Official Storm Thread Nov 29-Dec 6 2007

[dyndrite]

The Storm Begins.

Thursday system moving SE through the northern Rockies with heavy snow mountains of Oregon. This will move surface low in Southern South Dakota East alone old artic boundary. This system is moisture starved and will produce light snow showers in Southern North Dakota. This will be the trigger for the southward movement of Cold Modified Artic air SE into West Kansas, Nebraska, Iowa and points East.

The Southern Stream system is pumping subtropical moisture north and precipitation has developed over Arizona and New Mexico. This will be the moisture shield with this developing storm. Expect Heavy Snow Warnings to be issued for the mountains of Utah, Colorado for Friday.

Friday night the Storm moves east and will effect residents into New England over the next 5-7 days.

Dyndrite

[traci1972]

i noticed watches are being issued for NE and SW IA we were planning a trip to MO but that might not happen.

[traci1972]

the whole state and many others are in a watch now

[dyndrite]

Just looking at the 00Z, 7 pm EST temps in South Dakota and N Nebraska, they are 15-20 degrees colder than forecast this morning. 12 hours can be a long time in forecasting winter storms.

Dyndrite

[dyndrite]

Morning update.

Looking at the morning temperatures to forecast temps from primary model run last night.
Temperatures along east slopes of Rockies 10-20 degrees colder than forecast as far south as Texas border.

Heavy rain moving into southern California, Arizona and New Mexico, flood warning will be issued. Precipitation shield is further north than forecast. Snow developing Southern Utah and Colorado. Rain developing West Texas.

No changes in current guidance for storm with the exception that it may stall in the gulf of Maine next week. Good luck with all of that.

Dyndrite

[traci1972]

NW MO is in an ice storm warning sounds like this is going to be a bad one. they are telling us to prepare for loss of power is what the news said this morning.

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE DES MOINES IA
409 AM CST FRI NOV 30 2007

...SIGNIFICANT WINTER STORM TO IMPACT IOWA SATURDAY INTO
SATURDAY NIGHT...

.STRONG LOW PRESSURE IS FORECAST TO DEVELOP IN THE FRONT RANGE OF
THE ROCKIES TONIGHT AND MOVE INTO WESTERN IOWA BY LATE SATURDAY. A
WIDE VARIETY OF PRECIPITATION IS EXPECTED ACROSS CENTRAL IOWA ON
SATURDAY THROUGH SATURDAY NIGHT BEFORE THE PRECIPITATION TAPER
OFF. SIGNIFICANT SNOW AND ICE ACCUMULATIONS ARE POSSIBLE DURING
THIS TIME.

IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-
081>086-092>097-301800-
/O.CON.KDMX.WS.A.0008.071201T1200Z-071202T1200Z/
EMMET-KOSSUTH-WINNEBAGO-WORTH-PALO ALTO-HANCOCK-CERRO GORDO-
POCAHONTAS-HUMBOLDT-WRIGHT-FRANKLIN-BUTLER-BREMER-SAC-CALHOUN-
WEBSTER-HAMILTON-HARDIN-GRUNDY-BLACK HAWK-CRAWFORD-CARROLL-GREENE-
BOONE-STORY-MARSHALL-TAMA-AUDUBON-GUTHRIE-DALLAS-POLK-JASPER-
POWESHIEK-CASS-ADAIR-MADISON-WARREN-MARION-MAHASKA-ADAMS-UNION-
CLARKE-LUCAS-MONROE-WAPELLO-TAYLOR-RINGGOLD-DECATUR-WAYNE-
APPANOOSE-DAVIS-
INCLUDING THE CITIES OF...ESTHERVILLE...ALGONA...FOREST CITY...
NORTHWOOD...EMMETSBURG...GARNER...MASON CITY...POCAHONTAS...
HUMBOLDT...CLARION...HAMPTON...ALLISON...WAVERLY.. .SAC CITY...
ROCKWELL CITY...FORT DODGE...WEBSTER CITY...ELDORA...
GRUNDY CENTER...WATERLOO...DENISON...CARROLL...JEFFERSON. ..
BOONE...AMES...MARSHALLTOWN...TOLEDO...AUDUBON...G UTHRIE CENTER...
ADEL...DES MOINES...NEWTON...GRINNELL...ATLANTIC...GREENFIELD ...
WINTERSET...INDIANOLA...KNOXVILLE...OSKALOOSA...CO RNING...
CRESTON...OSCEOLA...CHARITON...ALBIA...OTTUMWA...B EDFORD...
MOUNT AYR...LEON...CORYDON...CENTERVILLE...BLOOMFIELD
409 AM CST FRI NOV 30 2007

...WINTER STORM WATCH REMAINS IN EFFECT FROM SATURDAY MORNING
THROUGH LATE SATURDAY NIGHT...

A WINTER STORM WATCH REMAINS IN EFFECT FROM SATURDAY MORNING
THROUGH LATE SATURDAY NIGHT.

