Powerful Winter Storm from the Upper Midwest into the Northeast; Severe Thunderstorms in the Midwest and Ohio Valley

A rapidly-intensifying storm is expected to bring heavy snow, blizzard conditions, and icing from the Upper Midwest through the Great Lakes and Northeast. Scattered severe thunderstorms may produce severe/damaging wind gusts and a couple of tornadoes across parts of the Midwest and lower Ohio Valley through the evening. Arctic air will expand across the central and southern U.S.. Read More >

Table C5

Reference Time designator A2

(when T1 = Q, X, or Y)

Instructions for the proper application of the reference time designator

1. The designator specified in this table should be used to the greatest extent possible to indicate the reference time of data contained within the text of the bulletin.

2. When the table does not contain a suitable designator for the reference time, an alphabetic designator which is not assigned in the table should be introduced and the WMO secretariat notified.

Designator	Data Type	Designator	Data Type
A	Analysis (00 hour)	N	39 hours forecast
B	3 hours forecast	O	42 hours forecast
C	6 hours forecast	P	45 hours forecast
D	9 hours forecasts	Q	48 hours forecast
E	12 hours forecast	R	54 hours forecast [48+6]
F	15 hours forecast	S	66 hours forecast [+12]
G	18 hours forecast	T	78 hours forecast
H	21 hours forecast	U	90 hours forecast
I	24 hours forecast	V	102 days forecast
J	27 hours forecast	W	114 days forecast
K	30 hours forecast	X	126 days forecast
L	33 hours forecast	Y	138 days forecast
M	36 hours forecast	Z	150 days forecast