Watching the Skies

This unseasonably late snowfall further increased the 2009-2010 snowfall totals for our area, bringing us within 1/2 an inch of the all-time snowiest winter on record! Additionally the last time this much snow fell this late in the season was March 29 1937! Preliminary snowfall totals listed graphically below.

As you can see, the heaviest snow was concentrated within Collin County including a report in Frisco of 6 inches, and 8 inches reported in Allen. DFW Airport officially documented 1.3 inches of snowfall total from this event. The statement from the NWS included below.

The snow will not remain very long, as temperatures will quickly recover to the 60s on Monday and 70s by Tuesday. The next storm system will begin to affect the region on Wednesday evening, with thunderstorms likely. A shot of cooler air will follow as this system passes, but nowhere near this level of winter weather we just received.

...Spring snow for dfw...

Dfw Airport recorded 1.2 inches of snow on March 20th. This breaks
the previous daily record for March 20th of 0.4 inches set in 1970.
An additional 0.1 of an inch officially fell on March 21st and the 

event total is 1.3 inches. 

The additional 1.3 inches brings the 2009-2010 winter total to 17.1
inches. This ranks second of all time and came 0.5 inches shy of
tying the all-time record of 17.6 inches set in 1977-1978. 

This snow event was unseasonably late in the year. The last time an
inch or more fell at dfw later than March 20th was when 2 inches
fell on March 29th in 1937.

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Dallas/Fort Worth - snowiest seasons

   1   17.6   1977-78
   2   17.1   2009-10*
   3   15.3   1963-64
   4   13.5   1923-24
   5   10.4   1976-77
   6    9.5   1909-10
   7    9.2   1916-17

   8    8.8   1947-48
   9    8.1   1937-38
  10    7.3   1965-66
        7.3   1941-42
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Hey folks, a significant arctic cold air blast will impact the area beginning tonight around midnight and last through Sunday at least. Air temperatures will fall as low as 11 to 14 degrees around the metroplex, with wind chills below zero! Freezing rain is also possible Wednesday night thru very early Thursday morning.

The arctic cold front originating from as far away as Siberia will plunge through the area late tonight around midnight, sending winds of 10-15mph and temperatures dropping to 22 degrees by sunrise. Freezing rain is possible in a narrow window overnight from maybe midnight to 3am? This could make for some patchy areas of ice on the roadways for Thursday. Temps will struggle to increase during the day, never exceeding 27 degrees. Overnight clear skies will promote strong radiational cooling and temperatures will drop as low as around 11 degrees to the north, 14 in and just south of the metroplex. Winds at this time will create very hazardous wind chill values below zero!

This cold air will persist on Friday as well, with highs once again not exceeding the freezing mark.Temperatures on Saturday will struggle to reach freezing, and very well could remain below freezing for the entire day on Saturday as well. Sunday will begin to warm up a bit with lows around 27, highs of 45.

Bundle up everyone, this is likely to be the coldest weather in the metroplex since January 2005!

This happens more than it should… sprinklers left on while its well below freezing outside, causing a very quick ice-over on a busy road.

On a somewhat related note, temperatures tonight will continue to fall well below freezing, to a low around 18 degrees for Frisco. Lower temps can be expected north of the metroplex, while temps in the mid 20s can be expected in and south of the metroplex. No significant weather forecast changes since the last update… rain chances still possible Friday thru Saturday morning, no winter precipitation is expected at this time.

Looks like a cold front, currently stalled out across the western parts of north Texas, will finally push through the area in the afternoon and evening hours of Sunday. This cold front will bring rain and some thunderstorms through in the late afternoon to evening. Thunderstorm activity is not expected to be substantial at this time. An isolated strong or weaker severe storm is possible, with primary threat being strong winds. The main limiting factor preventing severe weather development Sunday is weak mid-level lapse rates… meaning the rate of temperature decline with higher altitude is not favorable for severe weather.

After the frontal passage, expect much cooler temperatures and windy conditions. A low pressure system will be passing through north Texas with this cold front and sitting just to our east Monday, which will bring gusty winds, cloudy skies and helping with cold air transport from the northwest. The cloudy skies will begin to clear Monday afternoon and will be gone by Tuesday. The clear skies will help with heat evaporation Tuesday night bringing along some very cool overnight temperatures in the mid 30s!

Sunday afternoon and evening, rain chances sit around 50% with scattered showers and an isolated thunderstorm possible. Around 1 inch of rain is possible in heavier areas. Aside from maybe some minor water ponding in streets and low laying areas, flooding should not be a concern.

Rain is again possible this upcoming Thursday with one computer model forecasting a rapidly moving cold front passing through the area. Confidence on this solution is low but enough to warrant a 20% chance of rain at this time.

So for the next few days we can expect the following:
Sunday before frontal passage: Some chances of rain, mostly cloudy, highs in the low 70s. rain chances increase in the late afternoon and isolated thunderstorms are possible.
Sunday evening after frontal passage: Light rain still may be possible, mostly cloudy, fairly breezy and lows in the mid 40s.
Monday: Very breezy and cold, wear moderate or heavy windbreakers! Winds gusting to 30, highs in the low to mid 50s and mostly cloudy.
Monday night: Keep the jackets on, still somewhat breezy and cool. Lows in the upper 30s and partly cloudy.
Tuesday: Mostly clear and light winds, highs in the upper 50s.
Tuesday night: Bundle up! Clear, light winds, lows in the mid 30s! A freeze is possible around naturally cooler areas.
Wednesday: Warm up begins, moisture may begin to start returning with southern winds, highs in the upper 50s, lows in the mid 40s.

Forecasts beyond Wednesday are subject to large change, so I will send updates if needed later. At this time however we are looking at a cold front moving through quickly on Thursday, then another cold front Saturday.

Looks like we’ll have another relatively dormant weather pattern for us the next few days. An upper level high pressure is building into the region bringing clear, quiet and dry conditions for the next five days. Highs will remain in the mid 70s, lows in the low to mid 50s. Overall these temps are quite seasonable for this time of year. Moisture may begin to return to the region on Saturday and Sunday, with a possible cold front passing on Sunday bringing rain chances for that day. Overnight lows this upcoming weekend will warm slightly with the increase in moisture. Temperatures will be cooler after the frontal passage, current forecasts indicate highs in the low 60s and lows in the mid 40s. No severe weather is forecast for the next 7 days at this time.

You may also be wondering when is it going to get real cold here? Well nobody knows for sure, but when you consider weather history from years past, the answer would be ’soon’. According to the National Weather Service, DFW Airport’s average first freeze date is November 22. This, coupled with this years climate forecast indicating above average precipitation and normal or slightly below normal temperatures, might indicate that we can expect our first freeze within the next two to three weeks. Below is a graph of the average freeze days recorded per month from DFW Airport. You can see that December and January will likely be the two coldest months of the season.

For more information including seasonal averages and extremes, see the Freeze Summary for DFW Airport, provided by the National Weather Service.

As a side note, Tropical Storm Ida is about to make landfall in Mobile, AL with 60mph winds. The storm encountered strong upper level wind shearing and cooler gulf water temperatures and lost a majority of its strength prior to landfall. There is still some minor flooding occurring along several southern Alabama and extreme western Florida panhandle counties. Additionally high street flooding and 5 foot storm surge is reported in eastern New Orleans in areas outside the hurricane flood control system. This storm is forecast to make a right hand turn and dissipate within 36 hours.

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