HAMweather.com Area Forecast Discussion for County Warning Area RLX

Thu, 16 Feb 2012 11:47:22 GMT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON WV
537 AM EST THU FEB 16 2012

.SYNOPSIS...
COLD FRONT WILL PASS THURSDAY. HIGH PRESSURE FRIDAY AND FRIDAY 
NIGHT. NEXT SYSTEM THIS WEEKEND.

.NEAR TERM /THROUGH TONIGHT/...
LIGHT PRE-FRONTAL RAIN SHOWERS ARE SLOWLY OVERTAKING CWA FROM W TO 
E. MINOR CHANGES TO POP FIELDS WITH THIS ISSUANCE TO REFLECT LATEST 
RADAR TRENDS. WILL PRIMARILY STICK WITH PREVIOUS FORECAST TIMING OF 
HIGHEST POPS ENTERING CWA JUST AFTER 12Z. MAIN IMPETUS FOR THESE 
SHOWERS APPEARS TO BE STRONG VORT RIDING ALONG THE COLD FRONT 
CURRENTLY LOCATED AROUND THE CONFLUENCE OF THE OHIO AND MISSISSIPPI 
RIVERS. LATEST RUC/NAM HAVE THIS VORT MAX DIAGNOSED WELL IN 
TROPOPAUSE HEIGHT FIELD...TIMING OF POP FIELD REFLECTS THIS. 

WITH A 50KT H85 JET POISED TO PASS JUST SOUTH OF CWA COUPLED IN 
TIMING WITH HIGHEST PRECIPITATION CHANCES...CANT RULE OUT GUSTY 
WINDS REACHING THE SURFACE TODAY...ESPECIALLY IN STRONGER SHOWERS. 

COLD AIR BEHIND THE COLD FRONT WILL CHANGE OVER ANY LINGERING RAIN 
SHOWERS TO SNOW IN THE NORTHERN WV MOUNTAIN COUNTIES AFTER 00Z FRI. 
NOT EXPECTING ANY ACCUMULATION ATTM...HOWEVER...IF TIMING OF CAA 
SPEEDS UP POST FROPA...LIGHT SNOW ACCUMULATION COULD OCCUR.

BUMPED UP TEMPS TODAY A FEW NOTCHES AS THIS MORNINGS TEMPS HAVE BEEN 
MODERATED WELL BY CONTINUED BL MIXING AND CLOUD COVER. MAX TEMPS 
STILL A BIT TRICKY AS TIMING OF THE COLD FRONT WILL GREATLY IMPACT 
DAYTIME WARMING.

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
HIGH PRESSURE BUILDING EARLY FRIDAY BRINGS DRIER AIR ENDING ANY
LINGERING PRECIPITATION OVER THE NORTHERN MOUNTAINS. EXPECT MOSTLY
CLEAR SKIES...WITH AFTERNOON TEMPERATURES HOVERING INTO THE MID
TO UPPER 50S. NIGHTTIME TEMPERATURES WILL DROP BELOW FREEZING. 

TWO SYSTEMS...ONE NORTHERN STREAM AND ONE SOUTHERN STREAM...WILL
APPROACH FROM THE WEST ON SATURDAY...BRINGING SMALL PRECIPITATION
CHANCES BACK TO THE REGION.

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
MODELS CONTINUE TO HANDLE THE SOUTHERN STREAM LOW PRESSURE SYSTEM 
SATURDAY NIGHT AND SUNDAY A BIT DIFFERENTLY...THE 00Z/12Z ECMWF RUNS 
STILL SHOWING THE BULK OF THE PRECIP WILL PASS SOUTH OF CWA...AND 
HAVE BEEN FAIRLY CONSISTENT WITH THIS. THE 12Z GFS HAS GONE QUITE A 
BIT FARTHER NORTH WITH EXTENT OF PRECIP. WITH FAIRLY LOW CONFIDENCE 
SETTLED ON A SOLUTION BETWEEN THE TWO...TRENDING TOWARDS THE MORE 
CONSISTENT ECMWF. THIS IS ALSO PRETTY CLOSE TO HPC GUIDANCE. STILL 
THINK THAT PRECIP WILL BE MOSTLY RAIN ON SUNDAY...CHANGING OVER TO 
LIGHT SNOW SHOWERS AS SOME COLDER AIR WORKS IN BEHIND THE 
LOW...GRANTED THIS ALSO CORRESPONDS TO BEST MOISTURE MOVING OUT.

EXPECTING HIGH PRESSURE ON MONDAY WITH ANOTHER LOW PRESSURE SYSTEM 
FOR MID WEEK. TIMING DIFFERENCES EXIST BETWEEN THE OPERATIONAL 
MODELS...BUT IN GENERAL SHOULD SEE INCREASING CHANCES OF PRECIP 
TUESDAY INTO WEDNESDAY. THIS ONE AGAIN LOOKS LIKE MOSTLY RAIN FOR 
PRECIP TYPE.

.AVIATION /12Z THURSDAY THROUGH MONDAY/...
CURRENT VFR IN LIGHT RAIN SHOWERS WILL GIVE WAY TO MVFR WEST TO
EAST GOING THROUGH THE MORNING HOURS. WHILE GENERAL MVFR
CONDITIONS ARE EXPECTED AHEAD OF THE FRONT IN THE
RAIN...OCCASIONAL IFR CONDITIONS ARE POSSIBLE IN THE HEAVIER
SHOWERS...AND ESPECIALLY IN THE MOUNTAINS. IMPROVEMENT TO VFR IN
THE WEST AFTER 18Z...FOLLOWING FRONTAL PASSAGE.

LIGHT SOUTHERLY FLOW AT THE SURFACE WILL SHIFT TO WESTERLY AND
INCREASE THROUGHOUT AFTERNOON/EVENING TIME FRAME. STRONGER GUSTS AT
THE SURFACE ARE POSSIBLE...ESPECIALLY IN MODERATE RAIN SHOWERS.

FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z FRIDAY...
     
FORECAST CONFIDENCE: MODERATE TO HIGH.

ALTERNATE SCENARIOS: TIMING AND LIKELIHOOD OF MVFR AND POSSIBLE IFR
THURSDAY COULD VARY.

EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH:   TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW:    TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.

UTC 1HRLY       11   12   13   14   15   16   17   18   19   20   21   22
EST 1HRLY       06   07   08   09   10   11   12   13   14   15   16   17
CRW CONSISTENCY  M    L    L    M    H    M    M    M    H    H    H    H
HTS CONSISTENCY  L    L    L    H    L    M    M    M    H    H    H    L
BKW CONSISTENCY  M    M    M    H    H    L    H    L    H    H    L    L
EKN CONSISTENCY  H    H    M    H    H    M    H    M    M    M    M    M
PKB CONSISTENCY  L    L    L    M    L    L    L    L    M    H    H    L
CKB CONSISTENCY  M    H    H    H    H    M    H    M    M    M    M    M

AFTER 12Z FRIDAY...
IFR POSSIBLE IN SCATTERED SHOWERS SATURDAY NIGHT.

.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.