Jump to content
  • Member Statistics

    17,609
    Total Members
    7,904
    Most Online
    NH8550
    Newest Member
    NH8550
    Joined

Feb 21-22 Snow/Sleet Storm Obs/Nowcasting/Weenie/Panic/Hallucinations


Ji

Recommended Posts

Winter Storm Warning going in effect NOW

URGENT - WINTER WEATHER MESSAGE

NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC

511 PM EST MON FEB 21 2011

MDZ003>007-501-502-WVZ051-220615-

/O.EXT.KLWX.WS.W.0004.110221T2211Z-110222T1200Z/

WASHINGTON-FREDERICK MD-CARROLL-NORTHERN BALTIMORE-HARFORD-

EXTREME WESTERN ALLEGANY-CENTRAL AND EASTERN ALLEGANY-MORGAN-

INCLUDING THE CITIES OF...HAGERSTOWN...FREDERICK...WESTMINSTER...

FROSTBURG...CUMBERLAND

511 PM EST MON FEB 21 2011

...WINTER STORM WARNING NOW IN EFFECT UNTIL 7 AM EST TUESDAY...

THE WINTER STORM WARNING IS NOW IN EFFECT UNTIL 7 AM EST TUESDAY.

* PRECIPITATION TYPE...FREEZING RAIN...SLEET AND SNOW. SNOW MAY BE

HEAVY AT TIMES OVERNIGHT.

* ACCUMULATIONS...5 TO 8 INCHES OF SNOW AND SLEET...TRACE AMOUNTS

OF ICE.

* TIMING...FREEZING RAIN WILL CHANGE TO SLEET LATE THIS AFTERNOON...

THEN TO SNOW THIS EVENING. THE SNOW WILL CONTINUE THROUGH EARLY

MORNING...BECOMING HEAVIEST BETWEEN MIDNIGHT AND 4 AM.

* TEMPERATURES...TEMPERATURES IN THE UPPER 20S AND LOWER 30S THIS

EVENING... DROPPING TO THE MID 20S BY TUESDAY MORNING.

Link to comment
Share on other sites

  • Replies 754
  • Created
  • Last Reply

URGENT - WINTER WEATHER MESSAGE

NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC

511 PM EST MON FEB 21 2011

MDZ009>011-014-VAZ031-042-220615-

/O.CON.KLWX.WS.W.0004.110222T0200Z-110222T1200Z/

MONTGOMERY-HOWARD-SOUTHERN BALTIMORE-ANNE ARUNDEL-CLARKE-LOUDOUN-

INCLUDING THE CITIES OF...GAITHERSBURG...COLUMBIA...BALTIMORE...

ANNAPOLIS...LEESBURG

511 PM EST MON FEB 21 2011

...WINTER STORM WARNING REMAINS IN EFFECT FROM 9 PM THIS EVENING

TO 7 AM EST TUESDAY...

A WINTER STORM WARNING REMAINS IN EFFECT FROM 9 PM THIS EVENING

TO 7 AM EST TUESDAY.

* PRECIPITATION TYPE...SLEET AND SNOW AROUND MIDNIGHT...WHICH WILL

BE HEAVY AT TIMES OVERNIGHT.

* ACCUMULATIONS...4 TO 7 INCHES OF SNOW. WITHIN THIS RANGE...THE

HIGHER AMOUNTS WILL BE IN THE NORTHERN PART OF THESE COUNTIES.

* TIMING...RAIN AND SLEET WILL BEGIN LATE THIS AFTERNOON...THEN

WILL CHANGE OVER TO SNOW LATE THIS EVENING. THE SNOW WILL

CONTINUE UNTIL DAWN. THE HEAVIEST SNOWFALL IS EXPECTED BETWEEN

MIDNIGHT AND 5 AM.

* TEMPERATURES...TEMPERATURES IN THE MIDDLE 30S THIS EVENING...

DROPPING TO THE UPPER 20S BY TUESDAY MORNING.

Link to comment
Share on other sites

post-822-0-95117600-1298329247.gif

MESOSCALE DISCUSSION 0118

NWS STORM PREDICTION CENTER NORMAN OK

0458 PM CST MON FEB 21 2011

AREAS AFFECTED...SRN PA/MD

CONCERNING...HEAVY SNOW

VALID 212258Z - 220300Z

ONGOING MODERATE TO HEAVY SNOWFALL IN PORTIONS OF SWRN/S CNTRL PA

WILL CONTINUE TO EPISODICALLY PRODUCE INCH AN HOUR RATES WHILE

SPREADING EWD INTO SERN PA/MD.

