VALUES JUMPING AT OR ABOVE 1IN
BY MID AFTERNOON OVER THE WESTERN THIRD OF THE CWA /175 PERCENT OR
NORMAL OR MORE/. THE MAIN RESULT WILL BE INCREASED CLOUD COVER. A
WEAKENING SFC TROUGH WILL SINK FROM NW LAKE SUPERIOR AT DAYBREAK
WEDNESDAY. FCST MODELS ARE VERY CONSISTENT WITH THE TRACK/TIMING OF
THE TROUGH AS OF THE 12Z RUNS. EXPECT THE TROUGH TO PUSH ACROSS
CENTRAL LAKE SUPERIOR BY 18Z...AND THEN SINK ACROSS UPPER MI
WEDNESDAY AFTERNOON...TO JUST S OF THE CWA BY 06Z THURSDAY. A FEW
SHOWERS WILL BE POSSIBLE WEDNESDAY NIGHT THROUGH THURSDAY...WITH
TOTAL QPF AROUND A TENTH OF AN INCH OR LESS.
STRONG HIGH PRESSURE ACROSS MOST OF CENTRAL CANADA WILL SLOWLY SINK
IN BEHIND THE TROUGH...BRINGING WITH IT A RETURN OF DRIER AND COLDER
AIR. 850MB TEMPS ARE ANTICIPATED TO FALL FROM AROUND 9C WEDNESDAY
AFTERNOON TO AROUND 4C BY FRIDAY AFTERNOON.
LOOKING MORE AT THE FIRE FRONT...THE CENTRAL AND EASTERN UPPER
MICHIGAN WILL CONTINUE TO BE THE DRIEST THROUGH AT LEAST FRIDAY
NIGHT.
WINDS MAY BECOME A CONCERN ON SATURDAY...PICKING UP OUT OF A NW
DIRECTION THROUGHOUT THE DAY...BEHIND A STRONGER COLD FRONT WITH A
REINFORCING SHORTWAVE. A 30-35KT LLJ CORE AROUND 800BM THROUGH
MUCH OF THE DAY SATURDAY OVER THE WEST...RESULTING IN 20-25KT GUSTS
SATURDAY THROUGH MUCH OF SUNDAY.
ON A POSITIVE NOTE...A TENTH TO QUARTER OF AN INCH IS OF RAIN IS
FORECAST...AND MUCH COLDER AIR WILL BE SINKING IN. 850MB TEMPS WILL
COOL SIGNIFICANTLY...WITH THE 12Z ECMWF COMING IN WITH -8 TO -10C
READINGS FROM 06-18Z SUNDAY. WITH A DEEPER AND SLOWER SYSTEM
OVERALL...A FEW FLURRIES WILL BE POSSIBLE FROM SATURDAY THROUGH
SUNDAY. THE GOOD NEWS FOR THOSE WHO WOULD RATHER NOT SEE ANOTHER
SNOWFLAKE UNTIL THE FALL...MOST OF THE MOISTURE WILL BE OUT OF THE
AREA BEFORE THE COLD AIR ARRIVES. DO NOT EXPECT ANY TRAVEL CONCERNS
OR PLOWING NEEDED...GIVEN THE STRENGTH OF THE SUN THIS TIME OF
YEAR...AND THE WARM ROADWAYS. GRASSY SURFACES WILL REALLY SEE THE
ONLY CHANCE OF ANY DUSTING OF SNOW.
AFTER A COOL WEEKEND WITH HIGHS IN THE 40S TO AROUND 50...TEMPS WILL
WARM UP AGAIN TO NEAR NORMAL READINGS BY MONDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 125 AM EDT TUE MAY 7 2013
EXPECT LIGHT WINDS AT KIWD/KCMX/KSAW THIS TAF PERIOD WITH DRY HIGH
PRES DOMINATING. SOME FOG WITH MVFR VSBYS MAY DEVELOP AT KIWD AND
KCMX EARLY THIS MORNING. NOT OUT OF THE QUESTION THAT BRIEF IFR COULD
OCCUR AS WELL. OTHERWISE...VFR CONDITIONS WILL DOMINATE THROUGH THE
DAY ON TUE.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 405 PM EDT MON MAY 6 2013
QUIET WEATHER WILL CONTINUE OVER THE UPPER GREAT LAKES FOR THE NEXT
COUPLE OF DAYS. WITH HIGH PRES RIDGE REMAINING OVER THE AREA...WINDS
WILL LIKELY REMAIN UNDER 15KT THRU WED AFTN. THEN...A COLD FRONT
DROPPING SOUTHEAST ACROSS THE UPPER GREAT LAKES WEDNESDAY NIGHT WILL
BRING A WIND SHIFT AND STRONGER WINDS INTO THE 15-25KT RANGE FOR A
TIME LATER WED NIGHT INTO THU. WINDS WILL DIMINISH HEADING INTO FRI
AS A HIGH PRES SYSTEM MOVES ACROSS NRN ONTARIO. A STRONG COLD FRONT
PASSING FRI NIGHT/SAT MORNING WILL BRING ANOTHER ROUND OF 15-25KT
WINDS FOR SAT.
&&
.HYDROLOGY...
ISSUED AT 436 PM EDT MON MAY 6 2013
HYDROLOGY CONCERNS CONTINUE...BUT ARE SLOWLY DIMINISHING AT ALL
SITES EXCEPT FOR LAKE LINDEN ON THE TRAP ROCK RIVER WHICH HAS BEEN
SHOWING ITS USUAL DIURNAL INCREASE AS A RESULT OF THE SIGNIFICANT
SNOW PACK STILL MELTING ACROSS THE KEWEENAW PENINSULA. THE LATEST
SNOW DEPTH OBSERVATIONS /FROM EARLIER THIS MORNING AROUND 8AM/ STILL
HAVE AROUND 3IN AT IRONWOOD...AND 7IN AT ATLANTIC MINE. A FEW
POCKETS OF HIGHER AMOUNTS ARE LIKELY ACROSS THE KEWEENAW.
THE ONGOING FLOODING ON THE STURGEON RIVER AT ALSTON AND
CHASSELL...THE MICHIGAMME RIVER AROUND WITCH LAKE...AND THE PAINT
RIVER NEAR CRYSTAL FALLS WILL REMAIN A CONCERN FOR THE NEXT COUPLE
OF DAYS. 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...ROLFSON
LONG TERM...KF
AVIATION...KC
MARINE...ROLFSON
HYDROLOGY...KF
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
348 AM CDT TUE MAY 7 2013
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 329 AM CDT TUE MAY 7 2013
UPPER LEVEL LOW STILL CENTERED OVER NORTHWEST GEORGIA/NORTHEAST
ALABAMA IS FORECAST TO BEGIN MOVING SLOWLY NORTHEAST TODAY. THIS
SHOULD FINALLY BRING A CLEARING SKY AND WARMER TEMPERATURES TO THE
REGION. THERE IS A PERSISTENT BAND OF MID LEVEL CLOUDS AROUND
10,000FT WHICH JUST DON`T SEEM TO WANT TO GO AWAY. THE NAM SEEMS TO
BE HANDLING THE DECK PRETTY WELL AT THIS TIME...AND IT SLOWLY THINS
OUT THROUGH THE MORNING. THE RUC ON THE OTHER HAND KEEPS THE DECK
AROUND AT LEAST THROUGH EARLY AFTERNOON. AM LEANING TOWARD THE RUC
AT THIS TIME SINCE THIS IS CLOSER TO PERSISTENCE...AND THIS SYSTEM
HAS BEEN NOTHING IF NOT PERSISTENT. CLOUDS SHOULD BE THINNING OUT
DURING THE AFTERNOON...AND STRONG MAY SUNSHINE SHOULD EASILY PROPEL
HIGHS INTO THE MID AND UPPER 70S. THERE MAY BE ENOUGH INSTABILITY
AROUND THIS AFTERNOON FOR POP-UP SHOWERS AND THUNDERSTORMS...SO THE
SLIGHT CHANCE POPS CURRENTLY IN THE FORECAST LOOK TO BE ON TRACK.
MEANWHILE...THE COMPACT LITTLE CUTOFF LOW CURRENTLY OVER SOUTH
DAKOTA WILL START DRIFTING SOUTHEAST IN THE WAKE OF ITS BIG SISTER
OVER THE EASTERN U.S. AS THE SECOND LARGE CUTOFF NOW OVER THE
CALIFORNIA COAST DRIFTS INTO THE INTERMOUNTAIN WEST. MODELS HAVE
BEEN VERY CONSISTENT IN FORECASTING THE LITTLE NORTHERN PLAINS LOW
TO BREAK DOWN THE UPPER LEVEL RIDGING BETWEEN THE TWO LARGER LOWS ON
WEDNESDAY...BRINGING ANOTHER CHANCE FOR AFTERNOON THUNDERSTORMS
PRIMARILY TO CENTRAL MISSOURI. THE LOW OPENS UP INTO A SHORTWAVE
WEDNESDAY NIGHT INTO THURSDAY BRINGING LOW LEVEL BAROCLINICITY INTO
THE MID-MISSISSIPPI VALLEY...AND AN INCREASING LOW LEVEL JET FROM
THE SOUTHEAST PLAINS. THIS LOOKS LIKE ANOTHER PERIOD OF WET WEATHER
FROM WEDNESDAY NIGHT THROUGH THURSDAY NIGHT AS THE SHORTWAVE SLOWLY
AMPLIFIES OVER THE MIDWEST AND THE LOW LEVEL JET CONTINUES TO BRING
A PLUME OF MOISTURE UP FROM THE SOUTHWEST. NOT SAYING IT`S GOING TO
BE A TOTAL WASH...BUT A FEW WAVES OF STORMS FROM WEDNESDAY EVENING
THROUGH LATE THURSDAY NIGHT LOOK PRETTY LIKELY. LOW LEVEL FLOW
TURNS TO THE NORTHWEST ON FRIDAY WHICH SHOULD BEGIN TO SHUT THE
PRECIP OFF FROM NORTH TO SOUTH...BUT NOT BEFORE THERE MAY BE ANOTHER
WAVE OF SHOWERS OR STORMS ALONG AND SOUTH OF THE I-70 CORRIDOR.
TEMPERATURES THROUGH THE PERIOD LOOK TO BE NEAR OR ABOVE NORMAL IN
THE MID 70S TO AROUND 80 WITH LOWS GENERALLY IN THE UPPER 50S AND
LOW 60S.
CARNEY
.LONG TERM...(SATURDAY THROUGH MONDAY)
ISSUED AT 347 AM CDT TUE MAY 7 2013
ANOTHER STRONG SHORTWAVE MOVES ACROSS THE U.S. CANADA BORDER FRIDAY
NIGHT INTO SATURDAY WHICH AMPLIFIES THE AFOREMENTIONED MIDWEST
SHORTWAVE AND PUSHES A STRONG COLD FRONT DOWN THROUGH THE PLAINS
INTO THE MID-MISSISSIPPI VALLEY LATE SATURDAY. STILL LOOKS LIKE
THERE COULD BE A CHANCE OF SHOWERS ON SATURDAY AS THE FRONT MOVES
THROUGH...THOUGH MEDIUM RANGE MODELS ARE NOW SHOWING THAT MOST OF
THE PRECIP MAY BE SOUTH OF THE REGION. A 1030MB CANADIAN HIGH
FOLLOWS ON THE HEELS OF THE FRONT. HIGHS SATURDAY LOOK TO BE NEAR
OR JUST BELOW SEASONAL NORMALS IN THE UPPER 60S TO LOW 70S...BUT THE
COLD CANADIAN AIRMASS WILL PUSH TEMPERATURES WELL BELOW NORMAL ON
SUNDAY AND MONDAY. GUIDANCE IS GIVING ME HIGHS IN THE LOW TO MID
60S AND LOWS IN THE UPPER 30S TO MID 40S. HOWEVER...I WOULD NOT BE
SURPRISED IF ACTUAL TEMPERATURES ARE AS MUCH AS 5 TO 10 DEGREES
COLDER THAN GUIDANCE. GFS AND ECMWF ARE FORECASTING 850MB TEMPS
AROUND 0C ON BOTH SUNDAY AND MONDAY WHICH YIELDS MIX-DOWN TEMPS IN
MID TO UPPER 50S! AM NOT GOING QUITE THAT COLD YET...BUT DID TAKE A
FEW DEGREES OFF GUIDANCE TEMPS BOTH SUNDAY AND MONDAY.
CARNEY
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1135 PM CDT MON MAY 6 2013
MVFR TO IFR RADIATION FOG HAS DEVELOPED ACROSS PARTS OF WRN MO
WHERE SKIES HAVE CLEARED HOWEVER MID AND HIGH CLOUDS SHOULD
PERSIST OVER MOST OF THE TAF SITES TONIGHT WHICH WOULD LIMIT FOG
FORMATION. THE MOST FAVORABLE LOCATIONS FOR LIGHT FOG APPEAR TO BE
KCOU /WHERE SKIES HAVE STARTED TO CLEAR/ AND FAVORED VALLEY
LOCATIONS SUCH AS KSUS WHERE THE WINDS HAVE BEEN CALM FOR SEVERAL
HOURS. OTHER THAN THE POTENTIAL FOR A FEW HOURS OF LIGHT FOG
TONIGHT...VFR CONDITIONS ARE EXPECTED FOR THE MAJORITY OF THE TAF
PD. NLY TO NELY WINDS WILL BECOME LGT/VAR AROUND 00Z ONCE A SFC
RIDGE AXIS MOVES INTO THE REGION.
SPECIFICS FOR KSTL...PATCHY LIGHT FOG IS POSSIBLE LATE TONIGHT
HOWEVER VFR CONDITIONS ARE EXPECTED FOR THE MAJORITY OF THE TAF
PD. CONFIDENCE IN FOG AT KSTL REMAINS TOO LOW TO INCLUDE IN THE
TAF ATTM BASED ON EXPECTED CLOUD COVER AND CURRENT T/TD SPREAD.
NLY TO NELY WINDS BECOME LGT/VAR AROUND 00Z ONCE A SFC RIDGE AXIS
MOVES INTO THE REGION.
KANOFSKY
&&
.PRELIMINARY POINT TEMPS/POPS...
SAINT LOUIS 76 58 79 62 / 20 10 20 40
QUINCY 76 54 77 59 / 10 10 30 60
COLUMBIA 76 55 76 59 / 10 10 30 60
JEFFERSON CITY 76 54 77 60 / 10 10 30 60
SALEM 73 54 77 59 / 20 5 10 20
FARMINGTON 73 51 77 59 / 20 10 20 20
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
329 AM CDT TUE MAY 7 2013
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 329 AM CDT TUE MAY 7 2013
UPPER LEVEL LOW STILL CENTERED OVER NORTHWEST GEORGIA/NORTHEAST
ALABAMA IS FORECAST TO BEGIN MOVING SLOWLY NORTHEAST TODAY. THIS
SHOULD FINALLY BRING A CLEARING SKY AND WARMER TEMPERATURES TO THE
REGION. THERE IS A PERSISTENT BAND OF MID LEVEL CLOUDS AROUND
10,000FT WHICH JUST DON`T SEEM TO WANT TO GO AWAY. THE NAM SEEMS TO
BE HANDLING THE DECK PRETTY WELL AT THIS TIME...AND IT SLOWLY THINS
OUT THROUGH THE MORNING. THE RUC ON THE OTHER HAND KEEPS THE DECK
AROUND AT LEAST THROUGH EARLY AFTERNOON. AM LEANING TOWARD THE RUC
AT THIS TIME SINCE THIS IS CLOSER TO PERSISTENCE...AND THIS SYSTEM
HAS BEEN NOTHING IF NOT PERSISTENT. CLOUDS SHOULD BE THINNING OUT
DURING THE AFTERNOON...AND STRONG MAY SUNSHINE SHOULD EASILY PROPEL
HIGHS INTO THE MID AND UPPER 70S. THERE MAY BE ENOUGH INSTABILITY
AROUND THIS AFTERNOON FOR POP-UP SHOWERS AND THUNDERSTORMS...SO THE
SLIGHT CHANCE POPS CURRENTLY IN THE FORECAST LOOK TO BE ON TRACK.
MEANWHILE...THE COMPACT LITTLE CUTOFF LOW CURRENTLY OVER SOUTH
DAKOTA WILL START DRIFTING SOUTHEAST IN THE WAKE OF ITS BIG SISTER
OVER THE EASTERN U.S. AS THE SECOND LARGE CUTOFF NOW OVER THE
CALIFORNIA COAST DRIFTS INTO THE INTERMOUNTAIN WEST. MODELS HAVE
BEEN VERY CONSISTENT IN FORECASTING THE LITTLE NORTHERN PLAINS LOW
TO BREAK DOWN THE UPPER LEVEL RIDGING BETWEEN THE TWO LARGER LOWS ON
WEDNESDAY...BRINGING ANOTHER CHANCE FOR AFTERNOON THUNDERSTORMS
PRIMARILY TO CENTRAL MISSOURI. THE LOW OPENS UP INTO A SHORTWAVE
WEDNESDAY NIGHT INTO THURSDAY BRINGING LOW LEVEL BAROCLINICITY INTO
THE MID-MISSISSIPPI VALLEY...AND AN INCREASING LOW LEVEL JET FROM
THE SOUTHEAST PLAINS. THIS LOOKS LIKE ANOTHER PERIOD OF WET WEATHER
FROM WEDNESDAY NIGHT THROUGH THURSDAY NIGHT AS THE SHORTWAVE SLOWLY
AMPLIFIES OVER THE MIDWEST AND THE LOW LEVEL JET CONTINUES TO BRING
A PLUME OF MOISTURE UP FROM THE SOUTHWEST. NOT SAYING IT`S GOING TO
BE A TOTAL WASH...BUT A FEW WAVES OF STORMS FROM WEDNESDAY EVENING
THROUGH LATE THURSDAY NIGHT LOOK PRETTY LIKELY. LOW LEVEL FLOW
TURNS TO THE NORTHWEST ON FRIDAY WHICH SHOULD BEGIN TO SHUT THE
PRECIP OFF FROM NORTH TO SOUTH...BUT NOT BEFORE THERE MAY BE ANOTHER
WAVE OF SHOWERS OR STORMS ALONG AND SOUTH OF THE I-70 CORRIDOR.
TEMPERATURES THROUGH THE PERIOD LOOK TO BE NEAR OR ABOVE NORMAL IN
THE MID 70S TO AROUND 80 WITH LOWS GENERALLY IN THE UPPER 50S AND
LOW 60S.
CARNEY
.LONG TERM...(TUESDAY THROUGH NEXT MONDAY)
ISSUED AT 310 PM CDT MON MAY 6 2013
(TUESDAY AND TUESDAY NIGHT)
SOUTHEASTERN CONUS UPPER LOW WILL FINALLY HAVE LESS INFLUENCE ON OUR
WEATHER WHICH WILL ALLOW SOME WEAK RIDGING TO MOVE ACROSS THE CWA.
GFS SOUNDINGS ARE STILL SHOWING SOME NARROW UNCAPPED MUCAPE OVER THE
SOUTHEASTERN HALF OF THE CWA DURING THE AFTERNOON...SO WILL KEEP
GOING SLIGHT THUNDERSTORMS CHANCES. EXPECT THIS TO BE MAINLY
DIURNALLY DRIVEN...SO KEPT TUESDAY NIGHT DRY. EXPECT MORE SUNSHINE
ON TUESDAY THAN RECENT DAYS...SO AGREEABLE MOS HIGHS IN THE MID 70S
STILL LOOK GOOD.
(WEDNESDAY THROUGH SATURDAY)
RAIN STILL LOOKS TO RETURN TO THE AREA MID/LATE WEEK AS A FRONT
TEMPORARILY STALLS OVER THE MIDWEST THAT WILL INTERACT WITH ONE OR
TWO UPPER LOWS. CONFIDENCE DURING THIS PERIOD HAS LOWERED TODAY AS
GFS IS SHOWING LESS CONTINUITY THAN IN IT DID YESTERDAY. BY LATE
WEDNESDAY...THERE WILL BE AN ELONGATED COLD FRONT THAT WILL EXTEND
FROM THE GREAT LAKES INTO NEBRASKA. THE GFS BRINGS THE UPPER LOW
CURRENTLY OVER SOUTH DAKOTA ACROSS THE MIDWEST ON THURSDAY WHICH
CAUSES A SURFACE LOW TO DEVELOP ALONG THE FRONT THAT SWEEPS IT SOUTH
OF THE CWA BY EARLY FRIDAY. THE ECMWF INSTEAD SHEARS THIS FIRST
UPPER LOW OUT AND CONCENTRATES ON THE MORE PRONOUNCED LOW NOW OFF
THE WEST COAST. IT SLOWLY MOVES THIS LOW ONSHORE AND INTO THE
CENTRAL PLAINS BY THURSDAY NIGHT. ITS SOLUTION WILL KEEP THE
FRONT IN THE CWA THROUGH LATE FRIDAY. WILL STICK WITH THE MORE
CONSISTENT SOLUTION OF THE ECMWF. CHANCE OF SHOWERS/THUNDERSTORMS
WILL BEGIN BY LATE WEDNESDAY AS LOW LEVEL JET TRANSPORTS GULF
MOISTURE NORTH INTO MO/IL. LIKELY POPS STILL LOOK GOOD ON
THURSDAY/FRIDAY WHEN THE SURFACE FRONT WILL BE STALLED UNDER
PERSISTENT MID LEVEL ASCENT. WILL KEEP WITH HIGHS IN THE 70S WITH
LITTLE DIURNAL SWING AS 850MB TEMPS WILL BE AROUND 10C WITH
CLOUDS/RAIN CHANCES.
ECMWF/GFS STILL SHOW THAT A SHARP MID LEVEL TROUGH WILL DIG DOWN
INTO THE MIDWEST OVER THE WEEKEND WHICH WILL DRIVE A SECONDARY COLD
FRONT THROUGH THE AREA ON SATURDAY. BAND OF POST FRONTAL MOISTURE
AND LIFT FROM THE TROUGH WILL BE ENOUGH FOR SCATTERED SHOWERS ON
SATURDAY.
(SUNDAY THROUGH MONDAY)
ECMWF/GFS ARE IN GOOD AGREEMENT THAT WE WILL BE DRY IN THE WAKE OF
THE UPPER TROUGH THAT WILL MOVE FROM THE GREAT LAKES INTO THE
NORTHEASTERN CONUS. COLD AIR ADVECTION WILL CAUSE BELOW NORMAL
TEMPERATURES ON SUNDAY AND SUNDAY NIGHT BEFORE SURFACE WINDS TURN
OUT OF THE SOUTHWEST AS THE SURFACE HIGH MOVES OFF TO THE EAST.
BRITT
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1135 PM CDT MON MAY 6 2013
MVFR TO IFR RADIATION FOG HAS DEVELOPED ACROSS PARTS OF WRN MO
WHERE SKIES HAVE CLEARED HOWEVER MID AND HIGH CLOUDS SHOULD
PERSIST OVER MOST OF THE TAF SITES TONIGHT WHICH WOULD LIMIT FOG
FORMATION. THE MOST FAVORABLE LOCATIONS FOR LIGHT FOG APPEAR TO BE
KCOU /WHERE SKIES HAVE STARTED TO CLEAR/ AND FAVORED VALLEY
LOCATIONS SUCH AS KSUS WHERE THE WINDS HAVE BEEN CALM FOR SEVERAL
HOURS. OTHER THAN THE POTENTIAL FOR A FEW HOURS OF LIGHT FOG
TONIGHT...VFR CONDITIONS ARE EXPECTED FOR THE MAJORITY OF THE TAF
PD. NLY TO NELY WINDS WILL BECOME LGT/VAR AROUND 00Z ONCE A SFC
RIDGE AXIS MOVES INTO THE REGION.
SPECIFICS FOR KSTL...PATCHY LIGHT FOG IS POSSIBLE LATE TONIGHT
HOWEVER VFR CONDITIONS ARE EXPECTED FOR THE MAJORITY OF THE TAF
PD. CONFIDENCE IN FOG AT KSTL REMAINS TOO LOW TO INCLUDE IN THE
TAF ATTM BASED ON EXPECTED CLOUD COVER AND CURRENT T/TD SPREAD.
NLY TO NELY WINDS BECOME LGT/VAR AROUND 00Z ONCE A SFC RIDGE AXIS
MOVES INTO THE REGION.
KANOFSKY
&&
.PRELIMINARY POINT TEMPS/POPS...
SAINT LOUIS 76 58 79 62 / 20 10 20 40
QUINCY 76 54 77 59 / 10 10 30 60
COLUMBIA 76 55 76 59 / 10 10 30 60
JEFFERSON CITY 76 54 77 60 / 10 10 30 60
SALEM 73 54 77 59 / 20 5 10 20
FARMINGTON 73 51 77 59 / 20 10 20 20
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS GREAT FALLS MT
1055 PM MDT Mon May 6 2013
UPDATED AVIATION SECTION
.DISCUSSION...
Tonight through Wednesday...Fairly benign weather pattern will
continue overnight. An upper ridge remains in place across central
and northern Montana with associated subsidence providing cloud-
free skies and mild temperatures. Circulation from an upper low
offshore of the California coast is spreading moisture and
instability across the inter-mountain region and into extreme
southern and southwest Montana. Models indicate some CAPE is
available over the area but HRRR analysis indicates moisture is
lacking and very few thunderstorms are depicted through the early
evening hours. The upper low begins moving east on Tuesday with
showers and/or thunderstorms becoming a bit more numerous across
the south and southwest during the afternoon. By Wednesday, the
upper ridge gets suppressed to the south and northwest flow aloft
sets up over the area. Enough moisture and instability will be
present for isolated thunderstorms across the area. Temperatures
will remain above seasonal averages. Emanuel
Wednesday Night through Monday...Medium range models continue to
indicate that unsettled weather will remain across the area through
Saturday. An upper level ridge of high pressure from along the
California coast into the Pacific Northwest and an upper level
trough of low pressure over central/eastern Canada will combine to
keep Montana under a moist and cyclonic northwesterly flow aloft.
Weak disturbances in the flow will generally keep a chance of mainly
afternoon and evening showers and thunderstorms over the area.
Moisture being drawn north by an upper level low pressure area
moving across the central Rockies Wednesday night through Thursday
night will enhance this chance of measurable precipitation. However,
the models seem to agree with this forecast cycle that a strong
Canadian cold front will move south through the area on Friday. Have
therefore increased the overall chance for showers/thunderstorms
during this time and introduced breezy northerly winds in the wake
of the front. For Saturday night into Sunday night, models are in
better agreement with moving the upper level ridge will move east
into Montana. Have mostly gone with dry conditions during this time,
with only a slight chance of showers/thunderstorms in the mountains.
As the ridge axis moves east of the area, models are indicating that
a moist southwesterly flow aloft will combine with the passage of a
Pacific cold front to bring a slightly better chance for
showers/thunderstorms into Monday. Temperatures will generally be 5
to 10 degrees warmer than seasonal averages through Saturday, with a
brief cooling back to near normal associated with the cold frontal
passage on Friday. As the ridge builds into the area, temperatures
will reach 10 to 15 degrees above normal for the latter portion of
the weekend, but they will then cool about 5 to 10 degrees again on
Monday with the passage of the second cold front. Coulston
&&
.AVIATION...
UPDATED 0455Z.
VFR conditions expected across the region through 18Z Tuesday. High
pressure will keep skies mostly clear and winds relatively light
through tonight. Isolated showers over far Southwest Montana will
diminish after sunset but weak instability will result in isolated
showers and a few thunderstorms again Tuesday afternoon. Any
development will likely remain along and south of a KBZN-KBTM line.
Expect a front to move into the region from the northwest after 12z
Tuesday. Winds will turn to the north behind the front with gusts
to around 20 knots. Stronger winds are likely at KCTB during the
frontal passage with gusts up to 40 knots. Scattered low
clouds will develop behind the front. Langlieb
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 46 70 44 72 / 0 10 10 20
CTB 44 63 40 70 / 0 10 10 30
HLN 44 72 45 75 / 0 10 20 20
BZN 38 74 41 74 / 10 20 30 20
WEY 33 64 35 65 / 20 40 40 40
DLN 40 71 42 72 / 10 20 30 30
HVR 43 76 42 72 / 0 0 10 20
LWT 41 72 42 68 / 0 10 10 20
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
weather.gov/greatfalls
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
400 AM EDT TUE MAY 7 2013
.SYNOPSIS...
FAIR...DRY AND WARM WEATHER WILL PERSIST TODAY THROUGH MOST OF
WEDNESDAY AS HIGH PRESSURE MAINTAINS CONTROL OVER REGIONAL WEATHER
CONDITIONS. A TREND TOWARD COOLER AND MORE UNSETTLED WEATHER IS
EXPECTED BY THURSDAY ONWARD INTO NEXT WEEKEND AS THE COMBINATION OF
UPPER LEVEL LOW PRESSURE AND A SERIES OF SURFACE FRONTS BRING THE
CHANCE OF WELCOMED RAINFALL TO THE REGION.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 343 AM EDT TUESDAY...PERSISTENCE FORECAST WILL BE OFFERED
AGAIN TODAY AS IDEAL CHAMBER OF COMMERCE WEATHER PATTERN CONTINUES
UNDER DEEP LAYER BLOCKING HIGH PRESSURE. THUS VERY LITTLE CHANGE
FROM YESTERDAY WITH FULL SUN AND MILD TO WARM TEMPERATURES IN THE
UPPER 70S TO LOWER 80S UNDER LIGHT SURFACE WINDS. DID LEAN TOWARD
DRIEST MODEL TD/RH PROGS FOR OUR AREA THIS AFTERNOON...IN THIS
CASE THE RAW RUC13 VALUES. RECENT PERFORMANCE OF MOS GUIDANCE HAS
BEEN OVERLY MOIST AND FRANKLY QUITE POOR OVER THE PAST FEW
AFTERNOONS...SO SAW NO REASON TO LEAN IN THIS DIRECTION.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
AS OF 343 AM EDT TUESDAY...CLEAR SKIES AND LIGHT WINDS THEN
CONTINUE TONIGHT INTO THE FIRST HALF OF WEDNESDAY AS BLOCKING
RIDGE FINALLY BEGINS TO BREAK DOWN IN RESPONSE TO A LARGE CYCLONIC
GYRE TRUDGING SLOWLY NORTHEAST FROM THE SOUTHEAST/MID-ATLANTIC
STATES. LOWS TONIGHT GENERALLY FROM 45 TO 55 WITH CUSTOMARY COOLER
SPOTS IN THE DACKS/NERN VT. SFC MOISTURE WILL GRADUALLY INCREASE
OVERNIGHT BUT WIDESPREAD BR/FG NOT EXPECTED GIVEN RECENT DRY
STRETCH AND SFC SOIL MOISTURE VALUES REMAINING QUITE LOW.
BY LATER WEDNESDAY INTO WEDNESDAY NIGHT AFOREMENTIONED UPPER LOW
TRACKS INTO THE NORTHEAST WHILE WEAKENING INTO AN OPEN WAVE. AS
CUSTOMARY WITH SUCH SYSTEMS...HARD TO PINPOINT EXACT TIMING AND
COVERAGE OF SHOWERS...WHICH WILL BE TIED MOST CLOSELY TO BANDS OF
DEEPER MOISTURE AND VORTICITY ADVECTION. NONETHELESS...WITH
INCREASING CYCLONIC FLOW ALOFT AND PWATS CLIMBING NEAR OR SLIGHTLY
ABOVE 1 INCH EXPECT AN INCREASE IN CLOUDS AND SHOWER CHANCES FROM
SOUTH TO NORTH THROUGH THE EVENING AND NIGHTTIME HOURS. COULD ALSO
SEE A STRAY LATE AFTERNOON/EVENING STORM SOUTH AND ALSO OUT IN THE
SLV AS MODELS CONTINUE TO HINT AT SOME WEAK LOW TO MID-LEVEL
INSTABILITY DEVELOPING IN THESE AREAS. HIGHS ON WEDNESDAY RANGING
FROM THE LOWER TO MID 70S SOUTH AS CLOUDS ARRIVE EARLY IN THE
AFTERNOON...TO AROUND 80 ONCE AGAIN NORTH AS SUNSHINE HANGS ON
THROUGH A GOOD PORTION OF THE DAY.
