Glossary Geography

Wxrisk.com uses specific definitions for various weather conditions that may occur and affect your business and operations.

The WEATHER ALERT TABLES are intended to communicate -- briefly -- Advanced warning of significant or potentially significant weather events. I focus on the factors of IMPACT and CERTAINTY regarding potentially IMPORTANT Weather events.

The CERTAINTY of the potential WEATHER EVENT, as determined by WxRisk.Com is classified into 3 conditions of certainty from Lowest to Highest: RISK - THREAT - LIKELY.

RISK - "HEADS UP! Something to Watch out for..." The RISK box is highlighted when I believe there is some reason for the Weather Alert Box (WAB) to be issued for the Weather Event(s) described. The "RISK" category is the LOWEST level of threat and should NOT in any way be considered a Forecast. It is equivalent to a "Weather Notification" or a low grade Alert. There may be some meteorological support for the Weather Event(s) as described to occur but not nearly enough evidence or data to say that the Weather event(s) as described are likely to happen. There may be an equal Probability that the events described do not develop as forecasted.

THREAT - "AT LEAST 50% CHANCE of that weather event developing.." The "THREAT" cell is highlighted in the Weather Alert Box (WAB) when I believe there is an increased chance that the Weather Event(s) will occur. The category "THREAT" is used to show a moderate amount of certainty because there is significant meteorological support for the Weather Events occurring as described. However, current and/or recent Weather Models are not yet in sufficient agreement to show that the described Weather Events will occur. There is still a sizable Probability that either downplay or contradict the Weather Events as described.

LIKELY - "INCOMING!" The "LIKELY" box is highlighted in the Weather Alert Box (WAB) when I believe there is an high level of certainty that the Weather Event(s) described in the WAB will occur. The term "LIKELY" is used to show a high level of certainty because there is strong majority and/or preponderance of Weather Models and other factors such as (teleconnections) that support the described Weather Events to occur. A highlighted "LIKELY" category is equivalent to a forecast that one might here in the general public.

The IMPACT of a Weather Event, as determined by WxRisk.Com is divided into 3 Categories: MODERATE, SIGNIFICANT, and MAJOR events

	MODERATE	SIGNIFICANT	MAJOR
RAIN	0.25" to 0.50"	0.50" to 1.25"	> 1.25"+
SNOW	SEE SNOW MAP	SEE SNOW MAP	SEE SNOW MAP
TEMPS	+/- 2.0 degrees to +/- 3.9 degrees	+/- 4.0 degrees to +/- 6.9 degrees	+/- 7.0 degrees or More
WINDS	15 to 30 MPH wth higher Gusts	30 to 50 MPH with higher gusts	50 MPH or higher

RAIN.... generally a MODERATE rainfall ranges from 0.20" to 0.45" of an inch. SIGNIFICANT rainfall ranges from 0.45" to 1.00" of an inch and MAJOR rainfall ranges from 1.00" on upwards.

SNOW: It is imperative that one recognizes the what constitutes moderate ... significant .... or heavy snow varies greatly over the nation of this size and various climate regimes. For example given the climate and the local populace experience of Atlanta, Georgia a two inch snowfall can only be is considered Significant snowfall. However, a two inch snowfall in Washington DC may not even reach the lowest threshold event -- a Moderate event. Below is a map that the WxRisk.Com has developed graphically showing the Moderate, Significant and Major snowfall amounts over the Contiguous 48 states.

This map depicts the Moderate, Significant, and Major snowfall thresholds with a three digit number. For example the code "1/2/3' says that along that line and points north -- to the next line-- 1 inch of snow constitutes a Moderate snowfall...2 inches of snow a Significant snowfall ... and 3 inches a Major snowfall. These are not related to the NWS winter storm watches warning or winter weather advisory criteria. Instead these criteria are have been developed to reflect the general LOCAL public's perception and Business interaction and operations.