COLD ADVECTION AND WET BULB COOLING EFFECTS ARE LEADING TO

PLUMMETING SURFACE TEMPERATURES ACROSS THE MCD AREA...WITH THE

SURFACE COLD FRONT NOW ANALYZED WELL SOUTH NEAR THE VA/NC

BORDER...ARCING NWWD THEN WWD TO A SURFACE LOW NEAR THE KY/IND/OH

BORDER. MODERATE TO HEAVY SNOW IS ALREADY BEING REPORTED ON THE

LEADING EDGE OF GREATER MOISTURE IN S CNTRL PA AT JOHNSTOWN AND

ALTOONA. AREA VAD WIND PROFILE DATA REFLECTS NEAR 40 KTS WLY FLOW AT

4000 FT...OR AROUND 800 MB...WHICH IS LIKELY LEADING TO A FASTER

TRANSITION TO MODERATE TO HEAVY SNOW THAN 18Z DETERMINISTIC GUIDANCE

WOULD SUGGEST AS GREATER MOISTURE OVER THE OHIO VALLEY TRANSITIONS

EWD. UPPER ASCENT WILL INCREASE AS A LOW OVER ME/NEW BRUNSWICK

DRIFTS EWD...AND A SEPARATE LOW APPROACHES FROM THE W...MAXIMIZING

VERTICAL MOTION IN FAVORABLE MID/UPPER JET ENTRANCE/EXIT REGIONS.

CURRENT ANALYSIS SHOWS MAXIMIZED 850 MB CONVERGENCE OVER SRN

PA...SHIFTING SLIGHTLY SEWD INTO SERN PA/MD OVER THE NEXT FEW HOURS.

EXPECT HEAVIEST SNOW TO DEVELOP EWD ACCORDINGLY...WHILE PERIODS OF

HEAVY SNOW CONTINUE ACROSS WRN PORTIONS OF THE MCD AREA AS WELL.

..HURLBUT.. 02/21/2011

ATTN...WFO...PHI...CTP...LWX...PBZ...

LAT...LON 40908011 40827753 39997606 39267602 39187699 39787935

40308043 40908011

Link to comment
Share on other sites

You can clearly see the SLP on radar just over or south of Indianapolis. Low is going to track across WV and to the south of DC. We should get into some really nice rates as the low crosses WV and then to the S of DC. There should be some pretty dry fluffy snow to end the storm and the surface should be down to the mid 20's by that time.

Heck, I'm staying up for it. This one is worth it.

Link to comment
Share on other sites

I am guilty of radar watching, but I am concerned that the main moisture seems to be staying north of me ( Gaithersburg). Any cause for concern? I know it is early - but if there is a good explanation as to why the moisture will move south over time, I would love to hear it. Thanks.

Has been discussed a bit earlier. Precip doesn't always stay on a straight line. Also more precip an develop as the low comes towards us.

Link to comment
Share on other sites

Wait, come again? Isnt that early?

KDCA 212319Z 02013G20KT 3SM -RASN SCT020 BKN039 OVC070 04/01 A2983 RMK AO2 SFC VIS 5 P0001

KDCA 212300Z 36015KT 3SM -RASN BKN022 OVC035 04/01 A2983 RMK AO2 SFC VIS 5 P0000

KDCA 212252Z 02013G19KT 6SM -RASN SCT022 OVC035 04/01 A2983 RMK AO2 RAB2155E21B42SNB51 SLP099 P0000 T00440011

KDCA 212152Z 02014KT 7SM OVC035 05/01 A2981 RMK AO2 RAE15 SLP092 P0000 T00500006

KDCA 212052Z 01015KT 7SM -RA OVC033 05/01 A2979 RMK AO2 RAB38 SLP087 P0000 60000 T00500011 53018

Take it to the bank :D

Link to comment
Share on other sites

I am guilty of radar watching, but I am concerned that the main moisture seems to be staying north of me ( Gaithersburg). Any cause for concern? I know it is early - but if there is a good explanation as to why the moisture will move south over time, I would love to hear it. Thanks.

Post #164 above should make you feel better - has the map showing heavy snow area to shift more SEward with time

Link to comment
Share on other sites

I am guilty of radar watching, but I am concerned that the main moisture seems to be staying north of me ( Gaithersburg). Any cause for concern? I know it is early - but if there is a good explanation as to why the moisture will move south over time, I would love to hear it. Thanks.

I'll put you at ease. Look at the NWS Great Lakes Sector loop. Draw a line from Indianapolis to just south of Fredericksburg VA. Move the entire precip shield along that line and you will see that we have zero to worry about. That is the track of the LP and we will get into the goods for sure.

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

  • Recently Browsing   0 members

    • No registered users viewing this page.

×
×
  • Create New...