BY THURSDAY DECAYING UPPER LOW PASSES ACROSS OUR REGION WITH
CONTINUED CHANCE OF SHOWERS ALONG WITH AN ISOLATED STORM HERE OR
THERE. BEST COVERAGE TO OCCUR DURING THE AFTERNOON CONVECTIVE
MAXIMUM FROM NOON TO 6 PM OR SO. WITH MORE WIDESPREAD CLOUD COVER
ACROSS THE REGION TEMPERATURES WILL CONTINUE TO EASE BACK SLIGHTLY
TOPPING OUT GENERALLY IN THE 67 TO 73 RANGE.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 400 AM EDT TUESDAY...UNSETTLED WEATHER WILL CONTINUE INTO
THE LONG TERM WITH STATIONARY FRONT AFFECTING THE NORTH COUNTRY
GRADUALLY GAINING MOMENTUM EASTWARD ON FRIDAY. RAIN SHOWERS WILL
START THE PERIOD ASSOCIATED WITH THE AFOREMENTIONED STATIONARY
FRONT. LATE FRIDAY INTO EARLY SATURDAY...THE FRONT WILL EXIT EAST
ALONG THE NEW ENGLAND COAST...WITH A BRIEF PERIOD OF SFC RIDGING
BUILDING INTO THE NORTH COUNTRY FRIDAY NIGHT. SATURDAY WILL SEE
THE RIDGING WEAKEN AND SLIDE EAST AS AN UPPER LEVEL CUT OFF LOW
APPROACHES FROM THE NORTHWESTERN GREAT LAKES. AT THE SFC...A
CLOSED LOW ASSOCIATED WITH THE UPPER LOW WILL INTERACT WITH A
WEAKER...SOUTHERN STREAM LOW. DEPENDING HOW FAR NORTH THIS
SOUTHERN LOW MOVES...WILL AFFECT WHEN THE NEXT ROUND OF SHOWERS
ARE EXPECTED ON SATURDAY.
THE UPPER LEVEL CUTOFF LOW WILL MOVE JUST SOUTH OF JAMES BAY
SATURDAY NIGHT...SIGNIFICANTLY DECREASING 500MB HTS AND PRODUCING
SHOWERS OVER PORTIONS OF THE NORTH COUNTRY THROUGH LATE
SUNDAY/SUNDAY NIGHT ASSOCIATED WITH A SFC COLD FRONT. RIDGING
BEHIND THE FRONT WILL BE ACCOMPANIED BY W/NW WINDS AND COOLER
TEMPERATURES. THIS RIDGING MAY BE INTERRUPTED BY A POST FRONTAL
TROUGH BRINGING A LOW CHC FOR SHOWERS ON MONDAY AS THE UPPER LOW
IS SLOW TO EXIT TO THE EAST.
ABOVE NORMAL TEMPERATURES WILL START THE PERIOD WITH MAX TEMPS IN
THE 60S-L70S FRIDAY AND SATURDAY..COOLING BEHIND THE FRONT ON
SUNDAY TO 50S-L60S AND COOLING FURTHER INTO THE M40S-U50S ON
MONDAY. MIN TEMPS WILL SEE A SIMILAR TREND...STARTING IN THE 40S-
L50S THURSDAY NIGHT AND DECREASING TO THE 30S SUNDAY NIGHT.
&&
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
THROUGH 06Z WEDNESDAY...VFR CONDITIONS WILL PERSIST THROUGH AT
LEAST THE NEXT 24 HOURS. LOCAL EFFECTS WILL DOMINATE WIND
DIRECTION ALONG WITH LLJ OVER THE CPV BLOWING OUT OF THE SOUTH AT
25-35KTS AROUND 2000 FT AND ABV. THIS COULD CREATE SOME
OCCASIONAL GUSTS AT KBTV THROUGH SUNRISE. WITH CONTINUED HIGH
PRESSURE OVERHEAD...FCST SHOULD FOLLOW SIMILAR TREND TO PREVIOUS
24 HOURS.
CLEAR SKIES WITH GENERAL SOUTHERLY FLOW AT 6-12 KTS EXPECTED
TUESDAY...WITH WINDS GENERALLY SUBSIDING AFTER SUNSET.
OUTLOOK 06Z WEDNESDAY THROUGH SATURDAY...
06Z WEDNESDAY THROUGH 18Z WEDNESDAY...VFR CONDITIONS EXPECTED TO
CONTINUE TUESDAY NGT AND EARLY WEDNESDAY AS A RIDGE OF HIGH
PRESSURE AT THE SURFACE AND ALOFT REMAINS OVER THE REGION.
18Z WEDNESDAY ONWARD...INCREASING CLOUDS AS A CLOSED UPPER LOW
OVER THE MID ATLANTIC STATES EARLY WEDNESDAY NIGHT WILL MOVE
NORTHEAST AND BRING A CHANCE OF RAIN SHOWERS TO THE REGION
WEDNESDAY NIGHT THROUGH FRIDAY NIGHT...WITH SOME MVFR CONDITIONS
POSSIBLE IN RAIN SHOWERS. A COLD FRONT WILL MOVE INTO THE REGION
ON FRIDAY AND THEN BECOME NEARLY STATIONARY...WITH A CHANCE OF
RAIN SHOWERS FRIDAY AND SATURDAY...WITH SOME AREAS OF MVFR
POSSIBLE.
&&
.FIRE WEATHER...
HIGH PRESSURE OVERHEAD WILL KEEP PRECIPITATION OUT OF THE NORTH
COUNTRY THROUGH MID-DAY ON WEDNESDAY. FULL SUN IS EXPECTED TODAY
WITH AFTERNOON MINIMUM RELATIVE HUMIDITY VALUES FALLING INTO THE
15 TO 25 PERCENT RANGE. WINDS WILL GENERALLY BE LIGHT HOWEVER. A
SLOW CLIMB IN HUMIDITY VALUES IS EXPECTED TO START TONIGHT AND
INCREASE THROUGH LATE WEEK ALONG WITH INCREASING CHANCES FOR
WETTING RAINFALL. IN THE MEANTIME HOWEVER...HAVE CONTINUED TO
MENTION THE CONCERNS OF THE VERMONT DEPARTMENT OF FORESTS...PARKS
AND RECREATION REGARDING OPEN BURNING IN SUCH DRY CONDITIONS IN
OUR HAZARDOUS WEATHER OUTLOOK.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JMG
NEAR TERM...JMG
SHORT TERM...JMG
LONG TERM...KGM
AVIATION...KGM
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
343 AM EDT TUE MAY 7 2013
.SYNOPSIS...
FAIR...DRY AND WARM WEATHER WILL PERSIST TODAY THROUGH MOST OF
WEDNESDAY AS HIGH PRESSURE MAINTAINS CONTROL OVER REGIONAL WEATHER
CONDITIONS. A TREND TOWARD COOLER AND MORE UNSETTLED WEATHER IS
EXPECTED BY THURSDAY ONWARD INTO NEXT WEEKEND AS THE COMBINATION OF
UPPER LEVEL LOW PRESSURE AND A SERIES OF SURFACE FRONTS BRING THE
CHANCE OF WELCOMED RAINFALL TO THE REGION.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 343 AM EDT TUESDAY...PERSISTENCE FORECAST WILL BE OFFERED
AGAIN TODAY AS IDEAL CHAMBER OF COMMERCE WEATHER PATTERN CONTINUES
UNDER DEEP LAYER BLOCKING HIGH PRESSURE. THUS VERY LITTLE CHANGE
FROM YESTERDAY WITH FULL SUN AND MILD TO WARM TEMPERATURES IN THE
UPPER 70S TO LOWER 80S UNDER LIGHT SURFACE WINDS. DID LEAN TOWARD
DRIEST MODEL TD/RH PROGS FOR OUR AREA THIS AFTERNOON...IN THIS
CASE THE RAW RUC13 VALUES. RECENT PERFORMANCE OF MOS GUIDANCE HAS
BEEN OVERLY MOIST AND FRANKLY QUITE POOR OVER THE PAST FEW
AFTERNOONS...SO SAW NO REASON TO LEAN IN THIS DIRECTION.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
AS OF 343 AM EDT TUESDAY...CLEAR SKIES AND LIGHT WINDS THEN
CONTINUE TONIGHT INTO THE FIRST HALF OF WEDNESDAY AS BLOCKING
RIDGE FINALLY BEGINS TO BREAK DOWN IN RESPONSE TO A LARGE CYCLONIC
GYRE TRUDGING SLOWLY NORTHEAST FROM THE SOUTHEAST/MID-ATLANTIC
STATES. LOWS TONIGHT GENERALLY FROM 45 TO 55 WITH CUSTOMARY COOLER
SPOTS IN THE DACKS/NERN VT. SFC MOISTURE WILL GRADUALLY INCREASE
OVERNIGHT BUT WIDESPREAD BR/FG NOT EXPECTED GIVEN RECENT DRY
STRETCH AND SFC SOIL MOISTURE VALUES REMAINING QUITE LOW.
BY LATER WEDNESDAY INTO WEDNESDAY NIGHT AFOREMENTIONED UPPER LOW
TRACKS INTO THE NORTHEAST WHILE WEAKENING INTO AN OPEN WAVE. AS
CUSTOMARY WITH SUCH SYSTEMS...HARD TO PINPOINT EXACT TIMING AND
COVERAGE OF SHOWERS...WHICH WILL BE TIED MOST CLOSELY TO BANDS OF
DEEPER MOISTURE AND VORTICITY ADVECTION. NONETHELESS...WITH
INCREASING CYCLONIC FLOW ALOFT AND PWATS CLIMBING NEAR OR SLIGHTLY
ABOVE 1 INCH EXPECT AN INCREASE IN CLOUDS AND SHOWER CHANCES FROM
SOUTH TO NORTH THROUGH THE EVENING AND NIGHTTIME HOURS. COULD ALSO
SEE A STRAY LATE AFTERNOON/EVENING STORM SOUTH AND ALSO OUT IN THE
SLV AS MODELS CONTINUE TO HINT AT SOME WEAK LOW TO MID-LEVEL
INSTABILITY DEVELOPING IN THESE AREAS. HIGHS ON WEDNESDAY RANGING
FROM THE LOWER TO MID 70S SOUTH AS CLOUDS ARRIVE EARLY IN THE
AFTERNOON...TO AROUND 80 ONCE AGAIN NORTH AS SUNSHINE HANGS ON
THROUGH A GOOD PORTION OF THE DAY.
BY THURSDAY DECAYING UPPER LOW PASSES ACROSS OUR REGION WITH
CONTINUED CHANCE OF SHOWERS ALONG WITH AN ISOLATED STORM HERE OR
THERE. BEST COVERAGE TO OCCUR DURING THE AFTERNOON CONVECTIVE
MAXIMUM FROM NOON TO 6 PM OR SO. WITH MORE WIDESPREAD CLOUD COVER
ACROSS THE REGION TEMPERATURES WILL CONTINUE TO EASE BACK SLIGHTLY
...TOPPING OUT GENERALLY IN THE 67 TO 73 RANGE.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 425 PM EDT MONDAY...UNSETTLED WEATHER EXPECTED THROUGH THE
PERIOD WITH A CHANCE OF RAIN SHOWERS AND COOLER TEMPERATURES.
THE CLOSED UPPER LOW CURRENTLY OVER THE SOUTHEASTERN U.S. WILL BE OVER
EASTERN PENNSYLVANIA EARLY THURSDAY. THIS UPPER LOW WILL MOVE
NORTHEAST INTO THE GULF OF MAINE BY THURSDAY NIGHT. THIS UPPER LOW
WILL BRING A CHANCE OF RAIN SHOWERS TO THE NORTH COUNTRY THURSDAY
AND FRIDAY. A COLD FRONT WILL MOVE SOUTH INTO THE REGION FROM CANADA
ON FRIDAY AND WILL BRING MORE RAIN SHOWERS TO THE REGION FRIDAY
AND FRIDAY NIGHT. A WARM FRONT WILL APPROACH THE REGION ON SATURDAY
BRINGING ANOTHER CHANCE FOR RAIN SHOWERS TO THE NORTH COUNTRY. A
STRONG COLD FRONT WILL MOVE SOUTHEAST FROM CANADA ON SUNDAY AND
WILL BRING MORE RAIN SHOWERS ALONG WITH MUCH COOLER AIR. ON MONDAY...
ECMWF AND GFS MODELS IN GOOD AGREEMENT IN BRINGING A CLOSED UPPER LOW
THROUGH THE REGION ON MONDAY. 500 MB TEMPERATURES BY MONDAY AFTERNOON
WILL BE -30C TO -35C. HIGH TEMPERATURES ON MONDAY WILL ONLY BE IN
THE 50S...WITH SOME 40S OVER THE HIGHER ELEVATIONS OF THE
ADIRONDACKS AND GREEN MOUNTAINS. HAVE GONE WITH A 30 PERCENT
CHANCE OF SHOWERS FOR MONDAY. GIVEN THE STRONG COLD POOL OF AIR
ALOFT AT 500 MB...WOULD NOT BE SURPRISED TO SEE SMALL HAIL MONDAY AFTERNOON
ALONG WITH AN ISOLATED LOW TOP THUNDERSTORM OR TWO. GIVEN THAT
THIS IS 7 DAYS OUT HAVE NOT INCLUDED THIS IN THE GRIDS AT THIS
TIME.
&&
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
THROUGH 06Z WEDNESDAY...VFR CONDITIONS WILL PERSIST THROUGH AT
LEAST THE NEXT 24 HOURS. LOCAL EFFECTS WILL DOMINATE WIND
DIRECTION ALONG WITH LLJ OVER THE CPV BLOWING OUT OF THE SOUTH AT
25-35KTS AROUND 2000 FT AND ABV. THIS COULD CREATE SOME
OCCASIONAL GUSTS AT KBTV THROUGH SUNRISE. WITH CONTINUED HIGH
PRESSURE OVERHEAD...FCST SHOULD FOLLOW SIMILAR TREND TO PREVIOUS
24 HOURS.
CLEAR SKIES WITH GENERAL SOUTHERLY FLOW AT 6-12 KTS EXPECTED
TUESDAY...WITH WINDS GENERALLY SUBSIDING AFTER SUNSET.
OUTLOOK 06Z WEDNESDAY THROUGH SATURDAY...
06Z WEDNESDAY THROUGH 18Z WEDNESDAY...VFR CONDITIONS EXPECTED TO
CONTINUE TUESDAY NGT AND EARLY WEDNESDAY AS A RIDGE OF HIGH
PRESSURE AT THE SURFACE AND ALOFT REMAINS OVER THE REGION.
18Z WEDNESDAY ONWARD...INCREASING CLOUDS AS A CLOSED UPPER LOW
OVER THE MID ATLANTIC STATES EARLY WEDNESDAY NIGHT WILL MOVE
NORTHEAST AND BRING A CHANCE OF RAIN SHOWERS TO THE REGION
WEDNESDAY NIGHT THROUGH FRIDAY NIGHT...WITH SOME MVFR CONDITIONS
POSSIBLE IN RAIN SHOWERS. A COLD FRONT WILL MOVE INTO THE REGION
ON FRIDAY AND THEN BECOME NEARLY STATIONARY...WITH A CHANCE OF
RAIN SHOWERS FRIDAY AND SATURDAY...WITH SOME AREAS OF MVFR
POSSIBLE.
&&
.FIRE WEATHER...
HIGH PRESSURE OVERHEAD WILL KEEP PRECIPITATION OUT OF THE NORTH
COUNTRY THROUGH MID-DAY ON WEDNESDAY. FULL SUN IS EXPECTED TODAY
WITH AFTERNOON MINIMUM RELATIVE HUMIDITY VALUES FALLING INTO THE
15 TO 25 PERCENT RANGE. WINDS WILL GENERALLY BE LIGHT HOWEVER. A
SLOW CLIMB IN HUMIDITY VALUES IS EXPECTED TO START TONIGHT AND
INCREASE THROUGH LATE WEEK ALONG WITH INCREASING CHANCES FOR
WETTING RAINFALL. IN THE MEANTIME HOWEVER...HAVE CONTINUED TO
MENTION THE CONCERNS OF THE VERMONT DEPARTMENT OF FORESTS...PARKS
AND RECREATION REGARDING OPEN BURNING IN SUCH DRY CONDITIONS IN
OUR HAZARDOUS WEATHER OUTLOOK.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JMG
NEAR TERM...JMG
SHORT TERM...JMG
LONG TERM...WGH
AVIATION...KGM
FIRE WEATHER...BTV
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
930 AM EDT TUE MAY 7 2013
.DISCUSSION...
CURRENT-THIS AFTERNOON...UPPER LEVEL LOW OVER THE SOUTHEAST UNITED
STATES HAS BEEN SLOWLY TRACKING EAST TOWARD THE ATLANTIC AND WAS
OVER WESTERN SOUTH CAROLINA AND NORTHEAST GEORGIA PER THE LATEST
SATELLITE IMAGERY AND RUC ANALYSIS. BAND OF CLOUDS ASSOCIATED WITH A
WEAK UPPER LEVEL DISTURBANCE WAS MOVING EAST SOUTHEAST ACROSS THE
NORTHEAST GULF OF MEXICO AND NORTH FLORIDA. ANOTHER AREA OF MID
LEVEL ENERGY WAS CROSSING THE CENTRAL GULF AND MOVING TOWARD
FLORIDA. THE RUC40 PROGS THESE AREAS TO CROSS OVER CENTRAL FLORIDA
DURING THE AFTERNOON TIME OF MAX HEATING. ALTHOUGH LAYER MOISTURE IS
LIMITED TO AN INCH OR LESS PER THE 12Z UPPER AIR SOUNDINGS...THE
LOWER LAYERS MAY DESTABILIZE ENOUGH DURING THE AFTERNOON FOR A
SLIGHT CHANCE OF PRECIPITATION.
MORNING UPDATE AMENDED THE SURFACE WIND AND RELATED GRIDS. THE REST
OF THE AFTERNOON FORECAST LOOKS GOOD.
PREVIOUS ZONE DISCUSSION
CURRENT-TONIGHT...ANOTHER COOL AND DRY START TO THE DAY WITH
TEMPERATURES MAINLY IN THE 50S APPROACHING 10 DEGREES BELOW SEASONAL
NORMALS. A FAIRLY DRY DAY ON TAP WITH YET ANOTHER WEAK TROUGH
DROPPING SOUTHEASTWARD INTO THE CENTRAL PENINSULA DURING THE DAY.
PRECIPITABLE WATER VALUES WILL STRUGGLE TO REACH 1 INCH...THOUGH
SHORT RANGE MODELS TRY TO SPIT OUT A BIT OF QPF FROM ORLANDO
NORTHWARD THIS AFTERNOON. DEWPOINT VALUES WILL STRUGGLE TO STAY IN
THE LOWER 50S. WILL KEEP POPS JUST UNDER 20 PERCENT FOR LIGHT
PRECIPITATION FROM ORLANDO NORTHWARD BUT THIS MAY BE GENEROUS AS
MOST AREAS WILL REMAIN DRY. LIGHT MORNING WINDS WILL BECOME WESTERLY
AND INCREASE TO 10-15 MPH IN THE AFTERNOON WITH OCCASIONAL HIGHER
GUSTS. IF THERE IS ANY KIND OF SEA BREEZE THIS AFTERNOON IT WILL
LIKELY BE FROM MARTIN COUNTY OR PALM BEACH COUNTY SOUTHWARD. THE
UPPER LOW OVER WESTERN GEORGIA IS FINALLY FORECAST TO MUSTER FORWARD
MOMENTUM AND WILL MOVE ACROSS THE MID ATLANTIC STATES OVER THE NEXT
24 HOURS WHILE UNDERGOING A GRADUAL WEAKENING TREND. WEAK MID LEVEL
IMPULSES PINWHEELING AROUND THE UPPER LOW WILL MOVE ACROSS THE
CENTRAL PENINSULA DURING THE DAY. THIS ENERGY MAY BE JUST ENOUGH TO
SQUEEZE OUT A LITTLE PRECIPITATION OVER OUR NORTHERN AREAS IN THIS
FAIRLY DRY ENVIRONMENT.
HIGHS IN THE UPPER 70S TO LOWER 80S NEAR AND NORTH OF THE I-4
CORRIDOR WITH LOWER 80S FURTHER SOUTHWARD TOWARD LAKE OKEECHOBEE AND
ALONG THE TREASURE COAST. ANOTHER UNSEASONABLY COOL NIGHT ON TAP
WITH LOWS MAINLY IN THE 50S WITH SOME LOWER 60S POSSIBLE NEAR LARGER
METROPOLITAN AREAS AND ALONG THE MARTIN COUNTY COAST.
WED...MID LYR CLOSED LOW AND SFC LOW WILL MOVE NE TWD THE MID ATLC
WITH SFC HIGH PRESSURE RIDGE OFFSHORE FROM S FL AND REDEVELOPING
OVER THE ERN GULF. A DRY AIRMASS WITH PWATS LESS THAN AN INCH AND
LOW LVL WESTERLY FLOW WILL MAKE FOR A MOSTLY DAY WITH HIGHS IN THE
LOWER 80S ALONG THE COAST TO MID 80S OVER THE INTERIOR.
WED NIGHT...EXPECT MOSTLY CLEAR SKIES WITH SFC HIGH PRESSURE ACROSS
THE CENTRAL PENINSULA. LOWS IN THE UPPER 50S TO LOWER 60S.
THU...HIGH PRESSURE ACROSS CENTRAL FL...A DRY AIRMASS AND WEAK LOW
LVL FLOW WILL ALLOW WELL DEVELOPED AFTERNOON SEA BREEZE BOUNDARIES
TO PUSH INLAND. SHORT RANGE MODELS HINTING AT SOME LIGHT QPF ACROSS
INLAND MARTIN AND ST LUCIE BUT THINK OVERALL DRY AIRMASS WILL LIMIT
THE POSSIBILITY FOR DEEP CONVECTION AND WILL KEEP POPS BELOW
MENTIONABLE RANGE AT FOR NOW. HIGHS WILL WARM INTO THE LOWER TO MID
80 ALONG THE COAST AND MID-UPPER 80S FOR THE INTERIOR.
FRI...SFC RIDGE EXTENDING FROM THE ATLC INTO THE ERN GULF WITH LOW
LVL SE FLOW DEVELOPING. ECMWF CONTINUES DRY FORECAST WITH GFS
SHOWING VERY LOW PRECIP CHANCES. WILL CONTINUE DRY FORECAST AT THIS
POINT WITH HIGHS IN THE MID 80S COAST TO NEAR 90 OVER THE INTERIOR.
SAT-TUE...MAIN CHANGE IN 00Z MODELS TONIGHT IS SHOWING A BIT HIGHER
MOISTURE LEVELS AND INSTABILITY SUNDAY FOR SCATTERED STORMS ACROSS
NRN SECTIONS SO BUMPED UP POPS A BIT ACROSS THE NORTH SUNDAY
AFTERNOON. FOR SATURDAY...SHOULD SEE SOME LATE AFTERNOON ISOLATED
SEA BREEZE STORMS FROM NEAR LAKE OKEECHOBEE NNE TOWARD COASTAL
VOLUSIA LATE IN THE DAY. SUNDAY INTO MONDAY...FRONT MOVING THROUGH
THE STATE WILL BRING SCATTERED SHOWERS AND STORMS SUNDAY WITH FRONT
MOVING THROUGH THE FORECAST AREA EARLY MONDAY WITH A CONTINUED
CHANCE OF SHOWERS AND STORMS. FOR TUESDAY...GFS/ECMWF INDICATE SFC
FRONT WILL MOVE TOWARD S FL WITH NE OR EASTERLY ONSHORE FLOW. WILL
KEEP A SLIGHT CHANCE SHOWER CHANCE ACROSS THE NORTH AND A CHANCE FOR
A SHOWER OR STORM ACROSS SRN SECTIONS WHERE DEEPER MOISTURE WILL
LIKELY LINGER ON TUESDAY.
&&
.AVIATION...
VFR. SLIGHT CHANCE OF AN AFTERNOON RAIN SHOWER BETWEEN 18Z-24Z PER
RECENTLY UPDATED WEATHER GRID.
&&
.MARINE...
CURRENT-THIS AFTERNOON...BUOY 41009 WAS RECORDING WESTERLY WINDS AT
10 TO 15 KNOTS AND 4 FOOT SEAS WITH A 3 FOOT LONG PERIOD SWELL
COMPONENT. THE WIND RIGHT AT THE BEACHES/NEARSHORE MAY TAKE ON A
SOUTHERLY COMPONENT DURING THE AFTERNOON AS THE BOUNDARY LAYER WINDS
REMAIN STRONG ENOUGH TO HINDER ANY SEA BREEZE THAT DOES DEVELOP FROM
PUSHING ON LAND.
CURRENT AFTERNOON FORECAST LOOKS TO BE ON TRACK.
PREVIOUS MARINE DISCUSSION
TODAY-TONIGHT...WESTERLY WINDS CONTINUE THROUGH THE PERIOD
WITH SPEEDS INITIALLY AROUND 15 KTS EARLY THIS MORNING DECREASING TO
AROUND 9-12 KTS AROUND DAYBREAK FOR THE REMAINDER OF THE DAY. SEAS 3
TO 5 FEET...MOSTLY IN AN ENE SWELL.
SFC RIDGE BUILDING NEAR THE WATERS FROM WED-FRI WILL ALLOW WINDS TO
DROP TO 5-10 KNOTS...EXCEPT SLIGHTLY STRONGER NEAR THE COAST EACH
AFTERNOON WITH DEVELOPING EAST COAST SEA BREEZE. SEAS 3-4 FT WED IN
A NE SWELL WILL DIMINISH TO 2-3 FT THU INTO FRI. SLIGHTLY STRONGER
SE FLOW FRIDAY AFTERNOON WITH A SLIGHT CHANCE OF LATE DAY SHOWERS OR
STORMS NORTH OF THE CAPE...THEN SCATTERED SHOWERS AND STORMS SUNDAY
INTO MONDAY ACROSS THE WATERS.
&&
.FIRE WEATHER...
TODAY...RH VALUES EXPECTED TO FLIRT WITH 35 PERCENT OR LESS FOR 1-3
HOURS ACROSS THE INTERIOR. ENERGY RELEASE COMPONENT (ERC) VALUES ARE
IN THE UPPER TEENS AND 20S EVERYWHERE EXCEPT FOR BREVARD COUNTY`S
ERC OF 30. THE 20 FOOT WIND VALUES TOP OUT AT AROUND 12 MPH FROM THE
WEST AND SOUTHWEST THIS AFTERNOON.
PREVIOUS FIRE WEATHER DISCUSSION
MIN RHS IN THE 35-40 RANGE FOR THE INTERIOR WED-FRI BUT WINDS
EXPECTED TO REMAIN BELOW 15 MPH.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM/AVIATION...WIMMER
LONG TERM/IMPACT WX...CRISTALDI
AREA FORECAST DISCUSSION
NWS GRAY ME
942 AM EDT TUE MAY 7 2013
.SYNOPSIS...
DRY WEATHER WILL CONTINUE THROUGH AT LEAST THE FIRST HALF OF
WEDNESDAY AS HIGH PRESSURE REMAINS IN CONTROL. HOWEVER...SOME
COASTAL LOW CLOUDS AND FOG IS EXPECTED AGAIN TONIGHT AND TUESDAY
NIGHT. LOW PRESSURE WILL GRADUALLY WORK UP THE COAST ON WEDNESDAY
ALLOWING US OUR FIRST SHOT OF MEASURABLE RAINFALL WEDNESDAY NIGHT
THROUGH FRIDAY...WITH YET ANOTHER SYSTEM POSSIBLE SATURDAY NIGHT
AND SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...THE FOG AND LOW CLOUDS ARE QUICKLY DISSIPATING INLAND FROM
THE COAST SO FORECAST WAS UPDATED TO GO MOSTLY SUNNY THIS MORNING
OVER INTERIOR SPOTS. SOME PATCHY LOW STRATUS AND FOG LINGER IN
THE PORTLAND AND COASTAL AREAS BUT WILL SOON DISSIPATE OVER ALL
AREAS EXCEPT THE CAPES AND ISLANDS GIVING WAY TO A MOSTLY SUNNY
DAY.
PREVIOUS DISCUSSION...COASTAL STRATUS HAS ABOUT REACHED ITS WWD
EXTENT ATTM...WHILE IT SLOWLY CREEPS NWD THRU SRN FRANKLIN AND
SOMERSET COUNTIES. WITHIN THE STRATUS...AREAS OF FOG WILL CONTINUE
THRU SUNRISE. VSBYS ARE GENERALLY AOA 1/2SM...SO DON/T FEEL THE
NEED FOR A DENSE FOG ADVISORY.
STRATUS WILL SLOWLY ERODE TODAY WITH DIURNAL HEATING...ESPECIALLY
ALONG THE IMMEDIATE COASTLINE. MET GUIDANCE IS AWFULLY BULLISH ON
HIGH TEMPS REACHING THE LOW 70S FOR SRN COASTAL ZONES DESPITE THE
CLOUDY START AND ONSHORE FLOW. FEEL A MORE CONSERVATIVE APPROACH
TO MAX TEMPS ON THE COAST WAS A BETTER BET...WITH THE LOCAL
WRF...BIAS CORRECTED MOS...AND CMC REGIONAL SUGGESTING CLOSER TO
THE MID 60S. ACROSS THE INTERIOR...THE CONTINUED DRY CONDS AND
FULL SUNSHINE TO START WILL RESULT IN QUICK WARMING. TEMPS HERE
WILL LIKELY BE A COUPLE DEGREES ABV GUIDANCE...NEAR 80.
HAVE ALSO UNDERCUT MOS GUIDANCE ON DEW POINTS FOR THE INTERIOR.
EVEN USING RAP VALUES...REPRESENTING THE COOLEST GUIDANCE...RH
VALUES REMAIN AROUND 25% AND WINDS ARE LIGHT ENOUGH THAT NO RED
FLAG CONDS ARE EXPECTED.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
STRATUS WILL LURK JUST OFFSHORE FOR MOST OF THE DAY TODAY...AND
SURGE BACK SWD ALONG THE COAST TONIGHT. EXPECT MAINLY MIDCOAST TO
BE AFFECTED BY LOW CIGS/VSBYS THIS TIME AROUND. INCREASING
MOISTURE WILL KEEP LOW TEMPS FROM BOTTOMING OUT AS COLD AS THE
PAST FEW NIGHTS. WITH LOW STRATUS AND INCREASINGLY MOIST AIR
MASS...HAVE STAYED AWAY FROM BIAS CORRECTED GRIDS GIVEN THE
CHANGING CONDS.
ON WED...UPR LOW WILL MEANDER OUT OF THE MID ATLANTIC. CLOUDS WILL
INCREASE FROM S TO N THRU THE DAY WED. BY LATE IN THE AFTERNOON
EXPECTED SHWRS TO MOVE INTO SRN NH AND ADJACENT ME. PRIOR TO 00Z
THU NOT MUCH IN THE WAY OF QPF SHOULD IMPACT THE AREA.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
THE BEST CHANCE FOR SHOWERS WILL BE WEDNESDAY NIGHT AS A SOUTHERLY
GRADIENT ALIGNS THROUGH A DEEP LAYER. MOISTURE AHEAD OF A
WEAKENING ARE OF LOW PRESSURE WILL ENTER FROM THE GULF OF MAINE.
THIS WILL CONTINUE ON THURSDAY...HOWEVER INFLOW WILL NOT BE AS
PROMINENT AS THE TROUGH WEAKENS OVERHEAD.
