M-4 2011 Houston Marathon Weather Guessing

I just finished the last real workout before the marathon: five miles overall and three miles at marathon pace on the track. The weather was beautiful, cool and dry and the sky filled with stars.
I wish I could say the same for Sunday's forecast. The latest NWS discussion talks about the marathon:

LOOKING AHEAD...OUR NEXT WEATHER MAKER WILL BE A STRONG SHORTWAVE WHICH IS FORECAST TO CROSS THE AREA SUNDAY. MODEL RUNS ARE INCREASINGLY FAVORING LOTS OF HUMIDITY AND PERIODS OF MODERATE SHOWERS SUNDAY MORNING...NOT THE MOST OPTIMUM CONDITIONS FOR THE HOUSTON MARATHON.


The hourly weather forecast looks better today with decent temperatures through 10AM. At start time it's showing temperature at 52°F and the dewpoint at 50°F with the winds south at 9 mph, and 10AM shows temperature up to 58°F but the dewpoint at 52°F with the winds south-southeast at 13 mph.

The 7.5-day model includes marathon morning [the graph is in UTC, six hours ahead of Houston]with the temperature in the 50s°F, rain ending, and a fairly strong east wind. The text version of the MRF model. shows a low of 53°F and wind at 8 mph in the morning.



The 84-hour ETA model now includes 6AM marathon morning [the graph is in UTC, six hours ahead of Houston]with the temperature and dewpoint near 60°F and a SSE wind at 8mph.



The Weather Channel tends to weight their long term predictions with seasonal averages. For Saturday night they show:
Overnight Low 53°F
Precip 40%
Wind: SE 4 mph
Max. Humidity: 802%
Showers


For Sunday they show:
High 65°F
Precip 40%
Wind: SE 9 mph
Max. Humidity: 802%
UV Index: 3 Moderate
Sunrise: 7:13 AM CT
Scattered T-Storms


AccuWeather has Saturday night and Sunday on their 1 to 5 day forecast. They're still raising their temperature predictions:

Saturday Night, Jan 29
Low: 50°F RealFeel®: 47°F
Considerable Cloudiness
Winds SE at 10 mph with gusts to 15

Sunday, Jan 30
High: 66°F RealFeel®: 63°F
Mostly Cloudy, chance of a little rain
Winds ESE at 11 mph with gusts to 18