SNOW IS EXPECTED TO SPREAD RAPIDLY NORTHEAST THROUGH CENTRAL IOWA
ON SATURDAY MORNING. THE SNOW IS FORECAST TO QUICKLY SWITCH TO SLEET AND
FREEZING RAIN IN SOUTHERN INTO CENTRAL IOWA...MAINLY SOUTH OF
HIGHWAY 20 DURING THE MORNING HOURS. SOME LIGHT SNOW AMOUNTS OF AN
INCH OR TWO ARE POSSIBLE BEFORE THE TRANSITION. OTHERWISE...
FREEZING RAIN MIXED AT TIMES WITH SLEET IS EXPECTED TO PERSIST
INTO THE AFTERNOON. SIGNIFICANT ICE ACCUMULATIONS WILL BE POSSIBLE
DURING THIS TIME WITH ONE QUARTER TO ONE HALF INCH OF ICE. THIS
WILL LIKELY MAKE TRAVEL VERY DIFFICULT. IN ADDITION....STRONG EAST
TO SOUTHEAST WINDS MAY COMPOUND PROBLEMS BY BREAKING BRANCHES
WEIGHED DOWN BY ICE. A CHANGE TO RAIN WILL OCCUR OVER FAR SOUTHERN
IOWA BY EARLY AFTERNOON. THIS TRANSITION ZONE IS FORECAST TO MOVE
NORTHWARD DURING THE AFTERNOON AND WILL LIKELY BE NEAR THE HIGHWAY
30 CORRIDOR BY EARLY EVENING. THIS MAY HELP TO ALLEVIATE PROBLEMS
BY EARLY EVENING.

OVER THE NORTHERN IOWA...THE EVENT WILL BE OF LONGER DURATION AS
TEMPERATURES REMAIN BELOW FREEZING. ANYWHERE FROM TWO TO SIX INCHES
OF SNOW SHOULD FALL IN THESE AREAS WITH THE HIGHEST AMOUNTS ALONG
AND NORTHEAST OF AN EMMETSBURG TO WATERLOO LINE. ON TOP OF THE
SNOW...TWO TO FIVE TENTHS OF ICE ACCUMULATIONS WILL BE POSSIBLE AS
WELL.

ADDITIONAL MINOR ACCUMULATIONS OF LIGHT FREEZING RAIN MAY
OCCUR SATURDAY NIGHT AS THE STORM EXITS THE AREA INTO THE GREAT
LAKES SUNDAY MORNING.

THE POTENTIAL FOR ICE STORM CONDITIONS EXISTS WITH THIS STORM.
GLAZING IN COMBINATION WITH BRISK SOUTHEAST WINDS GUSTING FROM
20 TO 35 MPH COULD PRODUCE SCATTERED POWER OUTAGES AND DOWNED
TREES. A WINTER STORM WATCH MEANS THERE IS A POTENTIAL FOR
SIGNIFICANT SNOW...SLEET...OR ICE ACCUMULATIONS THAT MAY IMPACT
TRAVEL. CONTINUE TO MONITOR THE LATEST FORECASTS AND NATIONAL

[dyndrite]

Storm up-date

Looking at the 12Z, 7 am EST data models I am reminded of the complexity of weather. The last 2 days the NAM was warm and the GFS was cold. Now the NAM is cold and the GFS is warm. What does this mean?

This means this is a dynamic Winter Storm. The GFS is trying to push the warm air north in response to the colder temps in west Kansas. It is wrong.

Subtropical moisture and Artic air are the ingredients for a Major Winter Storm, we have them. The subtropical moisture is just moving into the SW United States and the storm is brewing.

Computers try and make every thing all right. As we say down south, “Bless thier heart.”
This is when you need a weatherman, to see what is right.

Pre-storm prediction. Snow winner, Midwest, Minneapolis Saint Paul to 20 miles north. 10-15 inches of snow. Worst weather, North Central and NE Iowa, 3-5 inches of snow and 3/8 to ¼ inch of ice.

As the Storm moves East, think of Pennsylvania and New York state as Iowa, same weather. Storm reforms off the coast of NY City and Katie bar the door. Heavy snow New Hampshire, Vermont and Maine. Someone will get 2ft of snow here.

Ain’t this fun?

Dyndrite

[traci1972]

they are calling for possible ice storm conditions here in central IA.

[dyndrite]

Weather up-date

18Z, 1PM EST temps are 15-25 degrees colder in NW Missouri, Kansas and North Texas than forecast at 12Z, 7 AM EST.

Dyndrite

[dyndrite]

Morning update.

What a mess. Looks like the snow line is setting up on the Nebraska, South Dakota border . Moderate to heavy snow will fall across south Central Minnesota and west North West Wisconsin.


Special Forecast Marshal County Iowa

A little snow and sleet ½ inch is possible, Freezing Rain with up to 1/2 inch of ice. The good news is the warm air is coming and it should change to regular light rain and drizzle late this afternoon and tonight as the storm passes over Iowa, High may approach 34-40 degrees. Freezing temps return late tonight and Sunday.

Dyndrite