A COLD FRONT WILL APPROACH FROM THE WEST ON FRIDAY. HOWEVER...WEAK
WAVES OF LOW PRESSURE WILL LIKELY FORM ALONG THE SLOW MOVING
BOUNDARY. AN UPPER LEVEL TROUGH APPROACHING FROM THE NW WILL ALSO
ALLOW THIS SYSTEM TO STALL JUST SOUTH OF OUR FORECAST AREA. THIS
WILL ALLOW FOR A CHANCE OF (WELL NEEDED) SHOWERS RIGHT THROUGH THE
WEEKEND.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
SHORT TERM...LIFR CONDS TO LINGER ON COAST THRU 13 OR
14Z...ERODING FROM S TO N ALONG THE COAST. LOW CLOUDS MAY LINGER
INTO THE MIDDAY INVOF KRKD. VFR CONDS EXPECTED TODAY. IFR/LIFR
CIGS WILL WORK BACK INTO COASTAL AREAS AGAIN TONIGHT...ESPECIALLY
KRKD BUT NOT AS LIKELY AS FAR S AS KPWM. VFR CONDS TO START THE
DAY ON WED...WITH MVFR CIGS/VSBYS IN SHWRS ACROSS SRN NH LATE IN
THE AFTERNOON.
LONG TERM...
EXPECT SHOWERY WEATHER FROM WEDNESDAY NIGHT THROUGH
SATURDAY. CONDITIONS COULD BE MVFR OR IFR DURING THIS PERIOD.
&&
.MARINE...
SHORT TERM...WINDS AND SEAS EXPECTED TO REMAIN BLO SCA THRESHOLDS.
LONG TERM...
SLOW MOVING LOW PRESSURE WILL BRING SHOWERY WEATHER BUT THE
PRESSURE GRADIENT WILL BE TOO LIGHT TO CAUSE GUSTY WINDS THROUGH THIS
WEEKEND. SEAS WILL SLOWLY BUILD DURING THE MIDWEEK PERIOD.
&&
.FIRE WEATHER...
HIGH PRESSURE SLOWLY LOSING ITS GRIP ON THE AREA. NO RAIN IS
EXPECTED TODAY...WITH AFTERNOON RH VALUES DIPPING TO NEAR 25%
AWAY FROM THE COAST. WINDS WILL REMAIN LIGHT ACROSS THE
INTERIOR. THE CHANCE OF WETTING RAINS INCREASES LATER WEDNESDAY
FOR SOUTHERN AREAS...AND BY THURSDAY FOR THE NORTH COUNTRY. RH
VALUES ARE EXPECTED TO CLIMB FURTHER WEDNESDAY...AS AIR MASS
GRADUALLY MOISTENS.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...BLOOMER
AREA FORECAST DISCUSSION
NWS GRAY ME
841 AM EDT TUE MAY 7 2013
.SYNOPSIS...
DRY WEATHER WILL CONTINUE THROUGH AT LEAST THE FIRST HALF OF
WEDNESDAY AS HIGH PRESSURE REMAINS IN CONTROL. HOWEVER...SOME
COASTAL LOW CLOUDS AND FOG IS EXPECTED AGAIN TONIGHT AND TUESDAY
NIGHT. LOW PRESSURE WILL GRADUALLY WORK UP THE COAST ON WEDNESDAY
ALLOWING US OUR FIRST SHOT OF MEASURABLE RAINFALL WEDNESDAY NIGHT
THROUGH FRIDAY...WITH YET ANOTHER SYSTEM POSSIBLE SATURDAY NIGHT
AND SUNDAY.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
UPDATE...STRATUS AND FOG HAVE EXTENDED WELL INLAND SO INCLUDED
SOME FOG THROUGH MID MORNING AS FAR INLAND AS THE MOUNTAINS.
HOWEVER LATEST SATELLITE IMAGERY SHOWS FOG BEGINNING TO RAPIDLY
DISSIPATE SO EXPECT SKIES TO CLEAR IN ALL BUT COASTAL AREAS BY MID
TO LATE MORNING.
PREVIOUS DISCUSSION...COASTAL STRATUS HAS ABOUT REACHED ITS WWD
EXTENT ATTM...WHILE IT SLOWLY CREEPS NWD THRU SRN FRANKLIN AND
SOMERSET COUNTIES. WITHIN THE STRATUS...AREAS OF FOG WILL CONTINUE
THRU SUNRISE. VSBYS ARE GENERALLY AOA 1/2SM...SO DON/T FEEL THE
NEED FOR A DENSE FOG ADVISORY.
STRATUS WILL SLOWLY ERODE TODAY WITH DIURNAL HEATING...ESPECIALLY
ALONG THE IMMEDIATE COASTLINE. MET GUIDANCE IS AWFULLY BULLISH ON
HIGH TEMPS REACHING THE LOW 70S FOR SRN COASTAL ZONES DESPITE THE
CLOUDY START AND ONSHORE FLOW. FEEL A MORE CONSERVATIVE APPROACH
TO MAX TEMPS ON THE COAST WAS A BETTER BET...WITH THE LOCAL
WRF...BIAS CORRECTED MOS...AND CMC REGIONAL SUGGESTING CLOSER TO
THE MID 60S. ACROSS THE INTERIOR...THE CONTINUED DRY CONDS AND
FULL SUNSHINE TO START WILL RESULT IN QUICK WARMING. TEMPS HERE
WILL LIKELY BE A COUPLE DEGREES ABV GUIDANCE...NEAR 80.
HAVE ALSO UNDERCUT MOS GUIDANCE ON DEW POINTS FOR THE INTERIOR.
EVEN USING RAP VALUES...REPRESENTING THE COOLEST GUIDANCE...RH
VALUES REMAIN AROUND 25% AND WINDS ARE LIGHT ENOUGH THAT NO RED
FLAG CONDS ARE EXPECTED.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY/...
STRATUS WILL LURK JUST OFFSHORE FOR MOST OF THE DAY TODAY...AND
SURGE BACK SWD ALONG THE COAST TONIGHT. EXPECT MAINLY MIDCOAST TO
BE AFFECTED BY LOW CIGS/VSBYS THIS TIME AROUND. INCREASING
MOISTURE WILL KEEP LOW TEMPS FROM BOTTOMING OUT AS COLD AS THE
PAST FEW NIGHTS. WITH LOW STRATUS AND INCREASINGLY MOIST AIR
MASS...HAVE STAYED AWAY FROM BIAS CORRECTED GRIDS GIVEN THE
CHANGING CONDS.
ON WED...UPR LOW WILL MEANDER OUT OF THE MID ATLANTIC. CLOUDS WILL
INCREASE FROM S TO N THRU THE DAY WED. BY LATE IN THE AFTERNOON
EXPECTED SHWRS TO MOVE INTO SRN NH AND ADJACENT ME. PRIOR TO 00Z
THU NOT MUCH IN THE WAY OF QPF SHOULD IMPACT THE AREA.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
THE BEST CHANCE FOR SHOWERS WILL BE WEDNESDAY NIGHT AS A SOUTHERLY
GRADIENT ALIGNS THROUGH A DEEP LAYER. MOISTURE AHEAD OF A
WEAKENING ARE OF LOW PRESSURE WILL ENTER FROM THE GULF OF MAINE.
THIS WILL CONTINUE ON THURSDAY...HOWEVER INFLOW WILL NOT BE AS
PROMINENT AS THE TROUGH WEAKENS OVERHEAD.
A COLD FRONT WILL APPROACH FROM THE WEST ON FRIDAY. HOWEVER...WEAK
WAVES OF LOW PRESSURE WILL LIKELY FORM ALONG THE SLOW MOVING
BOUNDARY. AN UPPER LEVEL TROUGH APPROACHING FROM THE NW WILL ALSO
ALLOW THIS SYSTEM TO STALL JUST SOUTH OF OUR FORECAST AREA. THIS
WILL ALLOW FOR A CHANCE OF (WELL NEEDED) SHOWERS RIGHT THROUGH THE
WEEKEND.
&&
.AVIATION /13Z TUESDAY THROUGH SATURDAY/...
SHORT TERM...LIFR CONDS TO LINGER ON COAST THRU 13 OR
14Z...ERODING FROM S TO N ALONG THE COAST. LOW CLOUDS MAY LINGER
INTO THE MIDDAY INVOF KRKD. VFR CONDS EXPECTED TODAY. IFR/LIFR
CIGS WILL WORK BACK INTO COASTAL AREAS AGAIN TONIGHT...ESPECIALLY
KRKD BUT NOT AS LIKELY AS FAR S AS KPWM. VFR CONDS TO START THE
DAY ON WED...WITH MVFR CIGS/VSBYS IN SHWRS ACROSS SRN NH LATE IN
THE AFTERNOON.
LONG TERM...
EXPECT SHOWERY WEATHER FROM WEDNESDAY NIGHT THROUGH
SATURDAY. CONDITIONS COULD BE MVFR OR IFR DURING THIS PERIOD.
&&
.MARINE...
SHORT TERM...WINDS AND SEAS EXPECTED TO REMAIN BLO SCA THRESHOLDS.
LONG TERM...
SLOW MOVING LOW PRESSURE WILL BRING SHOWERY WEATHER BUT THE
PRESSURE GRADIENT WILL BE TOO LIGHT TO CAUSE GUSTY WINDS THROUGH THIS
WEEKEND. SEAS WILL SLOWLY BUILD DURING THE MIDWEEK PERIOD.
&&
.FIRE WEATHER...
HIGH PRESSURE SLOWLY LOSING ITS GRIP ON THE AREA. NO RAIN IS
EXPECTED TODAY...WITH AFTERNOON RH VALUES DIPPING TO NEAR 25%
AWAY FROM THE COAST. WINDS WILL REMAIN LIGHT ACROSS THE
INTERIOR. THE CHANCE OF WETTING RAINS INCREASES LATER WEDNESDAY
FOR SOUTHERN AREAS...AND BY THURSDAY FOR THE NORTH COUNTRY. RH
VALUES ARE EXPECTED TO CLIMB FURTHER WEDNESDAY...AS AIR MASS
GRADUALLY MOISTENS.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...MCB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
723 AM EDT TUE MAY 7 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 418 AM EDT TUE MAY 7 2013
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW W-E ORIENTED UPR
RDG STRETCHING ALONG THE US/CNDN BORDER TO THE N OF CLOSED UPR LOWS
OVER THE SE CONUS AND ANOTHER JUST OFF THE CA COAST. AT THE SFC...
HI PRES IS CENTERED OVER LK SUP...AND WINDS ARE NEAR CALM UNDER
SLACK PRES GRADIENT. WITH VERY DRY AIRMASS SHOWN ON THE 00Z GRB
RAOB...WHERE PWAT WAS ONLY 0.15 INCH OR 27 PCT OF NORMAL...QUIET WX
DOMINATES THE CWA. THERE ARE SOME HI CLDS OVER THE SCENTRAL...BUT
OTRW SKIES ARE CLR.
DRY HI PRES IS FCST TO DOMINATE THE UPR LKS TDAY/TNGT...SO QUIET
WX/MOCLR SKIES SHOULD CONTINUE. MAIN FCST CONCERNS ARE TEMPS/HOW LO
MIN RH WL FALL THIS AFTN. ANY SHALLOW GROUND FOG THAT FORMS OVER THE
INTERIOR W EARLY THIS MRNG WL BURN OFF QUICKLY AFT SUNRISE. WITH H85
TEMPS THIS AFTN IN THE 10-11C RANGE...ABOUT THE SAME OR 1C HIER THAN
YDAY...MAX TEMPS SHOULD BE SIMILAR TO WHAT OCCURRED ON MON. DEEP
MIXING TO H75 ON FCST SDNGS YIELDS HI TEMPS RISING WELL INTO THE 70S
AWAY FM LK MODERATION. ONE DIFFERENCE IS THE H925 FLOW IS FCST TO BE
A BIT STRONGER OUT OF THE S-SE THAN YDAY AND UP TO 10 KTS WITH HI
CENTER SHIFTING SLOWLY TO THE E. AS A RESULT...LK MODERATION OFF LK
SUP SHOULD NOT PENETRATE AS FAR INLAND AS ON MON. ON THE OTHER
HAND...MODERATION OFF LK MI WL BE A BIT MORE AGGRESSIVE. AWAY FM LK
COOLING/ MOISTENING...THE DEEP MIXING WL ALLOW SFC DEWPTS TO FALL TO
ARND 30 THIS AFTN...RESULTING IN MIN RH ARND 20 PCT. SINCE WINDS
SHOULD BE NO HIER THAN ABOUT 10 MPH...NO FIRE WX HEADLINES ARE
NECESSARY.
CONTINUED AIRMASS MODERATION...A SOMEWHAT STRONGER S WIND...AND THE
ARRIVAL OF MOISTER AIR ESPECIALLY OVER THE W...WHERE THE PWAT IS
FCST TO RISE TO NEAR 0.75 INCH BY 12Z WED...WL CONSPIRE TO KEEP MIN
TEMPS TNGT HIER THAN THIS MRNG. THE DIFFERENCE SHOULD BE MOST
PRONOUNCED OVER THE W CLOSER TO THE INCOMING MOISTER AIR.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 418 AM EDT TUE MAY 7 2013
LIMITED CHANGES TO THE GOING FORECAST FROM 24HRS AGO. THE HIGH
PRESSURE RIDGE THAT THE AREA IS CURRENTLY UNDER WILL BEGIN TO
LOOSEN IT/S GRIP ON THE AREA ON WEDNESDAY...BUT NOT BEFORE
PROVIDING ANOTHER ABOVE NORMAL TEMPERATURE DAY FOR MUCH OF UPPER
MICHIGAN. MOST AREAS WILL SEE TEMPERATURES IN THE 70S...BUT LAKE
BREEZES WILL LEAD TO SLIGHTLY COOLER VALUES NEAR THE GREAT LAKES.
MOST MODELS HAVE BACKED OFF ON PRECIPITATION FROM THE DIURNAL CU
OVER THE WESTERN CWA IN THE AFTERNOON...AND THAT SEEMS REASONABLE
BASED OFF THE MOISTURE BEING FOCUSED ABOVE 6-7KFT. WITH THE HIGH
BASED CLOUDS AND THE LINGERING LOW LEVEL DRY AIR...IT MAY BE TOUGH
TO GET PRECIPITATION TO REACH THE SURFACE. IN ADDITION...LOOKING AT
MODEL SOUNDINGS...THE VERY LOW LEVELS ARE TRYING TO OVER MOISTEN
THE SURFACE...WHICH INCREASES THE SFC BASED CAPE TOWARDS 500-750
J/KG. LOOKING AT MLCAPE...THAT DRY AIR CUTS BACK CAPE VALUES TO
50-250 J/KG AND WITH THE OTHER NEGATIVE VALUES...WILL CUT BACK
POPS TO SLIGHTS OVER THE FAR WEST. ALSO FOR WEDNESDAY...LOWERED
DEWPOINTS BASED OFF DRIER AIR HOLDING OVER THE AREA. THIS WILL LEAD
TO ANOTHER DAY OF RH VALUES IN THE 20S OVER THE INTERIOR CENTRAL AND
EAST. FORTUNATELY...THE WINDS WILL AGAIN REMAIN LIGHT AND BE THE
STRONGEST ALONG THE LEADING EDGE OF THE LAKE BREEZES.
FOR WEDNESDAY NIGHT INTO THURSDAY...FOCUS TURNS TO THE WEAK COLD
FRONT DROPPING SOUTHEAST ACROSS THE AREA IN THE EARLY EVENING AND
WEAK SHORTWAVE ENERGY AND ASSOCIATED MOISTURE PUSHING EAST FROM
SOUTHERN MINNESOTA AND INTO THE LOWER GREAT LAKES. WITH THE MOISTURE
FAIRLY LIMITED WITH THE COLD FRONT...THE PRECIPITATION CHANCES WILL
BE LARGELY DEPENDENT ON THE TRACK OF THE SHORTWAVE. WITH THE BEST
MOISTURE AND CLOSEST PROXIMITY TO THE ENERGY TO THE SOUTHWEST OF THE
AREA...WILL HAVE THE HIGHEST POPS OVER THE WEST...WITH LOW END
LIKELY AND HIGH END CHANCE VALUES FOR OVERNIGHT WEDNESDAY NIGHT AND
THURSDAY MORNING BEFORE DIMINISHING DURING THE AFTERNOON. QPF
AMOUNTS SHOULD BE ON THE LIGHT SIDE /LESS THAN A QUARTER OF AN
INCH/ UNLESS THE SHORTWAVE IS FARTHER TO THE NORTH...WHICH ALLOW
FOR GREATER INTERACTION BETWEEN THE WAVE AND THE FRONT.
BEHIND THE COLD FRONT...CANADIAN HIGH PRESSURE WILL BUILD OVER THE
AREA FROM THE NORTHWEST ON THURSDAY NIGHT AND REMAIN INTO FRIDAY
EVENING. THIS SHOULD LEAD TO DRY WEATHER...BUT WITH COOLER
TEMPERATURES ALOFT /850MB TEMPS AROUND 2-4C/ WOULD EXPECT HIGHS TO
BE IN THE 50S INLAND AND IN THE UPPER 40S TO AROUND 50 NEAR LAKE
SUPERIOR WITH THE NORTHEAST WINDS.
STRONG NORTHERN STREAM UPPER TROUGH WILL DIVE SOUTHEAST ACROSS THE
AREA LATE FRIDAY NIGHT AND SATURDAY. WITH THE STRENGTH OF THE
FRONT...WOULD EXPECT A NICE LINE OF SHOWERS MOVING ACROSS THE
AREA LATE FRIDAY NIGHT AND SATURDAY. THE SPEED OF THE FRONT WILL
LIMIT ACCUMULATIONS...BUT MOST AREAS SHOULD SEE A TENTH OF AN INCH
OF RAIN. THERE IS THE POTENTIAL THE BACK SIDE OF THIS PRECIPITATION
COULD TURN OVER TO SNOW AND WILL CONTINUE THAT MENTION. WITH THE
VERY COLD AIR ALOFT BEHIND THE FRONT ON SATURDAY AFTERNOON...WOULD
EXPECT DIURNAL SHOWERS TO DEVELOP ON THE BACK SIDE OF THE LOW...DUE
TO THE SFC-700MB LAPSE RATES AROUND 8-8.5 C/KM. THIS PRECIPITATION
WILL START AS SNOW ALOFT AND P-TYPE AT THE SURFACE DEPENDS ON LOW
LEVEL TEMPERATURES. MODELS ARE HINTING AT SURFACE TEMPERATURES BEING
WARMER...BUT WITH THE DRY LOW LEVEL AIR AND INVERTED V LOOK TO THE
SOUNDING...OPTED TO UTILIZE THE WETBULB ZERO HEIGHT FOR RAIN/SNOW
LINE. THIS PLACES A RAIN/SNOW MIX OVER THE NORTH AND RAIN OVER THE
SOUTH. WITH THE LATEST MODEL TRENDS...IT MAY END UP BEING SNOW
ACROSS MUCH OF THE AREA. ALSO ADJUSTED HIGHS DOWN TOWARDS RAW MODEL
DATA...SINCE MOS TREND TOWARDS NORMAL IS BIASING THE COLD TEMPS.
THIS PRODUCES HIGHS IN THE LOW-MID 40S OVER THE NORTHWEST HALF OF
THE CWA AND UPPER 40S OVER THE SOUTHEAST HALF. THE COOLER
TEMPERATURES AND THE GUSTY NORTHWEST WINDS...25-30KTS...IT WILL NOT
FEEL LIKE A MID MAY DAY ACROSS UPPER MICHIGAN. COULD EVEN BE A FEW
LAKE EFFECT SNOW SHOWERS ON SATURDAY NIGHT OVER THE EAST. DECENT
SFC-775MB DELTA-T VALUES...BUT MOISTURE APPEARS LIMITED AT THIS
POINT WITH AN INVERTED V LOOK BELOW THE CLOUD BASE AND WILL ONLY
MENTION SLIGHT CHANCES.
UPPER TROUGH WILL BEGIN TO SHIFT EAST ON SUNDAY AND PULL THE
MOISTURE WITH IT. THUS...EXPECT A DIMINISHING TREND TO THE
PRECIPITATION ON SATURDAY NIGHT AND A DRY SUNDAY. TEMPERATURES WILL
REMAIN ON THE COLD SIDE ON SUNDAY...WITH HIGHS IN THE LOW 40S OVER
THE EAST AND MID 40S OVER THE WEST DUE TO WARMING TEMPERATURES
ALOFT. UPPER RIDGE WILL THEN BUILD OVER THE UPPER GREAT LAKES FOR
MONDAY INTO TUESDAY. MEANWHILE...A LOW PRESSURE SYSTEM MOVING
THROUGH NORTHERN ONTARIO WILL SWEEP A WARM FRONT ACROSS SOUTHERN
ONTARIO ON MONDAY NIGHT...WHICH COULD BRUSH THE CWA. THIS FRONT
WILL ALSO BRING TEMPERATURES BACK TO NORMAL ACROSS THE AREA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 722 AM EDT TUE MAY 7 2013
EXPECT VFR CONDITIONS AND LIGHT WINDS AT ALL 3 SITES THIS FCST
PERIOD WITH DRY HI PRES DOMINATING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 418 AM EDT TUE MAY 7 2013
HIGH PRESSURE WILL CONTINUE TO PRODUCE LIGHT WINDS TODAY AND
WEDNESDAY...BUT A COLD FRONT MOVING THROUGH ON WEDNESDAY AFTERNOON
AND EARLY EVENING WILL LEAD TO INCREASING NORTH-NORTHEAST WINDS
PEAKING IN THE 15-25KT RANGE ON WEDNESDAY NIGHT INTO THURSDAY
MORNING. HIGH PRESSURE WILL BUILD BACK OVER THE AREA FOR FRIDAY AND
DIMINISH THE WINDS. BUT A STRONGER COLD FRONT WILL SLIDE THROUGH
FRIDAY NIGHT AND SHIFT WINDS TO THE NORTHWEST AT 20-30KTS ON
SATURDAY. THESE WINDS WILL CONTINUE INTO SATURDAY NIGHT BEFORE
GRADUALLY DIMINISHING ON SUNDAY.
&&
.HYDROLOGY...
ISSUED AT 418 AM EDT TUE MAY 7 2013
HYDROLOGY CONCERNS REMAIN FOR TODAY AND WEDNESDAY...BUT THEY
ARE STARTING TO DIMINISH WITH THE DWINDLING SNOW PACK OVER
WESTERN UPPER MICHIGAN. VISIBLE SATELLITE AND MODIS IMAGERY
YESTERDAY STILL SHOWS SNOW REMAINING IN THE HIGHER TERRAIN LOCATIONS
OF THE HURON MOUNTAINS AND THE KEWEENAW PENINSULA. THE LATEST SNOW
DEPTH OBSERVATIONS /FROM EARLIER THIS MORNING AROUND 8AM/ STILL HAVE
AROUND 3IN AT IRONWOOD...AND 7IN AT ATLANTIC MINE. A FEW POCKETS OF
HIGHER AMOUNTS ARE LIKELY ACROSS THE KEWEENAW. DID SEE RISES AT SOME
OF THE SITES OVER THE WEST /ESPECIALLY TRRM4 AND BESM4/ WITH THE
WARMER TEMPERATURES YESTERDAY. BUT THE TRAP ROCK RIVER LEVELED OFF
MUCH FASTER OVERNIGHT AND THAT MAY BE A SIGN OF THE LACK OF SNOW
WATER EQUIVALENT LEFT IN THE BASIN. WITH THE SOLID RISE YESTERDAY OF
BESM4 AND DECENT SNOW COVER...WOULD THINK IT WOULD MAKE ANOTHER PUSH
TODAY. AT THIS TIME...AN EDUCATED GUESS WOULD PUT IT BETWEEN 8 AND 9
FEET THIS AFTERNOON/EVENING...WHICH WOULD LIKELY BE THE LAST MAJOR
PUSH.
THE ONGOING FLOODING ON THE MICHIGAMME RIVER AROUND WITCH LAKE WILL
REMAIN A CONCERN FOR THE NEXT COUPLE OF DAYS UNTIL THE SNOW WATER
MAKES IT OUT OF THE HIGHER TERRAIN OF NORTHWEST MARQUETTE COUNTY.
THE STURGEON RIVER AT ALSTON AND CHASSELL CONTINUES TO HOVER BETWEEN
ADVISORY AND WARNING LEVELS AND WOULD EXPECT THAT TO CONTINUE BASED
ON THE STEADY FLOW THROUGH THE STURGEON RIVER AT SIDNAW UPSTREAM.
OTHERWISE...THE REST RIVER LEVELS ARE ON THE DOWNWARD TREND AND
WILL LIKELY CONTINUE THIS WEEK.
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...UPDATED AVIATION
NWS ST LOUIS MO
550 AM CDT TUE MAY 7 2013
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 329 AM CDT TUE MAY 7 2013
UPPER LEVEL LOW STILL CENTERED OVER NORTHWEST GEORGIA/NORTHEAST
ALABAMA IS FORECAST TO BEGIN MOVING SLOWLY NORTHEAST TODAY. THIS
SHOULD FINALLY BRING A CLEARING SKY AND WARMER TEMPERATURES TO THE
REGION. THERE IS A PERSISTENT BAND OF MID LEVEL CLOUDS AROUND
10,000FT WHICH JUST DON`T SEEM TO WANT TO GO AWAY. THE NAM SEEMS TO
BE HANDLING THE DECK PRETTY WELL AT THIS TIME...AND IT SLOWLY THINS
OUT THROUGH THE MORNING. THE RUC ON THE OTHER HAND KEEPS THE DECK
AROUND AT LEAST THROUGH EARLY AFTERNOON. AM LEANING TOWARD THE RUC
AT THIS TIME SINCE THIS IS CLOSER TO PERSISTENCE...AND THIS SYSTEM
HAS BEEN NOTHING IF NOT PERSISTENT. CLOUDS SHOULD BE THINNING OUT
DURING THE AFTERNOON...AND STRONG MAY SUNSHINE SHOULD EASILY PROPEL
HIGHS INTO THE MID AND UPPER 70S. THERE MAY BE ENOUGH INSTABILITY
AROUND THIS AFTERNOON FOR POP-UP SHOWERS AND THUNDERSTORMS...SO THE
SLIGHT CHANCE POPS CURRENTLY IN THE FORECAST LOOK TO BE ON TRACK.
MEANWHILE...THE COMPACT LITTLE CUTOFF LOW CURRENTLY OVER SOUTH
DAKOTA WILL START DRIFTING SOUTHEAST IN THE WAKE OF ITS BIG SISTER
OVER THE EASTERN U.S. AS THE SECOND LARGE CUTOFF NOW OVER THE
CALIFORNIA COAST DRIFTS INTO THE INTERMOUNTAIN WEST. MODELS HAVE
BEEN VERY CONSISTENT IN FORECASTING THE LITTLE NORTHERN PLAINS LOW
TO BREAK DOWN THE UPPER LEVEL RIDGING BETWEEN THE TWO LARGER LOWS ON
WEDNESDAY...BRINGING ANOTHER CHANCE FOR AFTERNOON THUNDERSTORMS
PRIMARILY TO CENTRAL MISSOURI. THE LOW OPENS UP INTO A SHORTWAVE
WEDNESDAY NIGHT INTO THURSDAY BRINGING LOW LEVEL BAROCLINICITY INTO
THE MID-MISSISSIPPI VALLEY...AND AN INCREASING LOW LEVEL JET FROM
THE SOUTHEAST PLAINS. THIS LOOKS LIKE ANOTHER PERIOD OF WET WEATHER
FROM WEDNESDAY NIGHT THROUGH THURSDAY NIGHT AS THE SHORTWAVE SLOWLY
AMPLIFIES OVER THE MIDWEST AND THE LOW LEVEL JET CONTINUES TO BRING
A PLUME OF MOISTURE UP FROM THE SOUTHWEST. NOT SAYING IT`S GOING TO
BE A TOTAL WASH...BUT A FEW WAVES OF STORMS FROM WEDNESDAY EVENING
THROUGH LATE THURSDAY NIGHT LOOK PRETTY LIKELY. LOW LEVEL FLOW
TURNS TO THE NORTHWEST ON FRIDAY WHICH SHOULD BEGIN TO SHUT THE
PRECIP OFF FROM NORTH TO SOUTH...BUT NOT BEFORE THERE MAY BE ANOTHER
WAVE OF SHOWERS OR STORMS ALONG AND SOUTH OF THE I-70 CORRIDOR.
TEMPERATURES THROUGH THE PERIOD LOOK TO BE NEAR OR ABOVE NORMAL IN
THE MID 70S TO AROUND 80 WITH LOWS GENERALLY IN THE UPPER 50S AND
LOW 60S.
CARNEY
.LONG TERM...(SATURDAY THROUGH MONDAY)
ISSUED AT 347 AM CDT TUE MAY 7 2013
ANOTHER STRONG SHORTWAVE MOVES ACROSS THE U.S. CANADA BORDER FRIDAY
NIGHT INTO SATURDAY WHICH AMPLIFIES THE AFOREMENTIONED MIDWEST
SHORTWAVE AND PUSHES A STRONG COLD FRONT DOWN THROUGH THE PLAINS
INTO THE MID-MISSISSIPPI VALLEY LATE SATURDAY. STILL LOOKS LIKE
THERE COULD BE A CHANCE OF SHOWERS ON SATURDAY AS THE FRONT MOVES
THROUGH...THOUGH MEDIUM RANGE MODELS ARE NOW SHOWING THAT MOST OF
THE PRECIP MAY BE SOUTH OF THE REGION. A 1030MB CANADIAN HIGH
FOLLOWS ON THE HEELS OF THE FRONT. HIGHS SATURDAY LOOK TO BE NEAR
OR JUST BELOW SEASONAL NORMALS IN THE UPPER 60S TO LOW 70S...BUT THE
COLD CANADIAN AIRMASS WILL PUSH TEMPERATURES WELL BELOW NORMAL ON
SUNDAY AND MONDAY. GUIDANCE IS GIVING ME HIGHS IN THE LOW TO MID
60S AND LOWS IN THE UPPER 30S TO MID 40S. HOWEVER...I WOULD NOT BE
SURPRISED IF ACTUAL TEMPERATURES ARE AS MUCH AS 5 TO 10 DEGREES
COLDER THAN GUIDANCE. GFS AND ECMWF ARE FORECASTING 850MB TEMPS
AROUND 0C ON BOTH SUNDAY AND MONDAY WHICH YIELDS MIX-DOWN TEMPS IN
MID TO UPPER 50S! AM NOT GOING QUITE THAT COLD YET...BUT DID TAKE A
FEW DEGREES OFF GUIDANCE TEMPS BOTH SUNDAY AND MONDAY.
CARNEY
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 548 AM CDT TUE MAY 7 2013
VFR CONDITIONS EXPECTED WITH GRADUAL DECREASE IN MID LEVEL CLOUDS.
LIGHT NORTH WIND TO BECOME LIGHT AND VARIABLE TONIGHT.
SPECIFICS FOR KSTL...
VFR CONDITIONS EXPECTED TO CONTINUE.
CVKING
&&
.PRELIMINARY POINT TEMPS/POPS...
SAINT LOUIS 76 58 79 62 / 20 10 20 40
QUINCY 76 54 77 59 / 10 10 30 60
COLUMBIA 76 55 76 59 / 10 10 30 60
JEFFERSON CITY 76 54 77 60 / 10 10 30 60
SALEM 73 54 77 59 / 20 5 10 20
FARMINGTON 73 51 77 59 / 20 10 20 20
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
711 AM EDT TUE MAY 7 2013
.SYNOPSIS...
