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AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON OH
952 PM EST FRI FEB 27 2015

.SYNOPSIS...
SURFACE HIGH PRESSURE WILL BUILD EAST ACROSS THE REGION OVERNIGHT...
PROVIDING CONTINUED COLD TEMPERATURES. A WARM FRONT WILL DEVELOP
SOUTH OF THE REGION SATURDAY NIGHT AND LIFT NORTH ON SUNDAY. THIS
WILL BE FOLLOWED BY A COLD FRONT SUNDAY NIGHT. THIS SYSTEM WILL
PROVIDE A WINTRY MIX OF PRECIPITATION TO THE OHIO VALLEY. A POTENT
WEATHER SYSTEM IS EXPECTED TO PRODUCE SIGNIFICANT RAINFALL TUESDAY
INTO WEDNESDAY.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
HIGH CLOUDS HAVE OVERSPREAD THE MAJORITY OF THE FORECAST
AREA...AND MID-LEVEL CLOUDS ARE NOT FAR BEHIND OVER INDIANA AND
WESTERN KENTUCKY. WITH SOME CLEAR AREAS IN THE NORTHEASTERN
CWA...AND CLOUDY AREAS ELSEWHERE...THE VARIATION IN TEMPERATURES
ACROSS THE CWA IS ALREADY QUITE LARGE. WITH CLEAR SKIES AND CALM
WINDS...MARYSVILLE IS ALREADY DOWN TO -5 DEGREES (0234Z)...WHILE
THE KENTUCKY MESONET SITE NEAR CARROLLTON IS AT 17 DEGREES (0245Z)
WITH 5 KNOTS OF WIND.

MIN TEMPS WERE ADJUSTED SLIGHTLY UPWARD...WHERE CONFIDENCE EXISTS IN
CLOUDS AND A LITTLE BIT OF WIND (MAINLY THE SOUTHERN AND
SOUTHWESTERN CWA). TEMPERATURES WERE NOT CHANGED IN THE FAR
NORTH...BUT THE RAPID RATE OF RADIATIONAL REDUCTION SHOULD SLOW
DOWN AS CLOUDS MOVE IN.

PREVIOUS DISCUSSION >
BROAD MID LEVEL TROF WITH MUCH BELOW NORMAL HEIGHTS ACROSS THE
EASTERN CONUS. IN WESTERLY FLOW...ARCTIC SFC HIGH WILL BUILD EAST
BECOMING CENTERED OVER EASTERN OHIO BY SAT MORNING. SATELLITE...
OBSERVATIONS AND RADAR CONTINUE TO SHOW SOME LINGERING
FLURRIES...MAINLY ACROSS CENTRAL AND SOUTH CENTRAL OHIO. THESE
FLURRIES SHOULD DIMINISH BY SUNSET.

EXPECT CLOUDS TO DIMINISH THIS EVENING GIVING WAY TO MOSTLY CLEAR
SKY CONDITIONS. SFC HIGH WILL LEAD TO LIGHT WINDS AND WITH SNOW
PACK...VERY GOOD CONDITIONS WILL EXIST FOR RADIATIONAL COOLING.
INCREASING MID/HI LEVEL CLOUDS ENCROACHING INTO THE REGION FROM
THE SOUTH WILL LIKELY KEEP TEMPS UP A BIT THERE. HAVE LOWS RANGING
FROM THE SINGLE DIGITS BELOW ZERO NORTH TO THE SINGLE DIGITS ABOVE
ZERO SOUTH. THIS WILL PUT RECORD LOWS IN JEOPARDY.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
WESTERLY MID LEVEL FLOW WITH SURFACE HIGH PRESSURE BUILDING OFF TO
THE EAST OVER THE MID ATLANTIC STATES BY SATURDAY EVENING. RETURN
FLOW DEVELOP ON BACKSIDE OF RETREATING SFC HIGH PRESSURE. IN WAA
PATTERN EXPECT TO SEE AN INCREASE IN MID/HI LEVEL WAA CLOUDS.
ALTHOUGH TEMPERATURES WILL MODERATE SOME...READINGS WILL REMAIN 15
TO 20 DEGREES BELOW NORMAL. EXPECT HIGHS FROM NEAR 20 NORTH TO THE
LOWER 30S FAR SOUTH. 

