January Weather Discussion: Slight Chance Severe Storms

[srainhoutx]

00Z NAM suggests some qpf across the area with the front. New Braunfels radar tends to agree...

[Andrew]

00Z NAM suggests some qpf across the area with the front. New Braunfels radar tends to agree...

That would be quite something but I think it would only be rain.

[wxman666]

Okay guys, do we stand a better chance this time or are the models toying with us yet again? I will certainly be watching it, but not as intently as last week's storm...that really screwed me up with the lack of sleep while having a cold, lol. Srain...as far as the moderate snow for D-FW....what day are you seeing this possibility occurring? Interested to hear any thoughts.

[Mr. Weather]

Whats qpf

[srainhoutx]

00Z NAM suggests some qpf across the area with the front. New Braunfels radar tends to agree...

That would be quite something but I think it would only be rain.

Yep...

ob KBAZ 110151Z AUTO 04012G19KT 4SM -RA BR OVC006 04/03 A3019 RMK AO2 SLP224 P0000 T00390028

[srainhoutx]

Whats qpf

The Quantitative Precipitation Forecast (abbreviated QPF) is the expected amount of melted precipitation accumulated over a specified time period over a specified area.[1] A QPF will be created when precipitation amounts reaching a minimum threshold are expected during the forecast's valid period. Valid periods of precipitation forecasts are normally synoptic hours such as 0000, 0600, 1200 and 1800 GMT. Terrain is considered in QPFs by use of topography or based upon climatological precipitation patterns from observations with fine detail. Starting in the mid-to-late 1990s, QPFs were used within hydrologic forecast models to simulate impact to rivers throughout the United States. Forecast models show significant sensitivity to humidity levels within the planetary boundary layer, or in the lowest levels of the atmosphere, which decreases with height.[2] QPF can be generated on a quantitative, forecasting amounts, or a qualitative, forecasting the probability of a specific amount, basis.[3] Radar imagery forecasting techniques show higher skill than model forecasts within 6 to 7 hours of the time of the radar image. The forecasts can be verified through use of rain gauge measurements, weather radar estimates, or a combination of both. Various skill scores can be determined to measure the value of the rainfall forecast.

[Mr. Weather]

Whats qpf

The Quantitative Precipitation Forecast (abbreviated QPF) is the expected amount of melted precipitation accumulated over a specified time period over a specified area.[1] A QPF will be created when precipitation amounts reaching a minimum threshold are expected during the forecast's valid period. Valid periods of precipitation forecasts are normally synoptic hours such as 0000, 0600, 1200 and 1800 GMT. Terrain is considered in QPFs by use of topography or based upon climatological precipitation patterns from observations with fine detail. Starting in the mid-to-late 1990s, QPFs were used within hydrologic forecast models to simulate impact to rivers throughout the United States. Forecast models show significant sensitivity to humidity levels within the planetary boundary layer, or in the lowest levels of the atmosphere, which decreases with height.[2] QPF can be generated on a quantitative, forecasting amounts, or a qualitative, forecasting the probability of a specific amount, basis.[3] Radar imagery forecasting techniques show higher skill than model forecasts within 6 to 7 hours of the time of the radar image. The forecasts can be verified through use of rain gauge measurements, weather radar estimates, or a combination of both. Various skill scores can be determined to measure the value of the rainfall forecast.

Thanks for the help !

[txsnowmaker]

Quick question about the bigger picture. Does the shift to cooler and wetter weather indicate that the La Nina period may be nearing its end, or is this likely just a temporary reprieve until mid-year or so, when many have forecasted the pattern to shift?

[Ptarmigan]

Quick question about the bigger picture. Does the shift to cooler and wetter weather indicate that the La Nina period may be nearing its end, or is this likely just a temporary reprieve until mid-year or so, when many have forecasted the pattern to shift?

I think it could be a temporary reprieve. Than again, some La Ninas are not always dry. The Winter of 1988-89 was a strong La Nina like right now. By Spring of 1989, it was a dying La Nina. It had heavy rain in the winter, like in January of 1989. Also, there were severe weather events in late March and May and a major flood from heavy rains on May 17-18.

However, the La Nina is forecasted to be out by this summer. I am sure a Pro-Met could chime in.