FAIR...DRY AND WARM WEATHER WILL PERSIST TODAY THROUGH MOST OF
WEDNESDAY AS HIGH PRESSURE MAINTAINS CONTROL OVER REGIONAL WEATHER
CONDITIONS. A TREND TOWARD COOLER AND MORE UNSETTLED WEATHER IS
EXPECTED BY THURSDAY ONWARD INTO NEXT WEEKEND AS THE COMBINATION OF
UPPER LEVEL LOW PRESSURE AND A SERIES OF SURFACE FRONTS BRING THE
CHANCE OF WELCOMED RAINFALL TO THE REGION.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 343 AM EDT TUESDAY...PERSISTENCE FORECAST WILL BE OFFERED
AGAIN TODAY AS IDEAL CHAMBER OF COMMERCE WEATHER PATTERN CONTINUES
UNDER DEEP LAYER BLOCKING HIGH PRESSURE. THUS VERY LITTLE CHANGE
FROM YESTERDAY WITH FULL SUN AND MILD TO WARM TEMPERATURES IN THE
UPPER 70S TO LOWER 80S UNDER LIGHT SURFACE WINDS. DID LEAN TOWARD
DRIEST MODEL TD/RH PROGS FOR OUR AREA THIS AFTERNOON...IN THIS
CASE THE RAW RUC13 VALUES. RECENT PERFORMANCE OF MOS GUIDANCE HAS
BEEN OVERLY MOIST AND FRANKLY QUITE POOR OVER THE PAST FEW
AFTERNOONS...SO SAW NO REASON TO LEAN IN THIS DIRECTION.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
AS OF 343 AM EDT TUESDAY...CLEAR SKIES AND LIGHT WINDS THEN
CONTINUE TONIGHT INTO THE FIRST HALF OF WEDNESDAY AS BLOCKING
RIDGE FINALLY BEGINS TO BREAK DOWN IN RESPONSE TO A LARGE CYCLONIC
GYRE TRUDGING SLOWLY NORTHEAST FROM THE SOUTHEAST/MID-ATLANTIC
STATES. LOWS TONIGHT GENERALLY FROM 45 TO 55 WITH CUSTOMARY COOLER
SPOTS IN THE DACKS/NERN VT. SFC MOISTURE WILL GRADUALLY INCREASE
OVERNIGHT BUT WIDESPREAD BR/FG NOT EXPECTED GIVEN RECENT DRY
STRETCH AND SFC SOIL MOISTURE VALUES REMAINING QUITE LOW.
BY LATER WEDNESDAY INTO WEDNESDAY NIGHT AFOREMENTIONED UPPER LOW
TRACKS INTO THE NORTHEAST WHILE WEAKENING INTO AN OPEN WAVE. AS
CUSTOMARY WITH SUCH SYSTEMS...HARD TO PINPOINT EXACT TIMING AND
COVERAGE OF SHOWERS...WHICH WILL BE TIED MOST CLOSELY TO BANDS OF
DEEPER MOISTURE AND VORTICITY ADVECTION. NONETHELESS...WITH
INCREASING CYCLONIC FLOW ALOFT AND PWATS CLIMBING NEAR OR SLIGHTLY
ABOVE 1 INCH EXPECT AN INCREASE IN CLOUDS AND SHOWER CHANCES FROM
SOUTH TO NORTH THROUGH THE EVENING AND NIGHTTIME HOURS. COULD ALSO
SEE A STRAY LATE AFTERNOON/EVENING STORM SOUTH AND ALSO OUT IN THE
SLV AS MODELS CONTINUE TO HINT AT SOME WEAK LOW TO MID-LEVEL
INSTABILITY DEVELOPING IN THESE AREAS. HIGHS ON WEDNESDAY RANGING
FROM THE LOWER TO MID 70S SOUTH AS CLOUDS ARRIVE EARLY IN THE
AFTERNOON...TO AROUND 80 ONCE AGAIN NORTH AS SUNSHINE HANGS ON
THROUGH A GOOD PORTION OF THE DAY.
BY THURSDAY DECAYING UPPER LOW PASSES ACROSS OUR REGION WITH
CONTINUED CHANCE OF SHOWERS ALONG WITH AN ISOLATED STORM HERE OR
THERE. BEST COVERAGE TO OCCUR DURING THE AFTERNOON CONVECTIVE
MAXIMUM FROM NOON TO 6 PM OR SO. WITH MORE WIDESPREAD CLOUD COVER
ACROSS THE REGION TEMPERATURES WILL CONTINUE TO EASE BACK SLIGHTLY
TOPPING OUT GENERALLY IN THE 67 TO 73 RANGE.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 400 AM EDT TUESDAY...UNSETTLED WEATHER WILL CONTINUE INTO
THE LONG TERM WITH STATIONARY FRONT AFFECTING THE NORTH COUNTRY
GRADUALLY GAINING MOMENTUM EASTWARD ON FRIDAY. RAIN SHOWERS WILL
START THE PERIOD ASSOCIATED WITH THE AFOREMENTIONED STATIONARY
FRONT. LATE FRIDAY INTO EARLY SATURDAY...THE FRONT WILL EXIT EAST
ALONG THE NEW ENGLAND COAST...WITH A BRIEF PERIOD OF SFC RIDGING
BUILDING INTO THE NORTH COUNTRY FRIDAY NIGHT. SATURDAY WILL SEE
THE RIDGING WEAKEN AND SLIDE EAST AS AN UPPER LEVEL CUT OFF LOW
APPROACHES FROM THE NORTHWESTERN GREAT LAKES. AT THE SFC...A
CLOSED LOW ASSOCIATED WITH THE UPPER LOW WILL INTERACT WITH A
WEAKER...SOUTHERN STREAM LOW. DEPENDING HOW FAR NORTH THIS
SOUTHERN LOW MOVES...WILL AFFECT WHEN THE NEXT ROUND OF SHOWERS
ARE EXPECTED ON SATURDAY.
THE UPPER LEVEL CUTOFF LOW WILL MOVE JUST SOUTH OF JAMES BAY
SATURDAY NIGHT...SIGNIFICANTLY DECREASING 500MB HTS AND PRODUCING
SHOWERS OVER PORTIONS OF THE NORTH COUNTRY THROUGH LATE
SUNDAY/SUNDAY NIGHT ASSOCIATED WITH A SFC COLD FRONT. RIDGING
BEHIND THE FRONT WILL BE ACCOMPANIED BY W/NW WINDS AND COOLER
TEMPERATURES. THIS RIDGING MAY BE INTERRUPTED BY A POST FRONTAL
TROUGH BRINGING A LOW CHC FOR SHOWERS ON MONDAY AS THE UPPER LOW
IS SLOW TO EXIT TO THE EAST.
ABOVE NORMAL TEMPERATURES WILL START THE PERIOD WITH MAX TEMPS IN
THE 60S-L70S FRIDAY AND SATURDAY..COOLING BEHIND THE FRONT ON
SUNDAY TO 50S-L60S AND COOLING FURTHER INTO THE M40S-U50S ON
MONDAY. MIN TEMPS WILL SEE A SIMILAR TREND...STARTING IN THE 40S-
L50S THURSDAY NIGHT AND DECREASING TO THE 30S SUNDAY NIGHT.
&&
.AVIATION /11Z TUESDAY THROUGH SATURDAY/...
THROUGH 12Z WEDNESDAY...VFR CONDITIONS PERSIST WITH HIGH PRESSURE
STRETCHING ACROSS THE NORTH COUNTRY TODAY INTO TONIGHT. EXPECT
MOSTLY CLEAR SKIES WITH GENERAL SOUTHERLY FLOW AT 6-12 KTS DURING
THE DAY AND SUBSIDING AFTER SUNSET.
OUTLOOK 12Z WEDNESDAY THROUGH SATURDAY...
12Z WEDNESDAY THROUGH 18Z WEDNESDAY...VFR CONDITIONS EXPECTED TO
CONTINUE FOR THE FIRST HALF OF WEDNESDAY WITH INCREASING CLOUDS
FROM THE SOUTH.
18Z WEDNESDAY ONWARD...INCREASING CLOUDS AS A CLOSED UPPER LOW
OVER THE MID ATLANTIC STATES EARLY WEDNESDAY NIGHT WILL MOVE
NORTHEAST AND BRING A CHANCE OF RAIN SHOWERS TO THE REGION
WEDNESDAY NIGHT THROUGH FRIDAY NIGHT...WITH SOME MVFR CONDITIONS
POSSIBLE IN RAIN SHOWERS. A COLD FRONT WILL MOVE INTO THE REGION
ON FRIDAY AND THEN BECOME NEARLY STATIONARY...WITH A CHANCE OF
RAIN SHOWERS FRIDAY AND SATURDAY...WITH SOME AREAS OF MVFR
POSSIBLE.
&&
.FIRE WEATHER...
HIGH PRESSURE OVERHEAD WILL KEEP PRECIPITATION OUT OF THE NORTH
COUNTRY THROUGH MID-DAY ON WEDNESDAY. FULL SUN IS EXPECTED TODAY
WITH AFTERNOON MINIMUM RELATIVE HUMIDITY VALUES FALLING INTO THE
15 TO 25 PERCENT RANGE. WINDS WILL GENERALLY BE LIGHT HOWEVER. A
SLOW CLIMB IN HUMIDITY VALUES IS EXPECTED TO START TONIGHT AND
INCREASE THROUGH LATE WEEK ALONG WITH INCREASING CHANCES FOR
WETTING RAINFALL. IN THE MEANTIME HOWEVER...HAVE CONTINUED TO
MENTION THE CONCERNS OF THE VERMONT DEPARTMENT OF FORESTS...PARKS
AND RECREATION REGARDING OPEN BURNING IN SUCH DRY CONDITIONS IN
OUR HAZARDOUS WEATHER OUTLOOK.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JMG
NEAR TERM...JMG
SHORT TERM...JMG
LONG TERM...KGM
AVIATION...KGM
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1026 AM EDT TUE MAY 7 2013
.SYNOPSIS...
AN UPPER LEVEL LOW OVER THE WESTERN CAROLINAS TODAY WILL MOVE SLOWLY
NORTHEAST THROUGH TONIGHT AND OVER THE MID ATLANTIC REGION ON
WEDNESDAY. WEAK HIGH PRESSURE WILL THEN FILL IN BEHIND THE UPPER LOW
THURSDAY AND BRING SEASONAL TEMPERATURES BACK TO THE REGION THROUGH
FRIDAY. A WEAK COLD FRONT WILL APPROACH AND MOVE OVER THE CAROLINAS
OVER THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
1000 AM UPDATE...LOWERED POPS THIS MORNING...BUT KEPT SCHC POPS IN
MUCH OF THE MTNS AND NEAR ACTIVITY N AND SE OF THE CWFA WHERE
ENHANCED CU DEVELOPMENT NOTED. LATEST RAP REFLECTIVITY FCSTS SHOW
WIDESPREAD CONVECTIVE DEVELOPMENT BY MIDDAY BUT WITHOUT SUFFICIENT
DBZ TO EXPECT THUNDER IN THAT SCENARIO. 09Z SREF SHOWS HIGH PROBS OF
250 J CAPE BUT LOW PROBS OF 500 J. HAVE GOOD CONFIDENCE IN HIGH CHC
POPS FOR MOST PLACES WITH LOW LKLYS IN THE MTNS. DID MAINTAIN A TSTM
MENTION...BUT BACKED OFF PROBABILITY AND DELAYED ONSET OF THUNDER BY
A COUPLE HOURS TO ALLOW FIGURATIVE CU TO GROW.
CLOSED UPPER LOW CENTER...CURRENTLY PIVOTING ESE INTO GA...WILL BE
THE SYNOPTIC SCALE FEATURE OF INTEREST AS IT WOBBLES EAST ATOP THE
CWFA TODAY AND TOWARD THE VA PIEDMONT LATER TONIGHT. CLOSER TO THE
TRACK OF IT/S WEAK SFC REFLECTION...SHOWER CHANCES WILL BE GREATEST
THIS MORNING ACRS THE GA/SC PIEDMONT...BUT EXPAND AS THE DAY WEARS
ON WITHIN THE DEVELOPING WEAK INSTABILITY UNDER MID-LVL COOL POOL/
UPPER LOW CENTER. SHOWERS AND A FEW THUNDERSTORMS SHOULD BECOME
NUMEROUS THIS AFTERNOON...BUT WITH FCST SNDGS PROGGING JUST A THIN
AREA OF CAPE...WOULD BELIEVE EVEN THE TALLEST STORMS WOULD STRUGGLE
TO PRODUCE EVEN SMALL HAIL DESPITE THE LOW WBZ HEIGHTS. FOR MAX TEMPS
TODAY...HAVE MADE LITTLE MORE THAN TWEAKS TO THE INHERITED COOL
NUMBERS...ABOUT 8-10 DEG F BELOW CLIMO. DEEP CONVECTIVE CHANCES
SHOULD DIMINISH THIS EVENING WITH LOSS OF HTG...BUT THE POTENTIAL
FOR REDEVELOPMENT OF SHOWERS WITHIN DEFORMATION ZONE EXISTS
TONIGHT...ESPECIALLY ACRS W NC.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
AS OF 315 AM TUESDAY...THE UPPER LOW WILL FINALLY SPIN AWAY TO THE
NORTHEAST ACROSS THE MID ATLANTIC REGION ON WEDNESDAY. RESIDUAL LOW
LEVEL MOISTURE AND COOLER AIR ALOFT SHOULD BE ENOUGH TO PROVIDE FOR
SOME INSTABILITY WITH DAYTIME HEATING WHILE THE ATMOSPHERE REMAINS
GENERALLY FAVORABLE FOR CONVECTION. A CHANCE OF SHOWERS AND SOME
THUNDERSTORMS STILL LOOKS LIKE A DECENT BET FOR WEDNESDAY
AFTERNOON...WITH SOME OF THAT ACTIVITY PERSISTING INTO THE EVENING.
TEMPS SHOULD REBOUND NICELY...BUT STILL BELOW NORMAL...WITH
ADDITIONAL SUN IN THE AFTERNOON.
AS THE UPPER LOW MOVES AWAY WEDNESDAY NIGHT AND THURSDAY...SOME
UPPER RIDGING WILL MOVE IN FROM THE WEST. THAT SHOULD PROVIDE FOR A
RELATIVELY QUIET PERIOD AS WEAK HIGH PRESSURE MOVES IN. THURSDAY
WILL NOT BE AS FAVORABLE FOR CONVECTION AS LOW LEVELS SHOULD BE
SOMEWHAT DRIER. THUS...HAVE LIMITED THE PRECIP CHANCES TO SLIGHT AND
MAINLY OVER THE MTNS AND FOOTHILLS. TEMPS WILL FINALLY MAKE IT BACK
TO NEAR NORMAL AND WE SHOULD CONTINUE TO DRY OUT.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 225 PM MONDAY...THE WET PATTERN WILL CONTINUE INTO THE EARLY
PART OF THE MEDIUM RANGE...AS A COLD FRONT ASSOCIATED WITH OHIO/MISS
VALLEY HEIGHT FALLS APPROACHES THE EASTERN STATES DURING LATE WEEK.
THIS WILL ENHANCE DIURNAL CONVECTIVE CHANCES ON FRIDAY...AND POPS IN
THE 30-50 PERCENT RANGE WILL BE ADVERTISED DURING THIS TIME. MUCH
MORE SUBSTANTIAL HEIGHT FALLS WILL OCCUR ACROSS THE EASTERN CONUS
OVER THE WEEKEND...CARVING OUT A MAJOR EASTERN TROUGH BY THE END OF
THE PERIOD. THIS WILL DRIVE A MORE SIGNIFICANT FRONTAL BOUNDARY INTO
THE REGION...SUPPORTING 50/60 POPS ACROSS THE FORECAST AREA BY
SATURDAY AFTERNOON...WITH HEALTHY POPS CONTINUING INTO SUNDAY.
TEMPERATURES SHOULD GENERALLY AVERAGE NEAR NORMAL THROUGH SUNDAY.
A MODEL CONSENSUS STRONGLY SUGGESTS THAT THE COLD FRONT WILL SWEEP
EAST OF THE AREA BY DAY 7...INTRODUCING MUCH COOLER AND (FINALLY)
DRIER AIR. POPS WILL TAPER DOWN TO SLIGHT CHANCE AT BEST BY DAY
7...WHILE TEMPERATURES WILL COOL WELL BELOW NORMAL IN A REGIME
CHARACTERIZED BY ANOMALOUSLY LOW HEIGHTS ALOFT.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
AT KCLT /15Z UPDATE/...CU DEVELOPMENT AS SHOWN ON SATELLITE LAGS
GUIDANCE A BIT AND NOW THINK THAT WHEN CU FORM THEY ARE LIKELY TO BE
WELL INTO VFR RANGE BEFORE MAKING A CIG. FURTHERMORE...PER LATEST
RAP SIMULATED RADAR AND SREF CAPE PROBABILITIES...INSTABILITY
APPEARS TO BE LIMITED ENOUGH THIS AFTN TO PRECLUDE THUNDER AT THE
FIELD. INCLUDED TEMPO FOR MVFR SHRA TO REPLACE PROB30 TSRA FROM 12Z
TAF.
ELSEWHERE...SIMILAR TO KCLT. SHOWER AND/OR TSTM CVRG SHOULD BECOME
NUMEROUS AS THE DAY WEARS ON...BUT CONFIDENCE OF OCCURRENCE AT ANY
ONE TERMINAL IS NOT HIGH ENUF TO GO HIGHER THAN A PROB30 OR TEMPO.
MOIST ENOUGH TONIGHT IN THE MTNS/FOOTHILLS TO EXPECT MINOR VSBY
RESTRICTIONS AT KAVL/KHKY THOUGH HIGHER CLOUDS SHOULD PREVENT
RESTRICTIONS BELOW MVFR AT THOSE SITES.
OUTLOOK...A MID LEVEL LOW WILL SLOW TRACK NE ACROSS THE CAROLINAS
AND MID ATLANTIC STATES THROUGH WED. RESTRICTIVE CEILINGS AND VIS
ARE POSSIBLE AROUND SUNRISE WED MORNING...ESPECIALLY THE MTN
VALLEYS.
CONFIDENCE TABLE...
14-20Z 20-02Z 02-08Z 08-14Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 100% HIGH 87% HIGH 93%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 93%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND MED 78% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...PM
NEAR TERM...CSH/WIMBERLEY
SHORT TERM...PM
LONG TERM...JDL
AVIATION...CSH/WIMBERLEY
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1032 AM MDT TUE MAY 7 2013
.UPDATE...
&&
.SHORT TERM...WEAKENING UPPER TROUGH CURRENTLY MOVING NORTH ACROSS
CWA. STILL SOME SHOWERS ONGOING ACROSS MOUNTAINS NORTH OF
INTERSTATE 70...PARTICULARLY IN LARIMER AND GRAND COUNTIES. FROM
SURFACE OBS AND WEB CAMS IT APPEARS SNOW LEVEL IS AROUND 10000
FEET. RECENT ACCUMULATIONS HAVE BEEN MINIMAL. SOME SHOWERS ALSO
OCCURRING ALONG NORTHERN FOOTHILLS AS WELL AS ACROSS PORTIONS OF
PLAINS...THESE SHOWERS WERE LIGHT. MODELS CONTINUE TO WEAKEN THIS
TROUGH AS IT MOVES INTO WYOMING AND NEBRASKA DURING THE AFTERNOON
WITH WEAK SUBSIDENCE ACROSS COLORADO. IN ADDITION LATEST RAP
SHOWING SOME DRYING. BUT AIRMASS IS EXPECTED TO BE SLIGHTLY
UNSTABLE AS NOTED BY LAPSE RATES AROUND 8 C/KM. RAP EVEN INDICATES
LOW LEVEL LAPSE RATES NEARING 10 C/KM. STILL SOME THREAT OF SHOWERS
THIS AFTERNOON WITH PERHAPS A FEW THUNDERSTORMS...MAINLY ACROSS
THE MOUNTAINS. WITH WEAKLY SHEARED ENVIRONMENT AND SURFACE BASED
CAPES AROUND 500 J/KG OR LESS...NOT EXPECTING STRONG/SEVERE STORMS.
CURRENT FORECASTS STILL SEEM ON TRACK...WITH MINOR CHANGES BASED
ON CURRENT CONDITIONS.
.AVIATION...CURRENT TAF TRENDS SEEM ON TRACK. A FEW LIGHT SHOWERS
MOVING SOUTHEAST ACROSS THE PLAINS...PRODUCING SOME BRIEF GUSTY
WINDS. OTHERWISE...NORTHERLY WINDS PREVAILING WITH SPEEDS AROUND
8 KTS. WINDS TO BECOME NORTHEAST DURING THE AFTERNOON...THEN
SOUTHEAST BY 01Z. SPEEDS SHOULD REMAIN UNDER 10 KTS. VFR
CONDITIONS TO PREVAIL THROUGH THE DAY WITH ANY SHOWERS TO BE
ISOLATED IN COVERAGE. NOT EXPECTING CEILINGS BELOW 10000 FEET AGL
AT THIS TIME.
&&
.HYDROLOGY...ONLY LIGHT SHOWERS EXPECTED THROUGH THE EVENING WITH
A SLIGHT CHANCE OF WEAK THUNDERSTORMS. RAINFALL AMOUNTS OF LESS
THAN A TENTH OF AN INCH EXPECTED. BETTER CHANCE FOR HEAVIER
RAINFALL WEDNESDAY AFTERNOON...ESPECIALLY ALONG THE FOOTHILLS.
WILL CONTINUE TO MONITOR.
&&
.PREV DISCUSSION... /ISSUED 337 AM MDT TUE MAY 7 2013/
SHORT TERM...WATER VAPOR IMAGERY SHOWING WEAK UPPER TROF
CONTINUING TO SHEAR APART AS IT DRIFTS TO THE NORTH AND
NORTHEAST ACROSS CENTRAL COLORADO. SOME SNOW/RAIN SHOWERS HAVE
BEEN OCCURRING IN THE MOUNTAINS OVERNIGHT AND STILL SOME SHOWERS
MAINLY NORTH OF THE INTERSTATE 70 CORRIDOR AND ALONG THE DIVIDE.
MAINLY MID/UPPER LEVEL CLOUDS OVER THE PLAINS WITH THIS SYSTEM.
EXPECT SHOWERS WILL CONTINUE TO SHIFT NORTHWARD AND DISSIPATE
DURING THE MORNING HOURS OVER THE MOUNTAINS.
WEAK RIDGING ALOFT WILL MOVE IN BY MIDDAY BEHIND THE TROF AS QG
FIELDS SHOWING WEAK SUBSIDENCE AND SLIGHT DRYING. THE MAIN UPPER
LOW NOW MOVING INLAND OFF THE CENTRAL CALIFORNIA COST WILL
APPROACH SOUTHWEST COLORADO LATER TONIGHT AND EXPECT AN INCREASE
IN SHOWERS OVER THE MOUNTAINS LATER TONIGHT WITH INCREASING
ASCENT AHEAD OF THE LOW.
THE MAIN CHANGE TO THIS FORECAST WAS TO LOWER POPS A BIT OVER THE
PLAINS THIS AFTERNOON AND EVENING GIVEN THE SLIGHT DRYING AND
SUBSIDENT AIRMASS. STILL...CAN`T RULE OUT ISOLATED SHOWERS WITH
LINGERING MOISTURE AND SLIGHT INSTABILITY. SURFACE BASED CAPES
GENERALLY UNDER 500J/KG SO STRONG/SEVERE STORMS NOT EXPECTED TODAY
ALONG WITH WEAKLY SHEARED ENVIRONMENT. LITTLE CHANGE IN
TEMPERATURES TODAY VS MONDAY`S READINGS.
LONG TERM...A COOL AND WET PATTERN IS SETTING UP FOR WEDNESDAY
AND THURSDAY AS THE UPPER LOW SLOWLY SPINS NEAR THE FOUR CORNERS
REGION. HIGH PRESSURE FROM THE NORTHERN PLAINS WILL PUSH COOLER
AIR INTO NORTHEASTERN COLORADO AND CREATE UPSLOPE CONDITIONS. THIS
WILL FOCUS THE AVAILABLE MOISTURE NEAR AND AGAINST THE FOOTHILLS
THROUGH THE TWO DAY PERIOD. IN ADDITION...WEAK TO MODERATE UPWARD
QG VERTICAL MOTION IS PROGGED TO REMAIN OVER THE AREA ALL OF
WEDNESDAY. MOST MODELS HAVE OVER AN INCH OF LIQUID FALLING OVER
THIS AREA OVER THE TWO DAY PERIOD...WITH MOST FALLING OVER
WEDNESDAY. CAPE VALUES WILL BE HIGHEST OVER SOUTHEAST COLORADO YET
OUR FORECAST AREA SHOULD STILL SEE ENOUGH FOR WIDESPREAD SHOWERS
AND A SLIGHT CHANCE OF THUNDERSTORMS. HAVE PAINTED HIGHER POPS AND
QPF AMOUNTS OVER THE AREA FOR WEDNESDAY. TEMPERATURES WEDNESDAY WILL
LIKELY BE A FEW DEGREES COOLER OVER TODAYS OVER MOST OF THE AREA
EXCEPT THE FAR NORTHEAST CORNER WHERE ITS LEAST AFFECTED BY
UPSLOPE. EVEN COOLER AIR WILL PUSH DOWN THURSDAY AS ANOTHER
DISTURBANCE SLIDES SOUTH. TEMPERATURES WILL COOL INTO THE 50S OVER
THE PLAINS AND INTO THE 40S IN THE HIGHER TERRAIN. THIS WILL
LIKELY PRODUCE A LITTLE MORE STABILITY AND DECREASE CHANCES OF
THUNDERSTORMS BUT WILL STILL SEE SHOWERS. SNOW LEVELS WILL BE
AROUND 9K TO 10K AS THE UPPER LOW IS OVER/NEAR THE FORECAST AREA.
FRIDAY AND SATURDAY...NORTH TO NORTHWESTERLY FLOW ALOFT WILL KEEP
IN COOLER THAN AVERAGE TEMPERATURES AND SHOWERY WEATHER. SLIGHT
RIDGING ALOFT WILL ALLOW TEMPERATURES TO WARM FRIDAY ABOUT 5
DEGREES...BUT YET ANOTHER DISTURBANCE WILL PRODUCE A PUSH FROM THE
NORTH TO CREATE UPSLOPE COOL CONDITIONS SATURDAY. AVAILABLE
MOISTURE WILL BE LESS WITH THIS SYSTEM SO NOT AS MUCH QPF IS
EXPECTED AT THIS TIME.
STRONGER UPPER RIDGING WILL MOVE OVERHEAD SUNDAY AND INTO TUESDAY
TO WARM TEMPERATURES BACK UP TO NORMAL FOR THIS TIME OF YEAR AND
BRING DRIER WEATHER. THIS PATTERN WAS IN THE GRIDS ALREADY...ONLY
MADE SLIGHT TWEAKS TO THE TEMPERATURES LATE WEEKEND INTO EARLY
NEXT WEEK.
AVIATION...VFR EXPECTED TODAY AND TONIGHT. WITH THE 12Z ISSUANCE
WILL BE REMOVING THE PROB GROUP FOR SHOWERS TODAY AS FEEL ANY
SHOWERS WILL BE MORE ISOLATED IN COVERAGE. SURFACE WINDS STARTING
FROM THE SOUTH AND SOUTHWEST THIS AM BEFORE SHIFTING MORE NORTH TO
NORTHWEST THIS AFTERNOON. SPEEDS WILL BE LIGHT...GENERALLY UNDER
10KT THOUGH THIS EVENING.
HYDROLOGY...SHOWERS WILL GENERALLY BE ON THE LIGHTER SIDE WITH
AMOUNTS UNDER A TENTH OF AN INCH WITH PASSING SHOWERS.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...D-L
LONG TERM....KRIEDERMAN
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
535 PM EDT TUE MAY 7 2013
.SYNOPSIS...
AN UPPER LEVEL LOW WILL CONTINUE TO DRIFT TO OUR NE THROUGH
THURSDAY...GRADUALLY REDUCING OUR RAIN CHANCES. EXPECT MOISTURE
INCREASE AND THE NEXT FRONTAL SYSTEMS TO AFFECT OUR REGION LATE
FRIDAY THROUGH THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
LATE THIS AFTERNOON...SOME DRIER AIR ENTERED THE REGION FROM
THE WEST AROUND THE UPPER LOW TO THE NORTH IN NORTH CAROLINA.
WITH AN AREA OF SHOWERS AND MAYBE AN EMBEDDED THUNDERSTORM OR
TWO MOVING SOUTHEAST INTO THE NORTH PART OF THE FORECAST AREA
AND LAPS LIS -4 AND RUC13 SHOWING FAIRLY HIGH POPS IN THE NORTH
DECIDED TO INCREASE POPS TO 60-80 PERCENT NORTH FOR 2-3 HOURS
AND 30-50 PERCENT CENTRAL AND SOUTH PORTION. THERE WERE SEVERAL
REPORTS OF SMALL HAIL AND ONE OF DIME SIZED HAIL IN RICHLAND
COUNTY. WILL DROP POPS BACK TO 20-30 PERCENT THIS EVENING AS
SUN GOES DOWN AND SURFACE HEATING DIMINISHES. OTHERWISE...
AFTERNOON TEMPERATURES STILL OK.
TONIGHT...UPPER LEVEL STAYS TO THE NORTH AND LEFTOVER LOW LEVEL
MOISTURE MAY LEAD TO SOME FOG DEVELOPMENT AFTER MIDNIGHT. HOWEVER
WIDESPREAD DENSE FOG IS NOT ANTICIPATED AT THIS TIME. CONSENSUS
OVERNIGHT LOWS IN THE LOWER 50S WERE CONTINUED.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY/...
UPPER LOW WILL SLOWLY DRIFT TO THE NE ACROSS THE MID ATLANTIC REGION
AND INTO NEW ENGLAND. LINGERING TROUGHINESS AND WEAK IMPULSES IN ITS
WAKE WILL REMAIN ALONG THE EAST COAST. PRECIPITABLE WATER VALUES ARE
PROGGED TO REMAIN AROUND OR JUST OVER ONE INCH...NEAR CLIMO. BEST
MOISTURE AND LOWER UPPER HEIGHTS/TEMPS WILL BE ACROSS OUR
NORTHERN FA. PREMISE FOR LESS MID AND UPPER CLOUDINESS AND WARMER
TEMPS COULD RESULT IN WEAK DIURNAL INSTABILITIES...AND POTENTIAL
FOR SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS. CHANCE POPS
FAVORING THE NORTHERN FA APPEAR IN ORDER.
MODEL POPS LOWER THU...GIVEN EXPECTATIONS OF LESS INSTABILITY AS
UPPER HEIGHTS/TEMPS CONTINUE TO RISE. FORECAST SOUNDINGS INDICATE
WEAK DIURNAL INSTABILITY...BUT INDICATIONS OF WEAK NVA PSBL BY
AFTN. ISO TO SLIGHT CHANCE SHOWER POSSIBLE...BUT DID NOT INCLUDE
AT THIS TIME DUE TO LOW CONFIDENCE.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
GFS/ECMWF INDICATE WEAK UPPER RIDGE OVER THE EAST COAST THU
NT/FRIDAY...TO BE REPLACED BY UPPER TROUGH OVER THE EASTERN CONUS
FRI NT THRU MONDAY. MODELS PROG MOISTURE INCREASE FOR OUR REGION
AHEAD OF A WEAK FRONT BY LATE FRI...WITH ADDITIONAL MOISTURE AND A
STRONGER FRONT COMING IN OVER THE WEEKEND. MODEL CONSENSUS INDICATES
CHANCE POPS IN ORDER. MODELS AGREE ON PUSHING THE FRONT OFFSHORE BY
MON WITH HIGH PRESSURE BUILDING IN THROUGH EARLY NEXT WEEK.
ACCEPTED BLEND OF MOS AND HPC GUIDANCE.
&&
.AVIATION /22Z TUESDAY THROUGH SUNDAY/...
LOW PRESSURE CONTINUES TO SPIN TO THE NORTH OF THE REGION.
SOME DRIER AIR ENTERED FROM THE WEST. CONVECTIVE ACTIVITY IS
SITUATED NORTH OF THE TAF SITES...SO MAINLY VFR CONDITIONS ARE
EXPECTED LATE THIS AFTERNOON AND EVENING. CONVECTIVE ACTIVITY
SHOULD DIMINISH WITH THE LOSS OF SURFACE HEATING. NEXT MAJOR
CONCERN WILL BE FOG DEVELOPMENT AFTER MIDNIGHT. FOG IS EXPECTED
TO DEVELOP 06Z-12Z. SINCE AGS/OGB ARE MORE FOG- PRONE...HAVE
INCLUDED MVFR FOG. VFR ALL SITES AFTER 12Z-13Z WEDNESDAY MORNING
AS THE LOW PRESSURE SYSTEM LIFTS NORTH OF AREA. HOWEVER...WILL
CONTINUE TO MONITOR MODELS FOR MORE SIGNIFICANT FOG.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE SATURDAY AND
SATURDAY NIGHT AS A COLD FRONT MOVES INTO THE REGION.
&&
.HYDROLOGY...