FAVORABLE ISENTROPIC LIFT DEVELOPS SATURDAY NIGHT WITH PCPN 
DEVELOPING LATE. BASED ON TRENDS HAVE ONLY SLIGHTLY SLOWED DOWN
ONSET WITH CATEGORICAL POPS INTO WEST CENTRAL OHIO BY SUNDAY
MORNING. THERMAL PROFILES SUGGESTS THAT PRECIPITATION STARTS OUT
AS ALL SNOW WITH A CHANGE FROM THE SOUTH BEGINNING TOWARD SUNRISE
SUNDAY. A PERIOD OF WINTRY MIX...INCLUDING FREEZING RAIN WILL BE
POSSIBLE ACRS THE FAR SOUTH EARLY SUNDAY PRIOR TO TEMP WARMING
ABOVE FREEZING.

EXPECT EARLY LOWS SATURDAY NIGHT FROM THE MID TEENS NORTH
TO THE MID/UPR 20S SOUTH WITH RISING TEMPERATURES OVERNIGHT. 

40-45 KT LLJ DEVELOPS SUNDAY WITH CONTINUED ISENTROPIC LIFT. WEAK
SFC WAVE TO TRACK NE THRU NRN OHIO SUNDAY AFTN. UNDER CONTINUED
WAA EXPECT PCPN TO TRANSITION FROM SNOW TO RAIN FROM SOUTH TO
NORTH. IN THE FAR NW NEVER GO COMPLETELY TO RAIN...KEEPING A
RAIN/SNOW MIX. WITH THE PASSAGE OF THE SFC WAVE A COLD FRONT TO
DROP SE THRU ILN/S FA SUNDAY NIGHT AND PCPN WILL CHANGE BACK TO
SNOW AND DIMINISH FROM THE NW.

STORM TOTAL FCST SNOW RANGES FROM 5 INCHES ACRS THE FAR NW TO LESS
THAN AN INCH SE. EXPECT THAT HEADLINES WILL BE ISSUED AT SOME POINT
FOR THIS SYSTEM. AT THIS TIME HAVE NOT ISSUED A WATCHES...WITH THE
FCST TRENDS BEING WARMER...NOT FORECASTING WARNING CRITERIA AND
CONFIDENCE IN REACHING WARNING THRESHOLD IS NOT HIGH ENOUGH IN THE
5TH PERIOD.

TEMP WISE...SUNDAYS HIGHS TO RANGE FROM THE LOWER 30S NW TO THE
LOWER 40S SOUTH. LOWS SUNDAY NIGHT TO RANGE FROM NEAR 20 NW TO THE
LOWER 30S SE.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
HIGH PRESSURE WILL PROVIDE DRY CONDITIONS ON MONDAY. POTENT LOW 
PRESSURE AND A COLD FRONT WILL AFFECT THE REGION TUESDAY THROUGH 
WEDNESDAY. MODELS INDICATE ABUNDANT MOISTURE ON A SOUTHWEST FLOW 
ALOFT ASSOCIATED WITH THE SYSTEM...SHOWING OVER 300 PERCENT OF 
NORMAL PRECIPITABLE WATER TRANSPORTED BY A 60+ KNOT 850 MB JET. THE 
EXTREMELY MOIST AIRMASS LIFTED ALONG THE WARM CONVEYOR BELT AHEAD OF 
THE LOW IS NEARLY CERTAIN TO PRODUCE PERIODS OF HEAVY PRECIPITATION. 
CURRENT MODEL RUNS INDICATE PRECIP OVERSPREADING THE AREA TUESDAY 
MORNING AND THEN CONTINUING WELL INTO WEDNESDAY AS THE COLD FRONT 
NEARLY PARALLEL TO THE UPPER FLOW TRANSLATES SLOWLY EASTWARD. MODEL 
SOUNDING PROFILES SUGGEST A MIX OF SNOW...SLEET AND FREEZING RAIN TO 
START. A STRONG SURGE OF WARM ADVECTION ON A SOUTHERLY SURFACE FLOW 
SHOULD CHANGE PRECIP TO RAIN BY AROUND NOON TUESDAY. HEAVY RAIN 
FALLING ON A SIGNIFICANT SNOW PACK IS LIKELY TO CAUSE FLOODING 
PROBLEMS THAT MAY FIRST APPEAR WHEN LOCALIZED FLOODING OCCURS IN LOW 
LYING AREAS SUCH AS UNDERPASSES...THEN WHEN RIVER FLOODING ARISES 
AFTER RUNOFF FROM SNOW MELT AND RAINFALL REACHES STREAMS. ALSO 
CANNOT RULE OUT ISOLATED WEAK TORNADOES TUESDAY NIGHT INTO WEDNESDAY 
WITH MODELS SHOWING A FAVORABLE LOW LEVEL SHEAR ENVIRONMENT FOR SPIN 
UPS EVEN IN THE ABSENCE OF STRONG SURFACE BASED INSTABILITY. PRECIP 
IS EXPECTED TO CHANGE TO SNOW BEFORE ENDING WEDNESDAY NIGHT. FOR 
THURSDAY AND FRIDAY...THE NEXT AREA OF HIGH PRESSURE AND DRY AIR 
WILL PUSH PRECIP OUT. 

