Latest 2010 Houston Marathon Weather Forecasts

The forecasts are starting to get meaningful now. The big weather story remains a gradual warm-up into the week as air from the Gulf returns. Then a low pressure area developing in the Western Gulf causing heavy rain Thursday-Friday, with strong north winds blowing in colder air Saturday. The big question right now is when the North winds start decreasing. A strong North wind can make the trip up Post Oak very difficult. Today's NWS discussion mentions the Marathon:

TUE 00Z A COLD FRONT NEAR THE RED RIVER WILL DROP SOUTH AND SHOULD REACH THE HOUSTON METRO AREA AROUND 15Z TUESDAY. THIS WILL REINFORCE THE COOL AND DRY AIR BUT OUR WEATHER PATTERN WILL BE UNDERGOING SOME MAJOR CHANGES THIS WEEK. AFTER THIS RECORD SETTING ARCTIC COLD SNAP THE PATTERN WILL BECOME DOMINATED BY A SLOW MOVING UPPER LOW TRACKING THROUGH THE SW U.S. AND NRN MEX WED-FRI. THE 850 RIDGE OVER CRP 12Z WED WILL SHIFT EAST LEADING TO INCREASINGLY STRONG SE-E FLOW. VIGOROUS MOISTURE RETURN THURSDAY WILL MOISTEN UP THE ATMOSPHERE DRAMATICALLY AND THE RAINS SHOULD BEGIN. SOME INDICATIONS ARE THAT THE COASTAL WATERS MAY BE VERY ACTIVE THURSDAY THEN EXPAND NORTH. THE STRONG FLOW WILL LIKELY LEAD TO ELEVATED TIDES...SEE MARINE SECTION FOR MORE DETAILS. SOUNDINGS APPEAR TO BE VERY SATURATED AND CAPABLE OF PERIODS OF HEAVY RAINFALL THURSDAY EVENING THROUGH FRIDAY AFTERNOON. WILL CARRY FAIRLY HIGH POPS FOR THIS PERIOD WITH SHRA/TSRA TRANSITIONING TO RA/SHRA SATURDAY AS THE UPPER LOW PULLS AWAY. GFS/ECMWF ARE BOTH SIMILAR WITH SURFACE CYCLOGENESIS IN THE COASTAL BEND REGION TO NEAR MATAGORDA BAY...EVENTUALLY KICKING OUT A LOW ESE ARCING UP FRIDAY NIGHT INTO LA. SLOWER UPPER MOVEMENT RESULTS IN A SURFACE LOW STILL OVER HARRIS COUNTY AT 12Z SATURDAY PER ECMWF WHEREAS THE GFS HAS A MORE ORGANIZED SURFACE LOW SOUTH OF LA. WILL BE FOLLOWING THE ECMWF SOLUTION WITH THE SLOWER MOVEMENT GIVEN THE UPPER CUTOFF FLOW. AS FOR TEMPERATURES HAVE TRENDED POPS TOWARD THE MEX GUIDANCE BUT HAVE BIASED THESE WARMER ON MINS AND COOLER ON MAX TEMPS ON ACCOUNT OF THE THICK CLOUD COVER AND RAINFALL. A MILD DRY PACIFIC AIRMASS SHOULD BE BUILDING IN ACROSS THE REGION BY LATE SATURDAY AND DURING THE DAY ON SUNDAY. THIS SHOULD MAKE FOR PLEASANT WEATHER FOR THE BIG MARATHON ON SUNDAY WITH MORNING TEMPERATURES IN THE MID 40S WARMING TO NEAR 50 BY NOON.
Here's the NWS hourly projection for Marathon Sunday. The NWS projects 42°F at the start and 49°F at 10AM, with the dewpoint in the 30s. That's nearly perfect for me. They have a NNW wind from 8 to 7 mph and partly cloudy with sky cover going from 40% to 32%.


The 7.5-day model includes marathon morning. This model follows right along with the NWS hourly projection [the graph is in UTC, six hours ahead of Houston]. The text version of the MRF model. shows a low of 37°F and strong winds (18mph) in the morning.




The Weather Channel tends to weight their long term predictions with seasonal averages. For Saturday night they show:
Overnight Low 39°F
Precip 20%
Wind: NW 9 mph
Max. Humidity: 82%
Clouds Early/Clearing Late


For Sunday they show:
High 57°F
Precip 10%
Wind: WNW 7 mph
Max. Humidity: 72%
UV Index: 4 Moderate
Sunrise: 7:17 AM CT
Partly Cloudy


AccuWeather has Saturday night and Sunday on their 6 to 10 day forecast. They predict:

Saturday Night, Jan 16
Low: 41 °F RealFeel®: 34 °F
Mostly cloudy

Sunday, Jan 17
High: 60 °F RealFeel®: 59 °F
Warmer with partial sunshine