Why is it raining now at 10AM? I thought it was going to start in the afternoon?
That’s a great question. I have no answer.
Every model from last night (RAP, HRRR, NAM, HIRESW, NAM-NEST, GFS, etc) had the rain starting about 1-3 PM. Even more incredible is that the new models from this morning 12z (8AM EDT) were still holding off the showers until the afternoon here.
Current Radar 10:20 AM EDT—
NEXRAD radar with Satellite Water Vapor superimposed. (Click on image for a larger view.)
Here’s the latest NAM model which is representative of all the NOAA and Canadian model forecasts for today—
This morning’s NAM model forecast for 10 AM, still showing the showers about 2 hours to our west. This model, which was run only two hours ago, was representative of all the US models from this morning and last night. (Click on image for a larger view.)
Interestingly, I took a look at the 2 AM German ICON model forecast for this morning. Not a bad forecast ! Would I have used its forecast instead of all the NOAA models. Not likely—
ICON model 06z rain and cloud forecast for 10 AM today. Clearly it did something right. (Click on image for a larger view.)
Sunday Forecast Updated Sun @ 10:05 AM, highlighted below Sunday Forecast Updated Sat @ 8:10 PM, highlighted below Sunday & Monday Forecast Updated Sat @ 8:15 AM, highlighted below
The forecast overview for this weekend – the upper level ridge that has dominated our weather for the past several weeks has given way to an upper level trough in the wake of Ida.
GFS jet stream trough position Monday at 9 AM. (Click on image for a larger view.)
This upper level trough will likely persist for much of the coming week, meaning cooler temperatures than we’ve had for awhile. In fact, we’ll be close to average temperature-wise over this weekend. (The seasonal average high temperature is 79-80º for this period.)
Saturday
A weak disturbance in the mid-levels of the atmosphere will rotate through early Saturday morning. Saturday morning will start cloudy, but after the the disturbance exits, mostly sunny skies are expected in the afternoon. High 76.8º ± 1.8º (NBM model, Blue Bell)
Sunday
Forecast Update Sun 10:05 AM: Clearly, the models weren’t doing too good yesterday. The showers have moved in even earlier than forecast. I don’t see any indication of this in last night’s models. I’ll have to talk to the weatherguy who was on duty last night. 🙂
Sun 10:14 AM Forecast Review — How does one account for rain occurring now that wasn’t even forecast by the hourly HRRR and RAP 00z model runs just two hours ago? I can’t answer that.
Update: Saturday’s models have increased the cloud cover on Sunday and several models have light showers earlier in the day, as early as 1-3 PM
Update: Latest HREF shows some very light widely scattered sprinkles between 4-6 PM Sunday—
HREF Sunday 5 PM precipitation forecast. (Click on image for a larger view.)
A warm front will slowly approach on Sunday, bringing considerable cloudiness for most of the day, but no showers until the evening. It’s not a certainty that we will have any showers at all, and the NBM keeps us dry. High 77.8º ± 2.8º (NBM model, Blue Bell High 76.8.8º ± 3.9º (NBM model, Blue Bell) ( high spread!)
A weak cold front moves through Sunday evening and night. High pressure builds in for Monday.
Monday
Update — original forecast back on track.
Some light showers with the cold front may linger until about 7 AM Monday. Then clearing for sunny skies.
High pressure builds in for sunny skies. A weak upper disturbance may bring a few fair weather clouds late in the afternoon. High 80.7º ±1.2º (NBM model, Blue Bell)
