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SE US freezes/frosts April 2-4 with mega frost possibly down to Hogtown April 3rd!

Columbia NWS: wow! Why is MOS so much colder than the regular model output?

LATEST GUIDANCE TRENDING A TAD COLDER, ESPECIALLY GFS MOS. GFS
MOS GIVES 25 AT CAE, WHICH WOULD ESTABLISH A NEW APRIL MONTHLY
RECORD LOW. GFS COOP MOS GIVES LOW TO MID 20S FOR SOME LOCATIONS
AND 18 AT NORMALLY COLDEST CEDAR CREEK. INCLINED TO THINK GFS
MOS A LITTLE TOO COOL FOR TONIGHT. NONETHELESS, EXPECTING
FREEZING TEMPS THROUGHOUT THE FA. LOCAL RADIATION SCHEME YIELDS
UPPER 20S FOR CAE/AGS, WHICH WOULD ENTER DAILY RECORD LOW
TERRITORY. FREEZE WARNING IN EFFECT FOR THE ENTIRE FA.
 
Our dewpoint is supposed to be 5 degrees right now according to the NWS . It’s currently 15. Dews verifying higher .
 
Chazwin said:
You are correct. For the most part at this point the strawberries should be ok as long as the basic stuff is done to protect them... it would have hurt them more if there had been an early bloom and then the hard freeze. What really might take a hit though tonight is peaches. The really bad thing about tonight and why I think some of these lower numbers on the guidance has a chance to verify is simply how low the highs are going to be today. I’m at 46 right with full sunshine and calm wind. With dewpoints already around 10... things may drop fast tonight and add more time below freezing
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This is bad for many farmers with peaches , and would delay strawberries though like you said not too bad maybe . No matter how you chop it up this is bad! I’m not looking forwards to 2-3 weeks of stunted plants and trees that are all brown and crisped . Our sun angle is over 60 degrees and barreling towards 70. This is nuts , bare ness and deadness with high sun angles and warm temps .
 
12z NAM MOS has lows of 27/26 for GSO/RDU, respectively. 12z GFS MOS has 26/25. It even has Tallahassee, FL getting to freezing! This is basically in line with RAH’s thinking, so I think their forecast low for tonight looks pretty good based on the modeling.
 
superjames1992 said:
12z NAM MOS has lows of 27/26 for GSO/RDU, respectively. 12z GFS MOS has 26/25. It even has Tallahassee, FL getting to freezing! This is basically in line with RAH’s thinking, so I think their forecast low for tonight looks pretty good based on the modeling.
Click to expand...

Would you please provide a link to find GFS and NAM MOS for individual cities?

Why would MOS be so much colder than regular model output?
 
Wow!
From NWS CHS:

A FEW
HOURS OF CALM WINDS ARE POSSIBLE FOR LOCATIONS AWAY FROM THE
IMMEDIATE COAST. THE COMBINATION OF ALL THESE THINGS WILL CAUSE
EXCELLENT RADIATIONAL COOLING, LEADING TO A VERY COLD NIGHT.
FREEZING TEMPERATURES ARE FORECASTED FOR A MAJORITY OF OUR
AREA. LOWS SHOULD RANGE FROM THE UPPER 20S FAR INLAND TO NEAR
FREEZING AT THE IMMEDIATE COAST, WHICH WOULD BE RECORDS FOR THIS
TIME OF YEAR. THE BEACHES WILL BE A FEW DEGREES "WARMER" WITH
LOWS IN THE MID TO UPPER 30S. WE HAVE FREEZE WARNINGS IN EFFECT
FOR A MAJORITY OF OUR AREA, INCLUDING CHARLESTON AND SAVANNAH.
 
Lickwx said:
This is bad for many farmers with peaches , and would delay strawberries though like you said not too bad maybe . No matter how you chop it up this is bad! I’m not looking forwards to 2-3 weeks of stunted plants and trees that are all brown and crisped . Our sun angle is over 60 degrees and barreling towards 70. This is nuts , bare ness and deadness with high sun angles and warm temps .
Click to expand...
Gonna look ugly ??
 
superjames1992 said:
12z NAM MOS has lows of 27/26 for GSO/RDU, respectively. 12z GFS MOS has 26/25. It even has Tallahassee, FL getting to freezing! This is basically in line with RAH’s thinking, so I think their forecast low for tonight looks pretty good based on the modeling.
Click to expand...

they are banking 100% on calm winds. I just don’t think it will happen.
 
GaWx said:
Would you please provide a link to find GFS and NAM MOS for individual cities?

Why would MOS be so much colder than regular model output?
Click to expand...

You can check them here:

MOS Text Bulletins

www.weather.gov

MOS uses some blending based on climatology and such, IIRC. I recall from some of my classes it is generally most accurate with high/low temperatures and that sort of thing, especially when it is clear/sunny. It’s hard for even meteorologists to outperform raw MOS forecast day to day.

Maybe our fellow mets can key me in on how much they use MOS, though? I don’t want to spread bad/outdated info, haha.
 
From NWS Jacksonville, FL:

BOUNDARY LAYER WINDS AT INLAND WILL DECOUPLE FROM THE
UPPER LEVEL FLOW AND BECOME CALM OVERNIGHT. CALM WINDS AND CLEAR
SKIES WILL ALLOW FOR EXCELLENT RADIATIVE COOLING CONDITIONS
TONIGHT. OVERNIGHT LOWS WILL BE COLD IN THE LOWER 30S FOR INLAND
SE GA AND MID-TO-UPPER 30S FOR INLAND NE FL (CHALLENGING RECORDS
FOR OUR AREA, SEE CLIMATE SECTION BELOW). NORTHEASTERLY WINDS AT
COASTAL LOCATIONS WILL REMAIN SLIGHTLY STRONGER, KEEPING
TEMPERATURES FROM GETTING TOO COLD. ALONG THE COAST AND THE ST.
JOHNS RIVER BASIN LOWS TONIGHT ARE EXPECTED TO BE IN THE 40S.
FROST AND LIGHT FREEZE CONDITIONS ARE EXPECTED AT INLAND
LOCATIONS. A FREEZE WARNING FOR NORTHERN INLAND SE GA AND A FROST
ADVISORY FOR OTHER INLAND SE GA AND NE FL LOCATIONS WILL GO INTO
EFFECT LATE TONIGHT UNTIL SHORTLY AFTER SUNRISE TOMORROW. THE
FROST ADVISORY WAS EXPANDED TO INCLUDE WESTERN AND CENTRAL MARION
COUNTY IN NE FL DUE TO THE ANOMALOUS NATURE
OF THIS LATE SEASON
FROST AND HIGHER SENSITIVITY TO ITS EFFECTS.
 
Holding steady at 48 degrees at 6 pm. No drop yet is a good sign. Not too mention dews never dropped to the low single digits as the NWS forecast had .
 
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Very good sign , temp only dropped 1 degree at 7. Almost sunset now as well! Very good signs , still early but this is looking up a bit more . Normally with these big radiational cooling nights temps begin their plummet 2 hours before sunset ! No such plummet here
 
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