RIVER FLOOD WARNINGS CONTINUE AT SEVERAL LOCATIONS. DETAILS CAN
BE OBTAINED FROM OUR RIVER FLOOD STATEMENTS...ON OUR WEBSITE...AND
ON NOAA WEATHER RADIO.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
522 PM EDT TUE MAY 7 2013
.SYNOPSIS...
AN UPPER LEVEL LOW WILL CONTINUE TO DRIFT TO OUR NE THROUGH
THURSDAY...GRADUALLY REDUCING OUR RAIN CHANCES. EXPECT MOISTURE
INCREASE AND THE NEXT FRONTAL SYSTEMS TO AFFECT OUR REGION LATE
FRIDAY THROUGH THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
LATE THIS AFTERNOON...SOME DRIER AIR ENTERED THE REGION FROM
THE WEST AROUND THE UPPER LOW TO THE NORTH IN NORTH CAROLINA.
WITH AN AREA OF SHOWERS AND MAYBE AN EMBEDDED THUNDERSTORM OR
TWO MOVING SOUTHEAST INTO THE NORTH PART OF THE FORECAST AREA
AND LAPS LIS -4 AND RUC13 SHOWING FAIRLY HIGH POPS IN THE NORTH
DECIDED TO INCREASE POPS TO 60-80 PERCENT NORTH FOR 2-3 HOURS
AND 30-50 PERCENT CENTRAL AND SOUTH PORTION. THERE WERE SEVERAL
REPORTS OF SMALL HAIL AND ONE OF DIME SIZED HAIL IN RICHLAND
COUNTY. WILL DROP POPS BACK TO 20-30 PERCENT THIS EVENING AS
SUN GOES DOWN AND SURFACE HEATING DIMINISHES. OTHERWISE...
AFTERNOON TEMPERATURES STILL OK.
TONIGHT...UPPER LEVEL STAYS TO THE NORTH AND LEFTOVER LOW LEVEL
MOISTURE MAY LEAD TO SOME FOG DEVELOPMENT AFTER MIDNIGHT. HOWEVER
WIDESPREAD DENSE FOG IS NOT ANTICIPATED AT THIS TIME. CONSENSUS
OVERNIGHT LOWS IN THE LOWER 50S WERE CONTINUED.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY/...
UPPER LOW WILL SLOWLY DRIFT TO THE NE ACROSS THE MID ATLANTIC REGION
AND INTO NEW ENGLAND. LINGERING TROUGHINESS AND WEAK IMPULSES IN ITS
WAKE WILL REMAIN ALONG THE EAST COAST. PRECIPITABLE WATER VALUES ARE
PROGGED TO REMAIN AROUND OR JUST OVER ONE INCH...NEAR CLIMO. BEST
MOISTURE AND LOWER UPPER HEIGHTS/TEMPS WILL BE ACROSS OUR
NORTHERN FA. PREMISE FOR LESS MID AND UPPER CLOUDINESS AND WARMER
TEMPS COULD RESULT IN WEAK DIURNAL INSTABILITIES...AND POTENTIAL
FOR SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS. CHANCE POPS
FAVORING THE NORTHERN FA APPEAR IN ORDER.
MODEL POPS LOWER THU...GIVEN EXPECTATIONS OF LESS INSTABILITY AS
UPPER HEIGHTS/TEMPS CONTINUE TO RISE. FORECAST SOUNDINGS INDICATE
WEAK DIURNAL INSTABILITY...BUT INDICATIONS OF WEAK NVA PSBL BY
AFTN. ISO TO SLIGHT CHANCE SHOWER POSSIBLE...BUT DID NOT INCLUDE
AT THIS TIME DUE TO LOW CONFIDENCE.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
GFS/ECMWF INDICATE WEAK UPPER RIDGE OVER THE EAST COAST THU
NT/FRIDAY...TO BE REPLACED BY UPPER TROUGH OVER THE EASTERN CONUS
FRI NT THRU MONDAY. MODELS PROG MOISTURE INCREASE FOR OUR REGION
AHEAD OF A WEAK FRONT BY LATE FRI...WITH ADDITIONAL MOISTURE AND A
STRONGER FRONT COMING IN OVER THE WEEKEND. MODEL CONSENSUS INDICATES
CHANCE POPS IN ORDER. MODELS AGREE ON PUSHING THE FRONT OFFSHORE BY
MON WITH HIGH PRESSURE BUILDING IN THROUGH EARLY NEXT WEEK.
ACCEPTED BLEND OF MOS AND HPC GUIDANCE.
&&
.AVIATION /21Z TUESDAY THROUGH SUNDAY/...
LOW PRESSURE AT THE SURFACE AND ALOFT CONTINUE TO SPIN OVER THE
REGION THIS AFTERNOON.
MAINLY VFR THROUGH THE EVENING HOURS. SCATTERED CONVECTION WILL
AFFECT THE TAF SITES THIS AFTERNOON AND EVENING IN UNSTABLE AIR
MASS. MVFR OR LOWER CONDITIONS POSSIBLE IN CONVECTION. THE
PROBABILITY OF OCCURRENCE OF THUNDER AT ANY ONE TAF SITE IS TOO LOW
TO INCLUDE. CONVECTION WILL DIMINISH WITH SUNSET. PATCHY FOG TO
DEVELOP 06Z-13Z. SINCE AGS/OGB ARE MORE FOG-PRONE...HAVE INCLUDED
MVFR FOG. VFR ALL SITES AFTER 08/13Z AS THE LOW PRESSURE SYSTEM
LIFTS NORTH OF AREA.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE SATURDAY AND
SATURDAY NIGHT AS A COLD FRONT MOVES INTO THE REGION.
&&
.HYDROLOGY...
RIVER FLOOD WARNINGS CONTINUE AT SEVERAL LOCATIONS. DETAILS CAN
BE OBTAINED FROM OUR RIVER FLOOD STATEMENTS...ON OUR WEBSITE...AND
ON NOAA WEATHER RADIO.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
334 PM EDT TUE MAY 7 2013
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
MAIN FORECAST CONCERN IN THE SHORT TERM IS ASSOCIATED WITH SOME
LINGERING MOISTURE AND WEAK VORT MAXS ROTATING AROUND THE PERSISTENT
UPPER LOW CURRENTLY SITUATED ACROSS THE CAROLINAS. SO FAR THIS
AFTERNOON...IT HAS ALLOWED FOR ENHANCED CU FIELD DEVELOPMENT AND
SOME ISOLATED SHOWERS AND STORMS JUST EAST OF THE CWA. THERE IS
ENOUGH ELEVATED INSTABILITY TO MAINTAIN THE LOW END CHANCE FOR
ISOLATED THUNDERSTORMS MAINLY ACROSS PORTIONS OF THE EAST THROUGH
THE REST OF TODAY.
FOR TONIGHT...POPS SHOULD BE ON THE DECREASE ACROSS THE NORTHEAST.
WITH GUIDANCE LIKELY UNDERDOING THE SFC MOISTURE PRESENT FROM RECENT
RAINFALL...THERE IS A GOOD CHANCE FOR FOG DEVELOPMENT UNDER THE CALM
TO LIGHT WINDS IN THE EARLY MORNING HOURS. GUIDANCE IS IN GENERAL
AGREEMENT WITH SOME LOW LEVEL MOISTURE ADVECTING INTO THE FAR
NORTHERN PORTION NEAR 12Z. SHORT RANGE ENSEMBLE RESTRICTED VSBY
PROBS AND RUC CONDENSATION PRESSURE DEFICIT SUPPORT THE GREATEST
CHANCE FOR MORE WIDESPREAD FOG DEVELOPMENT TO BE IN THE FAR NORTH OR
NORTHWEST. CONFIDENCE IS LOW AT THIS POINT ON DENSE FOG DEVELOPMENT
AND WILL MENTION PATCHY FOG AREA-WIDE FOR NOW.
AS UPPER LOW FINALLY BEGINS ITS EXIT NEWD AND WEAK RIDGING
TEMPORARILY BUILDS IN...HAVE TRENDED POPS TO MAINLY BE FOCUSED IN
THE FAR NORTH AND NORTHEAST THROUGH WEDNESDAY NIGHT. FORECAST
MUCAPE VALUES SUGGEST ISOLATED THUNDERSTORM DEVELOPMENT IS
POSSIBLE AGAIN DURING THE AFTERNOON WEDNESDAY.
FOR TEMPS...A GENERAL BLEND IN THE SHORT TERM GUIDANCE LOOKED
REASONABLE AS THE FORECAST AREA SHOULD CONTINUE A GRADUAL WARM-UP
AHEAD OF THE NEXT SYSTEM DURING THE WEEKEND.
BAKER
.LONG TERM /THURSDAY THROUGH TUESDAY/...
HAVE MADE NO CHANGES TO THE EXTENDED. MODELS AGREE O BRIEF BREAK
FOR MUCH OF THE CWA WEDNESDAY NIGHT INTO THURSDAY WITH RAIN
CHANCES INCREASING AGAIN ON FRIDAY. SERIES OF SHORT WAVES SHOULD
KEEP CHANCE OF RAIN ACROSS THE FORECAST AREA THROUGH SUNDAY...WITH
DRYING SUNDAY INTO MONDAY WITH PASSAGE OF A SURFACE FRONT. HAVE
INCLUDED THE PREVIOUS LONG TERM DISCUSSION BELOW.
41
LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
/ISSUED AT 411 AM EDT TUE MAY 7 2013/
BY WEDNESDAY NIGHT...PESKY UPPER LOW MOVES UP OVER THE MID
ATLANTIC STATES...WITH RESIDUAL MOISTURE ACROSS NORTH AND
NORTHEAST GEORGIA. BRIEF REPRIEVE EXPECTED ACROSS THE REMAINING
CWA THURSDAY INTO FRIDAY AHEAD OF THE NEXT BATCH OF RAIN. EXTENDED
MODELS STILL SHOWING COMBINATION OF ENHANCED MOISTURE FROM DEEP
SOUTHERLY FLOW AND SERIES OF UPPER LEVEL DISTURBANCES WILL BRING
BACK TO THE STATE BY FRIDAY AHEAD OF FRONT PUSHING THROUGH THE
STATE OVER THE WEEKEND. HAVE OPTED TO INCREASE POPS SLIGHTLY
FRIDAY...WITH GOOD CHANCE NORTH WITH SLIGHT CHANCE THROUGH THE
METRO AREA. HAVE CONTINUED WITH INCREASING TREND INTO SATURDAY
WITH LIKELY POPS NORTH AND GOOD CHANCE ACROSS MUCH OF THE REST OF
THE AREA. THUNDERSTORMS LOOK TO BE LIKELY WITH THIS EVENT WITH
GOOD MODEL AGREEMENT WITH THE INSTABILITY...ESPECIALLY SATURDAY.
MODELS CONTINUE TO DIFFER ON THE AMOUNT OF QPF EXPECTED FRIDAY
THROUGH SUNDAY...WITH THE WETTER ECMWF SHOWING LARGE PORTION OF
WESTERN GEORGIA COULD SEE 0.75 TO 1.25 INCHES WITH ISOLATED HIGHER
AMOUNTS...AND THE GFS SHOWING NORTH GEORGIA COULD SEE WIDESPREAD
0.5 INCHES...WITH PORTIONS OF NORTHWEST GEORGIA SEEING UP TO AN
INCH. HAVE GENERALLY GONE WITH THE GFS SOLUTION FOR QPF...WHICH
MAY BE WISHFUL THINKING AFTER THIS VERY WET WEEKEND ACROSS THE
STATE.
NEAR NORMAL TEMPERATURES ARE EXPECTED WEDNESDAY AND THURSDAY
MORNING...WITH WARM UP BY WEDNESDAY AFTERNOON TO ABOVE NORMAL
TEMPERATURES WHICH WILL REMAIN IN PLACE INTO THE WEEKEND. PRECIP
ACTIVITY SATURDAY AND SUNDAY WILL KEEP TEMPERATURES CLOSER TO
SEASONAL.
31
AVIATION...
18Z UPDATE...
MAINLY VFR CONDITIONS TO START OUT THIS AFTERNOON WITH SOME
LINGERING CIGS IN THE UPPER MVFR RANGE. CIGS SHOULD GENERALLY
SCATTER AND REMAIN NEAR 5 KFT INTO THE OVERNIGHT WITH SOME
POTENTIAL LOWERING FROM 10-15Z. SOME LINGERING SURFACE MOISTURE
WITH CALM TO LIGHT WINDS IN THE EARLY MORNING WILL BRING A
POTENTIAL FOR FOG DEVELOPMENT...THOUGH CONFIDENCE IS LOW AND BEST
CHANCE OF SIGNIFICANT LOWERING SHOULD BE NW OF KATL.
OTHERWISE...WINDS SHOULD BE MOSTLY WEST AT 8 KTS OR LESS DURING
THE DAYTIME.
//ATL CONFIDENCE...18Z UPDATE...
LOW CONFIDENCE ON EARLY MORNING CIGS AND VSBYS.
HIGH CONFIDENCE ALL ELSE.
BAKER
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 51 78 56 84 / 20 20 10 10
ATLANTA 54 77 59 81 / 10 10 5 10
BLAIRSVILLE 49 71 51 77 / 30 30 20 20
CARTERSVILLE 50 76 54 81 / 10 10 10 10
COLUMBUS 54 80 60 85 / 5 10 5 5
GAINESVILLE 52 74 56 80 / 20 20 20 10
MACON 49 79 56 84 / 10 10 10 5
ROME 50 77 53 83 / 10 10 10 10
PEACHTREE CITY 48 78 53 82 / 10 10 5 5
VIDALIA 55 80 61 85 / 5 10 10 5
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BAKER
LONG TERM....41
AVIATION...BAKER
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
700 PM EDT TUE MAY 7 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 403 PM EDT TUE MAY 7 2013
WATER VAPOR IMAGERY AND RUC ANALYSIS CONTINUE TO SHOW BLOCKY FLOW
ACROSS THE CONUS TO THE S OF PROGRESSIVE FLOW ACROSS CNTRL CANADA. A
NARROW RIDGE EXTENDS FROM SRN BRITISH COLUMBIA/NRN WA E ACROSS THE
UPPER GREAT LAKES TO NEW ENGLAND. FARTHER S...CLOSED MID LEVEL LOWS
WERE LOCATED OVER CA/SRN NV...OVER SD AND OVER THE SE CONUS. WITH
THE UPPER GREAT LAKES STILL UNDER THE RIDGE...IT`S BEEN ANOTHER
PLEASANT EARLY MAY DAY ACROSS UPPER MI AS DEEP VERY DRY COLUMN (NOTE
12Z KGRB/KAPX SOUNDINGS) IS ALLOWING FOR ABUNDANT SUNSHINE. SOME
VERY HIGH BASED CU HAS DEVELOPED OVER THE W WITH A FEW ALONG THE
LAKE BREEZE BOUNDARY OVER THE E. VERY DEEP MIXING HAS INTO THE DRY
AIR ALOFT HAS RESULTED IN DWPTS CRASHING OVER THE LAST FEW HRS. RH
HAS PLUNGED INTO THE 10-20PCT RANGE AT A NUMBER OF LOCATIONS ACROSS
THE CNTRL AND E. LAKE BREEZES HAVE AGAIN DEVELOPED ACROSS THE
BOARD...AND WHILE IT`S CHILLY ALONG LAKE SUPERIOR WITH TEMPS IN THE
40S JUST LIKE YESTERDAY...THE COOLING IS AGAIN VERY WEAK ALONG MOST
OF THE LAKE MI SHORELINE. INLAND...TEMPS HAVE SOARED WELL INTO THE
70S.
NARROW RIDGE OVER THE UPPER LAKES IS IN THE PROCESS OF BREAKING DOWN
AS MODEST AMPLIFICATION OF THE FLOW IS UNDERWAY ACROSS CNTRL/ERN
CANADA IN ASSOCIATION WITH VIGOROUS SHORTWAVE MOVING ACROSS NRN
MANITOBA TO HUDSON BAY. MUCH STRONGER AMPLIFICATION WILL OCCUR LATER
THIS WEEK AS TROF SHARP TROF DEVELOPS S INTO THE GREAT LAKES. COLD
FRONT ASSOCIATED WITH NRN MANITOBA SHORTWAVE IS CURRENTLY RUNNING
FROM NRN MANITOBA TO MT. WITH FRONT STILL WELL W OF THE AREA THRU
THE NIGHT AND WITH DRY AIR MASS LINGERING...ANOTHER MAINLY CLEAR
NIGHT IS ANTICIPATED. OVERALL...LOW-LEVEL WINDS WILL BE LIGHT
AGAIN...AND THERE IS LITTLE CHANGE IN PRECIPITABLE WATER...
SUGGESTING MIN TEMPS SHOULD BE SIMILAR TO LAST NIGHT. HOWEVER...WITH
AIR MASS CONTINUING TO MODERATE WITH STRONG HEATING THIS AFTN...
WOULD EXPECT MINS GENERALLY TO BE A FEW DEGREES HIGHER THAN LAST
NIGHT. DEVELOPING LIGHT S TO SW FLOW WILL BEGIN TO STIR IN THE
DOWNSLOPE AREAS NEAR LAKE SUPERIOR...SO MINS THERE WILL PROBABLY BE
HIGHEST. MIN TEMPS SHOULD RANGE FROM THE 30S INLAND TO THE LWR 40S
ALONG LAKE SUPERIOR.
ON WED...APPROACHING COLD FRONT SHOULD REACH WRN/NRN LAKE SUPERIOR
LATE IN THE AFTN/EARLY EVE. SOME OF THE MOISTURE NOTED ON TODAYS 12Z
KMPX/KINL SOUNDINGS SHOULD ADVECT E AND NE AHEAD OF THE APPROACHING
COLD FRONT. HOWEVER...WITH LIGHT WINDS AND LITTLE ADVECTION AT THE
LOW-LEVELS...DRIER AIR WILL LIKELY LINGER UNDERNEATH THE MOISTENING
OCCURRING HIGHER UP. IN THE END...THIS WILL WORK TO MINIMIZE SHRA
THREAT WED. HOWEVER...WITH MLCAPE UPWARDS OF A FEW HUNDRED J/KG...
CAN`T RULE OUT A FEW HIGH BASED SHRA OVER THE W WHERE AFTN LAKE
BREEZE WILL HELP TO POOL LOW-LEVEL MOISTURE AND PROVIDE A LOW-LEVEL
FORCING MECHANISM. OTHERWISE...IT WILL BE ANOTHER WARM DAY ON PAR
WITH WHAT IS GOING ON THIS AFTN.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 426 PM EDT TUE MAY 7 2013
WE WILL BEGIN WEDNESDAY NIGHT WITH A SERIES OF DISTURBANCES
SCATTERED ACROSS THE UNITED STATES. THE MAIN FEATURES INFLUENCING
OUR WEATHER OVER THE NEXT SEVERAL DAYS INCLUDE THE LARGE SCALE 500MB
TROUGH STRETCHED ACROSS MUCH OF CANADA...EXTENDING ACROSS MN/AND IA
AT 00Z THURSDAY...WITH AN ELONGATED SFC TROUGH SET UP FROM AROUND
IMT THROUGH ERY AND NORTHEASTWARD. THE TROUGH WILL CONTINUE TO SINK
SOUTHEAST OF THE CWA OVERNIGHT. THE NON-ECMWF SOLUTIONS CONTINUE TO
HIT THE NEXT SHORTWAVE A BIT HARDER...WITH 0.2-0.4IN OF QPF OVER
MUCH OF THE AREA. WILL CONTINUE THE HIGH CHANCE POPS...WITH A
CAVEAT. IF WE GET LESS PRECIP THAN ANTICIPATED...OR IT ENDS UP BEING
SLOWER...THE DOWNSLOPE AREAS FROM ESCANABA THROUGH MANISTIQUE...AND
EAST COULD BE QUITE A BIT LOWER /CURRENTLY FCST TO BOTTOM OUT 35-45
PERCENT/.
EXPECT THE SLOW MOTION 500MB TROUGH TO BE CENTERED OVER THE LAKE
SUPERIOR AND UPPER MI AT 00Z FRIDAY...WITH COOL HIGH PRESSURE
BUILDING IN AT THE SFC. 25-35KT 900-925MB WINDS ARE EXPECTED
THURSDAY NIGHT. THERE IS A SLIGHT CONCERN FOR FIRE CONCERNS...IF WE
HAVE POOR RH RECOVERIES...AS LOTS OF DRY AIR SLIDES IN FOR FRIDAY.
WENT WITH RH VALUES FALLING TO 25-35PERCENT...BUT WOULD NOT BE
SURPRISED TO SEE LOWER VALUES GIVEN THE VERY DRY AIR WITH MIXED
DEWPOINTS IN THE TEENS OR LOWER CENTRAL.
ZONAL FLOW WILL TAKE HOLD FRIDAY AFTERNOON/EVENING AHEAD OF YET
ANOTHER TROUGH ROTATING AROUND THE NORTHERN CANADIAN LOW. THIS ONE
LOOKS TO BE PARTICULARLY INTERESTING...AS IT INTENSIFIES INTO A
CLOSED LOW OVER EASTERN MANITOBA AND WESTERN ONTARIO FRIDAY NIGHT.
THERE IS SOME UNCERTAINTY TO THE POSITION OF THE 500MB LOW AT 00Z
SUNDAY...WHICH WILL LIKELY BE SOMEWHERE BETWEEN WESTERN UPPER MI TO
CENTRAL ONTARIO. THE 07/00Z ECMWF KEPT THE TREND OF BEING THE
DEEPEST WITH THE LOW...RUSHING COLD AIR IN FROM THE WEST DURING THE
DAY SATURDAY. KEPT A GOOD CHANCE OF MIXED PRECIP IN THE FCST FROM
SATURDAY THROUGH SUNDAY...WITH LITTLE TO NO REAL ACCUMULATION
EXPECTED AS THE BULK OF THE MOISTURE SHOULD BE EAST OF THE CWA BY
THE TIME THE -6 TO -10C AIR FILTERS IN. THE ECMWF REMAINS THE
COOLEST WITH THE SYSTEM.
FARTHER OUT...FEW CHANGES WERE MADE TO OUR MODERATING FCST FOR THE
START OF THE NEXT WORK WEEK...WITH W-SW WINDS AND DRY WX FIGURED
MONDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 655 PM EDT TUE MAY 7 2013
EXPECT VFR CONDITIONS AND LIGHT WINDS AT ALL 3 SITES TONIGHT INTO WED
MORNING WITH DRY HI PRES DOMINATING. APPROACHING COLD FRONT FM SRN
CANADA COULD BRING AN INCREASE IN MID CLOUDS LATE WED AFTERNOON BUT
OTHERWISE VFR CONDITIONS WILL PREVAIL.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 403 PM EDT TUE MAY 7 2013
HIGH PRESSURE WILL CONTINUE TO PRODUCE LIGHT WINDS THRU WED...
BUT A COLD FRONT MOVING ACROSS LAKE SUPERIOR LATE WED AFTN AND
EVENING WILL LEAD TO INCREASING NORTH-NORTHEAST WINDS PEAKING IN THE
15-25KT RANGE WED NIGHT INTO THU MORNING. HIGH PRESSURE WILL BUILD
BACK OVER THE AREA FOR FRI AND DIMINISH THE WINDS. A STRONGER
COLD FRONT WILL SLIDE ACROSS THE UPPER LAKES FRI NIGHT AND SHIFT
WINDS TO THE NW AT 20-30KTS SAT. THESE STRONGER WINDS WILL CONTINUE
INTO SAT NIGHT BEFORE GRADUALLY DIMINISHING FROM W TO E ON SUN.
&&
.HYDROLOGY...
ISSUED AT 426 PM EDT TUE MAY 7 2013
WE WILL MONITOR LOCAL RIVER LEVELS...BUT CONTINUE TO SEE FALLING
VALUES ACROSS MUCH OF THE REGION AS THE SNOW PACK FALLS TO NEAR ZERO
WITH OUR SERIES OF ABOVE NORMAL TEMPERATURES.
THE LATEST SNOW DEPTH OBSERVATIONS /FROM EARLIER THIS MORNING AROUND
8AM HAS IRONWOOD WITH NO SNOW LEFT ON THE GROUND...AND ATLANTIC MINE
WITH 4IN. A FEW POCKETS OF HIGHER AMOUNTS ARE LIKELY ACROSS THE
KEWEENAW...AND THE HIGHEST ELEVATIONS OF NORTHERN MARQUETTE COUNTY.
THE TRICKY LINGERING ISSUES AT AT TRRM4 /TRAP ROCK - LAKE LINDEN/
AND BESM4 /BESSEMER - BLACK RIVER/. 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...ROLFSON
LONG TERM...KF
AVIATION...VOSS
MARINE...ROLFSON
HYDROLOGY...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
427 PM EDT TUE MAY 7 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 403 PM EDT TUE MAY 7 2013
WATER VAPOR IMAGERY AND RUC ANALYSIS CONTINUE TO SHOW BLOCKY FLOW
ACROSS THE CONUS TO THE S OF PROGRESSIVE FLOW ACROSS CNTRL CANADA. A
NARROW RIDGE EXTENDS FROM SRN BRITISH COLUMBIA/NRN WA E ACROSS THE
UPPER GREAT LAKES TO NEW ENGLAND. FARTHER S...CLOSED MID LEVEL LOWS
WERE LOCATED OVER CA/SRN NV...OVER SD AND OVER THE SE CONUS. WITH
THE UPPER GREAT LAKES STILL UNDER THE RIDGE...IT`S BEEN ANOTHER
PLEASANT EARLY MAY DAY ACROSS UPPER MI AS DEEP VERY DRY COLUMN (NOTE
12Z KGRB/KAPX SOUNDINGS) IS ALLOWING FOR ABUNDANT SUNSHINE. SOME
VERY HIGH BASED CU HAS DEVELOPED OVER THE W WITH A FEW ALONG THE
LAKE BREEZE BOUNDARY OVER THE E. VERY DEEP MIXING HAS INTO THE DRY
AIR ALOFT HAS RESULTED IN DWPTS CRASHING OVER THE LAST FEW HRS. RH
HAS PLUNGED INTO THE 10-20PCT RANGE AT A NUMBER OF LOCATIONS ACROSS
THE CNTRL AND E. LAKE BREEZES HAVE AGAIN DEVELOPED ACROSS THE
BOARD...AND WHILE IT`S CHILLY ALONG LAKE SUPERIOR WITH TEMPS IN THE
40S JUST LIKE YESTERDAY...THE COOLING IS AGAIN VERY WEAK ALONG MOST
OF THE LAKE MI SHORELINE. INLAND...TEMPS HAVE SOARED WELL INTO THE
70S.
NARROW RIDGE OVER THE UPPER LAKES IS IN THE PROCESS OF BREAKING DOWN
AS MODEST AMPLIFICATION OF THE FLOW IS UNDERWAY ACROSS CNTRL/ERN
CANADA IN ASSOCIATION WITH VIGOROUS SHORTWAVE MOVING ACROSS NRN
MANITOBA TO HUDSON BAY. MUCH STRONGER AMPLIFICATION WILL OCCUR LATER
THIS WEEK AS TROF SHARP TROF DEVELOPS S INTO THE GREAT LAKES. COLD
FRONT ASSOCIATED WITH NRN MANITOBA SHORTWAVE IS CURRENTLY RUNNING
FROM NRN MANITOBA TO MT. WITH FRONT STILL WELL W OF THE AREA THRU
THE NIGHT AND WITH DRY AIR MASS LINGERING...ANOTHER MAINLY CLEAR
NIGHT IS ANTICIPATED. OVERALL...LOW-LEVEL WINDS WILL BE LIGHT
AGAIN...AND THERE IS LITTLE CHANGE IN PRECIPITABLE WATER...
SUGGESTING MIN TEMPS SHOULD BE SIMILAR TO LAST NIGHT. HOWEVER...WITH
AIR MASS CONTINUING TO MODERATE WITH STRONG HEATING THIS AFTN...
WOULD EXPECT MINS GENERALLY TO BE A FEW DEGREES HIGHER THAN LAST
NIGHT. DEVELOPING LIGHT S TO SW FLOW WILL BEGIN TO STIR IN THE
DOWNSLOPE AREAS NEAR LAKE SUPERIOR...SO MINS THERE WILL PROBABLY BE
HIGHEST. MIN TEMPS SHOULD RANGE FROM THE 30S INLAND TO THE LWR 40S
ALONG LAKE SUPERIOR.
ON WED...APPROACHING COLD FRONT SHOULD REACH WRN/NRN LAKE SUPERIOR
LATE IN THE AFTN/EARLY EVE. SOME OF THE MOISTURE NOTED ON TODAYS 12Z
KMPX/KINL SOUNDINGS SHOULD ADVECT E AND NE AHEAD OF THE APPROACHING
COLD FRONT. HOWEVER...WITH LIGHT WINDS AND LITTLE ADVECTION AT THE
LOW-LEVELS...DRIER AIR WILL LIKELY LINGER UNDERNEATH THE MOISTENING
OCCURRING HIGHER UP. IN THE END...THIS WILL WORK TO MINIMIZE SHRA
THREAT WED. HOWEVER...WITH MLCAPE UPWARDS OF A FEW HUNDRED J/KG...
CAN`T RULE OUT A FEW HIGH BASED SHRA OVER THE W WHERE AFTN LAKE
BREEZE WILL HELP TO POOL LOW-LEVEL MOISTURE AND PROVIDE A LOW-LEVEL
FORCING MECHANISM. OTHERWISE...IT WILL BE ANOTHER WARM DAY ON PAR
WITH WHAT IS GOING ON THIS AFTN.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 426 PM EDT TUE MAY 7 2013
WE WILL BEGIN WEDNESDAY NIGHT WITH A SERIES OF DISTURBANCES
SCATTERED ACROSS THE UNITED STATES. THE MAIN FEATURES INFLUENCING
OUR WEATHER OVER THE NEXT SEVERAL DAYS INCLUDE THE LARGE SCALE 500MB
TROUGH STRETCHED ACROSS MUCH OF CANADA...EXTENDING ACROSS MN/AND IA
AT 00Z THURSDAY...WITH AN ELONGATED SFC TROUGH SET UP FROM AROUND
IMT THROUGH ERY AND NORTHEASTWARD. THE TROUGH WILL CONTINUE TO SINK
SOUTHEAST OF THE CWA OVERNIGHT. THE NON-ECMWF SOLUTIONS CONTINUE TO
HIT THE NEXT SHORTWAVE A BIT HARDER...WITH 0.2-0.4IN OF QPF OVER
MUCH OF THE AREA. WILL CONTINUE THE HIGH CHANCE POPS...WITH A
CAVEAT. IF WE GET LESS PRECIP THAN ANTICIPATED...OR IT ENDS UP BEING
SLOWER...THE DOWNSLOPE AREAS FROM ESCANABA THROUGH MANISTIQUE...AND
EAST COULD BE QUITE A BIT LOWER /CURRENTLY FCST TO BOTTOM OUT 35-45
PERCENT/.
EXPECT THE SLOW MOTION 500MB TROUGH TO BE CENTERED OVER THE LAKE
SUPERIOR AND UPPER MI AT 00Z FRIDAY...WITH COOL HIGH PRESSURE
BUILDING IN AT THE SFC. 25-35KT 900-925MB WINDS ARE EXPECTED
THURSDAY NIGHT. THERE IS A SLIGHT CONCERN FOR FIRE CONCERNS...IF WE
HAVE POOR RH RECOVERIES...AS LOTS OF DRY AIR SLIDES IN FOR FRIDAY.
WENT WITH RH VALUES FALLING TO 25-35PERCENT...BUT WOULD NOT BE
SURPRISED TO SEE LOWER VALUES GIVEN THE VERY DRY AIR WITH MIXED
DEWPOINTS IN THE TEENS OR LOWER CENTRAL.
ZONAL FLOW WILL TAKE HOLD FRIDAY AFTERNOON/EVENING AHEAD OF YET
ANOTHER TROUGH ROTATING AROUND THE NORTHERN CANADIAN LOW. THIS ONE
LOOKS TO BE PARTICULARLY INTERESTING...AS IT INTENSIFIES INTO A
CLOSED LOW OVER EASTERN MANITOBA AND WESTERN ONTARIO FRIDAY NIGHT.
