The 12Z (3 a.m.) balloon sounding launched from the Fairbanks International Airport this morning set some quite impressive records.
1) The 850 mb temperature of 9.4°C is a January record and is also at or above any temperature measured in November, December, March or April; but not February.
2) The 700 mb temperature of 1.4°C is a record for any month between November and March.
3) The 1000-500 mb thickness of 5545 meters is also a record for any month between November and March (from Rick).
4) The 850-500 mb thickness of 4202 m appears to be a record for November through April (from Richard).
5) The interpolated freezing level of 3,229 m is a January and seasonal record. The previous record was 3,217 m on Jan 18, 1963.
The chart below shows today's 12Z sounding and the 1/18/63 (12Z) sounding side by side. If you discount the very shallow surface inversion where temperatures were below freezing (~24m), you have to ascend another 10,000+ feet to drop back below freezing. For comparison, the 3,229 m freezing level was only slightly lower than the 3,395 m at Bermuda and the 3,329 m at Lake Charles, Louisiana.