Jump to content
  • Member Statistics

    17,606
    Total Members
    7,904
    Most Online
    ArlyDude
    Newest Member
    ArlyDude
    Joined

Tuesday Clipper System 12/17


Ralph Wiggum

Recommended Posts

  • Replies 100
  • Created
  • Last Reply

I know they're really hard to pinpoint, especially this far out, but the NAM (which is probably the best model to use for this type of thing), is showing what I believe to be a norlun trough forming as the 2nd vort swings by. 

 

Late Tuesday night. 

what is a norlun trough?

Link to comment
Share on other sites

Wasn't that 2009?  Or is this some completely different event?

 

Feb. 3, 2009 was considered a norlun event, at least in this discussion:

 

http://www.easternuswx.com/bb/index.php?/topic/189286-lancaster-pa-heavy-snowfall/

 

Some pictures in Princeton area:

http://www.wunderground.com/wximage/appledust36/183?gallery=

 

http://www.wunderground.com/wximage/appledust36/187?gallery=

Link to comment
Share on other sites

Hi Greg,

Actually Wxsim only forecasts temps and precip water equiv - it uses a straight 10:1 for snow so the Wxsim simply shows a GFS/NAM blend based on what those models are forecasting for precip....I then take the water equiv and do a calculation of potential ratios depending on the temps - if it busts (and it does from time to time) it is usually on the precip totals (as an example it went from 0.29" yesterday to just 0.19" (so 2"-4"today as we get closer to the event. I noticed with the last one it was actually printing out more snow accumulating despite boundary layer forecast temps above frz.....The interesting thing is the programmer added a learning routine in the last couple months - it actually learns from it's mistakes and makes adjustments on future forecasts.....so maybe it will get even better. It really helps with start/stop times but it is a slave to those models

With all due respect to Paul, after following WxSim for a few years it appears that regarding final amounts, a formula of WxSim totals x .5 will put you in the ball park.

Link to comment
Share on other sites

Wxsim with 6z data shows light snow with 1st wave arriving around 330am temp 13.9
mainly periods of light snow with somewhat moderate around 930am - total liquid equiv from 1st wave 0.19" so with high ratios probably 2.5" to 4.0" (high temp during snow 24.5)
2nd wave looks very light with only .02" of liquid from around 10pm thru midnight so maybe another 0.3" of snow....

Link to comment
Share on other sites

Mt.Holly.

 

000
WWUS41 KPHI 161956
WSWPHI

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
256 PM EST MON DEC 16 2013

...WINTERS EMPHATIC DECEMBER START WITH BELOW NORMAL COLD AND
FREQUENT SNOWS WILL CONTINUE WITH A QUICK HITTING SNOW EVENT
TUESDAY MORNING...

.HAZARDOUS TRAVEL WILL DEVELOP DURING THE TUESDAY MORNING COMMUTE
AS LOW PRESSURE NOW OVER THE OHIO VALLEY REFORMS SOUTH OF LONG
ISLAND ON TUESDAY.

NJZ001-007>009-PAZ054-055-060>062-101-103-105-170930-
/O.NEW.KPHI.WW.Y.0025.131217T1000Z-131217T2000Z/
SUSSEX-WARREN-MORRIS-HUNTERDON-CARBON-MONROE-BERKS-LEHIGH-
NORTHAMPTON-WESTERN CHESTER-WESTERN MONTGOMERY-UPPER BUCKS-
INCLUDING THE CITIES OF...NEWTON...WASHINGTON...MORRISTOWN...
FLEMINGTON...JIM THORPE...STROUDSBURG...READING...ALLENTOWN...
BETHLEHEM...EASTON...HONEY BROOK...OXFORD...COLLEGEVILLE...
POTTSTOWN...CHALFONT...PERKASIE
256 PM EST MON DEC 16 2013

...WINTER WEATHER ADVISORY IN EFFECT FROM 5 AM TO 3 PM EST
TUESDAY...

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY HAS ISSUED A WINTER
WEATHER ADVISORY FOR SNOW...WHICH IS IN EFFECT FROM 5 AM TO 3 PM
EST TUESDAY.

* LOCATIONS...EASTERN PENNSYLVANIA FROM WEST OF PHILADELPHIA
NORTHWARD THROUGH THE LEHIGH VALLEY AND POCONOS INTO NORTHWEST
NEW JERSEY.

* SNOW ACCUMULATIONS...TWO TO 4 INCHES OF FLUFFY SNOW WILL FALL
DURING A 3 TO 6 HOUR PERIOD BEGINNING AROUND 5 AM. THE SNOW
WILL END FROM WEST TO EAST BETWEEN NOON AND 3 PM.