THERE IS SOME UNCERTAINTY TO THE POSITION OF THE 500MB LOW AT 00Z
SUNDAY...WHICH WILL LIKELY BE SOMEWHERE BETWEEN WESTERN UPPER MI TO
CENTRAL ONTARIO. THE 07/00Z ECMWF KEPT THE TREND OF BEING THE
DEEPEST WITH THE LOW...RUSHING COLD AIR IN FROM THE WEST DURING THE
DAY SATURDAY. KEPT A GOOD CHANCE OF MIXED PRECIP IN THE FCST FROM
SATURDAY THROUGH SUNDAY...WITH LITTLE TO NO REAL ACCUMULATION
EXPECTED AS THE BULK OF THE MOISTURE SHOULD BE EAST OF THE CWA BY
THE TIME THE -6 TO -10C AIR FILTERS IN. THE ECMWF REMAINS THE
COOLEST WITH THE SYSTEM.
FARTHER OUT...FEW CHANGES WERE MADE TO OUR MODERATING FCST FOR THE
START OF THE NEXT WORK WEEK...WITH W-SW WINDS AND DRY WX FIGURED
MONDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 139 PM EDT TUE MAY 7 2013
EXPECT VFR CONDITIONS AND LIGHT WINDS THRU THIS FCST PERIOD AT
KIWD/KCMX/KSAW AS DRY HIGH PRES CONTINUES TO DOMINATE.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 403 PM EDT TUE MAY 7 2013
HIGH PRESSURE WILL CONTINUE TO PRODUCE LIGHT WINDS THRU WED...
BUT A COLD FRONT MOVING ACROSS LAKE SUPERIOR LATE WED AFTN AND
EVENING WILL LEAD TO INCREASING NORTH-NORTHEAST WINDS PEAKING IN THE
15-25KT RANGE WED NIGHT INTO THU MORNING. HIGH PRESSURE WILL BUILD
BACK OVER THE AREA FOR FRI AND DIMINISH THE WINDS. A STRONGER
COLD FRONT WILL SLIDE ACROSS THE UPPER LAKES FRI NIGHT AND SHIFT
WINDS TO THE NW AT 20-30KTS SAT. THESE STRONGER WINDS WILL CONTINUE
INTO SAT NIGHT BEFORE GRADUALLY DIMINISHING FROM W TO E ON SUN.
&&
.HYDROLOGY...
ISSUED AT 426 PM EDT TUE MAY 7 2013
WE WILL MONITOR LOCAL RIVER LEVELS...BUT CONTINUE TO SEE FALLING
VALUES ACROSS MUCH OF THE REGION AS THE SNOW PACK FALLS TO NEAR ZERO
WITH OUR SERIES OF ABOVE NORMAL TEMPERATURES.
THE LATEST SNOW DEPTH OBSERVATIONS /FROM EARLIER THIS MORNING AROUND
8AM HAS IRONWOOD WITH NO SNOW LEFT ON THE GROUND...AND ATLANTIC MINE
WITH 4IN. A FEW POCKETS OF HIGHER AMOUNTS ARE LIKELY ACROSS THE
KEWEENAW...AND THE HIGHEST ELEVATIONS OF NORTHERN MARQUETTE COUNTY.
THE TRICKY LINGERING ISSUES AT AT TRRM4 /TRAP ROCK - LAKE LINDEN/
AND BESM4 /BESSEMER - BLACK RIVER/. 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...ROLFSON
LONG TERM...KF
AVIATION...ROLFSON
MARINE...ROLFSON
HYDROLOGY...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
404 PM EDT TUE MAY 7 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 403 PM EDT TUE MAY 7 2013
WATER VAPOR IMAGERY AND RUC ANALYSIS CONTINUE TO SHOW BLOCKY FLOW
ACROSS THE CONUS TO THE S OF PROGRESSIVE FLOW ACROSS CNTRL CANADA. A
NARROW RIDGE EXTENDS FROM SRN BRITISH COLUMBIA/NRN WA E ACROSS THE
UPPER GREAT LAKES TO NEW ENGLAND. FARTHER S...CLOSED MID LEVEL LOWS
WERE LOCATED OVER CA/SRN NV...OVER SD AND OVER THE SE CONUS. WITH
THE UPPER GREAT LAKES STILL UNDER THE RIDGE...IT`S BEEN ANOTHER
PLEASANT EARLY MAY DAY ACROSS UPPER MI AS DEEP VERY DRY COLUMN (NOTE
12Z KGRB/KAPX SOUNDINGS) IS ALLOWING FOR ABUNDANT SUNSHINE. SOME
VERY HIGH BASED CU HAS DEVELOPED OVER THE W WITH A FEW ALONG THE
LAKE BREEZE BOUNDARY OVER THE E. VERY DEEP MIXING HAS INTO THE DRY
AIR ALOFT HAS RESULTED IN DWPTS CRASHING OVER THE LAST FEW HRS. RH
HAS PLUNGED INTO THE 10-20PCT RANGE AT A NUMBER OF LOCATIONS ACROSS
THE CNTRL AND E. LAKE BREEZES HAVE AGAIN DEVELOPED ACROSS THE
BOARD...AND WHILE IT`S CHILLY ALONG LAKE SUPERIOR WITH TEMPS IN THE
40S JUST LIKE YESTERDAY...THE COOLING IS AGAIN VERY WEAK ALONG MOST
OF THE LAKE MI SHORELINE. INLAND...TEMPS HAVE SOARED WELL INTO THE
70S.
NARROW RIDGE OVER THE UPPER LAKES IS IN THE PROCESS OF BREAKING DOWN
AS MODEST AMPLIFICATION OF THE FLOW IS UNDERWAY ACROSS CNTRL/ERN
CANADA IN ASSOCIATION WITH VIGOROUS SHORTWAVE MOVING ACROSS NRN
MANITOBA TO HUDSON BAY. MUCH STRONGER AMPLIFICATION WILL OCCUR LATER
THIS WEEK AS TROF SHARP TROF DEVELOPS S INTO THE GREAT LAKES. COLD
FRONT ASSOCIATED WITH NRN MANITOBA SHORTWAVE IS CURRENTLY RUNNING
FROM NRN MANITOBA TO MT. WITH FRONT STILL WELL W OF THE AREA THRU
THE NIGHT AND WITH DRY AIR MASS LINGERING...ANOTHER MAINLY CLEAR
NIGHT IS ANTICIPATED. OVERALL...LOW-LEVEL WINDS WILL BE LIGHT
AGAIN...AND THERE IS LITTLE CHANGE IN PRECIPITABLE WATER...
SUGGESTING MIN TEMPS SHOULD BE SIMILAR TO LAST NIGHT. HOWEVER...WITH
AIR MASS CONTINUING TO MODERATE WITH STRONG HEATING THIS AFTN...
WOULD EXPECT MINS GENERALLY TO BE A FEW DEGREES HIGHER THAN LAST
NIGHT. DEVELOPING LIGHT S TO SW FLOW WILL BEGIN TO STIR IN THE
DOWNSLOPE AREAS NEAR LAKE SUPERIOR...SO MINS THERE WILL PROBABLY BE
HIGHEST. MIN TEMPS SHOULD RANGE FROM THE 30S INLAND TO THE LWR 40S
ALONG LAKE SUPERIOR.
ON WED...APPROACHING COLD FRONT SHOULD REACH WRN/NRN LAKE SUPERIOR
LATE IN THE AFTN/EARLY EVE. SOME OF THE MOISTURE NOTED ON TODAYS 12Z
KMPX/KINL SOUNDINGS SHOULD ADVECT E AND NE AHEAD OF THE APPROACHING
COLD FRONT. HOWEVER...WITH LIGHT WINDS AND LITTLE ADVECTION AT THE
LOW-LEVELS...DRIER AIR WILL LIKELY LINGER UNDERNEATH THE MOISTENING
OCCURRING HIGHER UP. IN THE END...THIS WILL WORK TO MINIMIZE SHRA
THREAT WED. HOWEVER...WITH MLCAPE UPWARDS OF A FEW HUNDRED J/KG...
CAN`T RULE OUT A FEW HIGH BASED SHRA OVER THE W WHERE AFTN LAKE
BREEZE WILL HELP TO POOL LOW-LEVEL MOISTURE AND PROVIDE A LOW-LEVEL
FORCING MECHANISM. OTHERWISE...IT WILL BE ANOTHER WARM DAY ON PAR
WITH WHAT IS GOING ON THIS AFTN.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 418 AM EDT TUE MAY 7 2013
LIMITED CHANGES TO THE GOING FORECAST FROM 24HRS AGO. THE HIGH
PRESSURE RIDGE THAT THE AREA IS CURRENTLY UNDER WILL BEGIN TO
LOOSEN IT/S GRIP ON THE AREA ON WEDNESDAY...BUT NOT BEFORE
PROVIDING ANOTHER ABOVE NORMAL TEMPERATURE DAY FOR MUCH OF UPPER
MICHIGAN. MOST AREAS WILL SEE TEMPERATURES IN THE 70S...BUT LAKE
BREEZES WILL LEAD TO SLIGHTLY COOLER VALUES NEAR THE GREAT LAKES.
MOST MODELS HAVE BACKED OFF ON PRECIPITATION FROM THE DIURNAL CU
OVER THE WESTERN CWA IN THE AFTERNOON...AND THAT SEEMS REASONABLE
BASED OFF THE MOISTURE BEING FOCUSED ABOVE 6-7KFT. WITH THE HIGH
BASED CLOUDS AND THE LINGERING LOW LEVEL DRY AIR...IT MAY BE TOUGH
TO GET PRECIPITATION TO REACH THE SURFACE. IN ADDITION...LOOKING AT
MODEL SOUNDINGS...THE VERY LOW LEVELS ARE TRYING TO OVER MOISTEN
THE SURFACE...WHICH INCREASES THE SFC BASED CAPE TOWARDS 500-750
J/KG. LOOKING AT MLCAPE...THAT DRY AIR CUTS BACK CAPE VALUES TO
50-250 J/KG AND WITH THE OTHER NEGATIVE VALUES...WILL CUT BACK
POPS TO SLIGHTS OVER THE FAR WEST. ALSO FOR WEDNESDAY...LOWERED
DEWPOINTS BASED OFF DRIER AIR HOLDING OVER THE AREA. THIS WILL LEAD
TO ANOTHER DAY OF RH VALUES IN THE 20S OVER THE INTERIOR CENTRAL AND
EAST. FORTUNATELY...THE WINDS WILL AGAIN REMAIN LIGHT AND BE THE
STRONGEST ALONG THE LEADING EDGE OF THE LAKE BREEZES.
FOR WEDNESDAY NIGHT INTO THURSDAY...FOCUS TURNS TO THE WEAK COLD
FRONT DROPPING SOUTHEAST ACROSS THE AREA IN THE EARLY EVENING AND
WEAK SHORTWAVE ENERGY AND ASSOCIATED MOISTURE PUSHING EAST FROM
SOUTHERN MINNESOTA AND INTO THE LOWER GREAT LAKES. WITH THE MOISTURE
FAIRLY LIMITED WITH THE COLD FRONT...THE PRECIPITATION CHANCES WILL
BE LARGELY DEPENDENT ON THE TRACK OF THE SHORTWAVE. WITH THE BEST
MOISTURE AND CLOSEST PROXIMITY TO THE ENERGY TO THE SOUTHWEST OF THE
AREA...WILL HAVE THE HIGHEST POPS OVER THE WEST...WITH LOW END
LIKELY AND HIGH END CHANCE VALUES FOR OVERNIGHT WEDNESDAY NIGHT AND
THURSDAY MORNING BEFORE DIMINISHING DURING THE AFTERNOON. QPF
AMOUNTS SHOULD BE ON THE LIGHT SIDE /LESS THAN A QUARTER OF AN
INCH/ UNLESS THE SHORTWAVE IS FARTHER TO THE NORTH...WHICH ALLOW
FOR GREATER INTERACTION BETWEEN THE WAVE AND THE FRONT.
BEHIND THE COLD FRONT...CANADIAN HIGH PRESSURE WILL BUILD OVER THE
AREA FROM THE NORTHWEST ON THURSDAY NIGHT AND REMAIN INTO FRIDAY
EVENING. THIS SHOULD LEAD TO DRY WEATHER...BUT WITH COOLER
TEMPERATURES ALOFT /850MB TEMPS AROUND 2-4C/ WOULD EXPECT HIGHS TO
BE IN THE 50S INLAND AND IN THE UPPER 40S TO AROUND 50 NEAR LAKE
SUPERIOR WITH THE NORTHEAST WINDS.
STRONG NORTHERN STREAM UPPER TROUGH WILL DIVE SOUTHEAST ACROSS THE
AREA LATE FRIDAY NIGHT AND SATURDAY. WITH THE STRENGTH OF THE
FRONT...WOULD EXPECT A NICE LINE OF SHOWERS MOVING ACROSS THE
AREA LATE FRIDAY NIGHT AND SATURDAY. THE SPEED OF THE FRONT WILL
LIMIT ACCUMULATIONS...BUT MOST AREAS SHOULD SEE A TENTH OF AN INCH
OF RAIN. THERE IS THE POTENTIAL THE BACK SIDE OF THIS PRECIPITATION
COULD TURN OVER TO SNOW AND WILL CONTINUE THAT MENTION. WITH THE
VERY COLD AIR ALOFT BEHIND THE FRONT ON SATURDAY AFTERNOON...WOULD
EXPECT DIURNAL SHOWERS TO DEVELOP ON THE BACK SIDE OF THE LOW...DUE
TO THE SFC-700MB LAPSE RATES AROUND 8-8.5 C/KM. THIS PRECIPITATION
WILL START AS SNOW ALOFT AND P-TYPE AT THE SURFACE DEPENDS ON LOW
LEVEL TEMPERATURES. MODELS ARE HINTING AT SURFACE TEMPERATURES BEING
WARMER...BUT WITH THE DRY LOW LEVEL AIR AND INVERTED V LOOK TO THE
SOUNDING...OPTED TO UTILIZE THE WETBULB ZERO HEIGHT FOR RAIN/SNOW
LINE. THIS PLACES A RAIN/SNOW MIX OVER THE NORTH AND RAIN OVER THE
SOUTH. WITH THE LATEST MODEL TRENDS...IT MAY END UP BEING SNOW
ACROSS MUCH OF THE AREA. ALSO ADJUSTED HIGHS DOWN TOWARDS RAW MODEL
DATA...SINCE MOS TREND TOWARDS NORMAL IS BIASING THE COLD TEMPS.
THIS PRODUCES HIGHS IN THE LOW-MID 40S OVER THE NORTHWEST HALF OF
THE CWA AND UPPER 40S OVER THE SOUTHEAST HALF. THE COOLER
TEMPERATURES AND THE GUSTY NORTHWEST WINDS...25-30KTS...IT WILL NOT
FEEL LIKE A MID MAY DAY ACROSS UPPER MICHIGAN. COULD EVEN BE A FEW
LAKE EFFECT SNOW SHOWERS ON SATURDAY NIGHT OVER THE EAST. DECENT
SFC-775MB DELTA-T VALUES...BUT MOISTURE APPEARS LIMITED AT THIS
POINT WITH AN INVERTED V LOOK BELOW THE CLOUD BASE AND WILL ONLY
MENTION SLIGHT CHANCES.
UPPER TROUGH WILL BEGIN TO SHIFT EAST ON SUNDAY AND PULL THE
MOISTURE WITH IT. THUS...EXPECT A DIMINISHING TREND TO THE
PRECIPITATION ON SATURDAY NIGHT AND A DRY SUNDAY. TEMPERATURES WILL
REMAIN ON THE COLD SIDE ON SUNDAY...WITH HIGHS IN THE LOW 40S OVER
THE EAST AND MID 40S OVER THE WEST DUE TO WARMING TEMPERATURES
ALOFT. UPPER RIDGE WILL THEN BUILD OVER THE UPPER GREAT LAKES FOR
MONDAY INTO TUESDAY. MEANWHILE...A LOW PRESSURE SYSTEM MOVING
THROUGH NORTHERN ONTARIO WILL SWEEP A WARM FRONT ACROSS SOUTHERN
ONTARIO ON MONDAY NIGHT...WHICH COULD BRUSH THE CWA. THIS FRONT
WILL ALSO BRING TEMPERATURES BACK TO NORMAL ACROSS THE AREA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 139 PM EDT TUE MAY 7 2013
EXPECT VFR CONDITIONS AND LIGHT WINDS THRU THIS FCST PERIOD AT
KIWD/KCMX/KSAW AS DRY HIGH PRES CONTINUES TO DOMINATE.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 403 PM EDT TUE MAY 7 2013
HIGH PRESSURE WILL CONTINUE TO PRODUCE LIGHT WINDS THRU WED...
BUT A COLD FRONT MOVING ACROSS LAKE SUPERIOR LATE WED AFTN AND
EVENING WILL LEAD TO INCREASING NORTH-NORTHEAST WINDS PEAKING IN THE
15-25KT RANGE WED NIGHT INTO THU MORNING. HIGH PRESSURE WILL BUILD
BACK OVER THE AREA FOR FRI AND DIMINISH THE WINDS. A STRONGER
COLD FRONT WILL SLIDE ACROSS THE UPPER LAKES FRI NIGHT AND SHIFT
WINDS TO THE NW AT 20-30KTS SAT. THESE STRONGER WINDS WILL CONTINUE
INTO SAT NIGHT BEFORE GRADUALLY DIMINISHING FROM W TO E ON SUN.
&&
.HYDROLOGY...
ISSUED AT 418 AM EDT TUE MAY 7 2013
HYDROLOGY CONCERNS REMAIN FOR TODAY AND WEDNESDAY...BUT THEY
ARE STARTING TO DIMINISH WITH THE DWINDLING SNOW PACK OVER
WESTERN UPPER MICHIGAN. VISIBLE SATELLITE AND MODIS IMAGERY
YESTERDAY STILL SHOWS SNOW REMAINING IN THE HIGHER TERRAIN LOCATIONS
OF THE HURON MOUNTAINS AND THE KEWEENAW PENINSULA. THE LATEST SNOW
DEPTH OBSERVATIONS /FROM EARLIER THIS MORNING AROUND 8AM/ STILL HAVE
AROUND 3IN AT IRONWOOD...AND 7IN AT ATLANTIC MINE. A FEW POCKETS OF
HIGHER AMOUNTS ARE LIKELY ACROSS THE KEWEENAW. DID SEE RISES AT SOME
OF THE SITES OVER THE WEST /ESPECIALLY TRRM4 AND BESM4/ WITH THE
WARMER TEMPERATURES YESTERDAY. BUT THE TRAP ROCK RIVER LEVELED OFF
MUCH FASTER OVERNIGHT AND THAT MAY BE A SIGN OF THE LACK OF SNOW
WATER EQUIVALENT LEFT IN THE BASIN. WITH THE SOLID RISE YESTERDAY OF
BESM4 AND DECENT SNOW COVER...WOULD THINK IT WOULD MAKE ANOTHER PUSH
TODAY. AT THIS TIME...AN EDUCATED GUESS WOULD PUT IT BETWEEN 8 AND 9
FEET THIS AFTERNOON/EVENING...WHICH WOULD LIKELY BE THE LAST MAJOR
PUSH.
THE ONGOING FLOODING ON THE MICHIGAMME RIVER AROUND WITCH LAKE WILL
REMAIN A CONCERN FOR THE NEXT COUPLE OF DAYS UNTIL THE SNOW WATER
MAKES IT OUT OF THE HIGHER TERRAIN OF NORTHWEST MARQUETTE COUNTY.
THE STURGEON RIVER AT ALSTON AND CHASSELL CONTINUES TO HOVER BETWEEN
ADVISORY AND WARNING LEVELS AND WOULD EXPECT THAT TO CONTINUE BASED
ON THE STEADY FLOW THROUGH THE STURGEON RIVER AT SIDNAW UPSTREAM.
OTHERWISE...THE REST RIVER LEVELS ARE ON THE DOWNWARD TREND AND
WILL LIKELY CONTINUE THIS WEEK.
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...ROLFSON
LONG TERM...SRF
AVIATION...ROLFSON
MARINE...ROLFSON
HYDROLOGY...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
141 PM EDT TUE MAY 7 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 418 AM EDT TUE MAY 7 2013
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW W-E ORIENTED UPR
RDG STRETCHING ALONG THE US/CNDN BORDER TO THE N OF CLOSED UPR LOWS
OVER THE SE CONUS AND ANOTHER JUST OFF THE CA COAST. AT THE SFC...
HI PRES IS CENTERED OVER LK SUP...AND WINDS ARE NEAR CALM UNDER
SLACK PRES GRADIENT. WITH VERY DRY AIRMASS SHOWN ON THE 00Z GRB
RAOB...WHERE PWAT WAS ONLY 0.15 INCH OR 27 PCT OF NORMAL...QUIET WX
DOMINATES THE CWA. THERE ARE SOME HI CLDS OVER THE SCENTRAL...BUT
OTRW SKIES ARE CLR.
DRY HI PRES IS FCST TO DOMINATE THE UPR LKS TDAY/TNGT...SO QUIET
WX/MOCLR SKIES SHOULD CONTINUE. MAIN FCST CONCERNS ARE TEMPS/HOW LO
MIN RH WL FALL THIS AFTN. ANY SHALLOW GROUND FOG THAT FORMS OVER THE
INTERIOR W EARLY THIS MRNG WL BURN OFF QUICKLY AFT SUNRISE. WITH H85
TEMPS THIS AFTN IN THE 10-11C RANGE...ABOUT THE SAME OR 1C HIER THAN
YDAY...MAX TEMPS SHOULD BE SIMILAR TO WHAT OCCURRED ON MON. DEEP
MIXING TO H75 ON FCST SDNGS YIELDS HI TEMPS RISING WELL INTO THE 70S
AWAY FM LK MODERATION. ONE DIFFERENCE IS THE H925 FLOW IS FCST TO BE
A BIT STRONGER OUT OF THE S-SE THAN YDAY AND UP TO 10 KTS WITH HI
CENTER SHIFTING SLOWLY TO THE E. AS A RESULT...LK MODERATION OFF LK
SUP SHOULD NOT PENETRATE AS FAR INLAND AS ON MON. ON THE OTHER
HAND...MODERATION OFF LK MI WL BE A BIT MORE AGGRESSIVE. AWAY FM LK
COOLING/ MOISTENING...THE DEEP MIXING WL ALLOW SFC DEWPTS TO FALL TO
ARND 30 THIS AFTN...RESULTING IN MIN RH ARND 20 PCT. SINCE WINDS
SHOULD BE NO HIER THAN ABOUT 10 MPH...NO FIRE WX HEADLINES ARE
NECESSARY.
CONTINUED AIRMASS MODERATION...A SOMEWHAT STRONGER S WIND...AND THE
ARRIVAL OF MOISTER AIR ESPECIALLY OVER THE W...WHERE THE PWAT IS
FCST TO RISE TO NEAR 0.75 INCH BY 12Z WED...WL CONSPIRE TO KEEP MIN
TEMPS TNGT HIER THAN THIS MRNG. THE DIFFERENCE SHOULD BE MOST
PRONOUNCED OVER THE W CLOSER TO THE INCOMING MOISTER AIR.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 418 AM EDT TUE MAY 7 2013
LIMITED CHANGES TO THE GOING FORECAST FROM 24HRS AGO. THE HIGH
PRESSURE RIDGE THAT THE AREA IS CURRENTLY UNDER WILL BEGIN TO
LOOSEN IT/S GRIP ON THE AREA ON WEDNESDAY...BUT NOT BEFORE
PROVIDING ANOTHER ABOVE NORMAL TEMPERATURE DAY FOR MUCH OF UPPER
MICHIGAN. MOST AREAS WILL SEE TEMPERATURES IN THE 70S...BUT LAKE
BREEZES WILL LEAD TO SLIGHTLY COOLER VALUES NEAR THE GREAT LAKES.
MOST MODELS HAVE BACKED OFF ON PRECIPITATION FROM THE DIURNAL CU
OVER THE WESTERN CWA IN THE AFTERNOON...AND THAT SEEMS REASONABLE
BASED OFF THE MOISTURE BEING FOCUSED ABOVE 6-7KFT. WITH THE HIGH
BASED CLOUDS AND THE LINGERING LOW LEVEL DRY AIR...IT MAY BE TOUGH
TO GET PRECIPITATION TO REACH THE SURFACE. IN ADDITION...LOOKING AT
MODEL SOUNDINGS...THE VERY LOW LEVELS ARE TRYING TO OVER MOISTEN
THE SURFACE...WHICH INCREASES THE SFC BASED CAPE TOWARDS 500-750
J/KG. LOOKING AT MLCAPE...THAT DRY AIR CUTS BACK CAPE VALUES TO
50-250 J/KG AND WITH THE OTHER NEGATIVE VALUES...WILL CUT BACK
POPS TO SLIGHTS OVER THE FAR WEST. ALSO FOR WEDNESDAY...LOWERED
DEWPOINTS BASED OFF DRIER AIR HOLDING OVER THE AREA. THIS WILL LEAD
TO ANOTHER DAY OF RH VALUES IN THE 20S OVER THE INTERIOR CENTRAL AND
EAST. FORTUNATELY...THE WINDS WILL AGAIN REMAIN LIGHT AND BE THE
STRONGEST ALONG THE LEADING EDGE OF THE LAKE BREEZES.
FOR WEDNESDAY NIGHT INTO THURSDAY...FOCUS TURNS TO THE WEAK COLD
FRONT DROPPING SOUTHEAST ACROSS THE AREA IN THE EARLY EVENING AND
WEAK SHORTWAVE ENERGY AND ASSOCIATED MOISTURE PUSHING EAST FROM
SOUTHERN MINNESOTA AND INTO THE LOWER GREAT LAKES. WITH THE MOISTURE
FAIRLY LIMITED WITH THE COLD FRONT...THE PRECIPITATION CHANCES WILL
BE LARGELY DEPENDENT ON THE TRACK OF THE SHORTWAVE. WITH THE BEST
MOISTURE AND CLOSEST PROXIMITY TO THE ENERGY TO THE SOUTHWEST OF THE
AREA...WILL HAVE THE HIGHEST POPS OVER THE WEST...WITH LOW END
LIKELY AND HIGH END CHANCE VALUES FOR OVERNIGHT WEDNESDAY NIGHT AND
THURSDAY MORNING BEFORE DIMINISHING DURING THE AFTERNOON. QPF
AMOUNTS SHOULD BE ON THE LIGHT SIDE /LESS THAN A QUARTER OF AN
INCH/ UNLESS THE SHORTWAVE IS FARTHER TO THE NORTH...WHICH ALLOW
FOR GREATER INTERACTION BETWEEN THE WAVE AND THE FRONT.
BEHIND THE COLD FRONT...CANADIAN HIGH PRESSURE WILL BUILD OVER THE
AREA FROM THE NORTHWEST ON THURSDAY NIGHT AND REMAIN INTO FRIDAY
EVENING. THIS SHOULD LEAD TO DRY WEATHER...BUT WITH COOLER
TEMPERATURES ALOFT /850MB TEMPS AROUND 2-4C/ WOULD EXPECT HIGHS TO
BE IN THE 50S INLAND AND IN THE UPPER 40S TO AROUND 50 NEAR LAKE
SUPERIOR WITH THE NORTHEAST WINDS.
STRONG NORTHERN STREAM UPPER TROUGH WILL DIVE SOUTHEAST ACROSS THE
AREA LATE FRIDAY NIGHT AND SATURDAY. WITH THE STRENGTH OF THE
FRONT...WOULD EXPECT A NICE LINE OF SHOWERS MOVING ACROSS THE
AREA LATE FRIDAY NIGHT AND SATURDAY. THE SPEED OF THE FRONT WILL
LIMIT ACCUMULATIONS...BUT MOST AREAS SHOULD SEE A TENTH OF AN INCH
OF RAIN. THERE IS THE POTENTIAL THE BACK SIDE OF THIS PRECIPITATION
COULD TURN OVER TO SNOW AND WILL CONTINUE THAT MENTION. WITH THE
VERY COLD AIR ALOFT BEHIND THE FRONT ON SATURDAY AFTERNOON...WOULD
EXPECT DIURNAL SHOWERS TO DEVELOP ON THE BACK SIDE OF THE LOW...DUE
TO THE SFC-700MB LAPSE RATES AROUND 8-8.5 C/KM. THIS PRECIPITATION
WILL START AS SNOW ALOFT AND P-TYPE AT THE SURFACE DEPENDS ON LOW
LEVEL TEMPERATURES. MODELS ARE HINTING AT SURFACE TEMPERATURES BEING
WARMER...BUT WITH THE DRY LOW LEVEL AIR AND INVERTED V LOOK TO THE
SOUNDING...OPTED TO UTILIZE THE WETBULB ZERO HEIGHT FOR RAIN/SNOW
LINE. THIS PLACES A RAIN/SNOW MIX OVER THE NORTH AND RAIN OVER THE
SOUTH. WITH THE LATEST MODEL TRENDS...IT MAY END UP BEING SNOW
ACROSS MUCH OF THE AREA. ALSO ADJUSTED HIGHS DOWN TOWARDS RAW MODEL
DATA...SINCE MOS TREND TOWARDS NORMAL IS BIASING THE COLD TEMPS.
THIS PRODUCES HIGHS IN THE LOW-MID 40S OVER THE NORTHWEST HALF OF
THE CWA AND UPPER 40S OVER THE SOUTHEAST HALF. THE COOLER
TEMPERATURES AND THE GUSTY NORTHWEST WINDS...25-30KTS...IT WILL NOT
FEEL LIKE A MID MAY DAY ACROSS UPPER MICHIGAN. COULD EVEN BE A FEW
LAKE EFFECT SNOW SHOWERS ON SATURDAY NIGHT OVER THE EAST. DECENT
SFC-775MB DELTA-T VALUES...BUT MOISTURE APPEARS LIMITED AT THIS
POINT WITH AN INVERTED V LOOK BELOW THE CLOUD BASE AND WILL ONLY
MENTION SLIGHT CHANCES.
UPPER TROUGH WILL BEGIN TO SHIFT EAST ON SUNDAY AND PULL THE
MOISTURE WITH IT. THUS...EXPECT A DIMINISHING TREND TO THE
PRECIPITATION ON SATURDAY NIGHT AND A DRY SUNDAY. TEMPERATURES WILL
REMAIN ON THE COLD SIDE ON SUNDAY...WITH HIGHS IN THE LOW 40S OVER
THE EAST AND MID 40S OVER THE WEST DUE TO WARMING TEMPERATURES
ALOFT. UPPER RIDGE WILL THEN BUILD OVER THE UPPER GREAT LAKES FOR
MONDAY INTO TUESDAY. MEANWHILE...A LOW PRESSURE SYSTEM MOVING
THROUGH NORTHERN ONTARIO WILL SWEEP A WARM FRONT ACROSS SOUTHERN
ONTARIO ON MONDAY NIGHT...WHICH COULD BRUSH THE CWA. THIS FRONT
WILL ALSO BRING TEMPERATURES BACK TO NORMAL ACROSS THE AREA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 139 PM EDT TUE MAY 7 2013
EXPECT VFR CONDITIONS AND LIGHT WINDS THRU THIS FCST PERIOD AT
KIWD/KCMX/KSAW AS DRY HIGH PRES CONTINUES TO DOMINATE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 418 AM EDT TUE MAY 7 2013
HIGH PRESSURE WILL CONTINUE TO PRODUCE LIGHT WINDS TODAY AND
WEDNESDAY...BUT A COLD FRONT MOVING THROUGH ON WEDNESDAY AFTERNOON
AND EARLY EVENING WILL LEAD TO INCREASING NORTH-NORTHEAST WINDS
PEAKING IN THE 15-25KT RANGE ON WEDNESDAY NIGHT INTO THURSDAY
MORNING. HIGH PRESSURE WILL BUILD BACK OVER THE AREA FOR FRIDAY AND
DIMINISH THE WINDS. BUT A STRONGER COLD FRONT WILL SLIDE THROUGH
FRIDAY NIGHT AND SHIFT WINDS TO THE NORTHWEST AT 20-30KTS ON
SATURDAY. THESE WINDS WILL CONTINUE INTO SATURDAY NIGHT BEFORE
GRADUALLY DIMINISHING ON SUNDAY.