[weatherguy425]

NAM tries to sneak a lil "somthing somethin" in. Doubt itll make it to the ground though.

[txsnowmaker]

Quick question about the bigger picture. Does the shift to cooler and wetter weather indicate that the La Nina period may be nearing its end, or is this likely just a temporary reprieve until mid-year or so, when many have forecasted the pattern to shift?

I think it could be a temporary reprieve. Than again, some La Ninas are not always dry. The Winter of 1988-89 was a strong La Nina like right now. By Spring of 1989, it was a dying La Nina. It had heavy rain in the winter, like in January of 1989. Also, there were severe weather events in late March and May and a major flood from heavy rains on May 17-18.

However, the La Nina is forecasted to be out by this summer. I am sure a Pro-Met could chime in.

Thanks Ptarmigan!

[Ptarmigan]

Thanks Ptarmigan!

Your welcome! It is my opinion.

[Cleanupman]

Hey guys im not that good at reading the gfs outputs just kinda have general information, but when i look at the 180hr on the 00 gfs its seems to show a sort of omega block senario which would send the cold down the middle instead of the east coast. I know that the gfs that far out is in lala land but could someone just explain that senario for my learning sake. Am i seeing things right and if true what should be the result.

[Mr. T]

0z GFS MOS shows a low at IAH of 22 degrees tommorow night and 25 degrees the next night.

Also has a rare 32 degrees on Galveston Island.

[Paul]

0z GFS MOS shows a low at IAH of 22 degrees tommorow night and 25 degrees the next night.

Also has a rare 32 degrees on Galveston Island.

need some good CAA for that to happen....I leaning more to mid to upper 20's IAH....30-32 Houston Metro....33-34 Galveston....JMO of course......

[Paul]

Quick question about the bigger picture. Does the shift to cooler and wetter weather indicate that the La Nina period may be nearing its end, or is this likely just a temporary reprieve until mid-year or so, when many have forecasted the pattern to shift?

I think it could be a temporary reprieve. Than again, some La Ninas are not always dry. The Winter of 1988-89 was a strong La Nina like right now. By Spring of 1989, it was a dying La Nina. It had heavy rain in the winter, like in January of 1989. Also, there were severe weather events in late March and May and a major flood from heavy rains on May 17-18.

However, the La Nina is forecasted to be out by this summer. I am sure a Pro-Met could chime in.

Thanks Ptarmigan!

its forecasted to be out yes but dreaded Neutral conditions for the upcoming Hurricane season.....

[ronyan]

0z GFS MOS shows a low at IAH of 22 degrees tommorow night and 25 degrees the next night.

Also has a rare 32 degrees on Galveston Island.

A 10 degree difference between IAH and Galveston? That seems unusually large.

[Mr. T]

0z GFS MOS shows a low at IAH of 22 degrees tommorow night and 25 degrees the next night.

Also has a rare 32 degrees on Galveston Island.

need some good CAA for that to happen....I leaning more to mid to upper 20's IAH....30-32 Houston Metro....33-34 Galveston....JMO of course......

That good CAA is coming tonight.

It'll all be dependent on cloud cover the next few nights. Winds may not fully decouple, but with dewpoints in the single digits to low teens, this will still be supportive for temps to fall well into the 20s across most of SE TX

HGX currently going a big 6 degrees above guidance tommorow night. Lets hope they're right, or else there will be a lot of suprised people across the area this week.

[Mr. T]

0z GFS MOS shows a low at IAH of 22 degrees tommorow night and 25 degrees the next night.

Also has a rare 32 degrees on Galveston Island.

A 10 degree difference between IAH and Galveston? That seems unusually large.

During nights with radiatonal cooling, Galveston can be as much as 15 degrees warmer than inland obs... It's not unusual.

[TexasBreeze]

0z GFS MOS shows a low at IAH of 22 degrees tommorow night and 25 degrees the next night.

Also has a rare 32 degrees on Galveston Island.

A 10 degree difference between IAH and Galveston? That seems unusually large.

During nights with radiatonal cooling, Galveston can be as much as 15 degrees warmer than inland obs... It's not unusual.

...especially between IAH (heat island with planes) and well, anywhere else around this area that has no urban heat island effect. There's usually a big difference between Conroe and IAH too.