TEMPERATURES WILL VARY CONSIDERABLY. HIGHS MONDAY IN THE 30S WILL  
BE BELOW NORMAL. WARM ADVECTION AHEAD OF THE LOW SHOULD RESULT IN 
NEAR NORMAL HIGHS MAINLY IN THE 40S TUESDAY AND WEDNESDAY. A PLUNGE 
BACK DOWN TO THE 20S AND 30S IS FORECAST WITH THE RETURN OF A 
MODIFIED ARCTIC AIRMASS THURSDAY AND FRIDAY.

&&

.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
A FEW CUMULUS CLOUDS OVER THE REGION SHOULD DISSIPATE IN THE NEXT
SEVERAL HOURS. AFTER THAT...HIGH-LEVEL AND MID-LEVEL CLOUDS WILL
GRADUALLY MOVE INTO THE AREA FROM THE SOUTHWEST. SOME LOW CLOUDS
MAY DEVELOP BY SATURDAY AFTERNOON...BUT IF THIS OCCURS...CEILINGS
WILL LIKELY REMAIN IN THE VFR RANGE.

WINDS ARE FAIRLY LIGHT AT THE MOMENT...AND WILL ONLY GET LIGHTER
THROUGH THE OVERNIGHT HOURS. HOWEVER...EASTERLY FLOW WILL PICK UP
ON SATURDAY MORNING...SHIFTING TO THE SOUTHEAST BY AFTERNOON. WIND
SPEEDS ARE EXPECTED TO REMAIN AT OR BELOW 10 KNOTS.

JUST BEYOND THE END OF THE FORECAST PERIOD...PRECIPITATION IS
EXPECTED TO BEGIN. THIS PRECIPITATION IS LIKELY TO BEGIN AS
SNOW...AND REDUCED AVIATION CONDITIONS ARE EXPECTED.

OUTLOOK...MVFR/IFR CEILINGS AND VISIBILITIES ARE LIKELY IN SNOW
AND RAIN FROM SUNDAY INTO SUNDAY NIGHT. MVFR/IFR CEILINGS AND
VISIBILITIES ARE POSSIBLE TUESDAY INTO WEDNESDAY WITH RAIN.

&&

.CLIMATE...
RECORD LOWS FOR FEB 28
CINCINNATI...1 IN 1934 
COLUMBUS.....2 IN 1934 
DAYTON......-3 IN 1934

&&

.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.

&&

$$
SYNOPSIS...AR
NEAR TERM...HATZOS/AR
SHORT TERM...AR
LONG TERM...CONIGLIO
AVIATION...HATZOS
CLIMATE...




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