&&
.HYDROLOGY...
ISSUED AT 418 AM EDT TUE MAY 7 2013
HYDROLOGY CONCERNS REMAIN FOR TODAY AND WEDNESDAY...BUT THEY
ARE STARTING TO DIMINISH WITH THE DWINDLING SNOW PACK OVER
WESTERN UPPER MICHIGAN. VISIBLE SATELLITE AND MODIS IMAGERY
YESTERDAY STILL SHOWS SNOW REMAINING IN THE HIGHER TERRAIN LOCATIONS
OF THE HURON MOUNTAINS AND THE KEWEENAW PENINSULA. THE LATEST SNOW
DEPTH OBSERVATIONS /FROM EARLIER THIS MORNING AROUND 8AM/ STILL HAVE
AROUND 3IN AT IRONWOOD...AND 7IN AT ATLANTIC MINE. A FEW POCKETS OF
HIGHER AMOUNTS ARE LIKELY ACROSS THE KEWEENAW. DID SEE RISES AT SOME
OF THE SITES OVER THE WEST /ESPECIALLY TRRM4 AND BESM4/ WITH THE
WARMER TEMPERATURES YESTERDAY. BUT THE TRAP ROCK RIVER LEVELED OFF
MUCH FASTER OVERNIGHT AND THAT MAY BE A SIGN OF THE LACK OF SNOW
WATER EQUIVALENT LEFT IN THE BASIN. WITH THE SOLID RISE YESTERDAY OF
BESM4 AND DECENT SNOW COVER...WOULD THINK IT WOULD MAKE ANOTHER PUSH
TODAY. AT THIS TIME...AN EDUCATED GUESS WOULD PUT IT BETWEEN 8 AND 9
FEET THIS AFTERNOON/EVENING...WHICH WOULD LIKELY BE THE LAST MAJOR
PUSH.
THE ONGOING FLOODING ON THE MICHIGAMME RIVER AROUND WITCH LAKE WILL
REMAIN A CONCERN FOR THE NEXT COUPLE OF DAYS UNTIL THE SNOW WATER
MAKES IT OUT OF THE HIGHER TERRAIN OF NORTHWEST MARQUETTE COUNTY.
THE STURGEON RIVER AT ALSTON AND CHASSELL CONTINUES TO HOVER BETWEEN
ADVISORY AND WARNING LEVELS AND WOULD EXPECT THAT TO CONTINUE BASED
ON THE STEADY FLOW THROUGH THE STURGEON RIVER AT SIDNAW UPSTREAM.
OTHERWISE...THE REST RIVER LEVELS ARE ON THE DOWNWARD TREND AND
WILL LIKELY CONTINUE THIS WEEK.
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...ROLFSON
MARINE...SRF
HYDROLOGY...SRF
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1137 AM CDT TUE MAY 7 2013
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 329 AM CDT TUE MAY 7 2013
UPPER LEVEL LOW STILL CENTERED OVER NORTHWEST GEORGIA/NORTHEAST
ALABAMA IS FORECAST TO BEGIN MOVING SLOWLY NORTHEAST TODAY. THIS
SHOULD FINALLY BRING A CLEARING SKY AND WARMER TEMPERATURES TO THE
REGION. THERE IS A PERSISTENT BAND OF MID LEVEL CLOUDS AROUND
10,000FT WHICH JUST DON`T SEEM TO WANT TO GO AWAY. THE NAM SEEMS TO
BE HANDLING THE DECK PRETTY WELL AT THIS TIME...AND IT SLOWLY THINS
OUT THROUGH THE MORNING. THE RUC ON THE OTHER HAND KEEPS THE DECK
AROUND AT LEAST THROUGH EARLY AFTERNOON. AM LEANING TOWARD THE RUC
AT THIS TIME SINCE THIS IS CLOSER TO PERSISTENCE...AND THIS SYSTEM
HAS BEEN NOTHING IF NOT PERSISTENT. CLOUDS SHOULD BE THINNING OUT
DURING THE AFTERNOON...AND STRONG MAY SUNSHINE SHOULD EASILY PROPEL
HIGHS INTO THE MID AND UPPER 70S. THERE MAY BE ENOUGH INSTABILITY
AROUND THIS AFTERNOON FOR POP-UP SHOWERS AND THUNDERSTORMS...SO THE
SLIGHT CHANCE POPS CURRENTLY IN THE FORECAST LOOK TO BE ON TRACK.
MEANWHILE...THE COMPACT LITTLE CUTOFF LOW CURRENTLY OVER SOUTH
DAKOTA WILL START DRIFTING SOUTHEAST IN THE WAKE OF ITS BIG SISTER
OVER THE EASTERN U.S. AS THE SECOND LARGE CUTOFF NOW OVER THE
CALIFORNIA COAST DRIFTS INTO THE INTERMOUNTAIN WEST. MODELS HAVE
BEEN VERY CONSISTENT IN FORECASTING THE LITTLE NORTHERN PLAINS LOW
TO BREAK DOWN THE UPPER LEVEL RIDGING BETWEEN THE TWO LARGER LOWS ON
WEDNESDAY...BRINGING ANOTHER CHANCE FOR AFTERNOON THUNDERSTORMS
PRIMARILY TO CENTRAL MISSOURI. THE LOW OPENS UP INTO A SHORTWAVE
WEDNESDAY NIGHT INTO THURSDAY BRINGING LOW LEVEL BAROCLINICITY INTO
THE MID-MISSISSIPPI VALLEY...AND AN INCREASING LOW LEVEL JET FROM
THE SOUTHEAST PLAINS. THIS LOOKS LIKE ANOTHER PERIOD OF WET WEATHER
FROM WEDNESDAY NIGHT THROUGH THURSDAY NIGHT AS THE SHORTWAVE SLOWLY
AMPLIFIES OVER THE MIDWEST AND THE LOW LEVEL JET CONTINUES TO BRING
A PLUME OF MOISTURE UP FROM THE SOUTHWEST. NOT SAYING IT`S GOING TO
BE A TOTAL WASH...BUT A FEW WAVES OF STORMS FROM WEDNESDAY EVENING
THROUGH LATE THURSDAY NIGHT LOOK PRETTY LIKELY. LOW LEVEL FLOW
TURNS TO THE NORTHWEST ON FRIDAY WHICH SHOULD BEGIN TO SHUT THE
PRECIP OFF FROM NORTH TO SOUTH...BUT NOT BEFORE THERE MAY BE ANOTHER
WAVE OF SHOWERS OR STORMS ALONG AND SOUTH OF THE I-70 CORRIDOR.
TEMPERATURES THROUGH THE PERIOD LOOK TO BE NEAR OR ABOVE NORMAL IN
THE MID 70S TO AROUND 80 WITH LOWS GENERALLY IN THE UPPER 50S AND
LOW 60S.
CARNEY
.LONG TERM...(SATURDAY THROUGH MONDAY)
ISSUED AT 347 AM CDT TUE MAY 7 2013
ANOTHER STRONG SHORTWAVE MOVES ACROSS THE U.S. CANADA BORDER FRIDAY
NIGHT INTO SATURDAY WHICH AMPLIFIES THE AFOREMENTIONED MIDWEST
SHORTWAVE AND PUSHES A STRONG COLD FRONT DOWN THROUGH THE PLAINS
INTO THE MID-MISSISSIPPI VALLEY LATE SATURDAY. STILL LOOKS LIKE
THERE COULD BE A CHANCE OF SHOWERS ON SATURDAY AS THE FRONT MOVES
THROUGH...THOUGH MEDIUM RANGE MODELS ARE NOW SHOWING THAT MOST OF
THE PRECIP MAY BE SOUTH OF THE REGION. A 1030MB CANADIAN HIGH
FOLLOWS ON THE HEELS OF THE FRONT. HIGHS SATURDAY LOOK TO BE NEAR
OR JUST BELOW SEASONAL NORMALS IN THE UPPER 60S TO LOW 70S...BUT THE
COLD CANADIAN AIRMASS WILL PUSH TEMPERATURES WELL BELOW NORMAL ON
SUNDAY AND MONDAY. GUIDANCE IS GIVING ME HIGHS IN THE LOW TO MID
60S AND LOWS IN THE UPPER 30S TO MID 40S. HOWEVER...I WOULD NOT BE
SURPRISED IF ACTUAL TEMPERATURES ARE AS MUCH AS 5 TO 10 DEGREES
COLDER THAN GUIDANCE. GFS AND ECMWF ARE FORECASTING 850MB TEMPS
AROUND 0C ON BOTH SUNDAY AND MONDAY WHICH YIELDS MIX-DOWN TEMPS IN
MID TO UPPER 50S! AM NOT GOING QUITE THAT COLD YET...BUT DID TAKE A
FEW DEGREES OFF GUIDANCE TEMPS BOTH SUNDAY AND MONDAY.
CARNEY
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1057 AM CDT TUE MAY 7 2013
SCT DIURNAL CUMULUS CLOUDS WILL DEVELOP OVER THE REGION THIS
AFTN. THERE COULD BE A FEW SHOWERS/STORMS IN THE ST LOUIS METRO
AREA THIS AFTN...BUT WILL LEAVE THE TAFS IN THIS AREA DRY FOR NOW
AS THE BETTER THREAT FOR ANY PRECIPITATION WILL LIKELY BE SE OF
THIS AREA AND CLOSER TO THE PERSISTENT UPPER LEVEL/SFC LOW OVER
THE SERN US. THE CUMULUS CLOUDS SHOULD DISSIPATE EARLY THIS EVNG
DUE TO THE LOSS OF DAYTIME HEATING. WEAK N-NELY SFC WINDS WILL
CONTINUE THIS AFTN...THEN BECOME LIGHT THIS EVNG. WITH LITTLE IF
ANY CLOUD COVER TGT ALONG WITH LIGHT SFC WINDS COULD NOT RULE OUT
SOME LIGHT PATCHY FOG...BUT WILL PROBABLY LEAVE FOG OUT OF THE
TAFS FOR NOW. SFC WINDS WILL BECOME S-SWLY ON WED. THERE MAY BE
FEW-SCT DIURNAL CUMULUS CLOUDS DEVELOPING BY LATE WED MRNG ALONG
WITH MID-HIGH LEVEL CLOUDS ADVECTING EWD INTO THE REGION.
SPECIFICS FOR KSTL...THE MID LEVEL CLOUDS JUST E OF STL SHOULD
CONTINUE TO DISSIPATE THIS AFTN WITH DIURNAL CUMULUS CLOUDS
DEVELOPING BETWEEN 4000-6000 FT IN HEIGHT. COULD NOT RULE OUT
ISOLATED SHOWERS...BUT WILL LEAVE OUT OF THE STL TAF FOR NOW AS
THE BETTER COVERAGE SHOULD BE SE OF STL. THE CUMULUS CLOUDS SHOULD
DISSIPATE EARLY THIS EVNG. MAY HAVE SCT DIURNAL CUMULUS CLOUDS
AGAIN WED AFTN ALONG WITH MID-HIGH LEVEL CLOUDS ADVECTING EWD INTO
THE AREA. WEAK N-NELY SFC WIND WILL CONTINUE THIS AFTN...THEN
BECOME LIGHT THIS EVNG. THIS LIGHT SFC WIND WILL BECOME S-SWLY WED
AFTN...ALBEIT ONLY ABOUT 6 KTS.
GKS
&&
.PRELIMINARY POINT TEMPS/POPS...
SAINT LOUIS 77 58 79 62 / 20 10 20 30
QUINCY 77 54 77 59 / 10 10 30 70
COLUMBIA 77 55 76 59 / 10 10 30 60
JEFFERSON CITY 77 54 77 60 / 10 10 30 50
SALEM 74 54 78 59 / 20 5 10 20
FARMINGTON 74 51 77 59 / 20 10 20 20
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
600 PM EDT TUE MAY 7 2013
.SYNOPSIS...
A SLOW MOVING UPPER LEVEL STORM SYSTEM WILL BRING A CHANCE OF
SHOWERS AND A FEW THUNDERSTORMS THROUGH WEDNESDAY. HIGH PRESSURE
BUILDING IN BEHIND THIS SYSTEM THURSDAY AND FRIDAY WILL BRING
WARMER AND DRIER CONDITIONS. SHOWERS MAY RETURN THIS WEEKEND AS
A COLD FRONT MOVES SLOWLY ACROSS THE REGION. A LARGE AREA OF DRY
HIGH PRESSURE EARLY NEXT WEEK WILL BRING A COOLING TREND.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
AS OF 6 PM TUESDAY...SHOWER AND THUNDERSTORM INTENSITY AND
COVERAGE HAS RAPIDLY DECREASED LATE THIS AFTERNOON AND IS NOW
ISOLATED OR BELOW IN COVERAGE. HAVE UPDATED FORECAST ACCORDINGLY.
MOST EVERYWHERE WILL BE DRY OVERNIGHT. PREVIOUS DISCUSSION
FROM THIS AFTERNOON FOLLOWS:
POTENT AND SLOW-MOVING UPPER LOW WILL HELP SPAWN WIDESPREAD
SHOWERS WITH ISOLATED THUNDERSTORMS THIS AFTN. WV IMAGERY
CURRENTLY SHOWS EXPANSIVE...NEARLY STATIONARY...UPPER LOW CENTERED
ACROSS THE UPSTATE OF SC INTO CENTRAL NC. WHILE THIS LOW SPINS AND
MOVES VERY SLOWLY E/NE...A PIECE OF VORT ENERGY WILL MOVE OVERHEAD
THROUGH THIS EVE. THE COMBINATION OF THE VORT IMPULSE...SURFACE
HEATING...AND STEEP ML LAPSE RATES WILL ALLOW FOR THE DEVELOPMENT
OF SHOWERS AND THUNDERSTORMS THROUGH NIGHTFALL.
KLTX RADAR ATTM HAS A FEW CELLS BEGINNING TO DEVELOP...BUT ACTIVITY
HAS BEEN WEAK AND SPORADIC THUS FAR TODAY. EXAMINATION OF NAM BUFR
SOUNDINGS SUGGESTS A SLIGHTLY WARMER MID-LAYER THAT DEVELOPED WITHIN
CLOUD COVER...WHICH HAS SOMEWHAT SUPPRESSED THE ABILITY FOR SURFACE
PARCELS TO RISE. HRRR/RUC/NAM12 ALL SUGGEST LAPSE RATES STEEPENING
THROUGH THE EVE...WHICH IS SUPPORTED BY THE CLOSER PROXIMITY OF THE
UPPER LOW AS IT DRIFTS NE. 500MB TEMPS OF -22C WILL IMPINGE ON THE
WEST AND NW ZONES...STEEPENING THE 800-500MB LR`S TO AROUND 7C/KM.
THIS PROVIDES THE IMPETUS FOR INCREASING INSTABILITY IN THE FORM OF
SBCAPE TO AROUND 500 J/KG...AND -10C TO -30C CAPE TO 200-300 J/KG.
WITH FREEZING LEVELS ONLY AROUND 7000 FT...ANY STORM (AND EVEN MANY
SHOWERS) WILL HAVE THE CAPABILITY TO PRODUCE SMALL HAIL EVEN FROM
UPDRAFTS NOT USUALLY CONSIDERED VERY ROBUST.
THERE HAS BEEN MUCH TALK INTERNALLY ABOUT THE SIMILARITIES BETWEEN
THIS EVENT AND THAT OF MARCH 25, 2012...WHEN 17 STATEMENTS AND 3
WARNINGS WERE ISSUED FOR HAIL. WHILE THE GENERAL ENVIRONMENT IS
ABOUT THE SAME...SURFACE TEMPS THAT DAY WERE WARMER...WHICH CREATED
STEEPER LOW AND MID-LEVEL LAPSE RATES. STILL...HIGH RES GUIDANCE
SUGGESTS SCATTERED-TO-NUMEROUS SHOWERS/STORMS THIS AFTN...ANY OF
WHICH COULD PRODUCE SMALL HAIL. HAVE CONTINUED TO INDICATE SMALL
HAIL IN WX GRIDS...WITH HIGHEST POP IN THE NW ZONES CLOSEST TO THE
UPPER LOW CENTER.
SO FOR THE REST OF THE DAYLIGHT HOURS...WE WILL SEE INCREASING
COVERAGE OF CONVECTION WITH SMALL HAIL...AND TEMPS FLUCTUATING
WILDLY WITHIN SHOWERS. HIGHS WILL AVERAGE AROUND 70
DEGREES...WARMEST IN THE NORTHERN ZONES.
AFTER NIGHTFALL CLOUD COVER AND CONVECTION WILL WANE WITH LOSS OF
HEATING...AND BY MIDNIGHT THERE SHOULD BE NOTHING LEFT BUT SCT
DEBRIS CLOUDINESS...AND HAVE QUICKLY DROPPED POP TO SILENT AT THAT
TIME. WITH A WEAK PRESSURE GRADIENT AND IMPROVING SKY COVER...DECENT
RADIATIONAL COOLING WILL OCCUR AND HAVE SHOWN MINS IN THE LOW
50S...SLIGHTLY BELOW GUIDANCE. HAVE CONTINUED PATCHY FOG ACROSS THE
AREA AS WELL...AS TD/S WILL RISE TODAY AND SOME MOISTENING WILL
OCCUR FROM THE SHOWERS.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
AS OF 3 PM TUESDAY...COOL POOL ALOFT ASSOCIATED WITH AN EXPANSIVE
UPPER LOW WILL BE DRIFTING NORTH OVER THE NC/VA BORDER AT DAYBREAK
WEDNESDAY...BUT WILL CONTINUE TO PROVIDE FAVORABLE LAPSE RATES FOR
ISOLATED TO SCATTERED CONVECTION. SEVERAL IMPULSES ALOFT CAUGHT IN
THE WESTERN PERIPHERY OF THIS FEATURE...WILL MOVE EAST ACROSS OUR
FORECAST AREA WEDNESDAY...HELPING TO ENHANCE CONVECTIVE FORMATION.
OVERALL QPF VALUES WILL REMAIN LOW AS THE BULK OF RAIN GENERATION
RESIDES NORTH OF THE AREA.
AS THE UPPER CIRCULATION PULLS INTO SOUTHERN NEW ENGLAND THURSDAY
DRY AIR FROM THE W-NW WILL OVERSPREAD THE FORECAST AREA...AND THIS
SHOULD EFFECTIVELY REMOVE OR GREATLY REDUCE PROBABILITY OF PCPN AND
NO MENTIONABLE POP VALUES ARE PLANNED FOR THURSDAY.
AS THE COOL POOL ALOFT GRADUALLY LOOSENS ITS INFLUENCE OVER THE
FORECAST AREA...AND HEIGHTS REBOUND TO MORE NORMAL LEVELS...WE WILL
SEE A GRADUAL WARMING TREND WED AND THU. MEANWHILE IN PART DUE TO
GOOD RADIATIONAL COOLING AND RESIDUAL COOL AIR OVER THE REGION
INITIALLY...MORNING LOW WILL REMAIN BELOW NORMAL FOR EARLY MAY.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 3 PM TUESDAY...MEDIUM RANGE GUIDANCE REMAINS RELATIVELY
CONSISTENT WITH AN INITIAL SOUTHWESTERLY MID LEVEL PATTERN
TRANSITIONING TO DEEP TROUGHING BY THE END OF THE PERIOD. THIS
DRAMATIC PATTERN CHANGE WILL RESULT IN DRAMATIC CHANGES IN THE
SENSIBLE WEATHER ELEMENTS AS WELL.
FRIDAY REMAINS WARM AND RELATIVELY DRY ALTHOUGH SEA BREEZE
CONVECTION WARRANTS A CONTINUATION OF SLIGHT CHANCE POPS. SATURDAY
AND SUNDAY POPS RISE QUITE A BIT AS THE SLOW MOVING COLD
FRONT...COURTESY OF THE DEVELOPING MID LEVEL TROUGH STARTS MOVING
CLOSER. GUIDANCE HAS SLOWED SLIGHTLY WITH THE FRONT MOVING ACROSS
THE AREA LATE SUNDAY. TIMING APPEARS CONDUCIVE FOR GOOD INSTABILITY
WITH DECENT FORCING FOR POPS ALONG THE COAST AT LEAST AT THIS POINT.
A SECONDARY VORT EMBEDDED IN THE FLOW SLOWS THE PROGRESSION OF THE
FRONT AND WARRANTS AT LEAST SLIGHT CHANCE POPS INTO MONDAY ALONG THE
COAST.
TEMPERATURE TRENDS REMAIN IN PLACE WITH WARM READINGS EARLY TRENDING
DOWN WITH THE INCREASE IN MOISTURE AND FINALLY BELOW NORMAL AT THE
END OF THE PERIOD WITH TEMPERATURES APPROACHING TWO CATEGORIES BELOW
NORMAL.
&&
.AVIATION /22Z TUESDAY THROUGH SUNDAY/...
AS OF 18Z...SOME SHOWER ACTIVITY HAS ALREADY MOVED ACROSS THE AREA
THIS MORNING...AND MORE SHOWERS/ISO TSTMS ARE EXPECTED THIS AFTN.
LATEST HRRR RUN SUGGESTS PCPN COVERAGE WILL BE WIDELY SCATTERED THRU
THE AFTERNOON HOURS...SO HAVE INCLUDED PREVAILING VCSH FOR ALL TERMS
WITH TEMPO -SHRA INTO EARLY EVENING. VFR SHOULD PREVAIL WITH SHORT
PERIODS OF MVFR/IFR POSSIBLE IN HEAVIER SHOWERS/TSTMS. TSTMS MAY BE
CAPABLE OF PRODUCING SMALL HAIL WITH THE ABNORMALLY COLD AIR ALOFT.
RAIN CHANCES DIMINISH TONIGHT AND THE WINDS WILL BECOME LIGHT/CALM
DUE TO THE WEAK SFC PRESSURE GRADIENT. DEPENDING ON HOW MUCH CLOUD
COVER LINGERS OVERNIGHT...PATCHY FOG COULD BE AN ISSUE TMRW MORNING.
CONFIDENCE IS LOW ATTM...BUT HAVE INCLUDED MVFR VSBYS FOR OUR
FOG-PRONE TERMINALS.
EXTENDED OUTLOOK...SLIGHT CHANCE OF SHOWERS WEDNESDAY. MORNING FOG
POSSIBLE THURSDAY AND FRIDAY. CHANCE OF SHOWERS SATURDAY AND SUNDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 6 PM TUESDAY...LATEST OBS SHOW 3 TO 4 FT SEAS AND SOUTHERLY
WINDS IN THE 15 KT RANGE. NO CHANGES TO THE FORECAST WITH THE
LATEST UPDATE. PREVIOUS DISCUSSION FOLLOWS:
WEAK PRESSURE GRADIENT IN THE VICINITY OF A DIFFUSE AREA OF LOW
PRESSURE...IS KEEPING LIGHT S/SW WINDS ACROSS THE WATERS TODAY.
ALTHOUGH WIND WAVE CONTRIBUTION IS LIMITED DUE TO THESE LIGHT
WINDS...A COMBINATION OF A 3FT/7SEC SE SWELL...AND 3FT/11SEC EAST
SWELL WILL KEEP SEAS AT 2-4 FT THROUGH THE NEAR TERM PERIOD. WHILE
WIND/WAVE CONDITIONS WILL BE RELAXED...SCATTERED SHOWERS AND
THUNDERSTORMS ARE LIKELY INTO TONIGHT. THESE STORMS COULD IMPACT
ANY MARINE INTERESTS...CREATING BRIEF PERIODS OF HEAVY
RAINFALL...GUSTY WINDS...AND EVEN SOME SMALL HAIL.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 3 PM TUESDAY...MANAGEABLE MARINE CONDITIONS THIS PERIOD WITH
LIGHT TO MODERATE SW WINDS PREVAILING BOTH DAYS...AS LOW PRESSURE
INLAND TRACKS TO THE NORTH AND HIGH PRESSURE REMAINS OFFSHORE.
THE SEA SPECTRUM WILL BE COMPRISED OF A LIGHT TO MODERATE SW CHOP
ACCOMPANIED BY 2-3 FT SE WAVES IN 7-8 SECONDS INTERVALS. A FOOT
OR LESS OF LONG PERIOD E WAVES WILL ALSO BE IN THE MIX WITH WAVE
PERIODS AROUND 11-12 SECONDS.
LONG TERM /FRIDAY THROUGH SATURDAY/...
AS OF 3 PM TUESDAY...EXPECT MODEST SOUTHWEST WINDS INITIALLY IN
A RANGE OF 10-15 KNOTS. WITH A FRONT MOVING CLOSER SATURDAY AND
SUNDAY...THE GRADIENT WILL INCREASE TO A HEALTHY 15-20 KNOTS. THE
LATEST MEDIUM RANGE GUIDANCE HAS SLOWED THE PROGRESSION OF THE
FRONT EVER SO SLIGHTLY SO A WIND SHIFT IS NOT IN THE EXTENDED
FORECAST. SIGNIFICANT SEAS WILL FOLLOW THE WIND FIELDS FROM 2-3
FEET INITIALLY TO 2-5 LATER IN THE PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...REK/JDW
SHORT TERM...MJC
LONG TERM...SHK
AVIATION...MRR
MARINE...MJC/REK/JDW/SHK
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
234 PM EDT TUE MAY 7 2013
.SYNOPSIS...
A SLOW MOVING UPPER LEVEL STORM SYSTEM WILL BRING A CHANCE OF
SHOWERS AND A FEW THUNDERSTORMS THROUGH WEDNESDAY. HIGH PRESSURE
BUILDING IN BEHIND THIS SYSTEM THURSDAY AND FRIDAY WILL BRING
WARMER AND DRIER CONDITIONS. SHOWERS MAY RETURN THIS WEEKEND AS
A COLD FRONT MOVES SLOWLY ACROSS THE REGION. A LARGE AREA OF DRY
HIGH PRESSURE EARLY NEXT WEEK WILL BRING A COOLING TREND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM TUESDAY...POTENT AND SLOW-MOVING UPPER LOW WILL HELP
SPAWN WIDESPREAD SHOWERS WITH ISOLATED THUNDERSTORMS THIS AFTN. WV
IMAGERY CURRENTLY SHOWS EXPANSIVE...NEARLY STATIONARY...UPPER LOW
CENTERED ACROSS THE UPSTATE OF SC INTO CENTRAL NC. WHILE THIS LOW
SPINS AND MOVES VERY SLOWLY E/NE...A PIECE OF VORT ENERGY WILL MOVE
OVERHEAD THROUGH THIS EVE. THE COMBINATION OF THE VORT
IMPULSE...SURFACE HEATING...AND STEEP ML LAPSE RATES WILL ALLOW FOR
THE DEVELOPMENT OF SHOWERS AND THUNDERSTORMS THROUGH NIGHTFALL.
KLTX RADAR ATTM HAS A FEW CELLS BEGINNING TO DEVELOP...BUT ACTIVITY
HAS BEEN WEAK AND SPORADIC THUS FAR TODAY. EXAMINATION OF NAM BUFR
SOUNDINGS SUGGESTS A SLIGHTLY WARMER MID-LAYER THAT DEVELOPED WITHIN
CLOUD COVER...WHICH HAS SOMEWHAT SUPPRESSED THE ABILITY FOR SURFACE
PARCELS TO RISE. HRRR/RUC/NAM12 ALL SUGGEST LAPSE RATES STEEPENING
THROUGH THE EVE...WHICH IS SUPPORTED BY THE CLOSER PROXIMITY OF THE
UPPER LOW AS IT DRIFTS NE. 500MB TEMPS OF -22C WILL IMPINGE ON THE
WEST AND NW ZONES...STEEPENING THE 800-500MB LR`S TO AROUND 7C/KM.
THIS PROVIDES THE IMPETUS FOR INCREASING INSTABILITY IN THE FORM OF
SBCAPE TO AROUND 500 J/KG...AND -10C TO -30C CAPE TO 200-300 J/KG.
WITH FREEZING LEVELS ONLY AROUND 7000 FT...ANY STORM (AND EVEN MANY
SHOWERS) WILL HAVE THE CAPABILITY TO PRODUCE SMALL HAIL EVEN FROM
UPDRAFTS NOT USUALLY CONSIDERED VERY ROBUST.
THERE HAS BEEN MUCH TALK INTERNALLY ABOUT THE SIMILARITIES BETWEEN
THIS EVENT AND THAT OF MARCH 25, 2012...WHEN 17 STATEMENTS AND 3
WARNINGS WERE ISSUED FOR HAIL. WHILE THE GENERAL ENVIRONMENT IS
ABOUT THE SAME...SURFACE TEMPS THAT DAY WERE WARMER...WHICH CREATED
STEEPER LOW AND MID-LEVEL LAPSE RATES. STILL...HIGH RES GUIDANCE
SUGGESTS SCATTERED-TO-NUMEROUS SHOWERS/STORMS THIS AFTN...ANY OF
WHICH COULD PRODUCE SMALL HAIL. HAVE CONTINUED TO INDICATE SMALL
HAIL IN WX GRIDS...WITH HIGHEST POP IN THE NW ZONES CLOSEST TO THE
UPPER LOW CENTER.
SO FOR THE REST OF THE DAYLIGHT HOURS...WE WILL SEE INCREASING
COVERAGE OF CONVECTION WITH SMALL HAIL...AND TEMPS FLUCTUATING
WILDLY WITHIN SHOWERS. HIGHS WILL AVERAGE AROUND 70
DEGREES...WARMEST IN THE NORTHERN ZONES.
AFTER NIGHTFALL CLOUD COVER AND CONVECTION WILL WANE WITH LOSS OF
HEATING...AND BY MIDNIGHT THERE SHOULD BE NOTHING LEFT BUT SCT
DEBRIS CLOUDINESS...AND HAVE QUICKLY DROPPED POP TO SILENT AT THAT
TIME. WITH A WEAK PRESSURE GRADIENT AND IMPROVING SKY COVER...DECENT
RADIATIONAL COOLING WILL OCCUR AND HAVE SHOWN MINS IN THE LOW
50S...SLIGHTLY BELOW GUIDANCE. HAVE CONTINUED PATCHY FOG ACROSS THE
AREA AS WELL...AS TD/S WILL RISE TODAY AND SOME MOISTENING WILL
OCCUR FROM THE SHOWERS.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 3 PM TUESDAY...COOL POOL ALOFT ASSOCIATED WITH AN EXPANSIVE
UPPER LOW WILL BE DRIFTING NORTH OVER THE NC/VA BORDER AT DAYBREAK
WEDNESDAY...BUT WILL CONTINUE TO PROVIDE FAVORABLE LAPSE RATES FOR
ISOLATED TO SCATTERED CONVECTION. SEVERAL IMPULSES ALOFT CAUGHT IN
THE WESTERN PERIPHERY OF THIS FEATURE...WILL MOVE EAST ACROSS OUR
FORECAST AREA WEDNESDAY...HELPING TO ENHANCE CONVECTIVE FORMATION.
OVERALL QPF VALUES WILL REMAIN LOW AS THE BULK OF RAIN GENERATION
RESIDES NORTH OF THE AREA.
AS THE UPPER CIRCULATION PULLS INTO SOUTHERN NEW ENGLAND THURSDAY
DRY AIR FROM THE W-NW WILL OVERSPREAD THE FORECAST AREA...AND THIS
SHOULD EFFECTIVELY REMOVE OR GREATLY REDUCE PROBABILITY OF PCPN AND
NO MENTIONABLE POP VALUES ARE PLANNED FOR THURSDAY.
AS THE COOL POOL ALOFT GRADUALLY LOOSENS ITS INFLUENCE OVER THE
FORECAST AREA...AND HEIGHTS REBOUND TO MORE NORMAL LEVELS...WE WILL
SEE A GRADUAL WARMING TREND WED AND THU. MEANWHILE IN PART DUE TO
GOOD RADIATIONAL COOLING AND RESIDUALLY COOL AIR OVER THE REGION
INITIALLY...MORNING LOW WILL REMAIN BELOW NORMAL FOR EARLY MAY.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 3 PM TUESDAY...MEDIUM RANGE GUIDANCE REMAINS RELATIVELY
CONSISTENT WITH AN INITIAL SOUTHWESTERLY MID LEVEL PATTERN
TRANSITIONING TO DEEP TROUGHING BY THE END OF THE PERIOD. THIS
DRAMATIC PATTERN CHANGE WILL RESULT IN DRAMATIC CHANGES IN THE
SENSIBLE WEATHER ELEMENTS AS WELL.