* WINDS...WILL BE LIGHT.

* TEMPERATURES...WILL ONLY RISE TO BETWEEN 25 AND 30 DEGREES AS
THE SNOW ENDS DURING MIDDAY OR THE EARLY AFTERNOON HOURS.

* IMPACTS...TEMPERATURES WILL BE IN THE TEENS TO LOWER 20S DURING
THE MORNING COMMUTE WITH SNOW CREATING VERY HAZARDOUS CONDITIONS
ON ALL UNTREATED SURFACES. PLAN ON MORNING TRAVEL DELAYS AND
LEAVE EARLIER TO REACH YOUR DESTINATION ON TIME. TRAVEL CONDITIONS
SHOULD IMPROVE CONSIDERABLY TUESDAY AFTERNOON AS THE SNOW TAPERS
OFF.



PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WINTER WEATHER ADVISORY MEANS THAT PERIODS OF SNOW...SLEET...OR
FREEZING RAIN WILL CAUSE TRAVEL DIFFICULTIES. BE PREPARED FOR
SLIPPERY ROADS AND LIMITED VISIBILITIES...AND USE CAUTION WHILE
DRIVING.

&&

$

NJZ010-012>015-018>020-027-PAZ070-071-102-104-106-170930-
/O.NEW.KPHI.WW.Y.0025.131217T1100Z-131217T2100Z/
SOMERSET-MIDDLESEX-WESTERN MONMOUTH-EASTERN MONMOUTH-MERCER-
CAMDEN-NORTHWESTERN BURLINGTON-OCEAN-SOUTHEASTERN BURLINGTON-
DELAWARE-PHILADELPHIA-EASTERN CHESTER-EASTERN MONTGOMERY-
LOWER BUCKS-
INCLUDING THE CITIES OF...SOMERVILLE...NEW BRUNSWICK...FREEHOLD...
SANDY HOOK...TRENTON...CAMDEN...CHERRY HILL...MOORESTOWN...
MOUNT HOLLY...JACKSON...WHARTON STATE FOREST...MEDIA...
PHILADELPHIA...WEST CHESTER...KENNET SQUARE...NORRISTOWN...
LANSDALE...MORRISVILLE...DOYLESTOWN
256 PM EST MON DEC 16 2013

...WINTER WEATHER ADVISORY IN EFFECT FROM 6 AM TO 4 PM EST
TUESDAY...

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY HAS ISSUED A WINTER
WEATHER ADVISORY FOR SNOW...WHICH IS IN EFFECT FROM 6 AM TO 4 PM
EST TUESDAY.

* LOCATIONS...NEAR THE INTERSTATE 95 CORRIDOR FROM PHILADELPHIA
AND ITS NEARBY SUBURBS TO NEW BRUNSWICK NEW JERSEY INCLUSIVE OF
ALL OF CENTRAL NEW JERSEY TO THE COAST.

* SNOW ACCUMULATIONS...ONE TO 2 INCHES OF SNOW IS EXPECTED DURING
THE MORNING. LEFTOVER ADDITIONAL ACCUMULATION IS POSSIBLE DURING
THE AFTERNOON IN EAST CENTRAL AND COASTAL NORTHEAST NEW
JERSEY... PARTICULARLY MIDDLESEX AND MONMOUTH COUNTIES WHERE ISOLATED
3 OR 4 INCH STORM TOTALS MAY OCCUR.

* TIMING...SNOW WILL DEVELOP BETWEEN 5 AM AND 7 AM AND END FROM
WEST TO EAST BETWEEN 1 PM AND 4 PM.

* WINDS...WILL BE LIGHT.

* IMPACTS...SNOW WILL BE FALLING DURING THE MORNING COMMUTE WITH
TEMPERATURES MAINLY IN THE MID TO UPPER 20S. ALL UNTREATED
SURFACES WILL BE SLIPPERY AND HAZARDOUS. PLAN ON MORNING TRAVEL
DELAYS AND LEAVE EARLIER TO REACH YOUR DESTINATION ON TIME.
TRAVEL CONDITIONS SHOULD IMPROVE CONSIDERABLY TUESDAY AFTERNOON
AS THE SNOW TAPERS OFF AND TEMPERATURES RISE ABOVE FREEZING.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WINTER WEATHER ADVISORY MEANS THAT PERIODS OF SNOW...SLEET...OR
FREEZING RAIN WILL CAUSE TRAVEL DIFFICULTIES. BE PREPARED FOR
SLIPPERY ROADS AND LIMITED VISIBILITIES...AND USE CAUTION WHILE
DRIVING.

&&

$


DRAG

 

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...