FRIDAY REMAINS WARM AND RELATIVELY DRY ALTHOUGH SEA BREEZE
CONVECTION WARRANTS A CONTINUATION OF SLIGHT CHANCE POPS. SATURDAY
AND SUNDAY POPS RISE QUITE A BIT AS THE SLOW MOVING COLD
FRONT...COURTESY OF THE DEVELOPING MID LEVEL TROUGH STARTS MOVING
CLOSER. GUIDANCE HAS SLOWED SLIGHTLY WITH THE FRONT MOVING ACROSS
THE AREA LATE SUNDAY. TIMING APPEARS CONDUCIVE FOR GOOD INSTABILITY
WITH DECENT FORCING FOR POPS ALONG THE COAST AT LEAST AT THIS POINT.
A SECONDARY VORT EMBEDDED IN THE FLOW SLOWS THE PROGRESSION OF THE
FRONT AND WARRANTS AT LEAST SLIGHT CHANCE POPS INTO MONDAY ALONG THE
COAST.
TEMPERATURE TRENDS REMAIN IN PLACE WITH WARM READINGS EARLY TRENDING
DOWN WITH THE INCREASE IN MOISTURE AND FINALLY BELOW NORMAL AT THE
END OF THE PERIOD WITH TEMPERATURES APPROACHING TWO CATEGORIES BELOW
NORMAL.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
AS OF 18Z...SOME SHOWER ACTIVITY HAS ALREADY MOVED ACROSS THE AREA
THIS MORNING...AND MORE SHOWERS/ISO TSTMS ARE EXPECTED THIS AFTN.
LATEST HRRR RUN SUGGESTS PCPN COVERAGE WILL BE WIDELY SCATTERED THRU
THE AFTERNOON HOURS...SO HAVE INCLUDED PREVAILING VCSH FOR ALL TERMS
WITH TEMPO -SHRA INTO EARLY EVENING. VFR SHOULD PREVAIL WITH SHORT
PERIODS OF MVFR/IFR POSSIBLE IN HEAVIER SHOWERS/TSTMS. TSTMS MAY BE
CAPABLE OF PRODUCING SMALL HAIL WITH THE ABNORMALLY COLD AIR ALOFT.
RAIN CHANCES DIMINISH TONIGHT AND THE WINDS WILL BECOME LIGHT/CALM
DUE TO THE WEAK SFC PRESSURE GRADIENT. DEPENDING ON HOW MUCH CLOUD
COVER LINGERS OVERNIGHT...PATCHY FOG COULD BE AN ISSUE TMRW MORNING.
CONFIDENCE IS LOW ATTM...BUT HAVE INCLUDED MVFR VSBYS FOR OUR
FOG-PRONE TERMINALS.
EXTENDED OUTLOOK...SLIGHT CHANCE OF SHOWERS WEDNESDAY. MORNING FOG
POSSIBLE THURSDAY AND FRIDAY. CHANCE OF SHOWERS SATURDAY AND SUNDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM TUESDAY...WEAK PRESSURE GRADIENT IN THE VICINITY OF A
DIFFUSE AREA OF LOW PRESSURE...IS KEEPING LIGHT S/SW WINDS ACROSS
THE WATERS TODAY. ALTHOUGH WIND WAVE CONTRIBUTION IS LIMITED DUE TO
THESE LIGHT WINDS...A COMBINATION OF A 3FT/7SEC SE SWELL...AND
3FT/11SEC EAST SWELL WILL KEEP SEAS AT 2-4 FT THROUGH THE NEAR TERM
PERIOD. WHILE WIND/WAVE CONDITIONS WILL BE RELAXED...SCATTERED
SHOWERS AND THUNDERSTORMS ARE LIKELY INTO TONIGHT. THESE STORMS
COULD IMPACT ANY MARINE INTERESTS...CREATING BRIEF PERIODS OF HEAVY
RAINFALL...GUSTY WINDS...AND EVEN SOME SMALL HAIL.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 3 PM TUESDAY...MANAGEABLE MARINE CONDITIONS THIS PERIOD WITH
LIGHT TO MODERATE SW WINDS PREVAILING BOTH DAYS...AS LOW PRESSURE
INLAND TRACKS TO THE NORTH AND HIGH PRESSURE REMAINS OFFSHORE.
THE SEA SPECTRUM WILL BE COMPRISED OF A LIGHT TO MODERATE SW CHOP
ACCOMPANIED BY 2-3 FT SE WAVES IN 7-8 SECONDS INTERVALS. A FOOT
OR LESS OF LONG PERIOD E WAVES WILL ALSO BE IN THE MIX WITH WAVE
PERIODS AROUND 11-12 SECONDS.
LONG TERM /FRIDAY THROUGH SATURDAY/...
AS OF 3 PM TUESDAY...EXPECT MODEST SOUTHWEST WINDS INITIALLY IN
A RANGE OF 10-15 KNOTS. WITH A FRONT MOVING CLOSER SATURDAY AND
SUNDAY...THE GRADIENT WILL INCREASE TO A HEALTHY 15-20 KNOTS. THE
LATEST MEDIUM RANGE GUIDANCE HAS SLOWED THE PROGRESSION OF THE
FRONT EVER SO SLIGHTLY SO A WIND SHIFT IS NOT IN THE EXTENDED
FORECAST. SIGNIFICANT SEAS WILL FOLLOW THE WIND FIELDS FROM 2-3
FEET INITIALLY TO 2-5 LATER IN THE PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...JDW
SHORT TERM...MJC
LONG TERM...SHK
AVIATION...BJR/JDW
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
122 PM EDT TUE MAY 7 2013
.SYNOPSIS...
A SLOW MOVING STORM SYSTEM WILL IMPACT THE AREA INTO WEDNESDAY
BRINGING A RISK OF SHOWERS AND SOME THUNDERSTORMS. HAIL IS
POSSIBLE THIS AFTERNOON. WEAK HIGH PRESSURE WILL BUILD IN BEHIND
THIS SYSTEM THURSDAY AND FRIDAY. WARM AND DRY CONDITIONS ARE
EXPECTED LATE WEEK. SHOWERS MAY RETURN DURING THE WEEKEND AHEAD OF
A COLD FRONT. A LARGE AREA OF DRY HIGH PRESSURE EARLY NEXT WEEK
WILL BRING COOLER TEMPERATURES BACK INTO THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1020 AM TUESDAY...THE LARGE CUTOFF LOW PRESSURE OVER THE
EASTERN UNITED STATES CONTINUES TO IMPACT THE THE REGIONS WEATHER.
WATER VAPOR IMAGERY SHOWS A SHORT-WAVE TROUGH ROTATING NORTHWARD
ON THE SOUTHEAST PORTION OF THE LOW. THIS LIFTING MECHANISM WITH
VERY COOL TEMPERATURES ALOFT WILL PROVIDE FOR ACTIVE WEATHER LATE
THIS MORNING INTO THE EVENING. THE COOL TEMPERATURES ALOFT ARE
SEEN IN THE CHARLESTON SOUNDING THIS MORNING WITH -19C AT 500 MB
AND 5C AT 850 MB. THE 850MB TEMPERATURE AT CHARLESTON IS 2
STANDARD DEVIATIONS BELOW NORMAL. SO IF THE 400-500 JOULE PER
KILOGRAM CAPE CAN BE ESTABLISHED THEN THERE IS A GOOD CHANCE FOR
SOME SMALL HAIL THIS AFTERNOON.
THE COVERAGE OF CONVECTION THIS MORNING IS FAIRLY WIDESPREAD AND
MOVING NORTHWARD INTO THE WESTERN COUNTIES. THE PREVIOUS FORECAST
OF WIDE SPREAD SHOWERS AND ISOLATED THUNDERSTORMS IS TRENDING IN
THE CORRECT DIRECTION.
...FROM PREVIOUS DISCUSSION
TONIGHT...WITH LOSS OF HEATING...LINGERING CONVECTION SHOULD
SLOWLY COME TO AN END AND WILL DROP POPS BELOW THRESHOLD BY/AROUND
MIDNIGHT. CLOUD COVER SHOULD BECOME MORE PATCHY IN
NATURE...ALLOWING A WIDENING WINDOW OF OPPORTUNITY FOR TEMPS TO
DROP GIVEN THE UNCHARACTERISTICALLY LOW DEW POINTS. PATCHY FOG MAY
DEVELOP TOWARD MORNING. WILL FORECAST LOWS AROUND 50 DEGREES FOR A
LARGE PORTION OF THE AREA WITH LOWER TO MID 50S MORE COMMON ALONG
THE IMMEDIATE COAST.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 3 AM TUESDAY...AS THE CUTOFF UPPER LOW FINALLY GOES
PINWHEELING OFF THE THE NORTH AWAY FROM THE REGION A DRYING TREND
WILL BE UNDERWAY. SLIGHT CHANCE POPS MAINLY FOR NRN AND WRN ZONES AS
A LITTLE WRAP AROUND MOISTURE PAIRED THE STILL RELATIVELY COOL AIR
ALOFT COULD TOUCH OFF ISO CONVECTION. CLOUDS MAY BE SLOW TO DECREASE
DUE TO THE SLOW MOVEMENT OF THE SYSTEM FOR MUCH OF THE DAY BUT DRY
AIR ADVECTION AND DOWNSLOPING BOTH WELL UNDERWAY BY NIGHTTIME. THE
DRYING AND WARM ADVECTION WILL BRING A SUNNY AND SEASONABLE THURSDAY
AFTERNOON WITH LIGHT SW WINDS EVEN THE COOLING SEABREEZE SHOULD NOT
MAKE IT FAR INLAND AND ONLY TEMP TEMPS DOWN A LITTLE ALONG THE
IMMEDIATE COAST.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 3 AM TUESDAY...FAIRLY FLAT MID LEVEL FLOW IN PLACE ON FRIDAY
ALTHOUGH SEVERAL WEAK SHORTWAVES WILL BE MOVING THROUGH. ISOLATED
CONVECTION TOUGH TO RULE OUT MAINLY ALONG SEABREEZE. FLOW MAY BECOME
A LITTLE MORE CYCLONIC ON SATURDAY AHEAD OF DEEPENING TROUGH IN THE
GREAT LAKES. PIEDMONT TROUGH/WEAK FRONT ALSO DEVELOPING AND MAY
PROVIDE FOCUS FOR CONVECTIVE INTI. UPPER TROUGH CONTINUES TO DEEPEN
SAT NIGHT INTO SUNDAY AND FRONT BEGINS TO ACCELERATE...MOVING
THROUGH THE COAST EARLY SUNDAY. A PUSH OF COOLER AIR WILL BE ON THE
HEELS OF THIS SYSTEM FOR LATER SUNDAY AND MONDAY.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
AS OF 18Z...SOME SHOWER ACTIVITY HAS ALREADY MOVED ACROSS THE AREA
THIS MORNING...AND MORE SHOWERS/ISO TSTMS ARE EXPECTED THIS AFTN.
LATEST HRRR RUN SUGGESTS PCPN COVERAGE WILL BE WIDELY SCATTERED THRU
THE AFTERNOON HOURS...SO HAVE INCLUDED PREVAILING VCSH FOR ALL TERMS
WITH TEMPO -SHRA INTO EARLY EVENING. VFR SHOULD PREVAIL WITH SHORT
PERIODS OF MVFR/IFR POSSIBLE IN HEAVIER SHOWERS/TSTMS. TSTMS MAY BE
CAPABLE OF PRODUCING SMALL HAIL WITH THE ABNORMALLY COLD AIR ALOFT.
RAIN CHANCES DIMINISH TONIGHT AND THE WINDS WILL BECOME LIGHT/CALM
DUE TO THE WEAK SFC PRESSURE GRADIENT. DEPENDING ON HOW MUCH CLOUD
COVER LINGERS OVERNIGHT...PATCHY FOG COULD BE AN ISSUE TMRW MORNING.
CONFIDENCE IS LOW ATTM...BUT HAVE INCLUDED MVFR VSBYS FOR OUR
FOG-PRONE TERMINALS.
EXTENDED OUTLOOK...SLIGHT CHANCE OF SHOWERS WEDNESDAY. MORNING FOG
POSSIBLE THURSDAY AND FRIDAY. CHANCE OF SHOWERS SATURDAY AND SUNDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1020 AM TUESDAY...THE LAND BREEZE STILL IS SEEN ACROSS THE
NEAR SHORE WATERS WITH A WESTERLY WIND. AS THE LAND BREEZE BREAKS
DOWN THE WINDS WILL RETURN TO A MORE SOUTH TO SOUTHWEST FLOW AND
THE WINDS SPEEDS ARE EXPECTED TO REMAIN IN 10 KNOT RANGE WITH SEAS
CONTINUING TO SUBSIDE TO THE 2 TO 3 FEET RANGE BY AFTERNOON.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 3 AM TUESDAY...A QUIET AND FAIRLY UNCHANGING SET OF CONDITIONS
IN PLACE THROUGH THE PERIOD. WIND TO REMAIN OUT OF THE SW DUE TO THE
NE EXIT AND DISSIPATION OF LOW PRESSURE. ONCE THIS SYSTEM IS OUT OF
THE PICTURE ONLY A WEAK SW GRADIENT ON THE FAR PERIPHERY OF CENTRAL
ATLANTIC HIGH PRESSURE REMAINS. SEAS 2 TO 3 FT ON AVERAGE OVER MOST
ZONES COMPRISED OF SW WIND WAVE AND SE SWELL.
LONG TERM /FRIDAY THROUGH SATURDAY/...
AS OF 3 AM TUESDAY...JUST AS WITH THE SHORT TERM A SOUTHWEST WIND IS
EXPECTED FOR THE DURATION OF THE PERIOD. IN CONTRAST TO THE SHORT
TERM HOWEVER WIND SPEED WILL BE ON THE INCREASE ESPECIALLY DURING
THE SECOND HALF. ON FRIDAY THE HIGH PRESSURE IN THE ATLANTIC WILL
STILL BE VERY DISTANT BUT THE PRESSURE GRADIENT LOCALLY MAY GET A
SMALL BOOST BY A WEAK PIEDMONT TROUGH. THE APPROACH OF A COLD FRONT
ON SATURDAY WILL BRING A MORE PRONOUNCED INCREASE IN WIND
SPEED...ONE THAT WILL BE MORE EFFECTIVE IN BUILDING WAVE
HEIGHTS...POSSIBLY TO WHERE SCEC HEADLINES ARE NEEDED EVEN ONLY IF
LATE IN THE DAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HAWKINS
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...BJR/JDW
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
154 PM EDT TUE MAY 7 2013
.SYNOPSIS...
AN UPPER LEVEL LOW OVER THE WESTERN CAROLINAS WILL SLOWLY DRIFT
NORTHEAST REACHING THE MID ATLANTIC REGION ON WEDNESDAY. WEAK HIGH
PRESSURE WILL THEN FILL IN BEHIND THE UPPER LOW THURSDAY AND BRING
SEASONAL TEMPERATURES BACK TO THE REGION THROUGH FRIDAY. ANOTHER
COLD FRONT WILL MOVE THROUGH THE CAROLINAS FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
1000 AM UPDATE...LOWERED POPS THIS MORNING...BUT KEPT SCHC POPS IN
MUCH OF THE MTNS AND NEAR ACTIVITY N AND SE OF THE CWFA WHERE
ENHANCED CU DEVELOPMENT NOTED. LATEST RAP REFLECTIVITY FCSTS SHOW
WIDESPREAD CONVECTIVE DEVELOPMENT BY MIDDAY BUT WITHOUT SUFFICIENT
DBZ TO EXPECT THUNDER IN THAT SCENARIO. 09Z SREF SHOWS HIGH PROBS OF
250 J CAPE BUT LOW PROBS OF 500 J. HAVE GOOD CONFIDENCE IN HIGH CHC
POPS FOR MOST PLACES WITH LOW LKLYS IN THE MTNS. DID MAINTAIN A TSTM
MENTION...BUT BACKED OFF PROBABILITY AND DELAYED ONSET OF THUNDER BY
A COUPLE HOURS TO ALLOW FIGURATIVE CU TO GROW.
CLOSED UPPER LOW CENTER...CURRENTLY PIVOTING ESE INTO GA...WILL BE
THE SYNOPTIC SCALE FEATURE OF INTEREST AS IT WOBBLES EAST ATOP THE
CWFA TODAY AND TOWARD THE VA PIEDMONT LATER TONIGHT. CLOSER TO THE
TRACK OF IT/S WEAK SFC REFLECTION...SHOWER CHANCES WILL BE GREATEST
THIS MORNING ACRS THE GA/SC PIEDMONT...BUT EXPAND AS THE DAY WEARS
ON WITHIN THE DEVELOPING WEAK INSTABILITY UNDER MID-LVL COOL POOL/
UPPER LOW CENTER. SHOWERS AND A FEW THUNDERSTORMS SHOULD BECOME
NUMEROUS THIS AFTERNOON...BUT WITH FCST SNDGS PROGGING JUST A THIN
AREA OF CAPE...WOULD BELIEVE EVEN THE TALLEST STORMS WOULD STRUGGLE
TO PRODUCE EVEN SMALL HAIL DESPITE THE LOW WBZ HEIGHTS. FOR MAX TEMPS
TODAY...HAVE MADE LITTLE MORE THAN TWEAKS TO THE INHERITED COOL
NUMBERS...ABOUT 8-10 DEG F BELOW CLIMO. DEEP CONVECTIVE CHANCES
SHOULD DIMINISH THIS EVENING WITH LOSS OF HTG...BUT THE POTENTIAL
FOR REDEVELOPMENT OF SHOWERS WITHIN DEFORMATION ZONE EXISTS
TONIGHT...ESPECIALLY ACRS W NC.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
AS OF 315 AM TUESDAY...THE UPPER LOW WILL FINALLY SPIN AWAY TO THE
NORTHEAST ACROSS THE MID ATLANTIC REGION ON WEDNESDAY. RESIDUAL LOW
LEVEL MOISTURE AND COOLER AIR ALOFT SHOULD BE ENOUGH TO PROVIDE FOR
SOME INSTABILITY WITH DAYTIME HEATING WHILE THE ATMOSPHERE REMAINS
GENERALLY FAVORABLE FOR CONVECTION. A CHANCE OF SHOWERS AND SOME
THUNDERSTORMS STILL LOOKS LIKE A DECENT BET FOR WEDNESDAY
AFTERNOON...WITH SOME OF THAT ACTIVITY PERSISTING INTO THE EVENING.
TEMPS SHOULD REBOUND NICELY...BUT STILL BELOW NORMAL...WITH
ADDITIONAL SUN IN THE AFTERNOON.
AS THE UPPER LOW MOVES AWAY WEDNESDAY NIGHT AND THURSDAY...SOME
UPPER RIDGING WILL MOVE IN FROM THE WEST. THAT SHOULD PROVIDE FOR A
RELATIVELY QUIET PERIOD AS WEAK HIGH PRESSURE MOVES IN. THURSDAY
WILL NOT BE AS FAVORABLE FOR CONVECTION AS LOW LEVELS SHOULD BE
SOMEWHAT DRIER. THUS...HAVE LIMITED THE PRECIP CHANCES TO SLIGHT AND
MAINLY OVER THE MTNS AND FOOTHILLS. TEMPS WILL FINALLY MAKE IT BACK
TO NEAR NORMAL AND WE SHOULD CONTINUE TO DRY OUT.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 225 PM MONDAY...THE WET PATTERN WILL CONTINUE INTO THE EARLY
PART OF THE MEDIUM RANGE...AS A COLD FRONT ASSOCIATED WITH OHIO/MISS
VALLEY HEIGHT FALLS APPROACHES THE EASTERN STATES DURING LATE WEEK.
THIS WILL ENHANCE DIURNAL CONVECTIVE CHANCES ON FRIDAY...AND POPS IN
THE 30-50 PERCENT RANGE WILL BE ADVERTISED DURING THIS TIME. MUCH
MORE SUBSTANTIAL HEIGHT FALLS WILL OCCUR ACROSS THE EASTERN CONUS
OVER THE WEEKEND...CARVING OUT A MAJOR EASTERN TROUGH BY THE END OF
THE PERIOD. THIS WILL DRIVE A MORE SIGNIFICANT FRONTAL BOUNDARY INTO
THE REGION...SUPPORTING 50/60 POPS ACROSS THE FORECAST AREA BY
SATURDAY AFTERNOON...WITH HEALTHY POPS CONTINUING INTO SUNDAY.
TEMPERATURES SHOULD GENERALLY AVERAGE NEAR NORMAL THROUGH SUNDAY.
A MODEL CONSENSUS STRONGLY SUGGESTS THAT THE COLD FRONT WILL SWEEP
EAST OF THE AREA BY DAY 7...INTRODUCING MUCH COOLER AND (FINALLY)
DRIER AIR. POPS WILL TAPER DOWN TO SLIGHT CHANCE AT BEST BY DAY
7...WHILE TEMPERATURES WILL COOL WELL BELOW NORMAL IN A REGIME
CHARACTERIZED BY ANOMALOUSLY LOW HEIGHTS ALOFT.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
AT KCLT...DESPITE CONVECTIVE DEVELOPMENT WELL SOUTH OF THE FIELD
LITTLE LIGHTNING SEEN WITH ACTIVITY IN THAT AREA...SO THUNDER
CHANCES APPEAR TOO SMALL TO MENTION. INCLUDED MVFR SHRA IN A TEMPO
FOR NOW AND WILL WATCH TRENDS. CONVECTION AND SHOWER CHANCES WILL
DIMINISH BY SUNSET. MIDLEVEL MOISTURE INCREASES SOMEWHAT OVERNIGHT
BUT GUIDANCE KEEPS CIGS VFR...AND DESPITE HIGH SFC RH PROFILES ARE
UNFAVORABLE FOR FOG. SIMILAR TOMORROW IN THAT A FAIR AMOUNT OF
CONVECTION EXPECTED IN THE AREA...THOUGH CONDITIONS WILL BE A LITTLE
MORE STABLE. CHANCES WARRANT A PROB30 -SHRA AT THIS POINT.
ELSEWHERE...SCT TO NUMEROUS SHOWERS WILL CONTINUE THIS AFTERNOON
THOUGH THUNDERSTORMS WILL REMAIN ISOLATED. HIGHEST CHANCES IN BETTER
LLVL FORCING ALONG THE NRN BLUE RIDGE. VFR CIGS EXCEPT PERHAPS BRIEF
PERIODS OF MVFR IN HEAVIER SHOWERS. THINGS QUIET DOWN BY EVENING AS
DIURNAL INSTABILITY WANES. UPPER LEVEL IMPULSE EXPECTED TO REDEVELOP
SOME SHOWERS AS MIDLEVEL MOISTURE ARRIVES LATE...BUT THESE WILL
MAINLY AFFECT THE NW HALF OF THE AREA. KHKY AND KAVL LIKELY TO SEE
RESTRICTIONS AGAIN AS THEY DID THIS MORNING...BUT THINK THE MID
CLOUDS AND MVFR CIGS WILL PREVENT FOG DEVELOPMENT. EXPECT SOME
ISOLD/SCT CONVECTION AROUND THE AREA BY MIDDAY WED...THOUGH CHANCES
TOO LOW TO MENTION WITH THIS PACKAGE.
OUTLOOK...A MID LEVEL LOW WILL MOVE NORTHWARD OUT OF THE REGION
MIDWEEK ALLOWING FOR A BRIEF PERIOD OF MORE SETTLED WEATHER BY
THURSDAY. AFTERNOON SHOWERS AND THUNDERSTORM CHANCES WILL RETURN BY
FRIDAY.
CONFIDENCE TABLE...
18-24Z 00-06Z 06-12Z 12-18Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 94% HIGH 88% HIGH 100%
KHKY HIGH 100% HIGH 100% MED 71% HIGH 87%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 97% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...PAT
NEAR TERM...CSH/WIMBERLEY
SHORT TERM...PM
LONG TERM...JDL
AVIATION...WIMBERLEY
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
1250 PM CDT TUE MAY 7 2013
.AVIATION...
FOR THE 18Z TAFS...VFR CONDITIONS AND SOUTH FLOW ARE EXPECTED
THROUGH THE VALID FORECAST PERIOD.
IN GENERAL...RELATIVELY DRY AIR IN PLACE WILL BE THE PRIMARY
REASON VFR CONDITIONS HOLD OVER THE NEXT 24 TO 30 HRS. LEE SIDE
TROUGHING WILL PERSIST THROUGH THE PERIOD WHICH WILL KEEP WINDS IN
A GENERAL SOUTHERLY DIRECTION WITH A WEAK PRESSURE GRADIENT
SUPPORTING WIND SPEEDS BELOW 15 KTS.
FORECAST CONCERNS NOT MENTIONED IN THE TAFS INCLUDE STRATUS
CHANCES TOMORROW MORNING AND THUNDERSTORM CHANCES LATE THIS
AFTERNOON AND WEDNESDAY AFTERNOON.
STRATUS...THE NAM BRINGS A SURGE OF LOW-LEVEL RH UP THROUGH WACO
BY EARLY TOMORROW MORNING AND FORECAST SOUNDINGS SEEM TO SUPPORT
IFR STRATUS AFTER 11Z. THE RAP AND GFS ARE NOWHERE NEAR AS
AGGRESSIVE WITH THIS MOISTURE SURGE NEAR WACO TONIGHT...SO LEFT
STRATUS OUT OF THE KACT TAF AT THIS TIME. THE NAM WAS AGGRESSIVE
WITH SHALLOW MOISTURE RETURN LAST NIGHT AS WELL AND NO STRATUS
DEVELOPED. SOMETHING TO WATCH FOR IN FUTURE TAFS...BUT CONFIDENCE
IN VFR CONDITIONS IS FAIRLY HIGH AT THIS TIME.
THUNDERSTORM CHANCES...THUNDERSTORMS WILL LIKELY DEVELOP ALONG THE
DRYLINE ACROSS WEST TX THIS AFTERNOON OR EVENING. THESE STORMS ARE
NOT EXPECTED TO MOVE OVER ANY AREA TAF SITE THROUGH TONIGHT. THESE
STORMS WILL LIKELY SEND A BROKEN OR OVERCAST DECK OF CLOUDS AOA
15000 FT THIS EVENING...BUT THIS IS A VFR CIG...SO DID NOT PLACE A
CHANGE GROUP IN THE TAFS TO ACCOUNT FOR THIS. STORMS MAY GET
CLOSER TO DFW AREA TAF SITES WEDNESDAY EVENING AS STORMS PULL OFF
THE DRYLINE ONCE AGAIN...HOWEVER THIS WOULD LIKELY OCCUR AFTER 00Z
OR BEYOND THE DFW EXTENDED TAF.
CAVANAUGH
&&
.UPDATE...
LIGHT PRECIPITATION ASSOCIATED WITH A WEAK DISTURBANCE OVER THE
PLAINS CONTINUES TO SHOW UP ON RADAR OVER SOUTHWEST OKLAHOMA AND
NORTHWEST TEXAS. MEANWHILE UPPER LEVEL RIDGING OVER TEXAS
CONTINUES TO SHUT DOWN THIS PRECIP AS IT ATTEMPTS TO MOVE
SOUTHEAST INTO OUR NORTHERN COUNTIES. THERE MAY STILL BE A
SPRINKLE OR TWO OVER THE NORTHERN-MOST COUNTIES LATE THIS
MORNING...OTHERWISE MOSTLY SUNNY SKIES AND LIGHT SOUTH WINDS CAN
BE EXPECTED ACROSS THE REGION.
SOME OF THE LATEST HIGH-RESOLUTION GUIDANCE INDICATES STORM
DEVELOPMENT LATE THIS AFTERNOON AND THIS EVENING OVER WEST TX
AS A SUBTLE SHORTWAVE PROPAGATES ACROSS THE AREA...WITH SOME OF
THE ACTIVITY APPROACHING THE FAR NORTHWESTERN COUNTIES THIS
EVENING. WILL LEAVE POPS ALONE FOR NOW BUT WILL KEEP OPEN THE
POSSIBILITY OF ADDING LOW POPS NORTHWEST OF THE METROPLEX IN THE
AFTERNOON PACKAGE IF ADDITIONAL MODEL DATA SUPPORTS IT. FOR NOW
THE THOUGHT IS THAT THE RIDGE WILL TEND TO PREVENT CONVECTION
FROM REACHING NORTH TEXAS THIS AFTERNOON AND EVENING. IT STILL
LOOKS LIKE OUR BEST RAIN CHANCES WILL BE THURSDAY NIGHT AND
FRIDAY.
30
&&
.PREV DISCUSSION... /ISSUED 401 AM CDT TUE MAY 7 2013/
SCATTERED SHOWERS AND THUNDERSTORMS CONTINUE TO DEVELOP ACROSS
WEST TEXAS AND WEAKEN AS THEY APPROACH THE FORECAST AREA. GIVEN
HOW DRY IT IS IN THE LOWER 5000-6000 FEET...BELIEVE THAT JUST
LEAVING SOME SPRINKLES IN WILL SUFFICE SO WILL KEEP 10 PERCENT
POPS AND MENTION SOME SPRINKLES FOR THIS MORNING SOUTHWEST OF A
JACKSBORO TO WAXAHACHIE TO ATHENS LINE. OTHERWISE...DESPITE THE
MID AND HIGH CLOUDS...TEMPERATURES WILL WARM IN THE 80S ACROSS
MOST OF THE FORECAST AREA. WE WILL SEE AT OR ABOVE SEASONAL NORMAL
TEMPERATURES FOR THE NEXT SEVERAL DAYS.
AS THE UPPER LEVEL LOW CURRENTLY OVER CENTRAL/SOUTHERN CALIFORNIA
MOVES EAST TOWARD THE CENTRAL PLAINS...THERE WILL BE A CHANCE OF
SHOWERS AND THUNDERSTORMS TOMORROW AFTERNOON/EVENING MAINLY ALONG
AND WEST OF A BOWIE TO GOLDTHWAITE LINE AS DRYLINE ACTIVITY MOVES
EAST/NORTHEAST. A FEW OF THESE STORMS WILL BE CAPABLE OF
PRODUCING LARGE HAIL. A LOW CHANCE OF SHOWERS AND THUNDERSTORMS
WILL EXTEND ACROSS NORTHWESTERN TWO-THIRDS OF THE FORECAST
OVERNIGHT TOMORROW NIGHT.
THE UPPER LOW WILL OPEN UP AS IT MOVES SLOWLY EAST ACROSS THE
CENTRAL PLAINS THURSDAY INTO FRIDAY. AS THE TROUGH MOVES EAST...A
COLD FRONT WILL MOVE SOUTHEAST INTO THE NORTHWESTERN ZONES BEFORE
DAYBREAK FRIDAY AND THROUGH THE SOUTHEAST BY FRIDAY EVENING. WE
WILL SEE A CHANCE OF SHOWERS AND THUNDERSTORMS THURSDAY THROUGH
FRIDAY...WITH A FEW SEVERE STORMS POSSIBLE.
RAIN CHANCES WILL CONTINUE INTO SATURDAY BEHIND THE FRONT BEFORE
THE PRECIPITATION ENDS FROM NORTH TO SOUTH LATE AFTERNOON INTO
SATURDAY NIGHT.
58
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 82 63 85 63 82 / 10 10 10 20 20
WACO, TX 84 60 85 63 82 / 10 10 10 20 20
PARIS, TX 82 58 84 60 81 / 10 10 10 20 20
DENTON, TX 81 61 84 62 83 / 10 10 10 20 20
MCKINNEY, TX 81 60 85 61 83 / 10 10 10 20 20
DALLAS, TX 84 63 87 64 85 / 10 10 10 20 20
TERRELL, TX 82 59 86 61 82 / 10 10 10 20 20
CORSICANA, TX 83 60 86 62 82 / 10 10 10 20 20
TEMPLE, TX 84 60 84 63 81 / 10 10 10 20 20
MINERAL WELLS, TX 84 61 86 62 85 / 10 10 20 20 20
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/